Note: Descriptions are shown in the official language in which they were submitted.
STATUS MONITORING CABLES FOR GENERATORS
RELATED APPLICATIONS
[0001] This application, claims benefit of U.S. Provisional Application Serial
No. 61/646,140, filed May 11,2012.
TECHNICAL FIELD
[0002] The present invention relates to the systems and methods for providing
power to telecommunication loads and, more particularly, for cable systems and
methods that allow the status of a generator to be monitored remotely.
BACKGROUND
[0003] The present invention is of particular significance in the context of
generators used to supply power to electrical components located at remote
locations, and that application of the present invention will be discussed in
detail
below. However, the principles of the present invention may be applied to
other
types of power supplies used in a communications system and to generators
used to provide power to electrical components of systems other than
communications systems.
[0004] Distributed communications systems typically comprise electrical
components distributed at remote locations in a wide geographical area.
Electrical power to electrical components located at such remote locations may
be obtained from any one or more of a number of sources depending upon what
is available at a particular remote location. In many remote locations,
utility
power is available for use as at least a primary source of electrical power.
In
other remote locations, primary power may be provided by wind power systems,
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solar power systems, and/or generators. Even when not used to supply primary
power, generators are often used to provide at least standby power to
components located at remote locations, typically as part of an
uninterruptible
power supply (UPS) also including a battery power system.
[0005] When generators are used to provide primary or standby power to
communications systems components located at remote locations, it is desirable
for the communications system to determine the operational status of such
generators. However, generators are typically sourced from a variety of
different
manufacturers, and it may not be practical for the communications system to
interface directly with the generator control system for each brand of
generator
on the market.
[0006] The need thus exists for status monitoring systems for power sources,
such as generators, that are independent of the particulars of a given
generator,
may be retrofitted to existing generators, are easy to install, and are
reliable.
SUMMARY
[0007] The present invention may be embodied as a connector system
adapted to be connected to a generator, a UPS system, and a modem. The
connector system comprises a generator connector operatively connected to the
generator, a UPS connector operatively connected to the UPS system, a modem
connector operatively connected to the modem; a status monitoring cable system
comprising a first cable connector adapted to be connected to the generator
connector, a second cable connector adapted to be connected to the UPS
connector, a third cable connector adapted to be connected to the modem
connector, a jumper, first and second power conductors connected between the
first cable connector and the second cable connector, and a sensor module. The
sensor module comprises a current detect module and a connector detect
module. The current detect module is coupled to at least one of the first and
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second power conductors and operatively connected to the third cable
connector.
The connector detect module is operatively connected to the first cable
connector
and the third cable connector. The jumper is supported relative to the
generator
connector. The current detect module transmits a GEN ON signal to the modem
when a current is present in at least one of the first and second power
conductors. The connector detect module transmits a GEN_PRESENT signal to
the modem when a current flows through the first cable connector, the
generator
connector, the jumper, the generator connector, and the first cable connector.
[0008] The present invention may also be embodied as a method of
connecting a generator, a UPS system, and a modem comprising the following
steps. A generator connector is operatively connected to the generator. A UPS
connector is operatively connected to the UPS system. A modem connector is
operatively connected to the modem. A first cable connector adapted to be
connected to the generator connector is provided. A second cable connector
adapted to be connected to the UPS connector is provided. A third cable
connector adapted to be connected to the modem connector is provided. First
and second power conductors are connected between the first cable connector
and the second cable connector. A current detect module is coupled to at least
one of the first and second power conductors. The current detect module is
operatively connected to the third cable connector. A connector detect module
is
operatively connected to the first cable connector and the third cable
connector.
The jumper is supported relative to the generator connector. The current
detect
module is caused to transmit a GEN ON signal to the modem when a current is
present in at least one of the first and second power conductors. The
connector
detect module is caused to transmit a GEN_PRESENT signal to the modem
when a current flows through the first cable connector, the generator
connector,
the jumper, the generator connector, and the first cable connector.
