CN103995177A - Power transformer neutral point direct current measurement and wave-recording device and detection method - Google Patents

Power transformer neutral point direct current measurement and wave-recording device and detection method Download PDF

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Publication number
CN103995177A
CN103995177A CN201410162863.9A CN201410162863A CN103995177A CN 103995177 A CN103995177 A CN 103995177A CN 201410162863 A CN201410162863 A CN 201410162863A CN 103995177 A CN103995177 A CN 103995177A
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signal
voltage
fixture
current
current source
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CN201410162863.9A
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CN103995177B (en
Inventor
全江涛
邱凌
陈科基
阮羚
童歆
王亮
邓万婷
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WUHAN XINDIAN ELECTRICAL TECHNOLOGY Co Ltd
State Grid Corp of China SGCC
Electric Power Research Institute of State Grid Hubei Electric Power Co Ltd
Yichang Power Supply Co of State Grid Hubei Electric Power Co Ltd
Original Assignee
WUHAN XINDIAN ELECTRICAL TECHNOLOGY Co Ltd
State Grid Corp of China SGCC
Electric Power Research Institute of State Grid Hubei Electric Power Co Ltd
Yichang Power Supply Co of State Grid Hubei Electric Power Co Ltd
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Priority to CN201410162863.9A priority Critical patent/CN103995177B/en
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Abstract

The invention provides a power transformer neutral point direct current measurement and wave-recording device and a detection method, and thus the wave recording of a direct current and wave recording data wireless tele-transmission can be realized in AC/DC mixed signals flowing through transformer neutral point grounded flat steel. The device comprises a voltage clamp, a signal conditioning circuit, an analog-to-digital conversion circuit, a constant current source current measurement circuit, a trigger control circuit, a measurement channel CPU, a device head CPU, a GPS clock module, a GSM/GPRS communication module, a controllable constant current source and a current clamp. The voltage clamp is used for collecting voltage drop of a section of grounded flat steel of a transformer neutral point; the voltage signal is subjected to program control amplification through the signal conditioning circuit; then, the conditioned signal is corrected; and then, wide range and high-precision dynamic monitoring can be carried out on the weak DC signal in the AC/DC mixed signals flowing through the grounded flat steel. The device is capable of carrying out precise recording on the time when transformer substation DC magnetic bias phenomenon happens and ends, and is capable of rapidly accessing a system network and realizing a DC magnetic bias monitoring system covering the whole areas.

