Transformer turn-to-turn test system and method

Abstract

The invention relates to the technical field of transformers, and provides a transformer interturn test system and method, and the system comprises a partial discharge simulation module which is used for building a partial discharge simulation device based on an experimental transformer and a circuit assembly, and generating partial discharge through the partial discharge simulation device; the partial discharge detection module is used for detecting partial discharge based on a partial discharge tester to obtain partial discharge detection data; and the data analysis module is used for collecting and analyzing the partial discharge detection data based on an oscilloscope and a computer. Partial discharge is carried out based on the partial discharge simulation device, and partial discharge detection is carried out by using the partial discharge detection device, so that the detection efficiency of the turn-to-turn discharge fault of the transformer can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of transformers, and in particular to a test system and method for transformer turns. Background Art

[0002] In recent years, safety accidents caused by insulation failure of transformers due to the presence of corrosive sulfur in transformer oil have frequently occurred at home and abroad, seriously affecting the safe and reliable operation level of the power system. The highly active sulfides in the transformer oil react with the copper wire to form cuprous sulfide, which adheres to the copper wire and the surface of the insulation paper between the turns of the winding, reduces the electrical properties of the insulation paper and causes inter-turn insulation discharge, and then local breakdown causes high-energy arc faults, which causes local pressure surges and causes explosion accidents. The existing relay protection is a passive protection that reflects the large current and high-energy action of the fault. It cannot sensitively judge and quickly remove the fault in the initial stage of the fault, and the monitoring quantity of the online monitoring device does not have accurate discrimination for serious defects that occur in a shorter time scale (days-hours). The internal discharge fault of the transformer, represented by the inter-turn fault, has the characteristics of complex defect causes, rapid development speed, and serious consequences of the fault, and is in the blind spot of the current relay protection and online monitoring.

[0003] The characteristics and influence rules of cuprous sulfide deposition on the inter-turn insulation of windings are studied, the development process and multi-physical characteristic rules of inter-turn discharge faults caused by cuprous sulfide deposition are analyzed, the propagation characteristics of multi-physical signals are mastered, and a characterization method for cuprous sulfide deposition and a diagnosis and early warning technology for inter-turn discharge are proposed. This can achieve early detection of hidden dangers of cuprous sulfide deposition and early warning and early disposal of inter-turn discharge faults, thereby improving the safe operation level of the transformer.

[0004] Therefore, it is necessary to provide a test system and method for transformer turns. Summary of the invention

[0005] The present invention provides a test system and method for transformer interturns, which can effectively improve the detection efficiency of transformer interturn discharge faults by performing partial discharge based on a partial discharge simulation device and performing partial discharge detection using a partial discharge detection device.

[0006] The present invention provides a test system for transformer turns, comprising: A partial discharge simulation module is used to build a partial discharge simulation device based on an experimental transformer and circuit components, and to generate partial discharge using the partial discharge simulation device; A partial discharge detection module is used to detect partial discharge based on a partial discharge tester to obtain partial discharge detection data; The data analysis module is used to collect and analyze partial discharge detection data based on an oscilloscope and a computer.

[0007] Furthermore, the test transformer is a 120 V corona-free transformer, and the apparent charge of partial discharge at 120 kV is not greater than 5 picoules; the high-voltage lead of the test transformer is subjected to corona-free treatment.

[0008] Furthermore, the circuit component includes a protective resistor, a coupling capacitor, a detection impedance, and an electrode sample; the output end of the test transformer includes a first output terminal and a second output terminal; the first output terminal is connected to one end of the protective resistor, the other end of the protective resistor is respectively connected to one end of the coupling capacitor and one end of the electrode sample, the other end of the coupling capacitor is connected to one end of the detection impedance, and the second output terminal, the other end of the detection impedance and the other end of the electrode sample are all grounded.

