Note: Descriptions are shown in the official language in which they were submitted.
CA 02903912 2015-09-03
NETWORK FOR ONLINE MONITORING OF POWER
TRANSFORMER AT INTELLIGENT SUBSTATION
FIELD
[0001] The disclosure relates to a system for monitoring a power system, and
particularly
to an online monitoring network for a power transformer in a substation.
BACKGROUND
[0002] Presently, there is no complete and systematic specification and
restriction on a
technical parameter, software and hardware configuration, a system function
and the like of
an online monitoring unit for a nationwide power grid. Transformers in various
substations
are monitored in their substations respectively, operation status of all
transformers within an
area can not be understood as a whole, and it is difficult to give an
operation instruction.
SUMMARY
[0003] The object of the disclosure is to achieve a network system for online
monitoring
intelligently transformers in various substations within an area.
[0004] To achieve the above object, a technical solution according to the
disclosure is as
follows. An intelligent online monitoring network for a power transformer in a
substation is
provided, where a data communication server in the substation establishes
communication
with a monitoring unit in each of transformers in the substation, and
establishes
communication with a main station; the monitoring unit includes one or more of
an in-oil
dissolved gas and micro water monitoring unit, a bushing monitoring unit, a
winding
temperature monitoring unit, a partial discharge monitoring unit, an iron core
current
monitoring unit, an infrared thermometry monitoring unit, a vibration
monitoring unit, and a
transformer capacity expansion monitoring unit.
[0005] Each of the monitoring units is provided with a sensor and/or an
executor, and an
intelligent assembly, the sensor and/or the executor is arranged inside or
outside a high
voltage device or components of the high voltage device, the sensor is
connected to the
intelligent assembly via an analog signal cable, the executor is connected to
the intelligent
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assembly via an analog signal cable or an optical fiber network, and the
intelligent assembly
and the power transformer are organically integrated via the sensor or
executor, outputs
measurement data to the data communication server, backs up the measurement
data into an
internal storage, and outputs a control command to the executor.
[0006] The data communication server in the substation is provided with a
display unit
and a device for inputting a control command.
[0007] A monitoring method using an intelligent online monitoring network for
a power
transformer in a substation is provided, where monitoring data collection,
data processing,
standardized data communication agency, threshold comparison, and monitoring
and
pre-alarming are performed based on an acquired signal through a monitoring
unit;
where,
an dissolved gas in oil and micro water monitoring unit analyzes H2, CO, CO2,
CH4,
C2H4, C2H6, C2H2, and H20 acquired periodically through a sensor by
chromatography;
a bushing monitoring unit acquires periodically a voltage of a bus TV, a
harmonic
voltage of the bus TV, a system frequency of the bus TV, and an iron core
current through a
straight-through current transformer;
a winding temperature monitoring unit acquires periodically internal winding
temperature of the power transformer through a temperature sensor, and
acquires the
temperature when sensors of other monitoring units operating;
a partial discharge monitoring unit acquires discharge status of the power
transformer
in a real time manner by ultrasound partial discharge monitoring, ultra high
frequency
partial discharge monitoring, or high frequency partial discharge monitoring;
an iron core current monitoring unit periodically samples currents on an iron
core
grounding line by the straight-through current transformer;
an infrared thermometry monitoring unit implements real-time online
temperature
measurement through a fixed infrared monitoring apparatus;
a vibration monitoring unit acquires a transformer case vibration of the three-
phase
winding in a real time manner through a vibration sensor mounted at a high
voltage side
case wall for the three-phase winding of the power transformer;
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a transformer capacity expansion monitoring unit acquires periodically oil
temperature and winding temperature of the power transformer through a
temperature
sensor, calculates winding life of the power transformer, checks overload
operation ability
of the power transformer; and
parameters acquired by the above monitoring units are compared with preset
security
requirement thresholds respectively; the parameter are output to a data
communication
server in the case that the parameters are in ranges of the preset security
requirement
thresholds; or the parameters and an alarm signal are output to the data
communication
server in the case that the parameters are not in the ranges of the preset
security requirement
thresholds.