Description

The measurement of power transformer neutral point direct current and wave recording device and detection method
Technical field
While the present invention relates to a kind of large-scale power transformer running status generation DC magnetic biasing, device and the detection method of the DC current of the transformer neutral point of flowing through being measured and being recorded ripple; Relate in particular to a kind of without to transformer neutral point grounding flat steel transformation or install current sensor additional, can be from the alternating current-direct current mixed signal of the grounding flat steel of flowing through, the record that realizes DC current involves wireless remote transmitting device and the detection method thereof of recorder data.
Technical background
During DC power transmission line monopolar operation, can cause to some extent transforming plant DC bias phenomenon around.Transformer DC magnetic bias phenomenon can cause the problems such as transformer noise aggravation, reactive loss and the increase of exciting current harmonic content, when serious, can cause Transformer Insulation Aging even to damage, and seriously jeopardizes the safe operation of AC network.By the Real-Time Monitoring to transformer DC magnetic bias phenomenon, contribute to study the regularity of distribution of a regional alternating current-direct current mixing electrical network DC magnetic biasing, take precautions against the adverse effect of DC magnetic biasing to AC network.
For the measurement of large-scale power transformer DC magnetic biasing, mostly adopt open-loop current sensor or closed loop current sensor at present.Aspect the measurement of DC low current, there is the performance deficiency that zero point drift is large in open-loop current sensor; And the installation of closed loop current sensor need to disconnect transformer neutral point grounding flat steel under power down mode.Because power failure meeting has a negative impact to economic benefit and social benefit, so the installation current sensor that cannot have a power failure; In the situation that not adopting current sensor, from the alternating current-direct current mixed signal of the grounding flat steel of flowing through, realize DC current record ripple in addition, there is no effective means.
Summary of the invention
Object of the present invention, is to provide a kind of current sensor that do not adopt, and by measuring one section of small electric pressure drop and resistance value on band steel, can realize to the alternating current-direct current hybrid current of the grounding flat steel of flowing through device and the detection method of DC current measurement and record ripple.
For reaching above object, the present invention has adopted following technical proposals:
Described power transformer neutral point direct current is measured and wave recording device comprises signal conditioning circuit, analog to digital conversion circuit, for the GSM/GPRS communication module of communication transfer, for detection of the measurement channel C PU with control, install total CPU, it is characterized in that: described device also comprises voltage fixture, constant current source current measurement circuit, trigger control circuit, gps clock module, controlled constant current source, current fixture.Voltage fixture is for gathering the pressure drop on one section of grounding flat steel of transformer neutral point, through signal conditioning circuit, this voltage signal is carried out to program control amplification, and the signal after conditioning is revised, output signal access analog to digital conversion circuit, and finally by measuring channel C PU, complete the collection to voltage on this section of band steel; The break-make of controlled constant current source output current is controlled by installing total CPU, and controlled constant current source output current is through one section of band steel of current fixture access transformer neutral point ground connection; Constant current source current measurement circuit, for gathering the actual current value of controlled constant current source output, is measured channel C PU and from constant current source current measurement circuit, is read the actual current value of constant current source output; Trigger control circuit is for comparing the sampled signal of signal conditioning circuit output and the reference signal of measuring channel C PU setting, produce the external interrupt interface that trigger pulse sends to the total CPU of device, then by the total CPU of device, from gps clock module, read current time.
The output terminal of described voltage fixture is connected with the input end of signal conditioning circuit, the output terminal of signal conditioning circuit is connected with the input end of analog to digital conversion circuit, and the output terminal of analog to digital conversion circuit and constant current source current measurement circuit is connected with measurement channel C PU input port; The input end of described trigger control circuit connects respectively signal conditioning circuit and measures an output terminal of channel C PU, total CPU mono-input end of trigger control circuit output terminal coupling arrangement; An output terminal of the total CPU of described device is connected with the input end of controlled constant current source, and controlled constant current source output terminal is connected to current fixture; Described gps clock module provides clock signal for installing total CPU, and GSM/GPRS communication module is connected with both-way communication form with the total CPU of device; The total CPU of described device is connected with measurement channel C PU.