[0009] Furthermore, building a partial discharge simulation device based on the experimental transformer also includes performing a partial discharge function test on the partial discharge simulation device, specifically: Control the experimental transformer to slowly increase the voltage until it reaches the starting discharge voltage; When the initial discharge voltage is maintained for 10 seconds, after the initial defect is generated, the voltage is reduced to 40 kV at a rate of 2 kV / 5 seconds and kept constant; Based on a voltage of 40 kV, the electrode samples were subjected to pressure tests at pressure time lengths of 10 min, 30 min, 60 min, 90 min, 120 min and 180 min, respectively, to obtain pressure test data of the electrode samples; the same pressure time length includes multiple electrode samples; The partial discharge function of the partial discharge simulation device is tested based on whether the initial insulation state of the electrode test piece meets the set pressure test standard.

[0010] Furthermore, before the pressurization test, the electrode samples were heated at 105°C and a pressure of less than 100 Pa and vacuum-evacuated for more than 24 hours, then vacuum-filled with oil and kept in the oil for more than 24 hours.

[0011] Furthermore, one end of the partial discharge tester is connected to the other end of the detection impedance; the other end of the partial discharge tester is connected to one end of the oscilloscope; and the other end of the oscilloscope is connected to the computer.

[0012] Furthermore, based on an oscilloscope and a computer, partial discharge detection data is collected and analyzed, including: Based on the oscilloscope, the partial discharge detection data is collected; Based on the collected partial discharge detection data, a simplified feature data set of partial discharge is obtained; the features in the simplified feature data set include the average discharge amount of the pulse current signal, the maximum pulse amplitude, the pulse repetition rate and the skewness of the PRPD spectrum; The partial discharge detection data is stored and analyzed by computer.

[0013] Further, the partial discharge detection data is stored and analyzed by a computer, including: In the partial discharge detection data, samples at 15 time points are collected for hierarchical clustering, specifically: The samples are numbered in the order of 1 to 15 to obtain the sequence number; Normalize the reduced feature data set in the sample; The complete connection clustering method was used to obtain the clustering dendrogram of the samples; According to the optimal division scale, the partial discharge development process is divided into three stages, including: the discharge start stage with sequence numbers 1 to 7, the discharge development stage with sequence numbers 8 to 12, and the pre-breakdown stage with sequence numbers 13 to 15.

[0014] Furthermore, using a computer to store and analyze the partial discharge detection data also includes: early warning of partial discharge faults, specifically: Utilizing the FPGA+ARM multi-processor architecture, the partial discharge detection data is collected synchronously at 100M in multiple channels and analyzed in real time. The FPGA controls the synchronous collection of multiple independent 100M AD signals and the extraction of real-time pulse sequences, and the high-performance ARM is used to extract multiple feature quantities, process data, and diagnose the discharge status. Based on the set partial discharge standard database, the partial discharge data is matched and analyzed. If a mismatch occurs, a warning signal is generated, and a fault warning of the partial discharge experiment is performed based on the warning signal.

[0015] A test method for transformer turns, comprising: Based on the experimental transformer and circuit components, a partial discharge simulation device was built, and partial discharge was generated using the partial discharge simulation device; Detecting partial discharge based on a partial discharge tester to obtain partial discharge detection data; Based on oscilloscope and computer, partial discharge detection data is collected and analyzed.

[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects: by performing partial discharge based on a partial discharge simulation device and performing partial discharge detection using a partial discharge detection device, the detection efficiency of transformer inter-turn discharge faults can be effectively improved.

[0017] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0018] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 It is a schematic diagram of the structure of a test system for transformer turns; Figure 2 It is a schematic diagram of the connection of the test system components between transformer turns; Figure 3 The figure is a schematic diagram of the steps of a test method for transformer turns. DETAILED DESCRIPTION

[0020] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0021] The present invention provides a test system for transformer turns, such as Figure 1 As shown, including: A partial discharge simulation module is used to build a partial discharge simulation device based on an experimental transformer and circuit components, and to generate partial discharge using the partial discharge simulation device; A partial discharge detection module is used to detect partial discharge based on a partial discharge tester to obtain partial discharge detection data; The data analysis module is used to collect and analyze partial discharge detection data based on an oscilloscope and a computer.