[0009] The present invention may also be embodied as a cable assembly
adapted to be connected to a generator, a UPS system, and a modem. In this
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case, the connector system comprises a generator connector, a UPS connector,
a modem connector, and a status monitoring cable system. The generator
connector comprises a first generator contact, a second generator contact, a
third generator contact, and a fourth generator contact. The first and second
generator contacts are operatively connected to the generator. The UPS
connector comprises a first UPS contact and a second UPS contact. The first
and second UPS contacts are operatively connected to the UPS system. The
modem connector comprises a first modem contact and a second modem
contact. The first and second modem contacts are operatively connected to the
modem. The status monitoring cable system comprises first, second, and third
cable connectors, a jumper, first and second power conductors, and a sensor
module. The first cable connector comprises a first cable connector first
contact,
a first cable connector second contact, a first cable connector third contact,
and a
first cable connector fourth contact. The second cable connector comprises a
second cable connector first contact and a second cable connector second
contact. The third cable connector comprises a modem connector first contact
and a modem connector second contact. The first power conductor is connected
between the first cable connector first contact and the second cable connector
first contact. The second power conductor is connected between the first cable
connector second contact and the second cable connector second contact. The
sensor module comprises a current detect module and a connector detect
module. The current detect module is coupled to at least one of the first and
second power conductors and operatively connected to the modem connector
first contact. The connector detect module is operatively connected to the
first
cable connector third contact, the first cable connector fourth contact, and
the
modem connector second contact. The jumper is connected between the third
and fourth generator contacts. The current detect module transmits a GEN_ON
signal to the modem when a current is present in at least one of the first and
second power conductors. The connector detect module transmits a
GEN PRESENT signal to the modem when a current flows through the first
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cable connector third contact, the third generator contact, the jumper, the
fourth
generator contact, and the first cable connector fourth contact.
DESCRIPTION OF THE DRAWING
[0010] Figure 1 is a block diagram of a communications system including a
status monitoring cable of the present invention;
[0011] Figure 2 is a block diagram illustrating the example status monitoring
cable of Figure 1 in more detail;
[0012] Figure 3 is a schematic diagram of an example current detect module
of the example status monitoring cable;
[0013] Figure 4 is a schematic diagram of an example connector detect
module of the example status monitoring cable;
[0014] Figure 5 is a schematic diagram of an example power circuit of the
example status monitoring cable;
[0015] Figure 6 is a perspective view of a first example generator and an
example first cable connector of an example status monitoring system of the
present invention;
[0016] Figure 7A is a perspective view of the first example first cable
connector used with the first example generator;
[0017] Figure 7B is a perspective view of an example signal module that may
be used by the example connectors of the first example generator;
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[0018] Figure 8A is a front elevation view of the first example first cable
connector used with the first example generator;
[0019] Figure 8B is a front elevation view of an example generator connector
of the first example generator;
[0020] Figure 9 is a section view of the first example first cable connector
and
the example generator connector of the first example generator;
[0021] Figure 10 is a section view of the first example first cable
connector
engaging the example generator connector of the first example generator;
[0022] Figure 11 is a somewhat schematic view depicting the engagement of a
sensor housing with a second power cable of the example status monitoring
cable system;
[0023] Figure 12 is a front elevation view of a second example first cable
connector that may be used with a second example generator;
[0024] Figure 13 is a side elevation view of the second example first cable
connector and an example generator connector of the second example
generator; and
[0025] Figure 14 is a side elevation view of the second example first cable
connector engaging the example generator connector of the second example
generator.
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DETAILED DESCRIPTION
[0026] Referring initially to Figure 1 of the drawing, depicted therein is an
example communications system 20 comprising a first example connector
system 22 constructed in accordance with, and embodying, the principles of the
present invention. At least a portion of the communications system 20 is
located
at a local facility 24 as will be discussed in further detail below.