The total CPU of described device controls controlled constant current source electric current output, and output current is connected to one section of band steel of transformer neutral point ground connection with current fixture; Measure channel C PU and from constant current source current measurement circuit, read the actual current value of controlled constant current source output; Measure channel C PU and measure the magnitude of voltage on band steel between two voltage fixtures by voltage fixture, signal conditioning circuit and analog to digital conversion circuit, through continuous quadratic, measure and control operation, realize band steel resistance value function between nominal voltage fixture.
Voltage fixture and current fixture are aluminium alloy workpiece, and two voltage fixtures are arranged on current fixture inner side, use outer-hexagonal brass bolt that fixture and transformer neutral point grounding flat steel is fastening, make all fixtures and the impedance of band steel surface of contact minimum.
Analog to digital conversion circuit adopts a kind of integration type A/D, inputs the clock frequency of A/D chip by adjusting, and the integral time of A/D chip and power frequency period are consistent, and realizes the inhibition to power frequency in input signal and higher hamonic wave composition thereof.
In technique scheme, install total CPU and GSM/GPRS communication module carries out both-way communication, realize wave recording device network communication and function of receiving and sending short message; Described gps clock module provides clock signal for installing total CPU.
The present invention adopts technique scheme, has following effect and advantage:
1) in the project implementation process, without having a power failure to the transformation of transformer neutral point grounding flat steel or installing current sensor additional;
2) the small direct current signal in the alternating current-direct current mixed signal that can flow through grounding flat steel, carries out wide region, Dynamic High-accuracy monitoring;
3) device can, to the generation of transforming plant DC bias phenomenon and the finish time, carry out accurate record;
4), after device is installed, connecting system network, realizes and covers regional DC magnetic biasing monitoring system fast.
5) Monitoring Data contributes to study the regularity of distribution of a regional alternating current-direct current mixing electrical network DC magnetic biasing, takes precautions against the adverse effect of DC magnetic biasing to AC network.
Accompanying drawing explanation
Fig. 1 is block diagram of the present invention;
Fig. 2 is band steel fixture installation diagram of the present invention;
Fig. 3 is the scaling method figure of the tested band steel resistance R of the present invention x.
Wherein: 1-voltage fixture, 2-signal conditioning circuit, 3-analog to digital conversion circuit, 4-constant current source current measurement circuit, 5-trigger control circuit, 6-measure channel C PU, 7-total CPU, 8-gps clock module installed, 9-GSM/GPRS communication module, 10-controlled constant current source, 11-current fixture, 12-transformer neutral point grounding flat steel.
Embodiment
Below in conjunction with accompanying drawing and example, the present invention is described in further detail:
One, general structure
As shown in Figure 1.Described power transformer neutral point direct current is measured and wave recording device, comprise signal conditioning circuit 2, analog to digital conversion circuit 3, for the GSM/GPRS communication module 9 of communication transfer, for detection of the measurement channel C PU6 with controlling, install total CPU7, it is characterized in that: described device also comprises voltage fixture 1, constant current source current measurement circuit 4, trigger control circuit 5, gps clock module 8, controlled constant current source 10, current fixture 11.Voltage fixture 1 is for gathering the pressure drop on one section of grounding flat steel 12 of transformer neutral point, through 2 pairs of these voltage signals of signal conditioning circuit, carry out program control amplification, and the signal after conditioning is revised, output signal access analog to digital conversion circuit 3, and finally by measuring channel C PU6, complete the collection to voltage on this section of band steel; The break-make of controlled constant current source 10 output currents is controlled by installing total CPU7, and controlled constant current source 10 output currents are through one section of band steel 12 of current fixture 11 access transformer neutral point ground connection; Constant current source current measurement circuit 4, for gathering the actual current value of controlled constant current source 10 outputs, is measured channel C PU6 and from constant current source current measurement circuit 4, is read the actual current value of constant current source output; Trigger control circuit 5 is for comparing the sampled signal of signal conditioning circuit 2 outputs and the reference signal of measuring channel C PU6 setting, produce the external interrupt interface that trigger pulse sends to the total CPU7 of device, then by the total CPU7 of device, from gps clock module 8, read current time.
In Fig. 1, the output terminal of described voltage fixture 1 is connected with the input end of signal conditioning circuit 2, the output terminal of signal conditioning circuit 2 is connected with the input end of analog to digital conversion circuit 3, and the output terminal of analog to digital conversion circuit 3 and constant current source current measurement circuit 4 is connected with measurement channel C PU6 input port; The input end of described trigger control circuit 5 is connected with respectively signal conditioning circuit 2 and measures an output terminal of channel C PU6, total CPU7 mono-input end of trigger control circuit 5 output terminal coupling arrangement; An output terminal of the total CPU7 of described device is connected with the input end of controlled constant current source 10, and controlled constant current source 10 output terminals are connected to current fixture 11; Described gps clock module 8 provides clock signal for installing total CPU7, and GSM/GPRS communication module 9 is connected with both-way communication form with the total CPU7 of device; The total CPU7 of described device is connected with measurement channel C PU6.
