Note: Descriptions are shown in the official language in which they were submitted.
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TRANSMISSION LINE MEASURING DEVICE AND METHOD FOR
CONNECTIVITY
BACKGROUND
Technical Field
[0001] The present application relates to data
collecting and, more particularly, to a connector (e.g.,
data acquisition suspension clamp) for an electrical
conductor or other transmission line (e.g., a power
transmission line, a communications line, a gas line, a
water line, an oil line, a railroad, a highway, among
others that are deployed over geographic distances) which
collects data and reports measured conditions of the
conductor or transmission line to a monitoring device or
systems. However, illustrative embodiments of the present
invention need not be restricted to use as part of a
clamp. For example, embodiments of the present invention
can be implemented at a location next to a clamp or
implemented without dependence upon any clamp or other
device.
Background
[0002] Power Grids
[0003] Figs. 1-4 illustrate related art disclosed in
U.S. Patent No. 8,002,592. Fig. 1 shows a transmission
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tower 200 which is used to suspend power transmission
lines 202 above the ground. The tower 200 has
cantilevered arms 204. Insulators 206 extend down from
the arms 204. One or more suspension clamps 208 are
located at the bottom ends of the insulators 206. The
lines 202 are connected to the suspension clamps. The
clamps 208 hold the power transmission lines 202 onto the
insulator 206.
[0004] Figs. 2-4 illustrate an example embodiment of
the suspension clamp 208 which generally comprises an
upper section 210 and a lower support section 212. These
two sections 210, 212 each contain a body 214, 216 which
form a suspension case. The bodies 214, 216 each comprise
a longitudinal trough (or conductor receiving area) 215,
217 that allow the transmission conductor 202 to be
securely seated within the two sections and when the two
sections are bolted (or fastened) together by threaded
fasteners 201 (not shown). This encases the transmission
conductor 202 between the two bodies to securely contain
the transmission conductor 202 on the clamp 208. Threaded
fasteners are not required and any other suitable
fastening configuration may be provided.
[0005] The two bodies 214, 216 connected together are
suspended via a metal bracket 218 that attaches to the
lower body 216 at points via bolt hardware 220.
[0006] The lower body, or lower body section, 216
comprise a first end 219 and a second end 221. The
conductor receiving area (or conductor contact surface)
217 extends from the first end 219 to the second end 221
along a top side of the lower body 216. The conductor
receiving area 217 forms a lower groove portion for
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contacting a lower half of the conductor 202. A general
groove shape is not required, and any suitable
configuration may be provided.
[0007] In one
implementation, the upper and lower
sections 210, 212 each have imbedded within their
respective bodies 214, 216 one-half of a current
transformer 222, 224 that is commonly referred to in the
industry as a split core current transformer. When these
components 222, 224 are joined, they form an
electromagnetic circuit that allows, in some
applications, the sensing of current passing through the
conductor 202. In one implementation, the current
transformer is used to power sensing, data collection,
data analysis and data formatting devices. In some
implementations the current transformer may be located
outside of the clamp or similar device or, in some
implementations, power may be provided by another means.
[0008] The body 214 of
the upper section 210 contains
a first member 232 and a second member 234 forming a
cover plate. The first member 232 comprises a first end
233, a second end 235, and a middle section 237 between
the first end 233 and the second end 235. The conductor
receiving area (or conductor contact surface) 21 5
extends from the first end 233 to the second end 235
along a bottom side of the first member 232. The
conductor receiving area 215 forms an upper groove
portion for contacting an upper half of the conductor
202. A general groove shape is not required, and any
suitable configuration may be provided. In one
implementation, the first member 232 further comprises a
recessed cavity 226 at the middle section 237 that
effectively contains an electronic circuit 228. In this
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implementation, the electronic circuit 228 is designed to
accept inputs from several sensing components. This
cavity 226 may be surrounded by a faraday cage 230 to
effectively nullify the effects of high voltage EMF
influence from the conductor 202 on the circuitry 228.
The faraday cage may also surround the current
transformer 222. The cover plate, or cover plate member,
234 can cover the top opening to the cavity 226 to retain
the electronic circuit inside the body, or upper body
section, 214. The electronics may be housed in a metal or
plastic container, surrounded by the noted faraday cage,
and the entire assembly can be potted, such as with epoxy
for example.
[0009] The electronic circuit 228 can accept and
quantify in a meaningful manner various inputs for
monitoring various parameters of the conductor 202 and
the surrounding environment. The inputs can also be
derived from externally mounted electronic referencing
devices/components. The inputs can include, for example:
1 ) Line Voltage reference (as derived from the faraday
cage 230 or other means); 2) Line Current reference (as
derived from the Current transformer 222, 224 or other
means); 3) Barometric pressure and Temperature
references¨ internal and ambient (as derived from
internal and external thermocouples 236, 238 or other
means); 4) Vibration references of the conductor (as
derived from the accelerometer 240, such as a 10- 50 KHz
vibration sensor for example, or other means); and 5)
Optical references (as derived from the photo transistor
242 in a fiber optic tube or other means). The optical
reference portion may, for example, allow the clamp to
look up and see flashes of light from corona if the
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insulator starts to fail, or lightening indication storm
activity, and/or tensile references (as derived from the
tension strain device 244 which may be included in
certain implementations). The tensile references from the
tensile indicators 244 may, for example, provide
information indicating that ice is forming as the weight
of the conductor increases due to ice build up.
[0010] Supervisory Control And Data Acquisition
(SCADA) generally refers to an industrial control system
such as a computer system monitoring and controlling a
process. Information derived by the electrical/electronic
circuitry can exit the circuit 228 via a non-conductive
fiber optic cable 246 and be provided up and over to the
transmission tower 200 and ultimately at the base of the
tower and fed into the user's SCADA system to allow the
end user to access and view electrical and environmental
conditions at that sight, or the information can be
transmitted to a remote or central site. This
implementation, however, has proven to be problematic.
For example, routing fiber to a clamp that is operating
at very high voltage creates a voltage creep path that
can cause an arc even though glass fiber and plastic
sheath are provided as insulators. Arcs form along the
boundary between the air and the solid insulator. If the
insulator were just a simple rod, it would have to be 3
times longer. The suspension clamp or other sensing
device may be alternatively configured to wirelessly
transmit information from the electronic circuit 228 to a
receiver system. However, this implementation has
likewise been problematic due to the complexity of the
software needed to accommodate the distances over which
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the clamps are used and the number of clamps being
monitored.
[0011] Certain Problems Can Occur in Current Grids
[0012] Transmission lines face numerous problems. Wind
causes vibration which can gradually crack the wire or
destroy it outright. Excessive heat may cause lines to
sag into trees or traffic. Corroded wires will generate
more heat when current passes through, but there is no
way to know the extent of any corrosion since it is
generally interior to the wire. Corona is a type of
electrical discharge which will eat away at wire,
insulators, and anything else in the vicinity. Ice
buildup can break wire due to the weight. Trees may fall
naturally over wires and pose a hazard if not trimmed.
Natural and man-made disasters, such as earthquakes and
forest fires can damage transmission power lines. In
addition, wildlife, and squirrels in particular, can get
carbonized when they crawl into certain components of a
power grid, thereby causing disruption of power
transmission via the power transmission lines. Line
optimization to boost capacity is temperature dependent
and can only be done via conservative estimates of local
conditions.
[0013] Grid Monitoring
[0014] In conventional power grids, current and
voltage are measured at substations. Current capacity of
a line is estimated based on the wire diameter, age of
the wire, the ambient temperature, and wind speed.
However, due to many variables, it is an educated guess.
In addition, there is no early warning with regard to ice
build-up and ice is detected when a wire breaks during
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icing. Vibration dampers are routinely attached to the
power lines to reduce vibration; however, their
effectiveness is only estimated by how many lines break
due to vibration stress, in spite of the dampers being
present. The power lines can generate corona that can be
heard as a sizzling sound and can also be seen by using
special cameras that can see in the ultraviolet spectrum.
However, such cameras are large and expensive. The
cameras are generally sent to places where someone has
heard a sizzling sound or where an insulator appears to
be eaten away but may not be effective since corona can
be intermittent and is affected by many environmental
conditions such as moisture and air pressure. Further,
most proposed telemonitoring devices require battery
power. Battery power is not suitable in these
applications that are elevated above ground and
distributed over large geographic areas, making their
maintenance untenable. In addition to powering
challenges, existing monitoring devices are relatively
expensive and large, which limits their use to occasional
applications or installation to limited sites. As a
result, there is no opportunity to gather widespread data
and make determinations such as lightning location by way
of triangulation or real-time power carrying capacity
based upon full transmission line weather conditions.
[0015] Repair or Servicing a Transmission Line
[0016] Initially, one must locate where a power
transmission line is broken. However, power transmission
lines can run hundreds of miles between substations, and
the only information generally available is that one
substation is supplying power and the next one is not
receiving the supplied power. Accessibility to power
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transmission lines may vary. In some cases, the power
transmission lines may be accessible by motorized ground
vehicles. In other cases, lines may only be accessible by
helicopter, wherein a service technician must hang under
the helicopter to service or repair a line. Such repairs
or maintenance can be very expensive.
[0017] Communication Issues
[0018] In order to retrieve information about the
system, rapid and secure communication is necessary.
Radio communication via Ethernet is one option. However,
organizing an Ethernet network requires the use of
devices known as routers or switches. Each router or
switch will look at an Ethernet packet of information and
make note of the source address and the destination
address as the packet arrives at a port. If the
destination is known, the packet is forwarded to only one
port which is known to be connected to that destination
device. If it is not a known address, it is repeated to
all ports except the port where it arrived. When the
destination device responds, the source address will
appear in a packet on a single port which permit the
router or switch to learn where to send the next packet
with that particular destination address.
[0019] There are specific protocols which optimize the
route for delivering a packet and to remove the
opportunity for a packet to become repeated in a loop in
the network. Some of the more common protocols are
Spanning Tree Protocol and Rapid Spanning Tree Protocol.
[0020] A popular radio protocol for packet-based
transmission is Zigbee which is described in standard
IEEE 802.15.4. It is intended for relatively small radio
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networks in a small geographic area. It is well suited to
a single building or a property of several acres.
However, when the radios become numerous and spread out
over a large area, the system becomes unworkable. The
most distant radio message must be repeated by
coordinator elements (e.g., a more capable radio) until
the destination is reached. Because there is a time limit
for a reply, the physical dimensions of the network are
limited.
[0021] Although devices exist for monitoring
transmission lines, they face the powering, diagnostic
and communication challenges noted above. There is a need
for a system that allows for fast analysis of any actual
or potential repair problems and power optimization
capabilities along transmission lines (e.g., to permit,
for example, increased peak loads based upon real
operating conditions versus conservative estimates based
upon worst case weather), with lower costs of repair,
better preventative maintenance, and faster restore
times. Further, there is a need for a simple way of
communicating and collecting the substantial amount of
data that can be accumulated by a wide-spread
installation of sensing devices over large geographic
areas.
SUMMARY
[0022] Various aspects of examples of the invention
are set out in the claims.
