CN-121995180-A - Intelligent high-voltage test platform and method for transformer

CN121995180ACN 121995180 ACN121995180 ACN 121995180ACN-121995180-A

Abstract

The application relates to the technical field of diagnosis and evaluation of insulating property of a transformer, in particular to an intelligent high-voltage test platform and a test method of the transformer, wherein an impact signal is taken as a primary side input of the high-voltage transformer, and electric parameters of a secondary side and an insulating end of the transformer in each group of test impact processes are measured; the insulation maintenance degree of the transformer is obtained, and the insulation performance evaluation coefficient of the transformer is obtained by combining the overlapping condition of voltage waveform curves at two sides, so that the electromagnetic interference coefficient in each alternating current period after each group of test impact is obtained; and correcting the insulation resistance of the transformer in each alternating current period before the impact by utilizing the resistance distribution condition before the impact of each group of tests and the alternating current interference component, and correcting the insulation resistance of each alternating current period after the impact of each group of tests by combining the insulation performance evaluation coefficients of the transformer under each group of tests so as to evaluate the insulation performance of the transformer. The application improves the measurement accuracy of the insulation property of the transformer.

Inventors

WANG PENGCHENG
DUAN CHUNLIANG
ZHANG XINGNAN
LI HUIRU
FU JUN
CAI CHUBAO
KAN DONGWEI
CHI QINGZHI
JIANG YALI
ZHAO GENG
XUE NAILIANG
ZHAO JIANPING
LI MINGCHAO
MA JINHUI
LI FANGKAI
WEI LIANBO
LI JINGYU
JIN XIANCAI
GUO DAWEI
ZHANG JIAN
Cui Yinglan
MA HAIFENG
TANG SHENGLONG
ZHANG SHOUJUN

Assignees

国网黑龙江省电力有限公司鹤岗供电公司

Dates

Publication Date: 20260508
Application Date: 20260325

Claims (10)

1. The intelligent high-voltage test method for the transformer is characterized by comprising the following steps of: the impulse signal is input as the primary side of the high-voltage transformer, and the electric parameters of the secondary side and the insulation end of the transformer in each group of test impulse processes are measured, including voltage and current; Obtaining the insulation maintenance degree of the transformers under each group of tests according to the similarity degree and the waveform distribution difference of the primary side voltage and the secondary side voltage of the transformers under each group of tests, and obtaining the insulation performance evaluation coefficients of the transformers under each group of tests by combining the overlapping condition of the voltage waveform curves of the two sides; acquiring alternating current interference components before each group of test impact according to the fluctuation condition of the insulation resistance of each alternating current period before each group of test impact, and combining the deviation degree between the insulation resistance of each alternating current period after the impact and the average level of the resistance of each alternating current period before the impact to obtain the electromagnetic interference coefficient in each alternating current period after each group of test impact; and correcting the insulation resistance of the transformer in each alternating current period before the impact by utilizing the resistance distribution condition before the impact of each group of tests and the alternating current interference component, and correcting the insulation resistance of each alternating current period after the impact of each group of tests by combining the insulation performance evaluation coefficients of the transformer under each group of tests so as to evaluate the insulation performance of the transformer.
2. The intelligent high-voltage testing method of a transformer according to claim 1, wherein the insulation retention of the transformers under each group of tests is obtained by the following steps: wherein A represents the insulation retention of the transformer under the current set of tests, Representing the similarity of the primary and secondary voltage signals of the transformer under the current set of tests, The average value of the ratio of each peak value in the primary side voltage signal to the corresponding serial number peak value of the secondary side voltage signal of the current group of test transformers is represented, The boosting ratio of the transformer under ideal preset conditions is represented, wherein the boosting ratio is a fixed quantity related to the number of turns of coils at two sides of the transformer, winding distribution and iron core saturation degree, and belongs to a fixed parameter of the transformer.
3. The intelligent high-voltage testing method of a transformer according to claim 1, wherein the obtaining process of the insulation performance evaluation coefficient of the transformer under each group of tests is as follows: wherein B represents the insulation performance evaluation coefficient of the transformer under the current group test, norm () represents the normalization function, A represents the insulation retention of the transformer under the current group test, And the difference of the sealing area of the voltage curves at the two sides of the transformer under the current test is represented.
4. The intelligent high-voltage testing method of claim 3, wherein the process of obtaining the difference of the sealing areas of the voltage curves at two sides of the transformer under the current group test is as follows: , And Indicating the time of occurrence and end of the surge voltage under the current set of tests, The primary and secondary voltages of the transformer, respectively.
5. The intelligent high-voltage testing method of the transformer of claim 1, wherein the acquisition process of the alternating current interference component before each group of test impacts is that the insulation resistance corresponding to each alternating current period before each group of test impacts is calculated through ampere rule, and the average absolute deviation of the insulation resistances of all alternating current periods before each group of test impacts is counted to be used as the alternating current interference component before each group of test impacts.
6. The intelligent high-voltage testing method of a transformer according to claim 1, wherein the process of obtaining the electromagnetic interference coefficient in each alternating current period after each group of test impacts is as follows: In the formula (I), in the formula (II), Indicating the following of the current set of test impacts The electromagnetic interference coefficient in each ac cycle, Indicating the current group test post-impact The insulation resistance of the ac cycle, Representing the average value of insulation resistance for all ac cycles prior to the impact of the current set of tests, Representing the AC interference component before the current set of test impacts, max { R represents the insulation resistance and the insulation resistance of each alternating current period before the test impact of the current group The difference value takes the maximum value of absolute values.
7. The intelligent high voltage test method of a transformer according to claim 1, wherein the transformer insulation resistance correction process of each ac cycle before each group of test shocks is: In the formula (I), in the formula (II), And Respectively represent insulation resistances after correction and before correction of the mth alternating current period before the test impact of the current group, sign () represents a sign function, Representing the ac disturbance component before the current set of test impacts, And represents the bias value of the insulation resistance distribution before the impact of the current group test.
8. The intelligent high voltage testing method of claim 7, wherein if the distribution of insulation resistance of all ac cycles before the impact of the current group test shows a left bias, the bias value is Takes the value of-1, if the distribution shows right deviation, the deviation value is the same The value is 1.
9. The intelligent high voltage test method of a transformer according to claim 1, wherein the correction process of the insulation resistance of each alternating current period after each group of test impact is as follows: In the formula (I), in the formula (II), Post impact test for the current group The insulation resistance of the ac cycle, Post impact test for the current group The insulation resistance after correction of the ac cycle, Indicating the current group test post-impact Insulation resistance after AC period correction of (1), wherein In the time-course of which the first and second contact surfaces, Representing insulation resistance after correction of the last alternating current period before the current group of test impact; the correction coefficient is represented by a number of coefficients, Wherein B represents the insulation performance evaluation coefficient of the transformer under the current set of tests, Indicating the following of the current set of test impacts Electromagnetic interference coefficient in each alternating current period.
10. An intelligent high voltage test platform for a transformer, comprising a memory, a processor and a computer program stored in the memory and running on the processor, characterized in that the processor, when executing the computer program, carries out the steps of a method for intelligent high voltage testing of a transformer according to any one of claims 1-9.

