On-load tap-changer switching test device and test method

Abstract

The invention discloses an on-load tap-changer switching test device and test method, and relates to the technical field of on-load tap-changels.A first output end of a first commutation assembly is connected with a first input end of an on-load tap-changer sample, and a second output end of the first commutation assembly is grounded; the first output end of the second commutation assembly is connected with the second input end of the on-load tap-changer sample, the second output end of the second commutation assembly is grounded, and the positive electrode of the direct-current power supply is connected with the first input end of the first commutation assembly and the first input end of the second commutation assembly. The cathode of the DC power supply is connected with the second input end of the first commutation assembly and the second input end of the second commutation assembly, the output end of the on-load tap-changer sample is connected with one end of the compensation reactor, and the other end of the compensation reactor is grounded. The technical problems that a traditional on-load tap-changer testing device cannot carry out a switching test under a non-power-frequency working condition, and the operation reliability of the on-load tap-changer is reduced are solved.

Description

Technical Field

[0001] This invention relates to the field of on-load tap changer technology, and in particular to an on-load tap changer switching test device and test method. Background Technology

[0002] On-load tap changers are key components in transformers used for dynamically regulating winding voltage, playing a crucial role in grid voltage stability and power quality. Therefore, verifying the load capacity and switching capability of on-load tap changers is of paramount importance.

[0003] Currently, traditional on-load tap changer test equipment mainly consists of power frequency power supply, test transformer and load reactor, but it cannot perform on-load tap changer switching tests under non-power frequency conditions, which reduces the reliability of on-load tap changer operation. Summary of the Invention

[0004] This invention provides an on-load tap changer switching test device and test method, which solves the technical problem that traditional on-load tap changer test devices mainly consist of power frequency power supply, test transformer and load reactor, but cannot perform on-load tap changer switching tests under non-power frequency conditions, thus reducing the reliability of on-load tap changer operation.

[0005] The first aspect of the present invention provides an on-load tap changer switching test device, comprising a first converter assembly, a second converter assembly, a compensating reactor, an on-load tap changer sample, and a DC power supply;

[0006] The first output terminal of the first converter component is connected to the first input terminal of the on-load tap changer sample, and the second output terminal of the first converter component is grounded.

[0007] The first output terminal of the second converter component is connected to the second input terminal of the on-load tap changer sample, and the second output terminal of the second converter component is grounded.

[0008] The positive terminal of the DC power supply is connected to the first input terminal of the first converter component and the first input terminal of the second converter component, respectively.

[0009] The negative terminal of the DC power supply is connected to the second input terminal of the first converter component and the second input terminal of the second converter component, respectively.

[0010] The output terminal of the on-load tap changer sample is connected to one end of the compensation reactor, and the other end of the compensation reactor is grounded.

[0011] Optionally, the first converter assembly includes a first converter, a first converter reactor, a second converter reactor, and a first compensation capacitor;

[0012] The first output terminal of the first converter is connected to one end of the first compensation capacitor through the first converter reactor.

[0013] The second output terminal of the first converter is connected to the other end of the first compensation capacitor through the second converter reactor;

[0014] The first input terminal of the first converter serves as the first input terminal of the first converter component;

[0015] The second input terminal of the first converter serves as the second input terminal of the first converter component.

[0016] Optionally, one end of the first compensation capacitor serves as the first output terminal of the first converter component.

[0017] The other end of the first compensation capacitor serves as the second output terminal of the first converter component.

[0018] Optionally, the second converter assembly includes a second converter, a third converter reactor, a fourth converter reactor, and a second compensation capacitor;

[0019] The first output terminal of the second converter is connected to one end of the second compensation capacitor through the third converter reactor;

[0020] The second output terminal of the second converter is connected to the other end of the second compensation capacitor through the fourth converter reactor;

[0021] The first input terminal of the second converter serves as the first input terminal of the second converter component;

[0022] The second input terminal of the second converter serves as the second input terminal of the second converter component.

[0023] Optionally, one end of the second compensation capacitor serves as the first output terminal of the second converter component;

[0024] The other end of the second compensation capacitor serves as the second output terminal of the second converter component.