[0023] In accordance with one aspect of the invention,
a suspension clamp connecting assembly is disclosed. The
suspension clamp connecting assembly includes a clamping
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unit, a support member, and a corona ring. The clamping
unit includes a base section, extending arms, and clamp
contact portions. The extending
arms are between the
clamp contact portions and the base section. The
clamping unit is configured to clamp on to a suspension
clamp. The support member has a first end and a second
end. The first end of the support member is connected to
the base section. The support
member is configured to
support an electronics housing. The corona ring
is
connected to the second end of the support member.
[0024] In accordance with another aspect of the
invention, a clamping unit is disclosed. The clamping
unit includes a base section, extending arms, and clamp
contact portions. The extending
arms are between the
clamp contact portions and the base section. The
clamping unit is configured to clamp on to a suspension
clamp such that a main body portion of the suspension
clamp is between the extending arms.
[0025] In accordance with another aspect of the
invention, a method is disclosed. A clamping unit
including a base section, extending arms, and clamp
contact portions is provided. The extending
arms are
between the clamp contact portions and the base section.
The clamping unit is configured to clamp on to a
suspension clamp. A support member
is attached to the
clamping unit. The support member has a first end and a
second end. The first end of
the support member is
connected to the base section. The support
member is
configured to support an electronics housing. A corona
ring is connected to the second end of the support
member.
[0025A]
In a broad aspect, the present invention pertains to a
suspension clamp connecting assembly comprising a clamping unit
comprising a base section, extending arms, adjustment members, and clamp
contact portions, the extending arms being between the clamp contact
portions and the base section. The clamp contact portions comprise four
clamp contact portions each corresponding to an arm of the extending
arms. The adjustment members are spaced from the base section and
pivotably connected to the extending arm, and the clamping unit is
configured to clamp on to a suspension clamp. A support member has a
first end and a second end, the first end of the support member being
connected to the base section. The support member is configured to
support an electronics housing, and a corona ring is connected to the
second end of the support member.
[0025B]
In a further aspect the present invention provides a clamping
unit comprising a base section, extending arms, adjustment members, and
clamp contact portions, the extending arms being between the clamp
contact portions and the base section. The clamp portions comprise four
clamp contact portions each movably connected to a corresponding
extending arm of the extending arms. The adjustment members are spaced
from the base section and pivotably connected to the extending arms, and
the clamping unit is configured to clamp on to a suspension clamp such
that a main body portion of the suspension clamp is between the extending
arms.
[0025C]
In a still further aspect, the present invention embodies a
method comprising providing a clamping unit comprising a base section,
extending arms, adjustment members, and clamp contact portions. The
extending arms are between the clamp contact portions and the base
section, the clamp contact portions comprising four clamp contact
portions each corresponding to an arm of the extending arms.
The
adjustment members
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are spaced from the base section and pivotably connected to the extending
arms, and the clamping unit is configured to clamp onto a suspension
clamp. There is a support member attached to the clamping unit, the
support member having a first end and a second end, the first end of the
support member being connected to the base section, and the support
member being configured to support an electronics housing. A corona
ring is connected to the second end of the support member.
[0025D]
In a yet further aspect, the present invention provides a
clamping unit comprising a base section, extending arms, clamp contact
portions, and a clamp adjustment portion. The extending arms are between
the clamp contact portions and the base section. The clamp contact
portions comprise four clamp contact portions each corresponding to an
arm of the extending arms.
The clamp adjustment portion comprises
adjustment members, the adjustment members being spaced from the base
section and pivotably connected to the extending arms. The clamping
unit is configured to clamp on to a suspension clamp such that a main
body portion of the suspension clamp is between the extending arms.
10b
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BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The foregoing aspects and other features of the
invention are explained in the following description,
taken in connection with the accompanying drawings,
wherein:
[0027] Fig. 1 is a perspective view of a transmission
tower supporting transmission lines connected via
suspension clamps;
[0028] Fig. 2 is a perspective view of one of the
suspension clamps shown in Fig. 1;
[0029] Fig. 3 is a cross section view of the
suspension clamp shown in Fig. 2;
[0030] Fig. 4 a perspective view of a first member of
the suspension clamp shown in Fig. 2;
[0031] Fig. 5 is a perspective view of a smart clamp
constructed in accordance with an illustrative embodiment
of the present invention;
[0032] Fig. 6 is an exploded perspective view of the
smart clamp of FIG. 5;
[0033] Fig. 7 is a top view of the clamp body of the
smart clamp of FIG. 5;
[0034] Fig. 8 is a bottom view of the smart clamp of
FIG. 5;
[0035] Fig. 9 is a perspective view of the smart clamp
of FIG. 5 showing contents of the electronics housing and
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various sensors in accordance with an illustrative
embodiment of the present invention;
[0036] Fig. 10 shows various components of a smart
clamp constructed in accordance with an illustrative
embodiment of the present invention;
[0037] Figs. ha and llb are, respectively, a top view
and a side view of an electronics housing for a smart
clamp in accordance with an illustrative embodiment of
the present invention;
[0038] Fig. 12 is a perspective view of a main board
of a smart clamp in accordance with an illustrative
embodiment of the present invention;
[0039] Figs. 13a and 13b illustrate a communication
network comprising data acquisition devices (e.g.,
several of the smart clamp in FIG. 5) in radio
communication in accordance with an illustrative
embodiment of the present invention;
[0040] Fig. 14 illustrates a more complex example of a
communication network than that shown in FIG. 13a or 13b;
[0041] Fig. 15 illustrates a communication network
with more than one adaptor in accordance with an
illustrative embodiment of the present invention; and
[0042] Figs. 16 and 17 are screen shots generated by
an administrative system in accordance with an
illustrative embodiment of the present invention.
[0043] Fig. 18 is a perspective view of a suspension
clamp connecting assembly (clamped on to a transmission
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line suspension clamp) incorporating features of the
invention;
[0044] Fig. 19 is another perspective view of the
suspension clamp connecting assembly shown in Fig. 18;
[0045] Fig. 20 is a side view of the suspension clamp
connecting assembly shown in Fig. 18;
[0046] Fig. 21 is another side view of the suspension
clamp connecting assembly shown in Fig. 18;
[0047] Fig. 22 is a front view of the suspension clamp
connecting assembly shown in Fig. 18;
[0048] Fig. 23 is a top view of the suspension clamp
connecting assembly shown in Fig. 18;
[0049] Fig. 24 is a perspective view of the suspension
clamp connecting assembly shown in Fig. 18 [with the
clamping unit in a closed position];
[0050] Fig. 25 is a perspective view of the suspension
clamp connecting assembly shown in Fig. 18 [with the
clamping unit in an open position];
[0051] Fig. 26 is a top view of the clamping unit and
support member [with the clamping unit in an open
position];
[0052] Fig. 27 is a side view of the clamping unit and
support member;
[0053] Fig. 28 is a front view of the clamping unit
and support member [with the clamping unit in an open
position];
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[0054] Fig. 29 is a perspective view of the clamping
unit and support member [with the clamping unit in a
closed position];
[0055] Fig. 30 is a perspective view of the clamping
unit and support member [with the clamping unit in an
open position];
[0056] Fig. 31 is a perspective view of the suspension
clamp connecting assembly shown in Fig. 18 [with the
clamping unit in an open position];
[0057] Fig. 32 is a front view of the suspension clamp
connecting assembly shown in Fig. 18 [clamped on to a
transmission line suspension clamp]; and
[0058] Fig. 33 is a side view of another embodiment of
a suspension clamp connecting assembly (clamped on to a
transmission line suspension clamp) incorporating
features of the invention.
[0059] Throughout the drawings, like reference
numerals will be understood to refer to like elements,
features and structures.
DETAILED DESCRIPTION
[0060] This description is provided to assist with a
comprehensive understanding of illustrative embodiments
of the present invention described with reference to the
accompanying drawing figures. Accordingly, those of
ordinary skill in the art will recognize that various
changes and modifications of the illustrative embodiments
described herein can be made without departing from the
scope and spirit of the present invention. Also,
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descriptions of well-known functions and constructions
are omitted for clarity and conciseness. Likewise,
certain naming conventions, labels and terms as used in
the context of the present disclosure are, as would be
understood by skilled artisans, non-limiting and provided
only for illustrative purposes to facilitate
understanding of certain illustrative implementations of
the embodiments of the present invention.
[0061] Data Acquisition Device Overview
[0062] Figs. 5-17 illustrate illustrative embodiments
of the present invention that provide for a method,
system and apparatus for a smart grid comprising
networked data acquisition devices that monitor
transmission lines or conductors. The smart grid is
illustrated using power transmission lines; however, it
is to be understood that the data acquisition devices can
be configured to monitor other types of transmission
lines or conductors deployed over extensive geographic
distances (e.g., a communications line, a gas line, a
water line, an oil line, a railroad, a highway, among
others), and need not be restricted to use only with
connectors or clamps, in accordance with illustrative
embodiments of the present invention. A data acquisition
device is illustrated using a suspension clamp (e.g., on
a power transmission line) that is hereinafter referred
to as a "smart clamp." Data acquisition devices, however,
are understood to be any related smart connectors or
smart accessories or devices for data acquisition and
networked monitoring.
[0063] With reference to Figs. 5-9, a smart clamp 1 is
illustrated in Fig. 5. The smart clamp assembly includes
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a clamp body 110, a keeper body 310 resting on the clamp
body 110, an electronics housing 50, and a heat shield 70
that protects the electronic components in the
electronics housing 50. Also depicted are illustrative
clamp hanger hardware 20 for affixing the clamp 1 to a
power line or other conductor 30, for example, and a high
temperature cable 80 to connect a power source (e.g., a
power supply comprising a current transformer 330) to the
electronics in the electronics housing 50 as described
below.
[0064] As illustrated in Figs. 5, 6 and 7, the clamp
body 110 includes a central trough or channel 112 along
its length on to which a power line/wire 30 is to be
placed. The keeper body 310 likewise includes a central
trough or channel 312 along its longitudinal length to
accommodate the power line 30 such that, when the keeper
body 310 and the clamp body 110 are attached, the power
line 30 is secured between the two bodies 110, 310.
Illustrative hardware for securing the keeper body 310
and the clamp body 110 to each other can include, but is
not limited to, a U-bolt 210 inserted into bolt holes 214
and secured via nuts 216. A similar configuration of two
bolts holes 214 and nuts 216 for a U-bolt 210 can be
provided on opposite ends of the clamp 1.