The total CPU7 of described device controls controlled constant current source 10 electric current outputs, and output current is connected to one section of band steel of transformer neutral point ground connection with current fixture 11; Measure channel C PU6 and from constant current source current measurement circuit 4, read the actual current value of controlled constant current source 10 outputs; Measure channel C PU6 and measure the magnitude of voltage on band steel between two voltage fixtures 1 by voltage fixture 1, signal conditioning circuit 2 and analog to digital conversion circuit 3, through continuous quadratic, measure and control operation, realize band steel resistance value function between nominal voltage fixture 1.
Analog to digital conversion circuit 3 adopts a kind of integration type A/D, inputs the clock frequency of A/D chip by adjusting, and the integral time of A/D chip and power frequency period are consistent, and realizes the inhibition to power frequency in input signal and higher hamonic wave composition thereof.
Fig. 2 is band steel fixture installation diagram, and voltage fixture 1 and current fixture 11 are aluminium alloy workpiece, good conductivity, and material is lightweight; Voltage fixture 1 and current fixture 11 inner spaces are abundant, adapt to multi-thickness and width band steel installation requirement; When fixture is installed, under fixture, medial surface and transformer grounding band steel 12 are fitted completely, and on fixture, medial surface is fastening by fixture and transformer grounding band steel 12 by outer-hexagonal brass bolt, and above-mentioned mounting process makes fixture and band steel surface of contact impedance minimum.Two voltage fixtures 1 are arranged on current fixture 11 inner sides, reduce fixture and the impact of band steel contact resistance on current measurement precision.
Two, principle of work of the present invention and function realize:
The present invention is a kind of without transformer neutral point grounding flat steel is transformed or installed current sensor additional, can be from the alternating current-direct current mixed signal of the grounding flat steel of flowing through, and the record that realizes DC current involves the device of recorder data wireless remote transmission.
One section of band steel that wave recording device is chosen transformer neutral point grounding switch below by voltage fixture is made sample resistance.When measured DC flows through band steel, will on this section of band steel, produce pressure drop, according to Ohm law, calculate the DC current flowing through on band steel.
First need the voltage producing on measuring transformer neutral ground band steel.Device first carries out offset voltage correction, program control amplification by signal conditioning circuit to voltage signal, and signal amplitude is nursed one's health to analog to digital conversion circuit linear zone.Secondly this voltage is alternating current-direct current mixed signal, for realizing the inhibition to power frequency in signal and higher hamonic wave composition thereof, analog to digital conversion circuit in device adopts a kind of integration type A/D, inputs the clock frequency of A/D chip by adjusting, and the integral time of A/D chip and power frequency period are consistent.Because power frequency and higher hamonic wave thereof are the signal changing in the cycle, the positive and negative area under the curve of signal equates, after power frequency and the conversion of higher hamonic wave signal integration thereof, is zero, and direct current is the cumulative sum of signal amplitude in integral time.
One section of band steel resistance R x of its less important measuring transformer neutral ground.The scaling method of Rx is as shown in Figure 3: measure for the first time and turn-off controlled constant current source output, between measuring voltage fixture, band steel pressure drop is U 1, U wherein 1=I 0rx; And then under equal conditions connecting controlled constant current source electric current I s and measure for the second time, is now I by electric current on this section of band steel 0+ Is, recording band steel pressure drop between voltage fixture is U 2, U 2=(I 0+ Is) Rx.Two equatioies subtract each other, and can obtain Rx=(U 2-U 1)/Is.
Trigger control circuit to the simulating signal of signal conditioning circuit output with measure that the triggering reference signal that channel C PU arranges compares, filtering and shaping, the trigger pulse of outputting standard pulsewidth.Comparer output rising edge generates DC magnetic biasing relevant trigger pip occurs, and negative edge generates DC magnetic biasing and finishes relevant trigger pip.
Further, the millisecond timer that installs total CPU inside carries out 1 millisecond of counting, uses the pulse per second (PPS) rising edge of gps clock module output to carry out timing zero clearing to count value.When receiving the generation of DC magnetic biasing or end trigger signal, will in the total CPU external interrupt service routine of device, read the millisecond value that count value occurs as event this moment, and from gps clock module serial line interface, read the Hour Minute Second of event.By with upper type, realize DC magnetic biasing generation and the accurate record of the finish time.
By integrated GSM/GPRS module, utilize and cover nationwide wireless network, realize the deployment of the long-range access network of wave recording device.