[0025] Optionally, a controller may also be included;

[0026] The controller is connected to the first converter component and the second converter component respectively through a communication interface;

[0027] The controller is used to collect the operating parameters of the on-load tap changer switching test device through current transformers and voltage transformers, and to regulate the first converter component and the second converter component according to the preset experimental parameters and the operating parameters.

[0028] Optionally, the first capacitance value of the first compensation capacitor is equal to the second capacitance value of the second compensation capacitor;

[0029] Both the first capacitance value and the second capacitance value are determined based on the preset test angular frequency and the inductance value of the compensation reactor.

[0030] Optionally, the first AC voltage amplitude of the first converter is equal to the second AC voltage amplitude of the second converter;

[0031] The inductance value of the compensation reactor is determined based on the amplitude of the first AC voltage, the test angular frequency, and the rated current of the on-load tap changer sample.

[0032] Optionally, the first converter and the second converter are fully controlled power electronic devices.

[0033] A test method for the on-load tap changer switching test device provided in the second aspect of the present invention includes:

[0034] Obtain the test parameters and sample parameters of the on-load tap changer sample, and adjust the equipment parameters of the first converter assembly and the second converter assembly according to the test parameters and sample parameters.

[0035] Adjust the inductance value of the compensation reactor according to the test parameters and the sample parameters;

[0036] Connect the first converter component, the second converter component, the compensation reactor, the on-load tap changer sample, and the DC power supply, and conduct load switching tests and capacity tests.

[0037] As can be seen from the above technical solutions, the present invention has the following advantages:

[0038] This invention converts DC voltage into AC voltage with adjustable frequency through a first converter component and a second converter component, achieving flexible adjustment of the test frequency. This overcomes the technical problem of traditional on-load tap changer test devices, which mainly consist of a power frequency power supply, a test transformer, and a load reactor, but cannot perform on-load tap changer switching tests under non-power frequency conditions, thus reducing the reliability of on-load tap changer operation. Simultaneously, the on-load tap changer switching test device also incorporates a compensating reactor, effectively reducing the output current and capacity requirements of the first and second converter components, decreasing the cost and implementation difficulty of the test device, and improving the reliability of on-load tap changer operation. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a structural diagram of the on-load tap changer switching test device;

[0041] Figure 2 This is a flowchart illustrating the steps of a test method applied to an on-load tap changer switching test device according to an embodiment of the present invention.

[0042] The meanings of the reference numerals in the attached figures are as follows:

[0043] 1. DC power supply; 2. First converter; 3. Second converter; 4. On-load tap changer sample. Detailed Implementation

[0044] This invention provides an on-load tap changer switching test device and test method to solve the technical problem that traditional on-load tap changer test devices mainly consist of power frequency power supply, test transformer and load reactor, but cannot perform on-load tap changer switching tests under non-power frequency conditions, thus reducing the reliability of on-load tap changer operation.

[0045] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0046] Please see Figure 1 The present invention provides an on-load tap changer switching test device, comprising a first converter assembly, a second converter assembly, a compensation reactor L5, an on-load tap changer sample 4, and a DC power supply 1;

[0047] The first output terminal of the first converter component is connected to the first input terminal of the on-load tap changer sample 4, and the second output terminal of the first converter component is grounded.

[0048] The first output terminal of the second converter component is connected to the second input terminal of the on-load tap changer sample 4, and the second output terminal of the second converter component is grounded.

[0049] The positive terminal of DC power supply 1 is connected to the first input terminal of the first converter component and the first input terminal of the second converter component, respectively;

[0050] The negative terminal of DC power supply 1 is connected to the second input terminal of the first converter component and the second input terminal of the second converter component, respectively.

[0051] The output terminal of the on-load tap changer sample 4 is connected to one end of the compensating reactor L5, and the other end of the compensating reactor L5 is grounded.