[0022] The working principle of the above technical solution is as follows: in order to realize a test system for transformer turns, the present invention proposes a partial discharge simulation module, which is used to build a partial discharge simulation device based on an experimental transformer and circuit components, and use the partial discharge simulation device to generate partial discharge; proposes a partial discharge detection module, which is used to detect partial discharge based on a partial discharge tester and obtain partial discharge detection data; proposes a data analysis module, which is used to collect and analyze partial discharge detection data based on an oscilloscope and a computer.

[0023] The beneficial effect of the above technical solution is: by adopting the solution provided in this embodiment, the detection efficiency of transformer inter-turn discharge faults can be effectively improved by performing partial discharge based on a partial discharge simulation device and performing partial discharge detection using a partial discharge detection device.

[0024] In one embodiment, the test transformer is a 120 V corona-free transformer, and the apparent charge of partial discharge at 120 kV is no more than 5 picoules; the high-voltage lead of the test transformer is subjected to corona-free treatment; the winding turns of the test transformer are composed of a flat copper wire and a wrapped insulating paper layer, and different thicknesses of turn insulation layers are used according to the requirements of different voltage levels of the winding. The specifications of the winding turns in this embodiment are: the flat copper wire is 11.25 mm wide and 1.25 mm thick, and the total thickness of the insulation layers on both sides is 2.45 mm.

[0025] The working principle of the above technical solution is: the test transformer is a 120 V corona-free transformer, and the apparent charge of partial discharge at 120 kV is not more than 5 picoules; the high-voltage lead of the test transformer is treated with corona-free treatment.

[0026] The beneficial effect of the above technical solution is: by adopting the solution provided in this embodiment, by setting the parameters of the test transformer, a basis is provided for the function of the test transformer.

[0027] In one embodiment, Figure 2 As shown, the circuit components include a protective resistor, a coupling capacitor, a detection impedance, and an electrode sample; the output end of the test transformer includes a first output terminal and a second output terminal; the first output terminal is connected to one end of the protective resistor, the other end of the protective resistor is respectively connected to one end of the coupling capacitor and one end of the electrode sample, the other end of the coupling capacitor is connected to one end of the detection impedance, and the second output terminal, the other end of the detection impedance and the other end of the electrode sample are all grounded.

[0028] The working principle of the above technical solution is: in order to achieve effective discharge of the experimental transformer, a circuit component needs to be set, and the circuit component of the present invention includes a protective resistor, a coupling capacitor, a detection impedance, and an electrode sample; the output end of the test transformer includes a first output terminal and a second output terminal; the first output terminal is connected to one end of the protective resistor, and the other end of the protective resistor is respectively connected to one end of the coupling capacitor and one end of the electrode sample, and the other end of the coupling capacitor is connected to one end of the detection impedance, and the second output terminal, the other end of the detection impedance and the other end of the electrode sample are all grounded.

[0029] The beneficial effect of the above technical solution is: by adopting the solution provided in this embodiment, by setting up circuit components, a basis can be provided for the effective discharge of the experimental transformer.

[0030] In one embodiment, a partial discharge simulation device is built based on an experimental transformer, and a partial discharge function test is performed on the partial discharge simulation device, specifically: Control the experimental transformer to slowly increase the voltage until it reaches the starting discharge voltage; When the initial discharge voltage is maintained for 10 seconds, after the initial defect is generated, the voltage is reduced to 40 kV at a rate of 2 kV / 5 seconds and kept constant; Based on a voltage of 40 kV, the electrode samples were subjected to pressure tests at pressure time lengths of 10 min, 30 min, 60 min, 90 min, 120 min and 180 min, respectively, to obtain pressure test data of the electrode samples; the same pressure time length includes multiple electrode samples; The partial discharge function of the partial discharge simulation device is tested based on whether the initial insulation state of the electrode test piece meets the set pressure test standard.