[0008] A network system and a controlling method thereof according to the
disclosure
have the following advantages.
[0009] 1) Online monitoring intelligent alarm analysis and auxiliary decision
prompting
[0010] The system has a function of alarming in stratified classification way
and in
different colors and levels. The system has a function of alarming in
different colors and
levels and in stratified and classified way. it is provided an online
monitoring intelligent
alarm window, which pops up automatically at the time of alarming, and a
auxiliary
decision is provided in the window under the state of alarming. An intelligent
decision is
made based on a rule database /an expert base containing historical data and
various
abnormalities, and the causes of the abnormities are prompted and a prevention
and
treatment is provided.
[0011] 2) State evaluation, risk assessment, and health level intelligent
analysis
[0012] The system may be operated manually to evaluate a transformer offline
and online
and generate a state evaluation report, based on a component deduction rule
and a state
evaluation rule, by analyzing various data and information provided by an
device analyzing
center and a monitoring center. The system may also execute automatically
state evaluation
on a power transformer periodically, and an evaluation content and an
evaluation period
may be set by a user.
[0013] The system may execute risk assessment on a transformer from security,
operation,
and cost, in conjunction with a state evaluation result, the abnormalities,
and the historical
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data. Health level of a transformer is determined based on an assessment
content, historical
tendency analysis, sudden changing in a state, and an extent of overlimit. The
health level is
divided into four levels, which are a normal state, an attention state, an
abnormal state, and
a serious state respectively.
[0014] 3) Synchronous display of electric quantity information and non-
electric quantity
information
[0015] The system has a powerful and rich graphical display function, and
based on a
user's own needs, the user can execute a plurality of controls, such as
translation and partial
zooming of a graphical display result of data, and customization of a display
effect.
[0016] The system may display monitored data values of a plurality of
monitored items
for a power transformer, such as dissolved gas in oil and micro water, a
bushing, winding
temperature, partial discharge, an iron core current, infrared thermometry,
vibration, and
transformer capacity expansion. The system may provide a plurality of display
ways, such
as a tendency chart, a bar chart, single data display, and multiple data
simultaneous display;
and electric and non-electric quantity information from the same transformer
or different
transformers may be displayed and compared in the same coordinate chart or
table.
[0017] 4) A multi-functional communication way and an information transmission
approach
[0018] The online monitoring system achieves communication both with a local
monitoring device for a power transformer and with a state monitoring system
of a distant
networking province (city) and large monitoring center. A communication
specification of
the system meets the IEC61850 communication standard, and information
transmission may
be performed in a dedicated line, network or the like.
[0019] 5) Extensibility and secondary development function
[0020] The system has an extensibility and secondary development function, and
there is
no limitation to a type of an accessible monitoring apparatus, a monitoring
screen, an
analysis report and the like; and functions of the system may also be
extended, and an
application software uses an service-oriented architecture (SOA) to support an
adding
operation, a deleting operation, and a modifying operation of a state
detection data analysis
algorithm, thus being capable of adapting the continuous development of online
monitoring
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and operation management.
BRIEF DESCRIPTION OF THE DRAWINGS
100211 To describe the technical solutions in the embodiments of the invention
or in the
prior art more clearly, the drawings to be used in describing the embodiments
or the prior art
will be introduced briefly hereinafter. Apparently, the drawings in the
following descriptions
are only the embodiments of the invention, and other drawings can be obtained
by those
skilled in the art according to the provided drawings without creative effort.
[0022] Figure 1 is an architectural diagram of an intelligent online
monitoring network for
a power transformer in a substation;
Figure 2 is an architectural diagram of a modification of an intelligent
online
monitoring network for a power transformer in a substation; and
Figure 3 is a flowchart of an intelligent advanced application.