[0052] In this embodiment of the invention, the on-load tap changer switching test device includes a first converter component, a second converter component, a compensating reactor L5, an on-load tap changer sample 4 (i.e., the on-load tap changer to be tested), and a DC power supply 1. The first output terminal of the first converter component is connected to the first input terminal of the on-load tap changer sample 4, and the second output terminal of the first converter component is grounded. The first output terminal of the second converter component is connected to the second input terminal of the on-load tap changer sample 4, and the second output terminal of the second converter component is grounded. The positive voltage output terminal of the DC power supply 1 is connected to the first input terminals of both the first and second converter components. The negative voltage output terminal of the DC power supply 1 is connected to the second input terminals of both the first and second converter components. The output terminal of the on-load tap changer sample 4 is connected to one end of the compensating reactor L5, and the other end of the compensating reactor L5 is grounded. The inductance value of the compensating reactor L5 is adjustable. The compensating reactor L5 is used to adjust the device inductance value of the on-load tap changer switching test device to ensure that the output voltage meets the test requirements.

[0053] It is worth mentioning that during the switching test, the on-load tap changer sample 4 is embedded in the insulating medium of the actual operating environment to simulate real working conditions. The rated parameters (such as rated current, stage voltage, etc.) of the on-load tap changer sample 4 must match the test equipment. This eliminates the need for a companion phase switch to simulate multi-phase conditions, reducing the complexity and cost of the test equipment while improving the flexibility and efficiency of the test.

[0054] Please see Figure 1 The first converter assembly includes a first converter 2, a first converter reactor L1, a second converter reactor L2, and a first compensation capacitor C1; the first output terminal of the first converter 2 is connected to one end of the first compensation capacitor C1 through the first converter reactor L1; the second output terminal of the first converter 2 is connected to the other end of the first compensation capacitor C1 through the second converter reactor L2; the first input terminal of the first converter 2 serves as the first input terminal of the first converter assembly; the second input terminal of the first converter 2 serves as the second input terminal of the first converter assembly.

[0055] In this embodiment of the invention, the first converter assembly includes a first converter 2, a first converter reactor L1, a second converter reactor L2, and a first compensation capacitor C1. The first output terminal of the first converter 2 is connected to one end of the first compensation capacitor C1 and the first input terminal of the on-load tap changer sample 4 via the first converter reactor L1. The second output terminal of the first converter 2 is connected to the other end of the first compensation capacitor C1 via the second converter reactor L2. The first input terminal of the first converter 2 is connected to the positive terminal of the DC power supply 1. The second input terminal of the first converter 2 is connected to the negative terminal of the DC power supply 1.

[0056] It is worth mentioning that the first converter reactor L1 and the second converter reactor L2 can limit the current, thereby protecting the first converter 2 from damage by excessive current. Furthermore, the inductance values ​​of the first converter reactor L1 and the second converter reactor L2 can be adjusted according to the test frequency and current requirements.

[0057] Please see Figure 1 One end of the first compensation capacitor C1 serves as the first output terminal of the first converter component; the other end of the first compensation capacitor C1 serves as the second output terminal of the first converter component.

[0058] In this embodiment of the invention, one end of the first compensation capacitor C1 serves as the first output terminal of the first converter component, the other end of the first compensation capacitor C1 is grounded, and the other end of the first compensation capacitor C1 serves as the second output terminal of the first converter component.

[0059] It is worth mentioning that the first compensation capacitor C1 is used to compensate for the current and reduce the output current and capacity of the first converter 2.

[0060] Please see Figure 1 The second converter assembly includes a second converter 3, a third converter reactor L3, a fourth converter reactor L4, and a second compensation capacitor C2; the first output terminal of the second converter 3 is connected to one end of the second compensation capacitor C2 through the third converter reactor L3; the second output terminal of the second converter 3 is connected to the other end of the second compensation capacitor C2 through the fourth converter reactor L4; the first input terminal of the second converter 3 serves as the first input terminal of the second converter assembly; the second input terminal of the second converter 3 serves as the second input terminal of the second converter assembly.

[0061] In this embodiment of the invention, the second converter assembly includes a second converter 3, a third converter reactor L3, a fourth converter reactor L4, and a second compensation capacitor C2. The first output terminal of the second converter 3 is connected to one end of the second compensation capacitor C2 and the second input terminal of the on-load tap changer sample 4 via the third converter reactor L3. The second output terminal of the second converter 3 is connected to the other end of the second compensation capacitor C2 via the fourth converter reactor L4. The first input terminal of the second converter 3 serves as the first input terminal of the second converter assembly and is connected to the positive terminal of the DC power supply 1. The second input terminal of the second converter 3 serves as the second input terminal of the second converter assembly and is connected to the negative terminal of the DC power supply 1.

