A thyristor-level field insulation testing device, method, and storage medium

Abstract

This invention discloses a thyristor-level field insulation testing device, method, and storage medium. The device includes a discharge module, a DC voltage module, a changeover switch module, a first measurement module, a second measurement module, and a control module. One end of the discharge module and one end of the DC voltage module are connected to one end of the thyristor-level test sample. The other end of the discharge module is connected to the first measurement module between its first input terminal and the changeover switch module. The other end of the DC voltage module is connected to the second measurement module between its second input terminal and the changeover switch module. The output terminal of the changeover switch module is connected to the other end of the thyristor-level test sample. The changeover switch module switches the connection between the thyristor-level test sample and the DC voltage module or the discharge module. This device is simple and reliable, can obtain information on thyristor-level insulation aging, avoids damage to equipment caused by high-voltage field measurements, and can meet the application requirements of engineering sites.

Description

Technical Field

[0001] This invention relates to the field of thyristor-level testing technology, specifically to a thyristor-level field insulation testing device, method, and storage medium. Background Technology

[0002] The converter valve is the core equipment of the converter station, and the thyristor stage is the most basic electrical structure unit of the converter valve, which has the advantages of large current capacity and high pressure resistance.

[0003] As operating time increases, the thyristor stages are subjected to long-term electrical and thermal stress, leading to defects such as insulation aging. Multiple thyristor stage failures can cause a DC system outage. Therefore, equipment maintenance units regularly conduct on-site testing of the converter valve thyristor stages.

[0004] In the existing technology, the field testing equipment for thyristors does not have the function of detecting insulation performance, cannot identify insulation aging problems in thyristors, and cannot meet the requirement of early detection and elimination of defects in thyristors. Summary of the Invention

[0005] The purpose of this invention is to provide a thyristor-level field insulation testing device, method, and storage medium to solve the problem that existing thyristor-level field testing equipment lacks insulation performance detection functions and cannot identify insulation aging problems at the thyristor level.

[0006] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0007] In a first aspect, the present invention discloses a thyristor-level field insulation testing device, wherein the device is connected in parallel with a thyristor-level test sample and includes a discharge module, a DC voltage module, a changeover switch module, a first measurement module, a second measurement module, and a control module;

[0008] One end of the discharge module and one end of the DC voltage module are connected to one end of the thyristor-stage test sample;

[0009] A first measurement module is connected between the other end of the discharge module and the first input terminal of the changeover switch module. The first measurement module is used to measure the voltage change of the discharge module.

[0010] A second measurement module is connected between the other end of the DC voltage module and the second input terminal of the changeover switch module. The second measurement module is used to measure the voltage change of the DC voltage module.

[0011] The output terminal of the switching module is connected to the other end of the thyristor-level test sample; when the switching module is switched to connect the thyristor-level test sample to the DC voltage module, the DC voltage module charges the thyristor-level test sample; when the switching module is switched to connect the thyristor-level test sample to the discharge module, the thyristor-level test sample discharges through the discharge module.

[0012] When the thyristor-stage test sample discharges, the control module fits the test waveform of the thyristor-stage test sample based on the voltage change of the discharge module measured by the first measurement module, and calculates the time constant t based on the test waveform;

[0013] The control module is also used to compare the time constant t with the standard value of the time constant T, and obtain the insulation aging information of the thyristor-level test sample based on the comparison result.

[0014] Furthermore, the DC voltage module, measurement module, transfer switch module, and control module are also connected to an external AC power source via a power conversion module.

[0015] Furthermore, the DC voltage module, the changeover switch module, the first measurement module, and the second measurement module are all signal-connected to the control module.

[0016] Furthermore, if the amplitude of the time constant t is less than or equal to 10% of the amplitude of the standard value of the time constant T, then the thyristor-level test specimen is judged to be aging in either the forward or reverse insulation direction; otherwise, the thyristor-level test specimen is judged to be qualified in either the forward or reverse insulation direction.