DETAILED DESCRIPTION
100231 To make the solutions according to the embodiments of the invention be
understood better by those skilled in the art, the embodiments of the
invention are further
explained in detail in connection with the drawings and the description.
100241 Referring to Figure 1, an intelligent online monitoring network for a
power
transformer in a substation is divided into three-tier architecture, where a
top layer is a main
station 1, which is mainly configured to perform overall monitoring, and
generally arranged
in a control room within an area; a second layer is a data communication
server 2, which is
arranged in each substation, and configured to acquire monitoring data of a
transformer 3 in
the each substation and transmit the data to the main station 1 via a network;
a third layer is
transformers 3 in the substation, several monitoring units are arranged in
each of the
transformers 3, and each of the monitoring units transmits data acquired by
itself to the data
communication server 2 in the substation where the monitoring unit is
arranged, where the
IEC61850 communication standard is adopted in the communication between the
monitoring unit and the data communication server 2.
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[0025] Referring to Figure 2, in a modified intelligent substation, since the
IEC61850
communication standard is not adopted in all monitoring units of the existing
transformer, a
comprehensive monitoring unit 12 may be configured in the transformer 3, and
the
comprehensive monitoring unit 12 is configured to convert the data acquired by
the
monitoring units as the data which conforms to the IEC61850 communication
standard and
transmits the data converted to the data communication server 2.
[0026] The monitoring unit of each transformer 3 may include one or more of
the
following units: a dissolved gas in oil and micro-water monitoring unit 4, a
bushing
monitoring unit 5, a winding temperature monitoring unit 6, a partial
discharge monitoring
unit 7, an iron core current monitoring unit 8, an infrared thermometry
monitoring unit 9, a
vibration monitoring unit 10, and a transformer capacity expansion monitoring
unit 11.
Each of the above monitoring units includes a sensor and/or an executor, and a
first level
intelligent assembly. The sensor or executor is arranged inside or outside a
high voltage
device or a component of the high voltage device. Generally, the sensor is
connected to the
intelligent assembly via an analog signal cable, and the executor is connected
to the
intelligent assembly via an analog signal cable or an optical fiber network.
The intelligent
assembly and the power transformer are organically integrated via the sensor
or executor, to
implement parts of or all of functions such as measurement, controlling,
metering,
monitoring, and protection. The intelligent assembly implements automatic
acquisition of a
state parameter, signal conditioning, analog-digital conversion, and data
preprocessing. In
addition, the intelligent assembly implements local digitalization and
buffering of a
monitoring parameter. Meanwhile the intelligent assembly backs up the data
during at least
one week into an internal storage.
[0027] Configuration of the network is explained below in detail through the
following
table:
substation
number name of device function of device remark
dissolved gas inincludes a sensor
monitors contents of gas components such
oil and
and a monitoring
as H2, CO, CO2, CI-L, C2ll4, C2H6, and
1 micro-water
sub-TED
C2H2 dissolved in oil, and a content of H20
online monitoring
in oil of a transformer
unit
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substation
number name of device function of device
remark
monitors a leakage current, capacitance,
includes a sensor
bushing insulation
2and dielectric loss of a casing, to measure and
a monitoring
monitoring unit
insulation of the casing sub-IED
winding optical
includes a sensor
fiber and
a monitoring
monitors temperature of a winding by a
3 thermometry sub-IED
optical fiber temperature sensor
online monitoring
unit
includes an
ultrasound partial monitors and locates partial discharge in a
ultrasound sensor
discharge online transformer through monitoring ultrasound
and a monitoring
monitoring unit generated by partial discharge
sub-TED
includes an
ultrahigh
monitors and locates partial discharge in a ultrahigh
frequency
transformer through monitoring an
frequency partial
partial discharge
4 ultrahigh frequency signal generated by discharge sensor
online monitoring
partial discharge and
a monitoring
unit
sub-TED
high frequency
Includes a high
monitors partial discharge through
frequency partial
partial discharge
monitoring an pulse current signal
discharge sensor
online monitoring