[0065] The keeper body 310 includes a cooling chimney
111 as shown in Figs. 5 and 6 to allow air to circulate
and cool the smart clamp 1. The keeper body assembly
comprises the keeper body 310, springs 320 and an upper
portion 331 of the transformer 330. Similarly, as shown
in Fig. 7, the clamp body 110 also includes a cooling
chimney 111 that also facilitates air circulation to cool
the smart clamp 1. Accordingly, the clamp body assembly
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comprises the clamp body 110 and lower portion 332 of the
transformer 330. The upper and lower portions 331 and 332
of the transformer 330 in the power supply can be
provided with troughs or channels similar to the channel
112 in the clamp body (e.g., as illustrated in the lower
portion 332 of the transformer depicted in Fig. 7) to
accommodate a conductor 30, and are positioned and
secured in their respective keeper body 310 and clamp
body 110 so as to be aligned to one another. When the
clamp body 110 and the keeper body 310 are secured
together, the springs 320 are loaded or compressed by the
upper and lower portions of the transformer 330. The
spring fitting of the current transformer 330 to the
keeper body 310 allows for floating the conductor 30
within ranges to avoid over pressing the conductor yet
provide good seal and minimize vibrations. While the
illustrated embodiments depict the power supply assembly
with current transformer 330 having portions 331 and 332
provided within the keeper body 310 and clamp body 110,
respectively, it is to be understood that the current
transformer 330 can be deployed in another location
relative to the clamp 1. For example, portions 331 and
332 of the transformer 330 can be attached to the
conductor via a clamp at a location adjacent to the clamp
1. The underside of the clamp body 110 is shown in Fig. 8
and provides another view of the high temperature
conductor 80 extending from the power supply comprising
the current transformer 330 toward electronics housing
50. The power supply comprises an electronics circuit
board (not shown) configured to condition AC voltage from
the current transformer 330 and convert it to DC voltage
to be supplied to the main electronics board 500 via the
cable 80.
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[0066] Power for the Data Acquisition Device and
Resolution of Thermal Issues
[0067] While it does not seem reasonable, conventional
systems have difficulty getting a few watts of power
(e.g., for powering a processor or sensors) from a power
line carrying a million watts of power. The present
invention overcomes these difficulties, that is, the
smart clamp 1 is able to extract a small amount of power
from a power line or wire 30 to which it is secured in
accordance with an illustrative embodiment of the present
invention.
[0068] A practical means to extract power from the
power line is a current transformer; however, to
accommodate a 3 amps (A) to 3000 A conductor 30 current
range, this transformer becomes a substantial piece of
iron (e.g., about 4 pounds) with copper windings (e.g.,
about 9000 turns) which extracts power from the magnetic
fields surrounding the main conductor 30 created by the
electron flow therein. For example, a conventional split,
square current transformer can be used (e.g., a model
CTS-1250-300A current transformer available from
Continental Control Systems LLC, Boulder, Colorado). One
side can be removed to permit clamping the transformer
330 over the conductor 30. The extracted power is
utilized to power the smart clamp 1 and its various
sensors, data analysis components and communication
equipment, which can consume as many as 10 watts.
Alternatively to extracted power (e.g., via a power
supply assembly with current transformer 330), batteries
and solar cells can also be used to power the clamp 1
electronics, among other power sources for electronics.
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[0069] As stated above, the smart clamp 1 uses the
power supply assembly with current transformer 330 to
extract power from the magnetic field generated by the
current passing through the main conductor 30 to which
the current transformer 330 surrounds. The transformer
330 can be a split transformer having an upper portion
331 and a lower portion 332 so that can be clamped around
the power line or wire 30 as described below in
connection with Figs. 6, 7 and 8. As stated above, a high
temperature wire 80 extends from an output of the power
supply assembly to an input of the electronics housing 50
to provide power to the electronic circuits therein. An
energy storage device can optionally be provided in the
smart clamp 1 (e.g., a capacitor on the main board 500 as
shown in Figs. 9 and 12) to allow the smart clamp 1 to
operate long enough to send a last message (e.g., to a
base station or other network monitoring device) before
power is lost.
[0070] The conductor 30 enclosed by the clamp body 110
and keeper body 310 can get quite warm due to the very
large current carried by the conductor. Typically, older
style wire is allowed to get to about 75 C before it gets
soft and starts to sag. Newer style wire is starting to
be deployed which can reach 250 C before it gets soft and
starts to sag. Electronics generally will not tolerate
this temperature, and therefore the electronics housing
50 is positioned to the side and separated from the main
body of the smart clamp by a heat shield 70. The heat
shield 70 can be connected to the side of the clamp 1
(e.g., with separators 72 for thermal insulation) and the
electronics housing 50 can be connected to the heat
shield 70, for example. The heat shield is constructed of
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aluminum. The electronics housing 50 can be made of non-
metallic material to facilitate operation of the radio
540 and GPS unit 510.
[0071] The current transformer 330 surrounds the main
conductor in order to harvest the energy, and, in some
implementations, the current transformer 330 will not
tolerate temperatures above 85 C. The holes or cooling
chimneys 111 in the keeper body 310 and the clamp body
110 of the smart clamp 1 allow air flow to cool the
transformer 330. Alternatively, as stated above, the
power supply assembly with portions 331 and 332 of the
transformer 330 can be attached to the conductor 30 via a
clamp at a location adjacent to the clamp 1. Further, the
smart clamp 1 itself acts as a heat sink to reduce the
temperature. The transformer 330 can be encased in
thermal insulation material to provide additional
protection.
[0072] Data Acquisition Device Sensors and Electronic
Components
[0073] The smart clamp 1 includes various sensors in
or near the electronics housing 50, which is insulated
from heat by the heat shield 70 as described above.
[0074] With reference to Fig. 9, the electronics
housing 50 is shown with a cover removed to expose a main
board 500 mounted inside in accordance with an
illustrative embodiment of the present invention. As
shown in Fig. 5, the electronics housing 50 has a section
52 extending from a main section 51. Parallel housing
sections 54 are connected to opposite sides of the
section 52 and extend oppositely to each other and
parallel to the longitudinal axis of the conductor 30 and
CA 02880129 2015-01-27
clamp 1. The main board 500 is secured in the section 51.
Additional sensor circuits for measuring wind speed and
ambient temperature (e.g., indicated generally at 610 and
620 in Figs. 9 and shown in Figs. 11A and 12) are
electrically connected to the main board 500 (e.g., via
ribbon cable) and extend therefrom for deployment in the
parallel sections 54 as described in further detail
below.
[0075] With continued
reference to Fig. 9, the main
board 500 supports and processes inputs from a number of
sensors and measurement devices including, but not
limited to, a Global Positioning Device (GPS) 510, a
sensor 520 for measuring conductor 30 temperature, a
conductor 30 current sensor 530, the wind speed detector
610, a vibration detector 630, an audio corona detector
640, the ambient temperature sensor 620, and at least one
camera 550 and its interface 504. Additional sensors,
such as additional cameras can be included. The sensors
are described in more detail below. In addition, the main
board 500 supports an encrypted radio 540 and encrypted
web access 560. These communications devices are
described in more detail below. The main board 500
comprises a central processing unit (CPU) 505 and
associated memory device 502 (e.g., a non-volatile memory
such as a flash disk) and program code for processing
data from the sensors and communications. In another
implementation, the electronic circuitry may be located
outside of the clamp or transmission line in an external
box which may or may not have a faraday cage. This
arrangement would be suitable, for example, for a gas
pipeline as well as for certain electrical transmission
lines.
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CA 02880129 2015-01-27
[0076] As shown in Fig. 11A, the electronics housing
50 can also be provided with connectors 501 and 508 for
power and fiber optics, respectively. As shown in Fig.
12, a connector 501 is electronically connected to a
power subsystem on the main board 500 such that, when the
high temperature cable 80 carrying DC power is connected
to the connector 508, the main board 500 can provide
power to the sensors and other electronic devices that it
supports.
[0077] Figs. 11A and 12 illustrate a main board 500
and other components in accordance with illustrative
embodiments of the present invention. Fig. 11A is a front
view of a main board 500 in an electronics housing 50.
The main board can be connected to a camera 550 having a
lens installed in an aperture provided in the electronics
housing 50 as shown on one side of the housing 50
depicted in Fig. 11B. The other side (not shown) of the
housing 50 and main board 500 can also be installed with
another camera (i.e., with lens mounted in an aperture of
the housing 50) to enable images to be taken along the
sections of the conductor 30 extending from both sides of
the clamp 1.
[0078] An illustrative small camera 550 operates in
the -40 C to +85 C range, and with fixed focus down to
two feet, for example. The head is Bmm x 5.6mm. The
camera(s) 550 can capture still images of line 30
conditions such as ice, sagging, carbonized debris and so
on. Video images can also be provided as communication
bandwidth permits. As described below, by representing
each smart clamp 1 with its own web page, the respective
web pages for smart clamps can present users with
convenient information regarding various line conditions
22
CA 02880129 2015-01-27
such as images of ice and the like, and listings of
measured parameters such as temperature, wind, among
others and whether they are in selected ranges or not or
meet selected thresholds.
[0079] There is no practical means that is cost-
effective to sense voltage directly from the power line
30, at the present time, without reliance upon a ground-
based system. While current can be sensed by a second
current transformer, a Hall Effect sensor integrated
circuit (IC) 530, which is smaller and less expensive,
can be utilized in the smart clamp 1 (e.g., on the main
board 500). The current sensor 530 can be based on the
Hall Effect rather than the more traditional Rogowski
coil, wherein harmonic distortion of the current sine
wave is measured by a distortion that can be caused by
unusual loads, a saturated transformer, or a
malfunctioning generator.
[0080] Conductor temperature can also be measured with
an IC. For example, the smart clamp 1 can be provided
with a thermal jumper 520 between the conductor or
transmission line to an electronic component on the main
board 500 that can empirically determine the temperature
of the transmission line.
[0081] The smart clamp I can include detectors 610,
620 and 630 for measuring wind speed sensor, ambient
temperature and conductor vibration, respectively, as
illustrated in Fig. 9. The wind speed detector 610 is
advantageous because it is implemented with no moving
parts. In accordance with an embodiment of the present
invention, wind speed is sensed by a heated element
extended from the body of the clamp 1. For example, two
23
CA 02880129 2015-01-27
wind detection devices are disposed proximally to the
electronics housing 50 and on the same axis as the
conductor or transmission line 30 coupled to the smart
clamp 1. The difference between the temperature of the
element predicted in still air and the temperature drop
in the other element caused by wind can be used to
calculate wind speed.
[0082] More specifically, as stated above, the
electronics housing 50 has parallel housing sections 54
which extend parallel to the longitudinal axis of the
conductor 30 and clamp 1 and in which the detectors 610
and 620 for measuring wind speed and ambient temperature
are deployed. As shown in Figs. 11A and 12, a main board
500 can have a main section 506 and at least one section
507 extending therefrom (e.g., via ribbon cable or other
conductor). The section 507 supports at least the wind
sensor 610 and the ambient temperature sensor. The wind
speed detector 610 operates generally using the same
principle as a hot wire anemometer in that it comprises
one of the parallel sections 54 (e.g., see "503a" in
Figs. 11A and 12), which is heated by an element (not
shown). As wind blows over the clamp 1 including the
parallel sections 54, the heated section 503a cools. The
other section 54 (e.g., see "503b" in Figs. 11A and 12)
is provided with the ambient temperature sensor 620. The
CPU 505 is programmed to determine wind speed based on
the difference between the measured ambient temperature
and the measured temperature of the heated section 503a.
The ambient temperature sensor 620 is placed in the
section 503b opposite from the heated section 503a so
that its measurement of ambient temperature is not skewed
by the heating element for the heated section 503a. The
24
CA 02880129 2015-01-27
CPU 505 can be programmed to determine wind speed in the
direction perpendicular to the longitudinal axis of the
conductor 30 (i.e., a parameter often sought by utility
companies) using various geometrically-
based
calculations.