[0017] In a second aspect, the present invention provides a thyristor-level field insulation testing method, implemented using the apparatus described in any one of the first aspects, comprising:

[0018] Switch the thyristor-level test sample to be connected to the DC voltage module to charge the thyristor-level test sample;

[0019] Once the thyristor-level test sample is charged to the preset voltage value, the thyristor-level test sample is switched to the discharge module for discharge.

[0020] When the thyristor stage test sample discharges, the test waveform of the thyristor stage test sample is acquired, and the time constant t is calculated based on the test waveform;

[0021] The time constant t is compared with the standard value of the time constant T, and the insulation aging information of the thyristor-level test specimen is obtained based on the comparison result.

[0022] Furthermore, if the amplitude of the obtained time constant t is less than or equal to 10% of the standard value of the time constant T, then the thyristor-level test specimen is judged to be aging in either the forward or reverse insulation direction; otherwise, the thyristor-level test specimen is judged to be qualified in either the forward or reverse insulation direction.

[0023] Furthermore, the time constant t is expressed by the formula y = y0 + Ae -x / t Obtained through fitting;

[0024] Wherein, the vertical axis y is the DC voltage across the thyristor stage test sample, y0 is the initial voltage of the thyristor stage test sample, A is the slope coefficient, the horizontal axis x is time, t is the time constant, and e is the base of the natural logarithm.

[0025] Furthermore, the preset voltage for charging the thyristor stage is less than half of the rated voltage of the thyristor stage.

[0026] Thirdly, the present invention discloses a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described in any of the second aspects.

[0027] Fourthly, the present invention discloses an apparatus comprising:

[0028] Memory, used to store instructions;

[0029] A processor is configured to execute the instructions, causing the device to perform operations implementing the thyristor-level field insulation testing method according to any one of the second aspects.

[0030] According to the above technical solution, the present invention has the following effects: The insulation testing device designed in this application uses a switching module to switch the connection relationship between the thyristor-level test sample and the discharge module and DC voltage module. When the thyristor-level test sample discharges, the control module fits the test waveform of the thyristor-level test sample according to the voltage change of the discharge module measured by the first measurement module, and calculates the time constant t. The insulation aging information of the thyristor-level test sample can be obtained by comparing the time constant t with the standard value of the time constant T. This device is simple and reliable, can obtain the insulation aging problem of the thyristor level, avoids damage to the equipment caused by high voltage measurement on site, and can meet the application needs of engineering sites. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the insulation testing device of the present invention;

[0032] Figure 2 A schematic diagram of charging the insulation testing device of the present invention;

[0033] Figure 3 This is a schematic diagram of the discharge of the insulation testing device of the present invention;

[0034] Figure 4 The waveform diagram shows the DC voltage module of the present invention after being charged and discharged when the voltage is applied forward to both ends of the thyristor stage.

[0035] Figure 5The waveform diagram shows the DC voltage module of the present invention after being charged and discharged by applying a reverse voltage to both ends of the thyristor stage;

[0036] Figure 6 This is a flowchart of the testing method of the present invention.

[0037] Wherein, R1 is the first resistor; R 41 Second resistor; R 41 Third resistor R 42 Cc1, first capacitor; Cc2, second capacitor; C3, third capacitor; TCE, trigger control circuit. Detailed Implementation

[0038] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0039] Example 1

[0040] like Figures 1 to 3 As shown, this invention discloses a thyristor-level field insulation testing device. The device is connected in parallel with a thyristor-level test sample and includes a discharge module, a DC voltage module, a changeover switch module, a first measurement module, a second measurement module, and a control module. One end of the discharge module and one end of the DC voltage module are connected to one end of the thyristor-level test sample. The first measurement module is connected between the other end of the discharge module and the first input terminal of the changeover switch module, and the first measurement module is used to measure the voltage change of the discharge module. The second measurement module is connected between the other end of the DC voltage module and the second input terminal of the changeover switch module, and the second measurement module is used to measure the voltage change of the DC voltage module. The output of the switching module is connected to the other end of the thyristor-level test specimen. When the switching module is switched to connect the thyristor-level test specimen to the DC voltage module, the DC voltage module charges the thyristor-level test specimen. When the switching module is switched to connect the thyristor-level test specimen to the discharge module, the thyristor-level test specimen discharges through the discharge module. When the thyristor-level test specimen discharges, the control module fits the test waveform of the thyristor-level test specimen based on the voltage change of the discharge module measured by the first measurement module, and calculates the time constant t based on the test waveform. The control module is also used to compare the time constant t with the standard value of the time constant T, and obtain the insulation aging information of the thyristor-level test specimen based on the comparison result.