[0027] In addition to the first example connector system 22, the example
communications system 20 comprises a power supply unit 30 configured to
transfer power from a utility power source 32 to a load 34. The example
communications system 20 further comprises a generator 36, and the example
power supply unit 30 is also configured to transfer power from the generator
36
to the load 34. In addition, the power supply unit 30 is also operatively
connected to a head end 38 to allow data communication between the power
supply unit 30 and the head end 38. The example power supply unit 30
comprises an uninterruptible power supply (UPS) system 40 and modem 42.
The example UPS system 40 comprises internal batteries (not shown) that
provide standby power to the load 34 when utility power from the utility 32 is
unavailable or not within acceptable parameters defined by the load 34.
[0028] The load 34, generator 36, head end 38, UPS system 40, and modem
42 all are or may be conventional components of a communications system such
as conventional telephony (landline) networks, cellular telephone networks,
and/or cable networks and will not be described herein beyond what is
necessary
for a complete understanding of the principles of the present invention.
[0029] The first example connector system 22, the example power supply unit
30, the load 34, and the generator 36 are all typically arranged in relatively
close
proximity at the local facility 24. The example utility power source 32 is
connected to the power supply unit 30 but typically comprises power
generation,
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regulation, and distribution components remotely located from the local
facility
24. The head end 38 is also typically, but not necessarily, located at a
location
remote from the local facility 24.
[0030] In addition, data is transmitted between the power supply unit 30 and
the head end 38 using any available communications system such as
conventional telephony (land line) systems, cellular telecommunications
systems,
and/or cable communications systems. The modem 42 is provided and
configured as necessary to collect, store, and format data collected at the
power
supply unit 30 and transmit this data to the head end 38 using one or more of
the
available communications systems.
[0031] Referring now to Figures 1 and 2, it can be seen that the first example
connector system 22 comprises a status monitoring cable system 50, a generator
connector 52, a UPS connector 54, and a modem connector 56. The example
status monitoring cable system 50 comprises a sensor module 60, a first cable
connector 62, a second cable connector 64, a third cable connector 66, and a
jumper 68 (Figure 2).
[0032] Turning now more specifically to Figure 2 of the drawing, the details
of
the first example connector system 22 are depicted in further detail. Figure 2
illustrates that the sensor module 60 comprises a current detect module 70, a
connector detect module 72, and a power circuit 74. The first example
connector
system 22 further comprises a first power conductor 80 and a second power
conductor 82 that extends between the first cable connector 62 and the second
cable connector 64. A first sensor conductor 84 and a second sensor conductor
86 extend between the sensor module 60 and the first cable connector 62. A
generator status conductor 90, a generator present conductor 92, a supply
conductor 94, a common conductor 96, and a chassis ground conductor 98
extend between the sensor module 60 and the third cable connector 66.
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[0033] The example sensor module 60 monitors two characteristics or
parameters associated with the example generator 36. The example sensor
module 60 monitors both of these characteristics or parameters even if the
generator 36 is not running, and the example sensor module 60 is not
configured
for any particular generator design and can in fact monitor these
characteristics
or parameters for generators of unknown make and manufacturer.
[0034] In particular, the example current detect module 70 generates a
GEN ON signal indicative of whether the generator 36 is operating by comparing
signal representative of a current through the second power conductor 82 with
a
reference value. The example current detect module 70 generates a signal
representative of the current through the second power conductor 82 non-
invasively and without making a direct electrical connection with either the
first or
the second power conductor 82.
[0035] The connector detect module 70 generates a GEN_PRESENT signal
indicative of whether the first cable connector 62 is connected to the
generator
connector 52. The first cable connector 62 is configured simply to detect the
presence of a short circuit at the generator 36 and, if that short circuit is
missing,
determines that the first cable connector 62 is not connected to the generator
connector 52. The short circuit can be established by modifying the generator
connector 52 such that the first and second sensor conductors 84 and 86 are
effectively connected together when the first cable connector 62 is connected
to
the generator connector 52. Alternatively, the short circuit may be
established by
bringing the first and second sensor conductors 84 and 86 into contact with a
conductive portion of a given generator or a conductive member attached to
that
generator.