[0083] It is to be
understood that the wind speed
detector 610 can be implemented using other
configurations in accordance with other illustrative
embodiments of the present invention than that shown in
Figs. 9, 11 and 12. For example, as shown in Fig. 10, a
clamp 1 can be provided with a protrusion from its
housing 50 to accommodate a hot wire anemometer 612, and
optionally a radio antenna 542 for a radio interface 540
described below.
[0084] The vibration
sensor 630 can be implemented a
number of different ways. For example, a tension meter
with adequate bandwidth (128Hz) can be used to measure
vibration. If a relatively large tension meter is not
present, then a smaller, 3-axis accelerometer can be
installed 1 or 2 feet away from the clamp 1, or a similar
device can be integrated into the smart clamp I itself.
If an external sensor is used, movement can be measured
and provided to the main clamp 1 via four wires (i.e.,
two for power and two for communication), for example,
for interfacing to the board 500 and its CPU 505.
[0085] More
specifically, measuring tension in a wire
conductor 30 can generally be performed using a device
(e.g., a Quick Balance tension meter available from
Dillon, an Avery Weigh-Tronix company in Fairmont, MN,
that is installed in or near the clamp 1 and clamped onto
the conductor 30) which deflects the wire 30 a little and
CA 02880129 2015-01-27
measures the force the wire exerts in an attempt to be
straight. The CPU 505 can use geometric-based
calculations to provide a scaling factor between the
force on the device and the tension in the wire 30.
Measuring tension can also be performed using an external
sensor such as a load cell with a mechanical disadvantage
to bring the 10,000 lb. max tension to 100-200 lbs., as
shown in Fig. 10, which can be sensed. Vibration can also
be sensed by sensing variation in tension or measured
with an accelerometer IC attached to the line a short
distance from the clamp 1.
[0086] As stated above,
the clamp 1 also has a corona
detector 640. Corona on insulators is not in the visible
spectrum. It is in deep ultra violet spectrum (e.g.,
about 280nm). Cameras that can take images of ultra
violet flashes are prohibitively expensive, particularly
when it is taken into account that corona is sporadic,
intermittent and significantly affected by air pressure,
moisture and other dynamic conditions. Silicon sensors
are not very sensitive to this range, that is, they are
about 10% efficient as compared to sensitivity to visible
light. A very good filter is required to remove visible
light, even at night. During the day, the sensor would be
swamped with visible light even with the filter. Visible
light cameras in general do not survive the temperature
extremes of the environment of the monitored line 30,
even if the cameras are turned off. In accordance with an
illustrative embodiment of the present invention, a
method of corona detection is provided that employs audio
corona detection (e.g., storing an audio signature(s) of
corona and employing sensors for detecting audio noise
and performing comparisons with signature(s) to detect
26
CA 02880129 2015-01-27
corona). The audio-detected corona can be time tagged and
its duration recorded, among other parameters.
[0087] With continued reference to Fig. 9, the audio
corona detector 640 can comprise a microphone and digital
signal processor (DSP) (not shown) to obtain and process
an audio signature ("sizzling sound") of corona. Samples
of frequency sampled corona sounds can be stored as
signatures. The output of the microphone can be
continually or periodically sampled by the DSP. The DSP
then compares the samples to signatures or otherwise
processes samples with respect to selected threshold
characteristics to determine if an alert should be
generated that a corona event has occurred. An alert can
be sent, for example, each time a corona event is
detected, or after a selected number of detected corona
events has occurred to assist with calibrating the DSP to
more accurately characterize sounds as corona events.
[0088] One or more smart clamps 1 may detect a
lightning event. The smart clamp system utilizes a GPS
unit 510 to precisely locate the positions of the smart
clamps 1. Using GPS also allows for the measurement of
the precise time information for measuring one or more
events sensed or detected by the smart clamps 1 (e.g.,
phase angle). An antenna is provided on the main board
500. A 300 kHz bandwidth filter is also provided to
detect surges from a lightning strike. It is not
necessary for lightning to strike the line to detect the
lightning. For instance, lightning strikes within a few
miles from a smart clamp can be detected and time
stamped. Geometry shared among three collocated smart
clamps 1 allows for triangulation of the strike location.
27
CA 02880129 2015-01-27
[0089] In addition, the smart clamp 1 can be
configured to take voltage measurement of the power line.
At present, it is very expensive to measure 110kv to
765kv, which is typical for a power transmission line.
Regardless, voltage with respect to the ground could be
measured using an external voltage detector which
communicates over the same radio links (not shown).
[0090] In accordance with an illustrative embodiment
of the present invention, a short range (e.g., 2 km)
radio network can be used in the smart grid system
whereby the smart clamps 1 or other data acquisition
devices can "hop" data along the transmission line 30
until aggregated data can be brought to a remote
terminal, which could interface to public or private land
based transmission as described in connection with Figs.
13-15.
[0091] With reference to Fig. 9, a clamp 1 is provided
with a radio (e.g., an encrypted radio) 540. For example,
the radio 540 can be a standard, FCC approved, digital
radio with a data rate of 250 kbps, and AES128
encryption, which is low cost, environmentally robust and
also saves development cost and minimizes deployment
cost. One such radio is a Synapse RF Engine ZigBee Radio
Board (RFET) available from Synapse Wireless Inc.,
Huntsville, AL. Having dimensions of approximately 1 .33"
per side, it can be provided on the main board 500 in the
electronics housing 50, as shown in Figs. 9 and 12. With
a 5" antenna, as shown in Fig. 11A, the radio 540 has a
range of approximately 2-3 km.
[0092] To interface to public or private land based
transmission, an optional illustrative optical interface
28
CA 02880129 2015-01-27
600 can be provided to a data acquisition device main
board 500 that operates as standard 100BaseFX Ethernet
100Mbps Media Independent Interface (Mil) to the main
processor on the board 500 in accordance with an
illustrative embodiment of the present invention.
[0093] Figs. 10 and 11A depict an optional optical
interface 600 installed on the main board 500 in
accordance with another illustrative embodiment of the
present invention. The optical cables 602 can be provided
with strain relief. Optical splitter/combiners are
indicated generally at 604. The optical interface 600 can
comprise a dual small-form factor pluggable (SFP) to
support linear fiber drop and continue topology.
[0094] An optical connector 606 (e.g., a weather tight
fiber optic connector) can be provided in the electronics
housing 50, in addition to a connector 608 for the power
cable 80. The optical interface 600 is useful at ground
level or in applications or in lower voltage applications
when the optical cable will not shunt the effect of high
voltage insulators. Alternately, the main board 500 can
be reused as a radio-to-Ethernet adaptor 710 at certain
sites and include, for convenience, a standard RJ45
electrical 0/ 00BaseT interface as well as or in lieu of
the 00BaseFX optical interface.
[0095] The low power radio 540 in each of the smart
clamps 1 in the smart clamp system includes powerful
encryption and is used to communicate back to a central
location 700, as will be described in connection with
Figs. 13-15. For a long power transmission line 30, there
could be hundreds of smart clamps 1 and, therefore,
hundreds of radio hops that would be required to reach a
29
CA 02880129 2015-01-27
switching node 700. Illustrative embodiments of the
present invention implement encryption and large numbers
of hops between data acquisition devices over long
distances and therefore accommodate the transmission
delays that remain a problem for existing radio
technology.
[0096] For ease of use and in accordance with an
advantageous, illustrative embodiment of the present
invention, the smart clamp system can require little or
no knowledge of communication protocols, radio
technology, or other technologies that are not presently
familiar to power companies that would use the smart
clamp system. As long as clamps 1 are installed within
their radio range, they will communicate with the main
computer system (e.g., a central monitoring location 700)
upon installation. Once installed, the clamp 1 begins to
operate automatically. Power is automatically provided to
the electronics 500, sensors automatically begin to
detect real-time conditions, the GPS 510 determines the
clamp location, the radio 540 detects neighboring clamps
and substation adaptors 710, and communications begin.
This embodiment is therefore superior to existing
technology that requires programming a central database
to organize remote sensing devices or the need to program
in individual nodes with cell phone numbers or IP
addresses to administer a sensor network.
[0097] In accordance with an illustrative embodiment
of the present invention, each smart clamp 1 is
configured to operate as an internet web server. The
communication can be set up over a private network, so
there is no connection to the public Internet, to improve
security. The smart clamp 1 can include an encrypted web
CA 02880129 2015-01-27
access unit 560 to enable secure access to the Internet,
as shown in Fig. 9, for e-mail alerts and to surf-the-
grid (i.e., browse web pages created for each clamp 1 to
obtain measured parameters and other information).
[0098] When a fault is detected, the smart clamp 1 is
configured (e.g., via firmware provided to the CPU 505)
to send a message (e.g., in the form of an e-mail) to a
programmable address with a short message to indicate the
problem and the location. One arrangement can include
measures to limit or coordinate the number of such
messages to minimize "overloading" a central monitoring
point 700. The messages are then communicated via a radio
communication link to an adaptor 710, for example, for
aggregation and optionally to other ground based
monitoring stations 700 (e.g., via ground based
communications) if not co-located with the adaptor 710.
[0099] The radios 540 used by the smart clamps 1 can
be adapted to standard Ethernet quite easily and tied to
an ordinary local area network. A user is able to access
the smart clamp devices 1 by entering respective web page
addresses and thereby searching or querying the grid. It
is noted that conventional monitoring systems require a
highly specialized and very expensive central computer
system and software to gather the measurements. The
simplicity of expanding the system and ability to be
accessed from many sites can be well established, and the
system can be easily implemented by using inexpensive
Ethernet equipment that is readily available.
[00100] Radio issues
[00101] At present, the Zigbee radio is a standard,
packet-based, low power radio intended for providing
31
CA 02880129 2015-01-27
communication within a building or over only a few acres.
However, it does include AES128 encryption which is
currently considered effective. However, in 5 years, such
encryption may be considered to be inadequate. It is
noted that all Zigbee radios in a network must use the
same encryption key. If the key changes, all radios must
be updated at the same time. For about 20 radios on one
property, that may be considered to be acceptable;
however, for tens of thousands of radios spread across an
electric grid or other network of data acquisition
devices as proposed in accordance with embodiments of the
present invention, using conventional Zigbee radios in a
network would not be a good system. For example, breaking
only one encryption key would make the entire system
vulnerable. In addition, the Zigbee standard sets a limit
on the response delay that is reasonable for 10 or 20
radio hops, but it cannot accommodate, for example, 500
hops, as needed for a power transmission line application
or other geographically expansive application
contemplated by illustrative embodiments of the present
invention.
[00102] The Zigbee
standard describes two kinds of
radios: a coordinator and a peripheral. Coordinators are
responsible for repeating messages to get them to the
desired destination if a repeat is needed. The provision
of a radio as either coordinator or peripheral is a
manual setup operation that needs to be avoided based
upon the potential deployment of tens of thousands of
smart clamps 1. In accordance with the illustrative
embodiments of the present invention, for simplicity and
ease of use, a technician can install the clamp 1 with a
ratchet wrench and complete the installation without
32
CA 02880129 2015-01-27
knowing anything about communication protocols or network
architecture.