Claims (5)

1. a power transformer neutral point direct current is measured and wave recording device, comprise signal conditioning circuit (2), analog to digital conversion circuit (3), for the GSM/GPRS communication module (9) of communication transfer, for detection of the measurement channel C PU (6) with controlling, install total CPU (7), it is characterized in that: described device also comprises voltage fixture (1), constant current source current measurement circuit (4), trigger control circuit (5), gps clock module (8), controlled constant current source (10), current fixture (11); Voltage fixture (1) is for gathering the pressure drop on one section of grounding flat steel of transformer neutral point, through signal conditioning circuit, this voltage signal is carried out to program control amplification, and the signal after conditioning is revised, output signal access analog to digital conversion circuit, and finally by measuring channel C PU, complete the collection to voltage on this section of band steel; The break-make of controlled constant current source (10) output current is controlled by installing total CPU, and controlled constant current source output current is through one section of band steel of current fixture (11) access transformer neutral point ground connection; Constant current source current measurement circuit (4), for gathering the actual current value of controlled constant current source output, is measured channel C PU and from constant current source current measurement circuit, is read the actual current value of constant current source output; Trigger control circuit (5) is for comparing the sampled signal of signal conditioning circuit output and the reference signal of measuring channel C PU setting, produce the external interrupt interface that trigger pulse sends to the total CPU of device, then by the total CPU of device, from gps clock module, read current time;
The output terminal of described voltage fixture (1) is connected with the input end of signal conditioning circuit (2), the output terminal of signal conditioning circuit (2) is connected with the input end of analog to digital conversion circuit (3), and the output terminal of analog to digital conversion circuit (3) and constant current source current measurement circuit (4) is connected with measurement channel C PU (6) input port; The input end of described trigger control circuit (5) is connected with respectively signal conditioning circuit (2) and measures an output terminal of channel C PU (6), total CPU (7) one input ends of trigger control circuit (5) output terminal coupling arrangement; An output terminal of the total CPU of described device (7) is connected with the input end of controlled constant current source (10), and controlled constant current source (10) output terminal is connected to current fixture (11); Described gps clock module provides clock signal for installing total CPU, and GSM/GPRS communication module (9) is connected with both-way communication form with the total CPU of device (7); The total CPU of described device (7) is connected with measurement channel C PU (6).
2. power transformer neutral point direct current according to claim 1 is measured and wave recording device, it is characterized in that: the total CPU of described device (7) controls the output of controlled constant current source (10) electric current, and current fixture for output current (11) is connected to one section of band steel of transformer neutral point ground connection; Measure channel C PU (6) and from constant current source current measurement circuit (4), read the actual current value of controlled constant current source (10) output; Measure channel C PU (6) and measure the magnitude of voltage on band steel between two voltage fixtures (1) by voltage fixture (1), signal conditioning circuit (2) and analog to digital conversion circuit (3), through continuous quadratic, measure and control operation, realize band steel resistance value function between nominal voltage fixture (1).
3. power transformer neutral point direct current according to claim 1 is measured and wave recording device, it is characterized in that: voltage fixture (1) and current fixture (11) are aluminium alloy workpiece, two voltage fixtures (1) are arranged on current fixture (11) inner side, use outer-hexagonal brass bolt that fixture and transformer neutral point grounding flat steel is fastening, make all fixtures and the impedance of band steel surface of contact minimum.
4. power transformer neutral point direct current according to claim 1 is measured and wave recording device, it is characterized in that: analog to digital conversion circuit (3) adopts a kind of integration type A/D, by adjusting, input the clock frequency of A/D chip, the integral time of A/D chip and power frequency period are consistent, realize the inhibition to power frequency in input signal and higher hamonic wave composition thereof.
5. for a detection method for the measurement of power transformer neutral point direct current and wave recording device, it is characterized in that carrying out as follows:
The voltage producing on a measuring transformer neutral ground band steel, by signal conditioning circuit, voltage signal is carried out to offset voltage correction, program control amplification, signal amplitude is nursed one's health to analog to digital conversion circuit linear zone, adopt integration type A/D analog to digital conversion circuit, regulate the clock frequency of input A/D chip, the integral time of A/D chip and power frequency period are consistent, to realize the inhibition of power frequency in this signal to being gathered and higher hamonic wave composition thereof;
One section of band steel resistance R x of b measuring transformer neutral ground, the scaling method of Rx is as follows: measure for the first time and turn-off controlled constant current source output, between measuring voltage fixture, band steel pressure drop is U 1, U wherein 1=I 0rx; And then under equal conditions connecting controlled constant current source electric current I s and measure for the second time, is now I by electric current on this section of band steel 0+ Is, recording band steel pressure drop between voltage fixture is U 2, U 2=(I 0+ Is) Rx, two equatioies subtract each other, and obtain Rx=(U 2-U 1)/Is;
C trigger control circuit to the simulating signal of signal conditioning circuit output with measure that the triggering reference signal that channel C PU arranges compares, filtering and shaping, the trigger pulse of outputting standard pulsewidth, comparer output rising edge generates DC magnetic biasing relevant trigger pip occurs, and negative edge generates DC magnetic biasing and finishes relevant trigger pip;
The millisecond timer of the total CPU of d device inside carries out 1 millisecond of counting, use the pulse per second (PPS) rising edge of gps clock module output to carry out timing zero clearing to count value, when receiving the generation of DC magnetic biasing or end trigger signal, will be in the total CPU external interrupt service routine of device, read the millisecond value that count value occurs as event this moment, and from gps clock module serial line interface, read the Hour Minute Second of event, realize DC magnetic biasing is occurred and the accurate record of the finish time;
E, by integrated GSM/GPRS module, utilizes and covers nationwide wireless network, realizes the deployment of the long-range access network of wave recording device.
CN201410162863.9A 2014-04-22 2014-04-22 The measurement of power transformer neutral point direct current and wave recording device and detection method Active CN103995177B (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108152559A (en) * 2017-12-23 2018-06-12 中国西电电气股份有限公司 A kind of integrated DC magnetic bias current measuring device and method
CN109116169A (en) * 2018-08-03 2019-01-01 西南交通大学 The detection and analysis device and its determination method of power transformer D.C. magnetic biasing
CN110824226A (en) * 2019-10-17 2020-02-21 深圳供电局有限公司 Direct current measuring method, device and system