[0031] The working principle of the above technical solution is as follows: in order to realize the partial discharge function test of the partial discharge simulation device, the present invention first controls the test transformer to slowly increase the voltage until the starting discharge voltage is reached; then, after maintaining the starting discharge voltage for 10 seconds, after the initial defect is generated, the voltage is reduced to 40 kV at a rate of 2kV / 5s and kept constant; then, based on the 40 kV voltage, the electrode sample is subjected to a pressurization test at pressurization time lengths of 10min, 30min, 60min, 90min, 120min and 180min, respectively, to obtain pressurization test data of the electrode sample; the same pressurization time length includes multiple electrode samples; finally, based on whether the initial insulation state of the electrode sample meets the set pressurization test standard, the partial discharge function of the partial discharge simulation device is detected.

[0032] The beneficial effect of the above technical solution is: by adopting the solution provided in this embodiment, by controlling the experimental transformer to rise slowly, effective testing of the electrode sample can be achieved.

[0033] In one embodiment, before the pressurization test, the electrode samples are heated at 105° C. and a pressure less than 100 Pa and vacuum-evacuated for more than 24 hours, and then vacuum-filled with oil and kept in the oil for more than 24 hours.

[0034] The working principle of the above technical solution is as follows: before the pressurization test, the electrode samples need to be treated. The electrode samples in the present invention are heated at 105°C and an air pressure less than 100Pa and vacuum-evacuated for more than 24 hours, and then vacuum-filled with oil and kept in the oil for more than 24 hours; after the above treatment, the moisture and gas inside the inter-turn electrode insulation are precipitated, meeting the requirements for the moisture and gas content of the internal insulation of the real transformer.

[0035] The beneficial effect of the above technical solution is: by adopting the solution provided in this embodiment, the requirements for the moisture content and gas content of the insulation inside the real transformer can be met by processing the electrode test sample, providing a basis for the development of detection.

[0036] In one embodiment, one end of the partial discharge tester is connected to the other end of the detection impedance; the other end of the partial discharge tester is connected to one end of the oscilloscope; and the other end of the oscilloscope is connected to the computer.

[0037] The working principle of the above technical solution is: by setting the connection relationship, the effective connection of the detection equipment can be guaranteed, one end of the partial discharge tester is connected to the other end of the detection impedance; the other end of the partial discharge tester is connected to one end of the oscilloscope; the other end of the oscilloscope is connected to the computer.

[0038] The beneficial effect of the above technical solution is: by adopting the solution provided by this embodiment, the effective connection of the detection equipment can be guaranteed by setting the connection relationship.

[0039] In one embodiment, partial discharge detection data is collected and analyzed based on an oscilloscope and a computer, including: Based on the oscilloscope, the partial discharge detection data is collected; Based on the collected partial discharge detection data, a simplified feature data set of partial discharge is obtained; the features in the simplified feature data set include the average discharge amount of the pulse current signal, the maximum pulse amplitude, the pulse repetition rate and the skewness of the PRPD spectrum; The partial discharge detection data is stored and analyzed by computer.

[0040] The working principle of the above technical solution is: in order to realize the collection and analysis of partial discharge detection data, the present invention first collects the partial discharge detection data based on an oscilloscope; then, based on the collected partial discharge detection data, a simplified feature data set of partial discharge is obtained; the features in the simplified feature data set include the average discharge amount of the pulse current signal, the maximum pulse amplitude, the pulse repetition rate and the skewness of the PRPD spectrum; finally, the partial discharge detection data is stored and analyzed by a computer.

[0041] The beneficial effect of the above technical solution is: by adopting the solution provided by this embodiment, effective detection of partial discharge data can be achieved by storing and analyzing partial discharge detection data.

[0042] In one embodiment, using a computer to store and analyze partial discharge detection data includes: In the partial discharge detection data, samples at 15 time points are collected for hierarchical clustering, specifically: The samples are numbered in the order of 1 to 15 to obtain the sequence number; Normalize the reduced feature data set in the sample; The complete connection clustering method was used to obtain the clustering dendrogram of the samples; According to the optimal division scale, the partial discharge development process is divided into three stages, including: the discharge start stage with sequence numbers 1 to 7, the discharge development stage with sequence numbers 8 to 12, and the pre-breakdown stage with sequence numbers 13 to 15.