[00103] Radio Protocol for Very Large Networks
[00104] While conventional Zigbee radio may be an
adequate starting point for a simple radio design, it is
inadequate for geographically expansive applications such
as those accommodated by illustrative embodiments of the
present invention. An illustrative embodiment of the
present invention provides a customized Zigbee radio
design that institutes advantageous changes for use with
the smart clamp 1 in a smart clamp system. Instead of
having one encryption key for all radios 540 in the
system, for improved security, the keys are dynamically
provided (e.g., negotiated at each transaction in a
manner similar to how internet bank transactions are
handled). For example, it can be implemented in the
Secure Socket Layer (SSL) which is part of all web
browsers. In addition, the tolerance for delay is
extended substantially. Instead of a few milliseconds,
replies on very long lines could take a minute. If an
Ethernet port that consists of smart clamp electronics
500 with both a radio 540 and optical or electrical
Ethernet interface 600 can be installed at the base of a
tower in the middle of long line, the data can be
backhauled over leased telecom lines or private lines
owned by the power company. This reduces the maximum
number of hops and reduces the response delay. However,
smart clamp communications message routing is uniquely
designed to be tolerant of the described very long delays
to support large networks even if leased telecom lines or
private lines are not available.
33
CA 02880129 2015-01-27
[00105] Each smart clamp 1 is configured (e.g., via the
programmed CPU 505, the radio 540 and other devices on
the main board 500) to implement message routing similar
to a common Ethernet switch. Some of the same concepts
are used, but substantial modification is provided in
accordance with illustrative embodiments of the present
invention to accommodate the radio environment as
described below.
[00106] The smart clamps 1 in accordance with
illustrative embodiments of the present invention are
intended to be installed, with a life expectancy of
approximately 20 years or longer. It is noted that
telecom equipment that lasts a similar period, in an
outside environment, is currently available. As an
alternative to using radios 540, smart clamps 1 can be
provide with lasers for optical communication, but their
life expectancy may be limited to 5 to 7 years, which is
far shorter than the radio equipment 540. At ground
level, where smart clamps 1 having with both a radio 540
and optical or electrical Ethernet interface 600 can be
used to communicate over a conventional utility or
telephone company circuit, an optical interface 600 is
easily serviced if it becomes necessary.
[00107] While the smart clamp 1 hardware can last as
long as 20 years, the software, encryption, communication
protocol, and other features of a smart clamp 1 are
likely to become obsolete over that time period. The
smart clamp 1, however, includes data storage that
operates like a disk drive (e.g., flash drive 502).
Software can therefore be updated remotely to accommodate
most of these changes or updates.
34
CA 02880129 2015-01-27
[00108] When future requirements simply outstrip the
capability of the existing hardware, new electronics can
be installed without removing the entire clamp. The side
box or electronics housing 50 containing the electronics
can be replaced separately. This is also an important
factor for replacing failed or malfunctioning smart
clamps 1.
[00109] As stated above, implementing a radio network
for a geographically transmission line grid (e.g., a
power transmission grid) presents challenges that are not
present in a smaller geographic area. Transmission lines
30 are inherently linear covering extremely long
distances - up to 500 miles or longer. In as much as
highways are often monitored mile by mile, it is
desirable to monitor transmission lines at least every
mile to help pinpoint issues and characterize
performance. While there are cost-effective unlicensed
radios with a nominal 1 mile range, sending a message via
such radios from one end of a 500 mile transmission line
to the other could require 500 radio repeats in each
direction which requires a communication protocol that
can accommodate very long delays. That is, the maximum
response time (before the message is deemed lost) would
necessarily be minutes instead of milliseconds.
[00110] The long transmission line 30 is not the only
issue. The network for monitoring smart clamps 1 also
branches when several radios 540 are in close proximity
(e.g., when smart clamps 1 are installed to monitor all 3
phases on one tower or when several transmission lines 30
converge at a substation). All of the smart clamps 1 need
to be able to assemble into a coherent communication
network without manual intervention in accordance with an
CA 02880129 2015-01-27
advantage of an illustrative embodiment of the present
invention.
[00111] In accordance with an illustrative embodiment
of the present invention, a more practical network is
achieved by adapting the smart grid to a more common
media and protocol stack such as Ethernet and TCP/IP.
Thus, a radio-to-copper or optical Ethernet adaptor 710
is placed strategically around the power grid, for
example. Certainly, substations are a likely place for
such an adaptor, but there could be convenient points
along a transmission line 30 for an adaptor as well. The
adaptor 710 comprises a radio 540, a standard Ethernet
port 712, and suitable protocol conversion. The resulting
Ethernet interface is therefore suitable to interface
with public ' communication lines (telcos), private
networks, cable TV modems, DSL, and/or other internet
type access technologies.
[00112] As stated above, a main board 500 can be used
as a radio-to-Ethernet adaptor 710 at certain sites. An
example of a data acquisition device main board that can
be configured as an adaptor 710 is provided in Figs. 10
and 11A. The adaptor 710 can be physically different from
the line data acquisition device (e.g., a smart clamp 1)
and has a different function. The adaptor 710 can
identify itself as a port where messages originate and
are terminated. It is a homing location. An illustrative
operation of the data acquisition devices (e.g., smart
clamps 1) and the network organization is to reach one of
these adaptors 710 with minimal delay which is defined as
the minimum number of repeats or hops required.
36
CA 02880129 2015-01-27
[00113] When a packet is received by a data acquisition
device (e.g., a smart clamp 1), there are three options
for disposition of the message, by way of an example. If
the message is intended for the same data acquisition
device, the CPU 505 of the data acquisition device
processes the message. If the message is not intended for
this local data acquisition device, either the message is
repeated, or it is not repeated because it will be routed
by another device. Messages can be images (e.g., still or
video images capture by the camera(s) 550), measured or
sensed parameters from the data acquisition device that
can be reported in various formats, standardized messages
or alerts (e.g., text, audio, or graphics), e-mails, HTML
files, among others. The messages are packetized by the
CPU 505, for example. As explained below, the messages
are aggregated (e.g., via an adaptor 710) for access by a
user (e.g., using a web browser and web address assigned
to each adaptor 710).
[00114] Each message can include an 8 byte long source
address and 8 byte destination address. These addresses
are the Media Access Control (MAC) address which is
programmed in during manufacturing and unique to every
radio. The MAC address is used to route the packets.
While a layer 3 protocol, such as Internet Protocol (IP),
might seem more appropriate, some manual setup (which
could be time consuming, require accurate records and be
unfamiliar to utility technicians who are bolting the
smart clamp or similar accessories in place) could be
required to set the IP address. In addition, each of the
data acquisition devices 1 is being used as a web server
in accordance with illustrative embodiments of the
present invention. This requires a fixed IP address
37
CA 02880129 2015-01-27
rather than an IP address that is assigned automatically
as would be the case if Dynamic Host Control Protocol
(DHCP) is used. To avoid the issue, the routing by data
acquisition devices such as a smart clamp 1 is performed
at layer 2, the media layer.
[00115] With each smart clamp 1 operating as a layer 2
router, each data acquisition device or smart clamp I
will need to track thousands of MAC addresses to know
whether to repeat or not repeat a message. This is not
practical for a moderately sized CPU 505. Instead, each
data acquisition device can be provided with a high speed
memory 502 attached to custom hardware (not shown) in the
main board 500 that compares a list of known MAC
addresses to that of the destination address in the
packet. Upon finding a match, the data acquisition device
will know whether the packet needs to be repeated or
simply ignored.
[00116] In an illustrative implementation, the number
of MAC addresses is limited to a selected number (e.g.,
on the order of 26,400) that is a compromise of
processing speed, packet duration time, and power
consumption while still maintaining the requirement of
thousands of devices in a single subnetwork. If required,
larger numbers of MAC addresses can be supported.
[00117] To create the table of MAC addresses in the
high speed memory 502, each data acquisition device needs
to announce it is present. In the simplest case, this is
begun with a broadcast message from an adaptor 710. Each
data acquisition device (e.g., smart clamp 1) forwards
the message but increments the hop count within the
message. Each device also replies to the message with the
38
CA 02880129 2015-01-27
minimum hop count received. Naturally, each device 1 will
see many copies of the message. In most cases, the
earliest message will have the smallest hop count, and
the device will reply with that hop count. However, there
are some less likely situations where a smaller hop count
can be received later in the process. The device will
reply to this smaller hop count which appears later.
However, it will not reply to the adaptor 710 with a
larger hop count.
[00118] During this process, each data acquisition
device (e.g., smart clamp 1) will become familiar with
devices in the immediate vicinity. Each device will know
the hop count to the adaptor 710 for its neighbors. In
general, the devices with the lowest hop count will be
responsible for performing repeat operations for devices
with higher hop counts. However, each device is
configured to perform a repeat or hop even when it
appears there is a lower count path available.
[00119] Consider a simple
linear case, as shown in
Figs. 13a and 13b. Data acquisition device #1 will be 1
hop count from the adaptor 710. Data acquisition device
#2 will be 2 hop counts since device #2 is not in range
of direct connection to the adaptor 710. Device #3 is 3
hop counts from the adaptor.
[00120] The adaptor 710 issues the configuration
broadcast. Device #1 repeats it with a hop count of one.
It also replies to the adaptor 710 with a hop count of 1.
Device #2 will receive the repeated configuration message
with a hop count of 1 and the reply from Device #1 with a
hop count of 1. Device #1 will take the reply from Device
#2 and repeat it to the adaptor 710 with an incremented
39
CA 02880129 2015-01-27
hop count. Device #2 repeats the configuration message
with a hop count of 2 and also replies toward the adaptor
710 with a hop count of 2. Device #3 receives the
repeated broadcast from the adaptor 710 and replies to it
with an incremented hop count. Device #2 repeats the
reply from Device #3 toward the adaptor 710 with an
incremented hop count.
[00121] Device #1 determines that it can communicate
directly to the adaptor 710. It also determines that the
Device #2 reply did not have a hop count of zero, and so
Device #2 must be relying on Device #1 to communicate to
the adaptor 1. Device #1 also determines from the
messages that another device is in the network (i.e.,
Device #3) and has an even larger hop count. Accordingly,
Device #1 repeats messages to the adaptor 710 from that
device as well.
[00122] In a more complex situation, there are multiple
valid paths back to the adaptor as shown in Fig. 14. This
example assumes all 3 phases of a power transmission line
30 are being measured at the same points.
[00123] In this case, all A devices (e.g., Devices Al,
A2, A3) can receive messages from each other and all B
devices (e.g., Devices Bl, B2, B3) and the adaptor 710.
All B devices can hear all A, B, and C devices (e.g.,
Devices Al, A2, A3, Bl, B2, B3, Cl, C2 and C3), but not
the adaptor. All C devices (Devices Cl, C2 and C3) can
hear B devices and C devices. The decision on the path is
not longer but rather just a matter of the only path
available. A decision factor in this case will be the MAC
address. For example, the device with the lowest MAC
address will be the repeater. While the MAC address is 8
CA 02880129 2015-01-27
bytes long, manageably short numbers are used in this
example. Device B1 will have address 10, B2 is 11, and B3
is 12. Devices B2 and B3 will be able to receive the
response of Device B1 and realize the number of hops
provided back to the adaptor 510 is the same as the
number of hops they are providing. The MAC address of
Device B1 is the lowest so Device B2 and Device B3 will
automatically defer to allow Device Bl to perform repeats
for Devices Cl, C2, and C3. The use of the lowest MAC
address is arbitrary. The decision can be made by using
some other fixed relationship between the MAC address
such as choosing the highest address or other factor.