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2731077A1 (en) * 1995-02-23 1996-08-30 Sarl Digital Way Three=phase network parameters, such as voltage, current, phase and frequency measuring appts.
CN101236224A (en) * 2007-12-24 2008-08-06 国网直流工程建设有限公司 Converter transformer DC magnetic bias electrical current practical test method
CN101241156A (en) * 2007-12-05 2008-08-13 国网直流工程建设有限公司 Method for loading direct current mutual-inductor for applying to converter transformer bias magnet monitoring
CN101551440A (en) * 2009-05-15 2009-10-07 东北大学 Generator transformer unit faults recorder analysis device
CN101667779A (en) * 2008-09-03 2010-03-10 华东电力试验研究院有限公司 Bias magnetic power supply device for detecting capacity of bearing direct current bias magnet of transformer
EP1397693B1 (en) * 2001-06-08 2010-06-09 Eaton Electric Limited Measuring devices
CN102411084A (en) * 2011-07-26 2012-04-11 东北电力科学研究院有限公司 Online monitoring device and method of grounding current of iron core of transformer
CN102522819A (en) * 2011-11-24 2012-06-27 浙江省电力公司 Record wave pattern modeling method for fault record device of intelligent transformer substation
CN203133146U (en) * 2013-03-21 2013-08-14 国家电网公司 Transformer neutral point current measuring device

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2731077A1 (en) * 1995-02-23 1996-08-30 Sarl Digital Way Three=phase network parameters, such as voltage, current, phase and frequency measuring appts.
EP1397693B1 (en) * 2001-06-08 2010-06-09 Eaton Electric Limited Measuring devices
CN101241156A (en) * 2007-12-05 2008-08-13 国网直流工程建设有限公司 Method for loading direct current mutual-inductor for applying to converter transformer bias magnet monitoring
CN101236224A (en) * 2007-12-24 2008-08-06 国网直流工程建设有限公司 Converter transformer DC magnetic bias electrical current practical test method
CN101667779A (en) * 2008-09-03 2010-03-10 华东电力试验研究院有限公司 Bias magnetic power supply device for detecting capacity of bearing direct current bias magnet of transformer
CN101551440A (en) * 2009-05-15 2009-10-07 东北大学 Generator transformer unit faults recorder analysis device
CN102411084A (en) * 2011-07-26 2012-04-11 东北电力科学研究院有限公司 Online monitoring device and method of grounding current of iron core of transformer
CN102522819A (en) * 2011-11-24 2012-06-27 浙江省电力公司 Record wave pattern modeling method for fault record device of intelligent transformer substation
CN203133146U (en) * 2013-03-21 2013-08-14 国家电网公司 Transformer neutral point current measuring device

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
完泾平 等: "基于变压器中性点电流的在线监测系统的研究", 《电力设备》 *
张红跃 等: "采用交流互感器测量变压器中性点直流分量的方法", 《电力系统保护与控制》 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108152559A (en) * 2017-12-23 2018-06-12 中国西电电气股份有限公司 A kind of integrated DC magnetic bias current measuring device and method
CN109116169A (en) * 2018-08-03 2019-01-01 西南交通大学 The detection and analysis device and its determination method of power transformer D.C. magnetic biasing
CN110824226A (en) * 2019-10-17 2020-02-21 深圳供电局有限公司 Direct current measuring method, device and system

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