generated by partial discharge and
a monitoring
unit
sub-TED
iron core
includes a sensor
grounding current monitors a grounding current of an iron and
a monitoring
online monitoring core and a clamp, sub-IED
unit
includes a sensor
infrared
thermometry
monitors temperature of a key component and a monitoring
6 sub-IED
online monitoring of a transformer by infrared thermometry
unit
monitors whether a component such as a
includes a sensor
transformer
winding or a clamp of a transformer is and
a monitoring
7 vibration online
loose by monitoring the case of the sub-IED
monitoring unit
transformer
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substation
number name of device function of device remark
monitors temperature of oil and a includes a
sensor
transformer
three-phase load of a transformer, has a and a monitoring
capacity sub-
IED
8 function of
overtemperature alarming, and
expansion online
checking overload operation ability of the
monitoring unit
transformer
bay level
number name of device function of device remark
implements functions of monitoring data main IED
transformer collection, data
processing, standardized
1 comprehensive data communication
agency, threshold
monitoring unit comparison, and monitoring pre-alarming
for a monitored device in a transformer
main station
number name of device function of device remark
acquires data of a monitored device, stores main frequency:?
temporarily and diagnoses primarily data 2.93 GHz.
of a substation, uniforms a communication memory: > 2G
communication protocol of the
substation, provides a hard disk: > 200G
1
system server uniform
communication interface based on
IEC61850, and allows the data of the
station to be communicated to a distant
data platform.
local area network is a high speed
switch for forwarding a
2 switch packet between data link sections
isolates the substation from a distant data meets a
longitudinal
center, and provides an authentication and requirement of
encryption and
3encryption serve for wide area network secondary safety
authentication
communication between a superior and a protection on
device
subordinate controlling system. power
is a high performance serial data interface,
data transmission and has high
reliability, fast speed, and
optical fiber distant
transmission. And supports an upper
4 channel layer data
transmission protocol such as
apparatus SCSI and ATM.
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substation
number name of device function of device remark
provides an auxiliary function for normal includes a
state
operation of the main devices, online
monitoring
substation screen, a
power
auxiliary device source, and a
communication
device
[0028] The intelligent online monitoring network for a power transformer in a
substation
is implemented by monitoring data mainly using the monitoring units, to find
abnormities in
time.
[0029] the dissolved gas in oil and micro water monitoring unit 4 of the
monitoring unit
5 monitors contents of H2, CO, CO2, CH4, C2H4, C2H6, C2H2, and H20 in oil,
where
chromatography is adopted in the monitoring. A fault may be diagnosed based on
component, content, ratio, increment rate of the gas and the like. The
dissolved gas in oil
and micro water monitoring unit 4 may sample an oil sample twice under the
same test
condition; and in the case that a deviation between the monitoring results
<10%, data is
determined to be valid; in the case that a deviation between the monitoring
results >10%,
data is determined to be invalid and an alarm signal is sent, to ensure
stability and accuracy
of the measurement data, where a sampling period is not larger than 2 hours
and a tolerant
pressure at an oil outlet is larger than or equal to 0.34 MPa.
[0030] A straight-through current transformer is used in current
sampling of the bushing
monitoring unit 5, and a leakage current, capacitance, and dielectric loss of
a casing may be
monitored. The installation of the sensor does not influence the safe
operation of the casing,
and the sensor may acquire periodically the voltage of a bus voltage
transformer (TV), the
harmonic voltage of the bus TV, the system frequency of the bus TV, and the
iron core
current, where a sampling period < 5 minutes.
[0031] The winding temperature monitoring unit 6 acquires periodically
internal winding
temperature of the power transformer through a temperature sensor, and
acquires the
temperature when sensors of other monitoring units operating.
[0032] The partial discharge monitoring unit 7 may be divided into three types
of
ultrasound partial discharge monitoring, ultrahigh frequency partial discharge
monitoring,
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and high frequency partial discharge monitoring based on different monitoring
principles.