[00124] In the above example, any one of the devices
could fail and there would still be a path back to the
adaptor 710 at the left side. Some reconfiguration could
be required. For that reason, the reconfiguration message
is periodically broadcast from the adaptor 710 (e.g.,
every 15 minutes). If a device realizes it can no longer
communicate with the adaptor 710, it can issue a request
to reconfigure which all devices will repeat toward the
adaptor 710.
[00125] A network, as shown in Fig. 15, can have more
than one adaptor 710. For example, another adaptor can be
representative of a transmission line 30 between two
substations where there is an adaptor at each substation.
[00126] Assume Device Al has the lowest MAC address
among Devices Al, A2, and A3. Device B1 has the lowest
MAC address among Devices Bl, B2, and E3. Device Cl has
the lowest MAC addresses among Devices Cl, C2, and C3.
The shortest number of hops to an adaptor for the A
devices is to the left. The shortest path to an adaptor
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CA 02880129 2015-01-27
for the C devices is to the right adaptor. The B devices
could reach either adaptor with 2 hops. The tie breaker
will be the MAC address of Device Al and Device Cl. The B
devices will use the path with the lowest MAC address of
either Device Al or Device Cl.
[00127] A system with three or more adaptors can be
accommodated with the same algorithm. First, find the
closest adaptor in terms of the number of hops. Where
there is a tie, use the MAC address of the nearest
repeaters to break the tie.
[00128] With continued reference to Figs. 13a and 13b,
an adaptor 710 can be mounted outside on a wall or a pole
and be within, preferably, line of sight of a clamp 1.
The adaptor 710 can be provided with a standard RJ45
10/10OBT electrical Ethernet connection for ground-based
network connections, and use 90VAC to 264VAC, 50Hz or
60Hz power and approximately 2W. Other power connections,
such as -48Vdc, may be used. If a telco provides only a
Ti (often called DS1) or El connection, standard
Ethernet-to-Tl or El adaptors may be used to convert the
adaptor 710 Ethernet signal to the telco Ti or El
interface to establish a Ti or El private line from the
adaptor site to the remote surveillance location 700. If
neither a Ti or El private line nor a fully private
network is used for the circuit between the adaptor 710
and the remote surveillance location or central station
700, a VPN network can be used to assure restricted
access. The adaptor 710 includes sophisticated encryption
to further address security concerns. In Fig. 13b, the
hand off from the intermediate utility to the telco VPN
can be Ti, El, DSL, cable modem, microwave hop to another
site, among other methods. If the adapted connects the
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CA 02880129 2015-01-27
grid or network to a remote surveillance point or central
station 700 by the internet, a gateway, firewall and VPN
connection can be used for security reasons.
[00129] Each clamp 1 adaptor 710 has an integral web
page server 560. One IF address is assigned at the remove
surveillance point or central station 700 for each
adaptor 710. For example, only one IP address need be
assigned per adaptor 710, while an IF address for each
clamp 1 does not need to be assigned. This IF address is
programmed into the one or two adaptors 710 in a network.
The adaptors 710 then automatically discover both the
remote surveillance point or central station connection
and all clamps 1 in the network as described above.
[00130] Surveillance personnel can then be provided
with a browser address for accessing the remote adaptor
710. Once the browser address is entered, a private web
page appears that provides access to the data from each
clamp 1, longitude and latitude for each clamp which may
be linked to a map, means to re-name clamps (Route 43 and
Highway 22, for example), means to set thresholds
(vibration, temperature etc.), and means to enter e-mail
addresses that should be used to notify specific
personnel if thresholds are crossed. The addresses can be
clamp-specific in case the transmission lines span
several maintenance regions. The number of e-mail alerts
that are sent can be limited.
[00131] Thus, in accordance with an illustrative
embodiment of the present invention, an administrative
system is provided to facilitate monitoring and
processing the collected data received from various data
acquisition devices (e.g., a clamp 1). The administrative
43
CA 02880129 2015-01-27
system can be implemented in processing devices used to
aggregate and analyze the collected data such as an
adaptor 710, central monitoring point 700, or a computing
device with internet connectivity provided at a base
station(s) or other locations. The administration system
can use screens or web pages and web servers, which can
be built-in. Firmware is provided to the data acquisition
devices. Thus, no external software is needed.
[00132] Figs. 16 and 17
are illustrative web pages
generated via the administrative system. A user (e.g.,
monitoring network administrator) is provided with an
assigned Internet Protocol (IP) address with which to
type into a web browser (e.g., Internet Explorer, Foxfire
and the like) to navigate to the home page shown in Fig.
16. The home page provides a number of options for
managing individual data acquisition devices and
network(s) of data acquisition devices, that is, by
selecting one of the options, a user can view system
conditions as well as provision their device(s) and/or
network(s). In the illustrated embodiment, the data
acquisition devices are clamps 1 and referred to as Data
Acquisition Suspension Clamps (DASCs). The IP address can
be assigned to a base station, for example. A base
station can be provided for each isolated network. By way
of an example, selecting the DASC List option causes a
screen or web page (not shown) to be provided to the user
that lists DASCs by device identifiers. The user can then
select one of the listed DASCs to navigate to a data page
for that DASC as shown in Fig. 17.
[00133] With reference to Fig. 17, the data page
indicates parameters for the selected DASC (e.g., clamp 1
) and their corresponding dates/times or measurement
44
CA 02880129 2015-01-27
which have been communicated to an aggregating device
(e.g., adaptor 710) via the multi-hop radio communication
system described above in connection with Figs. 13-15.
The parameters can be, but are not limited to, maximum
and minimum ambient temperatures, maximum and minimum
wind speeds, maximum and minimum current, maximum and
minimum vibration, and maximum and minimum wire
temperatures, among others. The data page 7 can also
indicate events such as corona events and tilt events
(e.g., number of and duration of such events as
determined by deviations from conditions at the time of
installation or upon a reset command to a particular
smart clamp) and numbers of surge and impulse events,
among others. Event history logs can be created based on
this data, allowing a user to select the Logs option on
the page depicted in Fig. 16 to view event histories.
[00134] With reference to
Fig. 6, a user can select a
DASC Samples option to navigate to a page (not shown)
listing a number of available datasets. For example, a
user can obtain a CSV file (i.e., comma separated values)
upon by selecting one of the listed items.
[00135] With continued reference to Fig. 16, by
selecting the DASC Map option on the home page, a user
can be provided with a map showing the locations of data
acquisition devices within a designated geographic area.
The location coordinates can be collected by the
administrative system and corresponding database either
dynamically using the GPS device 510 provided in each of
the data acquisition devices (e.g., via messaging) or
pre-configured at the time the devices are installed or
otherwise deployed.
CA 02880129 2015-01-27
[00136] For example, the integral GPS system 510 within
each clamp 1 reports back its precise longitude and
latitude. These data can be linked to, for example,
utility-based mapping or, if suitable firewall and
gateway safeguards are in place, Google maps. A typical
Google map will show a pushpin for each clamp 1 location,
include an ability to zoom in, and usually provide an
ability to retrieve stored satellite images for the
terrain in the vicinity of each clamp. If there is no
direct connection between a smart grid network and Google
maps, longitude and latitude information can be entered
into Google maps manually on a separate network and the
information used to establish a meaningful name for each
clamp 1. Alternatively, the location can be entered into
a proprietary map system already in use.
[00137] GPS positioning and DASC self-learning function
can be provided in each data acquisition device 1 to
permit DASC networks to evolve automatically. For
example, a DASC 1 can be configured to obtain its
position information and generate a location alert to a
base station 700 and/or adaptor 710 at start up and/or
periodically, in addition to sending parameter
measurement. Thus, every new DASC 1 can be automatically
recognized by a base station 700 and/or adaptor 710 with
its location automatically determined such that
corresponding data accumulation and reporting starts
immediately and automatically after an initial deployment
or restart. The administration system illustrated in
connection with Figs 16 and 17 is advantageous because it
provides a comprehensive view of transmission line
conditions to enable confident dynamic line ratings
(e.g., to help address peak and emergency demands),
46
CA 02880129 2015-01-27
immediate and precise identification of line failures,
proactive maintenance, diagnosis of recurring problems.
The clamps 1 themselves communicate with one another
which permits self-learning and awareness of long-term
trends to help predictive maintenance.
[00138] By selecting an Alerts option on the home page
depicted in Fig. 16, a user can access e-mail alerts that
are automatically generated by the data acquisition
devices 1 and transmitted to the base station 700 and/or
adaptor 710 Or other device implementing the
administrative system. As stated above, data acquisition
devices 1 can be configured to send alerts (e.g., e-mail
messages or other type of transmitted signal alert) when
measured parameters are outside a selected range or vary
from a selected threshold by a selected amount. The
Configuration option on the home page (Fig. 16) provides
one or more pages (not shown) that enable a user to
provision device(s) and/or network(s) of devices. For
example, configuration pages can be provided that enable
setting of parameter threshold deviations needed for
automated alerts (e.g., a parameter exceeds a threshold
be a selected amount or an event has occurred a selected
number of times within a selected time period). The
determination of such deviations can be performed at the
data acquisition devices (e.g., via the CPU 505 on the
main board 500 in accordance with the firmware).
Alternatively, the data acquisition devices can merely
report measurements of parameters to the base station or
other monitoring location 710, 700, which instead makes
the determination.
[00139] It is to be understood that other options and
web pages are available. For example, the data page (Fig.
47
CA 02880129 2015-01-27
17) and/or home page (Fig. 16) can provide a link or
navigation option to another page or a pop-up on the same
page that provides the live camera view(s) for a selected
DASC. For example, one or both views of the cameras in a
clamp 1 (e.g., the respective views of oppositely
extending sections of the monitored line 30) can be
provided to allow a user to make a visual assessment of
whether sag or galloping is occurring or to otherwise
assess damage to a line (e.g., icing, mechanical failure
of the line or tower, and so on). Image processing can
also be provided (e.g., at the base station or other
monitoring station) to automatically assess images
provided by the cameras (e.g., comparing different
images) to determine whether certain conditions are
present (e.g., sag) and to automatically generate alerts
as needed.
[00140] As described above and in accordance with
illustrative embodiments of the present invention, a
clamp 1 or other data acquisition device configuration
can be provided with one or more sensors for monitoring
selected transmission line 30 conditions including, but
not limited to ambient temperature, conductor
temperature, wind speed perpendicular to the line (e.g.,
measurement is done without moving parts to assure long-
term quality and reliability), vibration, current
amplitude, current quality (e.g., harmonic distortion),
current surges, precise location via GPS, precise timing
via the GPS, transient or surge location via precision
time stamping and automatic clamp-to-clamp
communications, corona, tilt changes (e.g., as measured
by the clamp's 3-axis accelerometer), sag changes (e.g.,
as displayed by a pair of integral clamp 1 cameras that
48
CA 02880129 2015-01-27
look down both directions of the line 30), galloping
(e.g., as detected by the vibration sensor and seen by
the cameras), local conditions (e.g., via still visual
images in both directions of the line 30 to help detect
icing or mechanical failure of the line or tower,
internal operation via continuous self diagnosis (e.g.,
as programmed into the CPU 505), operating conditions of
neighboring clamps on other phases, and so on.