[0041] In a further embodiment of this application, a power conversion module is also included, which converts external AC power into DC power of various voltage levels required by the device, and supplies power to the control module, the transfer switch, the first measurement module, the second measurement module, and the DC voltage module respectively.

[0042] The DC voltage module provides an adjustable DC power supply, which is generated through the power conversion module.

[0043] The changeover switch module is used to control the on / off state of the circuit, allowing the thyristor-level test sample to be connected to different circuits: one is the circuit of the discharge module, and the other is the circuit of the DC voltage module. These two connections are independent and cannot coexist.

[0044] Figure 2 and Figure 3 This is a typical thyristor stage circuit, in which the anode of the thyristor is connected to a second resistor R. 41 Third resistor R 42 The thyristor cathode is connected to a first resistor R1 and a first capacitor Cc1. A second capacitor Cc2 is connected to the thyristor cathode, and a TCE (trigger control circuit) and a third capacitor C3 are connected to the thyristor gate.

[0045] The control module is connected to the DC voltage module, the changeover switch module, the first measurement module, and the second measurement module. The control module sends control signals to control the changeover switch module to switch the circuit, specifically switching the connection between the thyristor-level test sample and the DC voltage module, and between the thyristor-level test sample and the discharge module. The control module is connected to the DC voltage module to control the DC voltage module to output a stable DC voltage. The control module is also connected to the first measurement module to acquire the voltage changes of the discharge module obtained through the first measurement module. The control module is connected to the second measurement module to acquire the voltage changes of the DC voltage module. A display can be connected to the control module to display data.

[0046] The insulation testing device designed in this application uses a switching module to change the connection between the thyristor-level test sample and the discharge module and DC voltage module. When the thyristor-level test sample discharges, the control module fits the test waveform of the thyristor-level test sample based on the voltage change of the discharge module measured by the first measurement module, and calculates the time constant t. The insulation aging information of the thyristor-level test sample can be obtained by comparing the time constant t with the standard value of the time constant T. This device is simple and reliable, can obtain the insulation aging problem of the thyristor level, avoids the damage to the equipment caused by high voltage measurement on site, and can meet the application needs of engineering sites.

[0047] Example 2

[0048] The second aspect of this application discloses a method for on-site insulation aging testing at the thyristor level in a converter station. The method utilizes the on-site insulation aging testing device for the thyristor level in a converter station described in Example 1, such as... Figure 6 As shown, the method includes the following steps:

[0049] Step 1) The DC voltage module is forward-biased and applied to the two ends of the thyristor-stage test sample via the transfer switch module to charge it. The DC voltage gradually increases until it reaches the preset value, such as... Figure 2 .

[0050] Step 2) When the voltage of the thyristor-level test sample reaches the preset value, the thyristor-level test sample is connected to the discharge module via the transfer switch module. The thyristor-level test sample is then discharged through the discharge module. Figure 3 The first measurement module measures the voltage change of the discharge module. The control module then fits the test waveform of the thyristor-stage sample based on the voltage change measured by the first measurement module. A typical forward test waveform is shown below. Figure 4 .

[0051] Step 3) Calculate the time constant t based on the experimental waveform. The calculation method is to use y = y0 + Ae -x / t Formula fitting curve. Where, the vertical axis y is the voltage across the thyristor stage test sample, y0 is the initial voltage of the thyristor stage test sample, A is the slope coefficient, the horizontal axis x is time, t is the time constant, and e is the base of the natural logarithm.

[0052] Step 4) Compare the amplitude of the time constant t with the set standard value T. If the amplitude of t is 10% or more less than T, the thyristor-level test sample is judged to be aging in the forward insulation. If the amplitude of t is not less than 10% of T, the thyristor-level test sample is judged to be qualified in the forward insulation.