[0036] The details of construction and operation of the first example
connector
system 22 will now be described in further detail with reference to Figures 2-
10.
Figure 2 shows that each of the example connectors 52, 54, 56, 62, 64, and 66
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defines a plurality of contacts. The following Table A defines the contacts
defined by the connectors 52, 54, 56, 62, 64, and 66 forming a part of the
first
example cable system 22:
TABLE A
Element Reference Diagram
Name Character Label
GENERATOR CONNECTOR 52 GC
first generator contact 52a G1
second generator contact 52b G2
third generator contact 52c G3
fourth generator contact 52d G4
UPS CONNECTOR 54 UC
first UPS contact 54a U1
second UPS contact 54b U2
MODEM CONNECTOR 56 MC
first modem contact 56a M1
second modem contact 56b M2
third modem contact 56c M3
fourth modem contact 56d M4
fifth modem contact 56e M5
FIRST CABLE CONNECTOR 62 Cl
first cable connector first contact 62a C1-1
first cable connector second contact 62b C1-2
first cable connector third contact 62c C1-3
first cable connector fourth contact 62d C1-4
SECOND CABLE CONNECTOR 64 C2
second cable connector first contact 64a C2-1
second cable connector second contact 64b C2-2
THIRD CABLE CONNECTOR 66 C3
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third cable connector first contact 66a 03-1
third cable connector second contact 66b C3-2
third cable connector third contact 66c C3-3
third cable connector fourth contact 66d 03-4
third cable connector fifth contact 66e C3-5
[0037] The first cable connector 62 is engages the generator connector 52
such that the generator connector contacts 52a, 52b, 52c, and 52d engage or
contact the first cable connector contacts 62a, 62b, 62c, and 62d,
respectively, to
form a low resistance electrical connection at each contact point. The second
cable connector 64 engages the UPS connector 54 such that the generator
connector contacts 54a and 54b engage or contact the second connector
contacts 64a and 64b, respectively, to form a low resistance electrical
connection
at each contact point. The third cable connector 66 engages the modem
connector 56 such that the modem connector contacts 56a, 56b, 56c, 56d, and
56e engage or contact the third connector contacts 66a, 66b, 66c, 66d, and
66e,
respectively, to form a low resistance electrical connection at each contact
point.
Finally, the jumper 68 engages the third and fourth generator contacts 52c and
52d to form a short circuit between these contacts 52c and 52d.
[0038] Turning now to Figures 3-5, Figure 3 depicts an example of a circuit
that may be used to form the current detect module 70, Figure 4 depicts an
example of a circuit that may be used to form the connector detect module 72,
and Figure 5 depicts an example of a circuit that may be used to form the
power
circuit 74.
[0039] The following components of these circuits 70, 72, and 74 are provided
for protection. A small profile integrated circuit referred to as D1 provides
clamp
diode connection from three channels to the +supply and circuit common, along
with a high current, low clamping voltage transient voltage suppression (TVS)
diode D1A connected across the +supply and circuit common. Resistors R7, R8,
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R9, R16, R17, and R18 provide current limiting for the TVS diode D1A in the
event of transient voltage events on those lines. Resistors R8 and R9 are
surge
rated resistors. Resistor R9 provides high resistance isolation to circuit
common
from the sense cable for the status monitor and modem circuitry. Circuit
common of the status monitor circuitry is connected to chassis to provide a
low
impedance return for line currents, voltage transient currents (i.e.,
lightning), and
radio frequency currents. Resistor R17 provides ground return isolation to the
modem, and, with the chassis connection described above, forms a divider to
provide a high attenuation path back to the modem along the circuit common.
Resistor R17 is surge rated. Capacitor C3, along with resistors R8 and R9,
form
a low pass filter at radio frequencies, forcing energy in the sense cable to
be
common ode with respect to the status monitor circuitry and modem circuitry.
[0040] The following components are involved with the current sensing.