Description

Intelligent high-voltage test platform and method for transformer Technical Field The application relates to the technical field of diagnosis and evaluation of insulating property of transformers, in particular to an intelligent high-voltage test platform and a test method of a transformer. Background In the transmission process of a power transmission line, in order to reduce the line loss of electric energy, the voltage of the transmission needs to be increased, and high-voltage or extra-high voltage transmission is involved. The insulation performance of the transformer directly affects the safety, reliability and service life of the transformer, so that an intelligent high-voltage test method is required to be designed for the high-voltage transformer to detect the insulation performance of the transformer. On a traditional intelligent high-voltage test platform, the insulation performance of a transformer is evaluated by applying an impulse voltage signal of a voltage generator to the transformer and an insulation terminal voltage current signal. However, in the running process of the high-voltage transformer, the high-voltage transformer is inevitably influenced by lightning overvoltage and alternating current impact, and at the moment, the transient voltage and current change easily generates strong electromagnetic interference, so that the insulation performance of the high-voltage transformer is measured with larger deviation, and the stability of the insulation performance is weaker. Disclosure of Invention In order to solve the technical problems, the application aims to provide an intelligent high-voltage test platform and an intelligent high-voltage test method for a transformer, and the adopted technical scheme is as follows: the embodiment of the application provides an intelligent high-voltage test method of a transformer, which comprises the following steps of: the impulse signal is input as the primary side of the high-voltage transformer, and the electric parameters of the secondary side and the insulation end of the transformer in each group of test impulse processes are measured, including voltage and current; Obtaining the insulation maintenance degree of the transformers under each group of tests according to the similarity degree and the waveform distribution difference of the primary side voltage and the secondary side voltage of the transformers under each group of tests, and obtaining the insulation performance evaluation coefficients of the transformers under each group of tests by combining the overlapping condition of the voltage waveform curves of the two sides; acquiring alternating current interference components before each group of test impact according to the fluctuation condition of the insulation resistance of each alternating current period before each group of test impact, and combining the deviation degree between the insulation resistance of each alternating current period after the impact and the average level of the resistance of each alternating current period before the impact to obtain the electromagnetic interference coefficient in each alternating current period after each group of test impact; and correcting the insulation resistance of the transformer in each alternating current period before the impact by utilizing the resistance distribution condition before the impact of each group of tests and the alternating current interference component, and correcting the insulation resistance of each alternating current period after the impact of each group of tests by combining the insulation performance evaluation coefficients of the transformer under each group of tests so as to evaluate the insulation performance of the transformer. Preferably, the process for obtaining the insulation retention of the transformer under each group of tests is as follows: wherein A represents the insulation retention of the transformer under the current set of tests, Representing the similarity of the primary and secondary voltage signals of the transformer under the current set of tests,The average value of the ratio of each peak value in the primary side voltage signal to the corresponding serial number peak value of the secondary side voltage signal of the current group of test transformers is represented,The boosting ratio of the transformer under ideal preset conditions is represented, wherein the boosting ratio is a fixed quantity related to the number of turns of coils at two sides of the transformer, winding distribution and iron core saturation degree, and belongs to a fixed parameter of the transformer. Preferably, the process for obtaining the insulation performance evaluation coefficients of the transformers under each group of tests is as follows: wherein B represents the insulation performance evaluation coefficient of the transformer under the current group test, norm () represents the normalization function, A represents the insulation retention of the transformer