[00141] Thus, the data acquisition device (e.g., clamp
1) provides an unprecedented ability to integrate
transmission line operating conditions in real-time.
Rather than piecemeal visibility at a single location or
reliance upon inferred data such as sag to estimate line
temperature, new Dynamic Line Rating capabilities and
visibility are made possible by the clamps that delivers
precise mile-by-mile data that can be integrated and used
to dynamically vary line 30 loading with confidence.
Risks associated with dependence upon a few data points
can be dramatically reduced and replaced by a Dynamic
Line Rating based upon (a) precise real-time wind speed
determination that automatically measures the cooling
effect of wind perpendicular to the line; (b) precise
total current measurements made along a line 30 to
uncover varying parasitic losses and other issues that
limit capacity; and (c) wide-bandwidth current
measurements in real-time. Wide-bandwidth current
measurements reveal harmonics that waste energy and
increase heating. These real-time data can then be used
to optimize network operation and uncover associated
stresses to components such as transformers.
[00142] As stated above, another advantage of the data
acquisition device (e.g., clamp 1) constructed in
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CA 02880129 2015-01-27
accordance with an illustrative embodiment of the present
invention is self-powering. The clamp 1 includes an
integral or associated current transformer 330 which
provides all necessary power. No batteries or connection
to external power is required. Energy storage without
batteries is also provided (e.g., a capacitor(s)) to
support final messages should a line 30 fail. The clamp 1
therefore can continue to operate (e.g., for several
seconds) to provide final reports.
[00143] As described above, wireless communications are
established between the clamps 1 and between a clamp
array (e.g., as illustrated in Figs. 13-15) and a
substation or other convenient ground location 710. Data
is then communicated over a private or public network to
surveillance locations 700. The multi-hop radio
communications described herein in accordance with an
illustrative embodiment of the present invention provide
resilient communications. Failure of a clamp 1 for any
reason is detected and reported by neighboring clamps
without disrupting end-to-end communications. Further,
the communications are secure. Security similar to that
used for on-line banking transactions is utilized along
with other measures to help assure network integrity as
described above in accordance with an illustrative
embodiment of the present invention.
[00144] The integral GPS 510 provides precise timing
and automatically locates each clamp 1. An integral web
browser 560 dramatically simplifies data acquisition via
web page selection of thresholds, alerting e-mail
addresses and comprehensive display (e.g., of up to 7
days of accumulated data).
CA 02880129 2015-01-27
[00145] There are several ways to utilize data
collected by a network. A few shall now be discussed for
illustrative purposes.
[00146] Flexible reporting is achieved by reports and
images that appear as web pages (i.e. HTML files). The
basic files display collected data in a series of tables
on multiple pages. If a different presentation or
appearance of the data is preferred, the system permits
new HTML files to be uploaded to each clamp. Each clamp 1
is operated independently and can have its own unique
HTML files. This may appear overly complicated initially,
but larger arrays that span multiple transmission
facilities can benefit from this ability to optimize the
presentation of data to fit varying circumstances.
[00147] Fault or alarm conditions are immediately
reported via e-mail. Each incident can then be
investigated further via the report and image pages.
[00148] A web-based form is provided to set alarm or
warning limits for various parameters such as maximum
current, current surge, maximum conductor temperature, or
maximum vibration. Local conditions such as corona can be
set to trigger an e-mail or be ignored. The form also
permits entry of e-mail addresses for notifications and a
means to limit the number of e-mails each clamp 1 can
send in an hour.
[00149] When a fault occurs, the network can identify
what the problem was and the area where the problem
occurred in accordance with illustrative embodiments of
the present invention. E-mails can be sent to first
responders so that a team can be dispatched (or not)
based upon real-time site data. Time is saved, dispatched
51
CA 02880129 2015-01-27
crews may be able to bring appropriate repair equipment,
repair progress can potentially be witnessed and the
repairs can be monitored.
[00150] Illustrative embodiments of the present
invention also improve upon finding stressed or
compromised facilities. Excessive temperature, tilt and
other factors can lead to a failure. Knowing that lines
are compromised enables pro-active maintenance to prevent
outages. With regard to finding and monitoring vibration
problems, dampers are deployed to limit the vibration.
Although real-world damper effectiveness has been
demonstrated and they work well in many applications,
real-time effectiveness based upon wind and tower
conditions can now be monitored to optimize effectiveness
and uncover unknown or suspected issues.
[00151] The illustrative embodiments of the present
invention allow maximizing capacity. Transmission
facilities have conventionally been designed for worst-
case conditions. In some instances, a 25% safety margin
has been used to assure resiliency. Knowing real-time
wind and temperature conditions in accordance with
illustrative embodiments of the present invention can
permit loads to be safely increased during peak periods
or when another segment is out of service.
[00152] The illustrative embodiments of the present
invention provide cascade failure analysis. A cascade
failure occurs when one element breaks and causes several
other network elements to fail unexpectedly. For
transmission lines 30, most recorded observations are
limited to measurements at substations or originating
points. The distributed intelligence available from a
52
CA 02880129 2015-01-27
smart clamp network helps the understanding of such a
failure, what precipitated it and how to engineer
improvements for existing and future lines.
[00153] The illustrative embodiments of the present
invention improve network planning. Detailed knowledge of
operating conditions permits better forecasting of
transmission line requirements and aids justification of
new construction.
[00154] Illustrative embodiments of the present
invention provide a smart grid system, method and
apparatus that measure the conductor temperature to
provide feedback on the actual capacity, as well as other
information, of a transmission line 30 (e.g. a power
transmission line) at many points. The power transmission
line may be overstressed, but it could have more capacity
than that which is actually being used. The illustrative
system of the present invention can measure the wind
speed and ambient temperature to determine the conditions
along a power transmission line that may be hundreds of
miles long. Some parts of the wire of the power
transmission line may be warmer than other parts because
the power transmission line may run through a valley
where there is no wind, for instance, or due to other
reasons. For example, an anemometer with no moving parts
can be used to determine the cooling effect of the wind.
[00155] The smart grid system is able to detect corona,
even when it is intermittent, using audio detection of
corona. The smart grid system is able to measure the
current in the line. If it is determined that the
measured current is different than the current launched
at a substation, there is a current leak or fault
53
CA 02880129 2015-01-27
somewhere. The smart grid system is able to take a
picture of the power transmission line and its
surroundings in order to visualize any ice, fallen trees,
vegetation, and the like growing on the power
transmission line, as well as sagging power transmission
lines, or even wildlife that may damage the power
transmission lines and smart grids.
[00156] The smart grid system can quickly determine if
there is an immediate or long term problem in the power
transmission line and communicate to a user/technician.
The smart grid system is easy to install, very robust,
simple to administer, and does not require regular
maintenance, such as replenishing or recharging
batteries. In addition, the system is cost effective and
secure. The integrated web server in the smart grid data
acquisition device simplifies and reduces the cost of
backend software. An improved radio protocol and routing
algorithms are provided which are particularly well
suited for long runs with modest branching; however, they
can be used for more general applications where Zigbee
and Zigbee-type technologies lack range or capacity.
[00157] The above-described exemplary embodiments of an
apparatus, system and method in computer-readable media
include program instructions to implement various
operations embodied by a computer. The media may also
include, alone or in combination with the program
instructions, data files, data structures, and the like.
The media and program instructions may be those specially
designed and constructed for the purposes of the present
invention, or they may be of the kind well-known and
available to those having skill in the computer software
arts. Examples of computer-readable media include
54
CA 02880129 2015-01-27
magnetic media such as hard disks, floppy disks, and
magnetic tape; optical media such as CD ROM disks and
DVD; magneto-optical media such as optical disks; and
hardware devices that are specially configured to store
and perform program instructions, such as read-only
memory (ROM), random access memory (RAM), flash memory,
and the like. The media may also be a transmission medium
such as optical or metallic lines, wave guides, and so
on, and is envisioned include a carrier wave transmitting
signals specifying the program instructions, data
structures, and so on. The computer-readable recording
medium can also be distributed over network-coupled
computer systems so that the computer-readable code is
stored and executed in a distributed fashion. Examples of
program instructions include both machine code, such as
produced by a compiler, and files containing higher level
code that may be executed by the computer using an
interpreter. The described hardware devices may be
configured to act as one or more software modules in
order to perform the operations of the above-described
embodiments of the present invention.
[00158] Referring now
also to Figs. 18-23, another
example embodiment of the invention will be described.
Figs. 18-23 show a suspension clamp connecting assembly.
Similar to the embodiments above, the suspension clamp
connecting assembly provides for a method, system and
apparatus for a smart grid comprising networked data
acquisition devices that monitor transmission lines or
conductors. However, in this
embodiment, the data
acquisition device is illustrated as a connecting
attachment clamped to an existing conventional suspension
clamp (e.g., on a power transmission line).
CA 02880129 2015-01-27
[00159] The suspension
clamp connecting assembly 810
comprises a clamping unit 812, the electronics housing
50, and a corona ring 816. The clamping unit
812 is
configured to clamp on to suspension clamp connected to a
transmission tower. The electronics
housing 50 and
electronic components therein operate generally in the
same fashion as described above for the smart clamp 1
embodiment above. The corona ring 816 comprises any
suitable type of corona ring and may be attached to the
suspension clamp connecting assembly in any suitable
fashion.
[00160] The clamping unit
812 is suitably sized and
shaped to clamp on to an existing suspension clamp. For
example Figs. 21, 22 illustrate views of a conventional
suspension clamp 818 connected to a bottom end of an
insulator 206 which extends down from the cantilevered
arms 204 of the transmission tower 200 (as shown in Fig.
1).
[00161] The suspension
clamp 818 may be any suitable
type of conventional transmission suspension clamp that
is common in the industry and extensively used, that is
designed to merely provide a mechanical means of
suspending the transmission conductor (or transmission
line) 202 safely and securely to the transmission tower
200. The suspension
clamp may be connected via
miscellaneous hardware, commonly called "string hardware"
to insulators 206 that are in turn attached to the
transmission tower 200 (as shown in Fig. 1).
[00162] According to this
example embodiment of the
invention, electronic sensing circuitry is incorporated
into the suspension clamp connecting assembly to allow
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CA 02880129 2015-01-27
utilities to gather key information about electrical and
environmental conditions occurring at a remote site.
Similar to the embodiments above, the device can operate
in a high voltage environment ranging up to 765,000 volts
and above. This environment creates electromagnetic and
electrical fields that create stress for the sensing
electronics. The features of
this suspension clamp
connecting assembly can sense and report electrical
(Voltage and Current), temperature, optical, tensile and
vibration parameters that are present in/on and around
the conductor/line being suspended. These key parameters
will allow further diagnosis by the user on the operating
condition of the line from many miles away.
[00163] As shown in Figs.
21, 22, the clamping unit 812
is configured to clamp on to a portion of the suspension
clamp 818. The suspension clamp 818 generally comprises
an upper section 820 and a lower support section 822.