Component U1 is an open loop Hall effect bi-directional current sensor
comprising a core large enough to accommodate the second power conductor
82, internal core offset and circuit nulling and signal processing circuitry,
and a
current sense, voltage out transfer function. Resistor R1 and capacitor C1
form a
low pass filter to provide high attenuation to line frequency components not
filtered by the Hall sensor. Resistor R4 provides current limiting into the
operational amplifier A input from capacitor C1 during power supply
transitions.
Resistors R2 and R3 set the center of the operating range for the Hall sensor
and
track a factor of the transfer function of the Hall sensor closely for a low
range of
measured currents (0 to 3A). Resistors R5 and R6 and capacitor 02 provide
dynamic hysteresis. Resistor R7 provides isolation between the cable to the
modem and the operational amplifier A. The output of the current detect module
70 is LO if the sensed current is greater than 3A, HI if the sensed current is
less
than 0.5A, and undefined between 0.5 and 3A.
[0041] The following components are involved in connector sensing.
Resistors R8, R9, and R10 set the sense current to approximate 2mA. Capacitor
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C4 and resistors R8 and R9 form a low pass filter for RF, and resistor R11 and
capacitor C5 perform the same function at line frequencies. Resistor R12
provides current limiting from capacitor C4 into the input of operational
amplifier
B during power transitions. Resistors R13 and R14 set the switching threshold,
and resistors R11, R12, and R15 provide short and long term hysteresis.
Resistor R16 provides isolation between the cable to the modem and the
operations amplifier A. The output of the connector detect module 72 is LO if
current flows through the first and second sensor conductors 84 and 86 (the
jumper 68 is present) and HI if no current flows through the first and second
sensor conductors 84 and 86.
[0042] Turning now to Figures 6-10 of the drawing, a first example of the
mechanical structure of the first example connecter system 22 will now be
described in further detail. The generator 36 comprises a generator enclosure
120 (Figure 6). The power supply unit 30 defines a power supply enclosure 122,
while the sensor module 60 defines a sensor housing 124 (Figure 11).
[0043] The generator connector 52 comprises a generator connector housing
126, and the first cable connector 62 defines a first cable connector housing
128
(Figures 6 and 7-10). The generator connector housing 126 is supported by the
generator enclosure 120, and the first cable connector housing 128 is
supported
by ends of the first and second power conductors 80 and 82 and the first and
second sensor conductors 84 and 86. It should be noted that the example
generator connector 52 and the example first cable connector 62 are identical
and further constructed such that they can be detachably attached from each
other in a reversed configuration. Other connector styles may be used in place
of the example connectors 52 and 62.
[0044] The generator connector 52 further comprises first and second
generator signal modules 130 and 132. The generator connector housing 126
defines first and second generator signal sockets 134 and 136 that are adapted
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to detachably attach the first and second generator signal modules 130 and 132
to the connector housing 126. The first cable connector 62 further comprises
first
and second cable signal modules 140 and 142. The first cable connector
housing 128 defines first and second generator signal sockets 144 and 146 that
are adapted to detachably attach the first and second generator signal modules
130 and 132 to the connector housing 126.
[0045] The first and second generator contacts 52a and 52b are supported by
the generator connector 52 and electrically connected to the generator 36 such
that the output of the generator 36 is present across these contacts 52a and
52b.
As shown in Figures 8B, 9, and 10, the third and fourth generator contacts 52c
and 52d are supported by the first and second generator signal modules 130 and
132. Further, the jumper 68 is supported by the first and second generator
signal
modules 130 and 132 to form a conductive path between the third and fourth
generator contacts 52c and 52d.
[0046] The first cable connector first and second contacts 62a and 62b are
supported by the first cable connector 62 and electrically connected to the
first
and second power conductors 80 and 82. When the first cable connector 62 is
detachably attached to the generator connector 52, the first cable connector
first
and second contacts 62a and 62b come into contact with the first and second
generator contacts 52a and 52b such that the output of the generator 36 is
present across the second cable connector first and second contacts 64a and
64b. And as shown in Figures 8A, 9, and 10, the first cable connector third
and
fourth contacts 62c and 62d are supported by the first and second cable signal
modules 140 and 142. When the first cable connector 62 is detachably attached
to the generator connector 52, the first cable connector third and fourth
contacts
62c and 62d come into contact with the third and fourth generator contacts 52c
and 52d such current can flow between the first and second sensor conductors
84 and 86 through the jumper 68.