[0062] It is worth mentioning that the third converter reactor L3 and the fourth converter reactor L4 can limit the current, thereby protecting the second converter 3 from damage by excessive current. Furthermore, the inductance values ​​of the third converter reactor L3 and the fourth converter reactor L4 can be adjusted according to the test frequency and current requirements.

[0063] Please see Figure 1 One end of the second compensation capacitor C2 serves as the first output terminal of the second converter component; the other end of the second compensation capacitor C2 serves as the second output terminal of the second converter component.

[0064] In this embodiment of the invention, one end of the second compensation capacitor C2 is connected to the second input terminal of the on-load tap changer sample 4 as the first output terminal of the second converter component. The other end of the second compensation capacitor C2 is grounded as the second output terminal of the second converter component.

[0065] It is worth mentioning that the second compensation capacitor C2 is used to compensate for the current, reducing the output current and capacity of the second converter 3.

[0066] It should be noted that the system also includes a controller; the controller is connected to the first converter component and the second converter component respectively through a communication interface; the controller is used to collect the operating condition parameters of the on-load tap changer switching test device through current transformers and voltage transformers, and to regulate the first converter component and the second converter component according to the preset experimental parameters and operating condition parameters.

[0067] In this embodiment of the invention, the on-load tap changer switching test device further includes a controller, a current transformer, and a voltage transformer. The output terminals of the voltage transformer and the current transformer are electrically connected to the input terminal of the controller, thereby enabling the voltage transformer and the current transformer to feed back operating parameters to the controller. The controller is connected to the first converter assembly and the second converter assembly respectively through a communication interface (i.e., optical fiber or isolated digital). The controller is used to collect the operating parameters of the on-load tap changer switching test device through the current transformer and the voltage transformer, and adjust the pulse width modulation signal input to the first converter 2 in the first converter assembly and the second converter 3 in the second converter assembly according to the preset experimental parameters and operating parameters. Operating parameters include, but are not limited to, the output voltage of the first converter 2, the output voltage of the second converter 3, the voltage value of the on-load tap changer sample 4, the voltage value of the compensating reactor L5, the output current of the first output terminal of the first converter 2, the output current of the second output terminal of the first converter 2, the output current of the first output terminal of the second converter 3, the input current of the first input terminal of the on-load tap changer sample 4, the input current of the second input terminal of the on-load tap changer sample 4, the grounding current, and the compensation current of the compensating reactor L5. Experimental parameters include, but are not limited to, the test angular frequency, interstage voltage, rated through current, and transition resistance.

[0068] It is worth mentioning that the voltage transformer can be set at the first and second output terminals of the first converter 2, the first and second output terminals of the second converter 3, the first and second input terminals of the on-load tap changer sample 4, and the two ends of the first compensation capacitor and the two ends of the second compensation capacitor.

[0069] It is worth mentioning that the current transformer can be installed at the first and second input terminals of the on-load tap changer sample 4 to monitor the input current of the on-load tap changer sample 4. The current transformer can also be installed in the circuit of the compensating reactor L5 to monitor the compensation current of the compensating reactor L5. Simultaneously, the current transformer can also be installed in the grounding circuit of the on-load tap changer switching test device to monitor the grounding current.

[0070] It is worth mentioning that the controller can be equipped with a protection logic module to implement short-circuit protection, transient impact protection, and overheat protection. This prevents damage to the circuit caused by abnormalities during the test.

[0071] It should be noted that the first capacitance value of the first compensation capacitor C1 is equal to the second capacitance value of the second compensation capacitor C2; both the first and second capacitance values ​​are determined based on the preset test angular frequency and the inductance value of the compensation reactor L5.

[0072] In this embodiment of the invention, the first capacitance value of the first compensation capacitor C1 is equal to the second capacitance value of the second compensation capacitor C2. By inputting the preset test angular frequency and the inductance value of the compensation reactor L5 into the preset compensation capacitance function, the corresponding first and second capacitance values ​​can be obtained.