[0053] Step 5): Apply the reverse DC power supply to both ends of the thyristor stage test sample, and repeat steps 1)-4).

[0054] Step 6) Combine the results of forward and reverse tests to determine the insulation aging status of the thyristor-level test specimen.

[0055] Advantages of the invention: This invention discloses a field insulation aging test device and method for thyristor level in converter stations. The device is simple and reliable, and the method is simple and easy to implement. It avoids damage to the equipment caused by high voltage measurement on site. By comparing the error between the fitted value of the time constant and the standard value, it can effectively meet the application requirements of engineering sites.

[0056] The following is a specific example: In a certain ultra-high voltage substation, the thyristor-level aging test was carried out using the converter station thyristor-level field insulation aging test device. The rated voltage of the thyristor was 8500V.

[0057] The DC voltage module in the thyristor-level field insulation aging test device of the converter station can be implemented using a capacitor, which is charged by rectifying the external AC power supply.

[0058] The discharge module in the device can be implemented using a small resistor, and a discharge circuit is formed by discharging the small resistor.

[0059] During testing, the preset value is generally selected to be less than half of the rated voltage, so that the test voltage will not damage the thyristor stage.

[0060] The test was conducted as follows:

[0061] 1) The DC voltage module is applied positively across the thyristor stage specimen through the switching module for charging, and the DC voltage gradually rises until it reaches the preset value, which is 3350V.

[0062] 2) When the thyristor stage voltage reaches 3350V, the thyristor stage specimen is connected to the discharge module through the switching module. The thyristor stage specimen discharges through the discharge module. The first measurement module measures the voltage change of the discharge module, and the control module fits the test waveform of the thyristor stage specimen based on the voltage change of the discharge module measured by the first measurement module, as Figure 5 shown.

[0063] 3) Calculate the time constant t according to the test waveform. The calculation method is to fit the curve using the formula y = y0 + Ae -x / t to obtain t = 0.2043.

[0064] 4) Judge by comparing the amplitude value of the time constant t with the set standard value T. The standard value T = 0.19. Since the amplitude value of t is greater than T, it is judged that the forward insulation of the thyristor stage specimen is qualified.

[0065] 5) The DC voltage module is applied negatively across the thyristor stage specimen through the switching module for charging, and the DC voltage gradually rises until it reaches the preset value, which is 3350V.

[0066] 6) When the voltage of the thyristor stage specimen reaches 3350V, the thyristor stage is connected to the discharge module through the switching module. The thyristor stage specimen discharges through the discharge module. The first measurement module measures the voltage change of the discharge module, and the control module fits the test waveform of the thyristor stage specimen based on the voltage change of the discharge module measured by the first measurement module, Figure 5 shown.

[0067] 7) Calculate the time constant t according to the test waveform. The calculation method is to fit the curve using the formula y = y0 + Ae -x / t to obtain t = 0.2036.

[0068] 8) Judge by comparing the amplitude value of the time constant t with the set standard value T. The standard value T = 0.19. Since the amplitude value of t is greater than T, it is judged that the reverse insulation of the thyristor stage is qualified.

[0069] 9) Based on the comprehensive forward and reverse test results, it is judged that the insulation performance of the thyristor stage specimen is qualified.

[0070] Example 3

[0071] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0072] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0073] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0074] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0075] As is known from common technical knowledge, this invention can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the disclosed embodiments described above are merely illustrative in all respects and are not the only ones. All modifications within the scope of this invention or its equivalents are included in this invention.