With the ultrasound partial discharge monitoring, an ultrasound sensor mounted
on the
surface of the transformer monitors an ultrasound signal generated by partial
discharge in a
transformer, to monitor the partial discharge in the transformer. It is
demanded that the
amplitude and phase of the ultrasound signal may be measured, and the source
of the partial
discharge may be located. With the ultrahigh frequency partial discharge
monitoring, an
ultrahigh frequency sensor mounted on an oil drain valve or a hand-hole
specially designed
of the transformer receives an ultrahigh frequency signal generated by the
partial discharge,
to monitor the partial discharge in the transformer. It is demanded that the
amplitude and
phase of the ultrasound signal may be measured. With the high frequency
partial discharge
monitoring, a wide-band straight-through current sensor mounted on the tap of
a bushing or
a clamp of an iron core of the transformer acquires a pulse current signal
generated by
partial discharge, and receives an ultrahigh frequency signal generated by the
partial
discharge, to monitor the partial discharge in the transformer. It is demanded
that the
amplitude and phase of the ultrasound signal may be measured. A corresponding
data
algorithm is required to eliminate interference of various noise signals in an
operation
environment of the device in measurement, thus acquiring discharge status in
the
transformer in a real time manner.
[0033] The iron core current monitoring unit 8 monitors a current on an iron
core
grounding line in a sampling way of a straight-through current transformer,
the
straight-through current transformer is mounted on the grounding copper bar of
the iron
core and acquires periodically the current on an iron core grounding line,
where the minimal
monitoring period is not larger than 1 minute.
[0034] The infrared thermometry monitoring unit 9 implements real-time online
temperature measurement through a fixed infrared monitoring apparatus, and has
functions
such as setting a monitoring area, periodically and automatically inspecting,
thus
implementing real-time online temperature measurement.
[0035] The vibration monitoring unit 10 measures the vibration of transformer
case
vibration of the three-phase winding through a vibration sensor mounted at a
high voltage
side case wall for the three-phase winding of the power transformer, and may
analyze a
transformer vibration spectrum and have functions of storing data and
comparing and
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analyzing historical data. In the vibration monitoring, a piezoelectric
acceleration sensor or
speed sensor is generally used and mounted outside an iron case of the
transformer, and
acquires a transformer case vibration of the three-phase winding in a real
time manner.
[0036] The transformer capacity expansion monitoring unit 11 acquires
periodically oil
temperature and winding temperature of the transformer through a temperature
sensor, and
is configured to monitor the oil temperature and the winding temperature of
the transformer.
The transformer capacity expansion monitoring unit 11 has a function of
overtemperature
alarming, deriving winding losses of the transformer, calculating winding life
of the
transformer, and checking overload operation ability of the transformer.
[0037] Parameters acquired by the above monitoring units are compared with
preset
security requirement thresholds (determined based on a power system safety
standard)
respectively, and the parameter are output to the data communication server 2
in the case
that the parameters are in the range of the preset security requirement
threshold; the
parameters and an alarm signal are output to the data communication server 2
in the case
that the parameters are not in the range of the preset security requirement
threshold.
[0038] After sending the alarm out, the monitoring system monitors and
eliminates the
alarm in accordance with a flowchart of an intelligent advanced application as
shown in
Figure 3. Specifically, each monitoring unit executes compares the acquired
data with the
preset security requirement threshold to detect whether the acquired data is
out of the range
of the preset security requirement threshold; and in the case that no data is
out of the range
of the preset security requirement threshold, the monitoring unit performs the
next
acquisition and comparison; in the case that the data is out of the range of
the preset security
requirement threshold, the monitoring unit analyzes the data based on a
certain rule, sends
an overlimit alarm and a corresponding alarm level, prompts a cause of the
abnormity, and
exports a specification and a treatment from the data base. In this case, the
monitoring unit
waits to be operated by an operator, and in the case that the abnormity is
eliminated by the
operator, the alarm is removed, in the case that the abnormity is not
eliminated by the
operator, the alarm remains.