[0043] The working principle of the above technical solution is: in order to use a computer to store and analyze partial discharge detection data, the present invention collects samples at 15 time points in the partial discharge detection data for hierarchical clustering, firstly numbering the samples in the order of 1 to 15 to obtain the sequence number; then normalizing the simplified feature data set in the sample; then, using the fully connected aggregation clustering method, obtaining the clustering dendrogram of the sample; finally, according to the optimal division scale, the partial discharge development process is divided into three stages, wherein the three stages include: a discharge start stage with sequence numbers 1 to 7, a discharge development stage with sequence numbers 8 to 12, and a pre-breakdown stage with sequence numbers 13 to 15.

[0044] The beneficial effect of the above technical solution is: by adopting the solution provided by this embodiment, the partial discharge process can be accurately obtained through hierarchical clustering analysis of partial discharge detection data.

[0045] In one embodiment, using a computer to store and analyze partial discharge detection data also includes: early warning of partial discharge faults, specifically: Utilizing the FPGA+ARM multi-processor architecture, the partial discharge detection data is collected synchronously at 100M in multiple channels and analyzed in real time. The FPGA controls the synchronous collection of multiple independent 100M AD signals and the extraction of real-time pulse sequences, and the high-performance ARM is used to extract multiple feature quantities, process data, and diagnose the discharge status. Based on the set partial discharge standard database, the partial discharge data is matched and analyzed. If a mismatch occurs, a warning signal is generated, and a fault warning of the partial discharge experiment is performed based on the warning signal.

[0046] The working principle of the above technical solution is: in order to use a computer to store and analyze partial discharge detection data, the present invention also includes: to warn of partial discharge faults, first use the FPGA+ARM multi-processor architecture to perform multi-channel 100-megahertz synchronous acquisition and real-time signal analysis on the partial discharge detection data; wherein, the FPGA controls the synchronous acquisition of multi-channel independent 100-megahertz AD signals and the extraction of real-time pulse sequences, and the high-performance ARM realizes the extraction of multiple feature quantities, data processing and discharge state diagnosis; then, based on the set partial discharge standard database, the partial discharge data is matched and analyzed, and if there is a mismatch, a warning signal is generated, and a fault warning of the partial discharge experiment is executed based on the warning signal.

[0047] The beneficial effect of the above technical solution is: by adopting the solution provided by this embodiment, by utilizing a multi-processing architecture to collect and analyze data and perform fault warning of partial discharge experiments, it is possible to ensure that fault warning is implemented efficiently.

[0048] A test method for transformer turns, such as Figure 3 As shown, including: Based on the experimental transformer and circuit components, a partial discharge simulation device was built, and partial discharge was generated using the partial discharge simulation device; Detecting partial discharge based on a partial discharge tester to obtain partial discharge detection data; Based on oscilloscope and computer, partial discharge detection data is collected and analyzed.

[0049] The working principle of the above technical solution is: in order to realize the test method for transformer turns, the present invention first builds a partial discharge simulation device based on the experimental transformer and circuit components, and uses the partial discharge simulation device to generate partial discharge; then detects the partial discharge based on the partial discharge tester to obtain partial discharge detection data; finally, based on an oscilloscope and a computer, collects and analyzes the partial discharge detection data.

[0050] The beneficial effect of the above technical solution is: by adopting the solution provided in this embodiment, the detection efficiency of transformer inter-turn discharge faults can be effectively improved by performing partial discharge based on a partial discharge simulation device and performing partial discharge detection using a partial discharge detection device.

[0051] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A test system for transformer turns, characterized in that: include: A partial discharge simulation module is used to build a partial discharge simulation device based on an experimental transformer and circuit components, and to generate partial discharge using the partial discharge simulation device; A partial discharge detection module is used to detect partial discharge based on a partial discharge tester to obtain partial discharge detection data; The data analysis module is used to collect and analyze partial discharge detection data based on an oscilloscope and a computer.

2. A transformer turn-to-turn test system according to claim 1, characterized in that: The test transformer is a 120 V corona-free transformer, and the apparent charge of partial discharge at 120 kV is not greater than 5 picoules; the high-voltage leads of the test transformer are treated with corona-free treatment.