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[0047] Figure 11 of the drawing shows the physical location of the sensor
module 60. In particular, the sensor housing 124 defines an opening 150 and is
located within the power supply enclosure 122. Within the sensor housing 124,
the Hall sensor is arranged such that the winding thereof is coiled around the
opening 150. The second power conductor 82 is extended through opening 150
such that the Hall sensor generates an output signal when current flows
through
the second power conductor 82.
[0048] Figure 11 further shows a cable bundle 152 comprising the generator
status conductor 90, generator present conductor 92, supply conductor 94,
common conductor 96, and chassis ground conductor 98 (Figure 2). The cable
bundle 152 electrically connects the sensor module 60 to the modem 42 through
the third cable connector 66 and modem connector 56 as shown in Figure 11.
[0049] Turning now to Figures 12-14 of the drawing, a second example of the
mechanical structure of the example connecter system 22 will now be described
in further detail. In this second example mechanical structure, the generator
36
comprises a generator enclosure 220 (Figures 13 and 14). A generator
connector 222 is supported by the generator enclosure 220. A first cable
connector 224 is supported by the ends of the first and second power
conductors
80 and 82. The example generator connector 222 and example first cable
connector 224 are conventional grounded three-prong sockets (generator
connector 222) and plugs (first cable connector 224). In particular, first,
second,
and third contacts 222a, 222b, and 222c of the generator connector 222 are
sized and dimensioned to receive first, second, and third prongs 224a, 224b,
and
224c, respectively, of the first cable connector 224.
[0050] Mounted on the first cable connector 224 is a cable signal module 226
that is operatively connected to the first and second sensor conductors 84 and
86. In particular, the cable signal module 226 comprises first and second
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contacts or terminals 226a and 226b that are connected to the first and second
sensor conductors 84 and 86.
[0051] If the generator enclosure 220 defines a conductive surface, the cable
signal module 226 may be positioned such that the contacts or terminals 226a
and 226b engage this conductive surface when the generator connector 222 is
properly engaged with the first cable connector 224 to allow current to flow
from
the generator to the second cable connector (not shown in Figures 12-14).
When properly engaged, current will flow from one of the contacts or terminals
226a, through the conductive surface, and then to the other of the contacts or
terminals 226b. The connector detect module 72 will thus determine that the
connectors 222 and 224 are properly connected as generally described above. If
the generator enclosure 220 is made of painted metal, a small portion of the
paint
can be removed to create a conductive surface.
[0052] If the generator enclosure 220 does not or can or should not be altered
to define a conductive surface, a jumper plate 230 made of conductive material
may be applied to the generator enclosure. In this case, the cable signal
module
226 is positioned such that the contacts or terminals 226a and 226b engage
this
jumper plate 230 when the generator connector 222 is properly engaged with the
first cable connector 224. When properly engaged, current will flow from one
of
the contacts or terminals 226a, through the jumper plate 230, and then to the
other of the contacts or terminals 226b. The connector detect module 72 will
thus determine that the connectors 222 and 224 are properly connected as
generally described above.
[0053] As another alternative, the contact or terminals 226a and 226b can be
arranged within the cable signal module 226, and a conductive member within
the cable signal module 226 may be displaced using magnetic force to complete
the circuit between the terminals 226a and 226b. In this case, a strong magnet
may be located on or within the generator enclosure 220 adjacent to the
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generator connector 222 to cause the conductive member within the cable signal
module 226 to engage the two terminals 226a and 226b when the generator
connector 222 properly receives the first cable connector 224.
[0054] As yet another alternative, a magnetic sensor may be formed between
the two terminals 226a and 226b and a magnet secured relative to the generator
enclosure 220 in place of the jumper plate.
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