These two sections 820, 822 may each contain a body which
include a longitudinal trough (or conductor receiving
area) that allows the transmission conductor 202 to be
securely seated within the two sections and when the two
sections are bolted (or fastened) together. This
generally sandwiches the transmission conductor 202
between the two bodies to securely contain the
transmission conductor 202 on the clamp 818. In the
embodiment shown, the clamping unit 812 clamps on to the
lower support section 822 (which generally forms a main
body portion of the suspension clamp) of the suspension
clamp 818.
[00164] Referring now
also to Figs. 23-31, additional
views of suspension clamp connecting assembly 810 are
shown. The clamping unit
812 comprises a base section
57
CA 02880129 2015-01-27
824, extending arms 825, 826, clamp contact portions 827,
828, and a clamp adjustment portion 829. The extending
arm 825 is movably connected to the base section 824 by
fasteners 830, 831. The extending arm
826 is movably
connected to the base section 824 by fasteners 832, 833.
The clamp contact portions 827 are movably connected to
the extending arm 825 by fasteners 834, 835. Similarly,
the clamp contact portions 828 are movably connected to
the extending arm 826 by fasteners 836, 837.
[00165] The clamp
adjustment portion 829 may comprise
any suitable configuration which allows for adjustment of
the extending arms and clamp contact portions between an
open position (for example as shown in Fig. 30) and a
closed position (for example as shown in Fig. 29).
According to various exemplary embodiments, the clamp
adjustment portion may include a fastener 838 (such as a
threaded eyebolt, for example) and adjustment members
839, 840. The adjustment member 839 is movably attached
to the arm 825 by fasteners 841, 842. The adjustment
member 840 is movably attached to the arm 826 by
fasteners 843, 844. The eyebolt 838 is suitably sized
and shaped to extend through openings 845, 846 of the
adjustment members 839, 840.
[00166] The clamp
adjustment portion is configured such
that rotation (such as clockwise or counter-clockwise) of
the eyebolt 838 causes the arms 825, 826 to pivot (about
the fasteners 830, 831, 832, 833) between the open
position (Fig. 30) and the closed position (Fig. 29).
Various exemplary embodiments may include the opening 845
or the opening 846 as a threaded opening to receive the
eyebolt 838 and provide for relative movement
therebetween. According to some embodiments a clockwise
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CA 02880129 2015-01-27
rotation of the eyebolt allows the arms 825, 826 to pivot
to the open position, and a counter-clockwise rotation of
the eyebolt allows the arms 825, 826 to pivot to the
closed position. However, in
alternate embodiments, a
clockwise rotation of the eyebolt allows the arms 825,
826 to pivot to the closed position, and a counter-
clockwise rotation of the eyebolt allows the arms 825,
826 to pivot to the open position.
[00167] The clamp contact portions 827, 828 are
suitably sized and shaped for contacting an outer portion
of the suspension clamp 818. For example in
this
embodiment, the contact portions 827, 828 extend over top
external portions of the suspension clamp lower support
section 822, and the contact portions 827, 828 extend
down to lower external portions of the suspension clamp
lower support section 822. This provides for
curved
inner surfaces 847, 848 of the clamp contact portions
827, 828 to contact the top external portions of the
suspension clamp lower support section 822, and lower
inner surfaces 849, 850 to contact the lower external
portions of the suspension clamp lower support section
822 (best shown in Fig. 32), and provide a clamped
connection to the suspension clamp 818 such that the
suspension clamp connecting assembly 810 is removably
connected to the suspension clamp 818. It should be
noted although the figures illustrate the clamp contact
portions contacting the suspension clamp 818 at surfaces
847, 848, 849, 850, in alternate embodiments, any
suitable contact surfaces, or contact configuration may
be provided. Additionally, in some embodiments, the
contact portions 828, 829 may further be spring biased to
a desired position.
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[00168] The electronics
housing 50 is attached to a
support member 851 of the suspension clamp connecting
assembly 810. The electronics housing 50 and electronic
components (for example, main electronics board 500, and
so forth) therein operate generally in the same fashion
as described above for the smart clamp 1 embodiment
above. However, rather than attaching the housing 50 to
a heat shield on the side of the smart clamp, in this
embodiment the electronics housing 50 is mounted to the
suspension clamp connecting assembly for attachment to an
existing suspension clamp. For example, in
some
embodiments, the electronics housing 50, may be fastened
to the support member 851 at openings 852 (see Fig. 27).
However, in alternate embodiments, and suitable
configuration may be provided.
[00169] Referring now also to Fig. 33, in this
embodiment, the electronics housing 50 further comprises
an attached articulated arm 853. The articulated arm 853
comprises an arm section 854 and a sensor shell section
855. The sensor shell
may comprise a substantially
cylindrical shape (with a longitudinal opening 856 to
allow for installation on the conductor 202) having an
inner surface suitably sized and shaped to mount sensors
857 (such as vibration, temperature, hall effect sensor,
or other sensors, for example). The spring loaded
articulated arm is generally configured to have a 1-2 lb
downward pressure on the transmission conductor 202 to
ensure the sensors 857 (that are internally mounted and
contained in the sensor shell section), remain in contact
with the transmission conductor 202. The arm section 854
comprises an insulated/shielded wire 858 connecting the
sensor shell section 855 to the electronic components in
CA 02880129 2015-01-27
the electronic housing 50. However, in
alternate
embodiments, any suitable connection may be provided.
[00170] As mentioned
above, the electronics housing 50
and electronic components therein operate generally in
the same fashion as described above for the smart clamp 1
embodiment above. However in this
embodiment, the
electronics in the electronics housing 50 are connected
to a separate power supply (instead of the current
transformer 330). Additionally,
according to some
embodiments of the invention, various temperature sensors
may be removed in the suspension clamp connecting
assembly configuration.
[00171] Various exemplary
embodiments of the invention
generally provide for a mechanical clamping apparatus
which securely retains the data acquisition electronic
components (for example in the electronics housing 50)
and the corona ring to an existing power line clamp (and
also serves as an attachment point for the spring loaded
articulated arm 853).
[00172] It should be
understood that components of the
invention can be operationally coupled or connected and
that any number or combination of intervening elements
can exist (including no intervening elements). The
connections can be direct or indirect and additionally
there can merely be a functional relationship between
components.
[00173] Below are provided further descriptions of
various non-limiting, exemplary embodiments. The below-
described exemplary embodiments may be practiced in
conjunction with one or more other aspects or exemplary
embodiments. That is, the
exemplary embodiments of the
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CA 02880129 2015-01-27
invention, such as those described immediately below, may
be implemented, practiced or utilized in any combination
(e.g., any combination that is suitable, practicable
and/or feasible) and are not limited only to those
combinations described herein and/or included in the
appended claims.
[00174] In one exemplary
embodiment, a suspension clamp
connecting assembly comprising: a clamping unit
comprising a base section, extending arms, and clamp
contact portions, wherein the extending arms are between
the clamp contact portions and the base section, and
wherein the clamping unit is configured to clamp on to a
suspension clamp; a support member having a first end and
a second end, wherein the first end of the support member
is connected to the base section, and wherein the support
member is configured to support an electronics housing;
and a corona ring connected to the second end of the
support member.
[00175] A suspension clamp connecting assembly as above
wherein the electronics housing is connected to the
support member, and wherein the electronics housing
comprises electronic components configured to acquire
data from a transmission line.
[00176] A suspension clamp connecting assembly as above
wherein the electronic components include at least one
sensor for determining at least one of a parameter and
image associated with the transmission line; a radio
interface for communicating to at least one of a
monitoring device and at least one neighboring data
acquisition device via a radio communication link within
a selected range; and a processing device connected to
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the at least one sensor and the radio interface, the
processing device being programmed to receive and process
inputs from the at least one sensor, and to generate
messages for transmission via the radio interface;
wherein the processing device is configured to
participate in multi-hop communications via the radio
communication link by receiving messages generated by
other data acquisition devices, and determining from
information provided in each of the messages which
operation to perform from among process the message,
repeat the message, and ignore the message.
[00177] A suspension clamp connecting assembly as above
wherein the electronics housing further comprises a
spring loaded articulated arm.
[00178] A suspension clamp connecting assembly as above
wherein the spring loaded articulated arm comprises an
arm section and a sensor shell section.
[00179] A suspension clamp connecting assembly as above
wherein the clamping unit further comprises a clamp
adjustment portion, wherein the clamp adjustment portion
is configured to allow for adjustment of the extending
arms and clamp contact portions between an open position
and a closed position.
[00180] A suspension clamp connecting assembly as above
wherein the clamp contact portions are movably connected
to the extending arms.
[00181] A suspension clamp connecting assembly as above
wherein the extending arms are movably connected to the
base section.
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[00182] A suspension clamp connecting assembly as above
wherein clamp contact portions are configured to contact
a main body portion of the suspension clamp.
[00183] In another exemplary embodiment a clamping unit
comprising: a base section, extending arms, and clamp
contact portions, wherein the extending arms are between
the clamp contact portions and the base section, and
wherein the clamping unit is configured to clamp on to a
suspension clamp such that a main body portion of the
suspension clamp is between the extending arms.
[00184] A clamping unit as above wherein the clamping
unit further comprises a clamp adjustment portion,
wherein the clamp adjustment portion is configured to
allow for adjustment of the extending arms and clamp
contact portions between an open position and a closed
position.
[00185] A clamping unit as above wherein the clamp
adjustment portion comprises an eyebolt.
[00186] A clamping unit as above wherein the clamp
contact portions are movably connected to the extending
arms.
[00187] A clamping unit as above wherein the extending
arms are movably connected to the base section.
[00188] A clamping unit as above wherein clamp contact
portions are configured to contact a main body portion of
the suspension clamp.
[00189] A clamping unit as above wherein the clamping
unit is movable between an open and closed position.
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CA 02880129 2015-01-27
[00190] A suspension clamp connecting assembly
comprising: a clamping unit as above; and a support
member having a first end and a second end, wherein the
first end of the support member is connected to the base
section, and wherein the support member is configured to
support an electronics housing.
[00191] A suspension clamp connecting assembly as above
wherein the electronics housing is connected to the
support member, and wherein the electronics housing
comprises electronic components configured to acquire
data from a transmission line.
[00192] In another exemplary embodiment a method
comprising: providing a clamping unit comprising a base
section, extending arms, and clamp contact portions,
wherein the extending arms are between the clamp contact
portions and the base section, and wherein the clamping
unit is configured to clamp on to a suspension clamp;
attaching a support member to the clamping unit, the
support member having a first end and a second end,
wherein the first end of the support member is connected
to the base section, and wherein the support member is
configured to support an electronics housing; and
connecting a corona ring to the second end of the support
member.
[00193] A method as above
further comprising: mounting
the electronics housing to the support member, wherein
the electronics housing comprises electronic components
configured to acquire data from a transmission line.
[00194] It should be understood that the foregoing
description is only illustrative of the invention.
Various alternatives and modifications can be devised by
CA 02880129 2015-01-27
those skilled in the art without departing from the
invention. Accordingly, the
invention is intended to
embrace all such alternatives, modifications and
variances which fall within the scope of the appended
claims.
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