3. A transformer turn-to-turn test system according to claim 1, characterized in that: The circuit components include a protective resistor, a coupling capacitor, a detection impedance, and an electrode sample; the output end of the test transformer includes a first output terminal and a second output terminal; the first output terminal is connected to one end of the protective resistor, the other end of the protective resistor is respectively connected to one end of the coupling capacitor and one end of the electrode sample, the other end of the coupling capacitor is connected to one end of the detection impedance, and the second output terminal, the other end of the detection impedance and the other end of the electrode sample are all grounded.

4. A transformer turn-to-turn test system according to claim 3, characterized in that: Building a partial discharge simulation device based on the experimental transformer also includes conducting partial discharge function tests on the partial discharge simulation device, specifically: Control the experimental transformer to slowly increase the voltage until it reaches the starting discharge voltage; When the initial discharge voltage is maintained for 10 seconds, after the initial defect is generated, the voltage is reduced to 40 kV at a rate of 2 kV / 5 seconds and kept constant; Based on a voltage of 40 kV, the electrode samples were subjected to pressure tests at pressure time lengths of 10 min, 30 min, 60 min, 90 min, 120 min and 180 min, respectively, to obtain pressure test data of the electrode samples; the same pressure time length includes multiple electrode samples; The partial discharge function of the partial discharge simulation device is tested based on whether the initial insulation state of the electrode test piece meets the set pressure test standard.

5. A transformer turn-to-turn test system according to claim 4, characterized in that: Before the pressure test, the electrode samples were heated at 105°C and the air pressure was less than 100 Pa, and vacuum-evacuated for more than 24 hours, and then vacuum-filled with oil and kept in the oil for more than 24 hours.

6. A transformer turn-to-turn test system according to claim 1, characterized in that: One end of the partial discharge tester is connected to the other end of the detection impedance; the other end of the partial discharge tester is connected to one end of the oscilloscope; and the other end of the oscilloscope is connected to the computer.

7. A transformer turn-to-turn test system according to claim 1, characterized in that: Based on oscilloscope and computer, partial discharge detection data is collected and analyzed, including: Based on the oscilloscope, the partial discharge detection data is collected; Based on the collected partial discharge detection data, a simplified feature data set of partial discharge is obtained; the features in the simplified feature data set include the average discharge amount of the pulse current signal, the maximum pulse amplitude, the pulse repetition rate and the skewness of the PRPD spectrum; The partial discharge detection data is stored and analyzed by computer.

8. A transformer turn-to-turn test system according to claim 3, characterized in that: Use computers to store and analyze partial discharge detection data, including: In the partial discharge detection data, samples at 15 time points are collected for hierarchical clustering, specifically: The samples are numbered in the order of 1 to 15 to obtain the sequence number; Normalize the reduced feature data set in the sample; The complete connection clustering method was used to obtain the clustering dendrogram of the samples; According to the optimal division scale, the partial discharge development process is divided into three stages, including: the discharge start stage with sequence numbers 1 to 7, the discharge development stage with sequence numbers 8 to 12, and the pre-breakdown stage with sequence numbers 13 to 15.

9. A transformer turn-to-turn test system according to claim 1, characterized in that: The computer is used to store and analyze the partial discharge detection data, and also includes: early warning of partial discharge faults, specifically: Utilizing the FPGA+ARM multi-processor architecture, the partial discharge detection data is collected synchronously at 100M in multiple channels and analyzed in real time. The FPGA controls the synchronous collection of multiple independent 100M AD signals and the extraction of real-time pulse sequences, and the high-performance ARM is used to extract multiple feature quantities, process data, and diagnose the discharge status. Based on the set partial discharge standard database, the partial discharge data is matched and analyzed. If a mismatch occurs, a warning signal is generated, and a fault warning of the partial discharge experiment is performed based on the warning signal.

10. A test method for transformer turns, characterized in that: include: Based on the experimental transformer and circuit components, a partial discharge simulation device was built, and partial discharge was generated using the partial discharge simulation device; Detecting partial discharge based on a partial discharge tester to obtain partial discharge detection data; Based on oscilloscope and computer, partial discharge detection data is collected and analyzed.

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