[0039] The network according to the disclosure may collect data by querying
auto polling.
In the networkõ a state parameter of a monitored device is monitored and
recorded
continuously or periodically, a state change of the device is tracked timely
and effectively.
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The manner of acquiring a signal by a monitoring apparatus does not influence
the wiring
and grounding of the transformer, and the safe operation of the transformer. A
data
acquisition period of the monitoring apparatus may be set locatedly or
remotely, and a
sampling period of the online monitoring system may also be set by a user
himself.
[0040] A uniform data base is established in the network, and data are stored
in
chronological order, to implement centralized management of online data.
Original data,
such as device parameters of a transformer, a test report, a description,
drawings, historical
monitoring data (a data list and primary graph) and alarm information are
stored. The
historical monitoring data and the drawings may be stored for ten years. The
data base has a
basic function of data query. A user may understand the transformer by the
data base.
[0041] The network further has a humanized man-machine interface, to
facilitate
operating and using. Information, such as real-time latest and historical
monitoring data, a
table, a tendency chart, alarm information, a state evaluation result, a risk
assessment result,
a device parameter, and historical data may be queried and viewed. The
interface provides a
monitored state data and analysis result publishing platform including a data
publishing tool
such as a graph, a curve, and a report. A data communication server 2 in a
substation may
further be provided with a display unit and a device for inputting a control
command.
[0042] The network established according to the disclosure, may be where a
secondary
safety protection condition of power is met, may implement in a remote login
way operation
on a system, such as remote maintenance, upgrade, and diagnosis and
elimination of a fault;
and has a function of sharing information, and different users may obtain
information
resources corresponding to their authority.
[0043] The disclosure is described above exemplarily in conjunction with the
drawings,
and obviously, a specific implementation of the disclosure is not limited to
the above ways,
and various insubstantial improvements made by using a concept of the method
and
technical solutions according to the disclosure, or application of the concept
and the
technical solutions according to the disclosure directly to other fields
without improvements
will fall into the scope of protection of the disclosure.
[0044] As can be seen from the above description of the embodiments, it can be
understood clearly by those skilled in the art that some or all of the steps
in the embodiment
of the method described above can be implemented by means of software in
addition to
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necessary common hardware platform. Based on such understanding, the part of
the
technical solution of the disclosure that is in essential or contributes to
the prior art can be
embodied in software product, which can be stored in the storage medium, such
as a
ROM/RAM, a magnetic disk, and an optical disk, and include several
instructions adapted
to cause a computer device (such as a personal computer, a server, or a
network
communication device such as a media gateway) to implement the method
described in all
or some of the embodiments of the disclosure.
[0045] It should be noted that, the various embodiments of the disclosure are
described in
a progressive manner. For the same or similar parts between the various
embodiments, one
can refer to the other embodiments, the emphasis of each of the various
embodiments points
to the difference between it and the other embodiments. Particularly, for the
embodiments of
the device and the system, the description thereof is relatively simple since
the device and
the system correspond to the method, and the relevant portion may refer to the
description
of the embodiment of the method. The embodiments of the device and the system
described
above is simply exemplary, where units explained as separated components may
be or may
also not be separated physically, and components displayed as units may be or
may also not
be physical units, that is, may located at one place or may also be
distributed onto multiple
network units. The object of the solutions according to the embodiments may be
achieved
by selecting some or all of modules in the device and the system based on
actual needs. The
device and the system may be understood and implemented by those skilled in
the art
without creative effort.
[0046] The above is only a preferred embodiment of the invention, and is not
used to limit
the scope of protection of the disclosure. Any modification, equivalent
replacement,
improvement or the like made within the spirit and principle of the disclosure
falls into the
scope of protection of the disclosure.
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