Claims

1. A thyristor level field insulation test device, said device being connected in parallel with a thyristor level test object, characterized in that The test device comprises a discharge module, a direct current voltage module, a conversion switch module, a first measuring module, a second measuring module and a control module. One end of the discharge module and one end of the direct current voltage module are connected to one end of the thyristor level test sample. A first measuring module is connected between the other end of the discharge module and a first input end of the conversion switch module, and the first measuring module is used for measuring voltage variation of the discharge module. A second measuring module is connected between the other end of the direct current voltage module and a second input end of the conversion switch module, and the second measuring module is used for measuring voltage variation of the direct current voltage module. An output end of the conversion switch module is connected to the other end of the thyristor level test sample; when the conversion switch module is switched to connect the thyristor level test sample with the direct current voltage module, the direct current voltage module charges the thyristor level test sample; when the conversion switch module is switched to connect the thyristor level test sample with the discharge module, the thyristor level test sample is discharged through the discharge module. When the thyristor level test sample is discharged, the control module fits a test waveform of the thyristor level test sample according to the voltage variation of the discharge module measured by the first measuring module, and calculates a time constant t according to the test waveform. The control module is further used for comparing the time constant t with a time constant standard value T, and obtaining insulation aging information of the thyristor level test sample according to a comparison result. The positive or negative of the direct current voltage module is applied to the two ends of the thyristor level test sample through the conversion switch module to charge the thyristor level test sample; when the thyristor level test sample is charged to a preset voltage value, the thyristor level test sample is switched to be connected with the discharge module through the conversion switch module to discharge the thyristor level test sample; if the amplitude of the time constant t is less than or equal to 10% of the time constant standard value T, it is determined that the thyristor level test sample is forward or reverse insulation aged, otherwise it is determined that the thyristor level test sample is forward or reverse insulation qualified. The preset voltage value of the thyristor level test sample is less than half of a rated voltage of the thyristor level test sample. The time constant t takes the form obtained from the fit; wherein the ordinate y is the DC voltage across the thyristor grade test piece, is the initial voltage of the thyristor grade test piece, A is the slope factor, the abscissa is time, t is the time constant, is the base of the natural logarithm; In the thyristor level test sample, the anode of the thyristor is connected with a second resistor R 41 , a third resistor R 42 and a first resistor R1 and a first capacitor Cc1, the cathode of the thyristor is connected with a second capacitor Cc2, and the gate of the thyristor is connected with a trigger control circuit and a third capacitor C3.

2. A thyristor level field insulation test device according to claim 1, characterized in that, The direct current voltage module, the measuring module, the conversion switch module and the control module are further connected with an external alternating current power supply through a power conversion module.

3. The thyristor level field insulation test device of claim 1, wherein, The direct current voltage module, the conversion switch module, the first measuring module and the second measuring module are all signal connected with the control module.

4. A method for testing the field insulation of thyristors, using the device according to any one of claims 1 to 3, characterized in that The test device comprises: The thyristor level test sample is switched to be connected with the direct current voltage module to charge the thyristor level test sample. When the thyristor level test sample is charged to a preset voltage value, the thyristor level test sample is switched to be connected with the discharge module to discharge the thyristor level test sample. When the thyristor level test sample is discharged, a test waveform of the thyristor level test sample is obtained, and a time constant t is calculated according to the test waveform. The time constant t is compared with a time constant standard value T, and insulation aging information of the thyristor level test sample is obtained according to a comparison result.

5. The thyristor level field insulation test method according to claim 4, wherein If the amplitude of the time constant t obtained is less than or equal to 10% of the time constant standard value T, it is determined that the thyristor level test sample is forward or reverse insulation aged, otherwise it is determined that the thyristor level test sample is forward or reverse insulation qualified.

6. The thyristor-level field insulation test method according to claim 4, characterized by, The time constant t takes the form obtained from the fit; wherein the ordinate y is the DC voltage across the thyristor grade test piece, is the initial voltage of the thyristor grade test piece, A is the slope factor, the abscissa is time, t is the time constant, is the base of the natural logarithm.

7. The thyristor-level field insulation test method according to claim 4, characterized by, The voltage preset value for charging the thyristor-level sample is less than half of the rated voltage of the thyristor-level sample.

8. A computer readable storage medium having stored thereon a computer program, characterized in that The program, when executed by the processor, implements the steps of the method of any one of claims 4-7.

9. An apparatus, comprising: Comprising: a memory for storing instructions; a processor for executing the instructions to cause the device to perform operations implementing the method of testing field insulation of a thyristor-level as claimed in any one of claims 4-7.

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