[0073] It should be noted that the compensation capacitor function is as follows:

[0074]

[0075] in, This is the first capacitance value. This is the second capacitance value. To compensate for the inductance value of reactor L5, The angular frequency is the test frequency.

[0076] It is worth mentioning that, taking the first compensation capacitor C1 as an example, the relationship between the impedance and capacitance of the first compensation capacitor C1 and the test angular frequency is as follows:

[0077]

[0078] in, The impedance of the first compensation capacitor C1 is given.

[0079] The relationship between the inductance, impedance, and test angular frequency of the compensating reactor L5 is as follows:

[0080]

[0081] in, To compensate for the inductive reactance of reactor L5.

[0082] To achieve complete compensation of capacitive and inductive currents and reduce the total current, the impedance of the compensation reactor L5 must be equal to the impedance of the first compensation capacitor C1 (i.e., = Thus, the compensation capacitor function is derived.

[0083] It should be noted that the amplitude of the first AC voltage of the first converter 2 is equal to the amplitude of the second AC voltage of the second converter 3; the inductance value of the compensation reactor L5 is determined based on the amplitude of the first AC voltage, the test angular frequency, and the rated current of the on-load tap changer sample 4.

[0084] In this embodiment of the invention, the amplitude of the first AC voltage of the first converter 2 is equal to the amplitude of the second AC voltage of the second converter 3. Furthermore, the amplitude of the phasor difference between the first AC voltage of the first converter 2 and the second AC voltage of the second converter 3 is equal to the stage voltage between the two taps of the on-load tap changer sample 4. This ensures the accuracy of the test conditions and improves the stability and reliability of the test system. By inputting the first AC voltage amplitude, the test angular frequency, and the rated current of the on-load tap changer sample 4 into a preset compensation inductance function, the inductance value of the compensation reactor L5 can be obtained.

[0085] It is worth mentioning that, in the AC circuit, the relationship between the inductance value of the compensating reactor L5 and the inductive reactance and the test angular frequency is as follows:

[0086]

[0087] in, To compensate for the inductive reactance of reactor L5.

[0088] According to Ohm's law, the relationship between the amplitude of the first AC voltage, the rated current of the on-load tap changer sample 4, and the impedance of the compensating reactor L5 is as follows:

[0089]

[0090] in, To compensate for the impedance of reactor L5.

[0091] In a purely inductive circuit, = The compensation inductance function can be obtained.

[0092] Therefore, the compensation inductance function is specifically as follows:

[0093]

[0094] in, The first AC voltage amplitude, This is the second AC voltage amplitude. The rated current of the on-load tap changer sample 4 is given.

[0095] It should be noted that the first converter 2 and the second converter 3 are fully controlled power electronic devices.

[0096] In this embodiment of the invention, the first converter 2 and the second converter 3 are fully controllable power electronic devices, such as IGBTs (Insulated Gate Bipolar Transistors), which have high precision and high response speed.

[0097] It is worth mentioning that the first converter 2 and the second converter 3 can be replaced with frequency converters, thereby enabling the output of variable frequency AC voltage.

[0098] In this embodiment of the invention, the DC voltage is converted into an adjustable frequency AC voltage through the first and second converter components, achieving flexible adjustment of the test frequency. This overcomes the technical problem that traditional on-load tap changer test devices mainly consist of power frequency power supplies, test transformers, and load reactors, but cannot perform on-load tap changer switching tests under non-power frequency conditions, thus reducing the reliability of on-load tap changer operation. Simultaneously, the on-load tap changer switching test device also includes a compensating reactor L5, which effectively reduces the output current and capacity requirements of the first and second converter components, reducing the cost and implementation difficulty of the test device and improving the reliability of on-load tap changer operation.

[0099] Please see Figure 2 , Figure 2 This is a flowchart illustrating the steps of a test method applied to an on-load tap changer switching test device according to an embodiment of the present invention.

[0100] This invention provides a test method for an on-load tap changer switching test device, comprising:

[0101] Step 101: Obtain the test parameters and sample parameters of the on-load tap changer sample 4, and adjust the equipment parameters of the first converter assembly and the second converter assembly according to the test parameters and sample parameters.

[0102] In this embodiment of the invention, test parameters and sample parameters of the on-load tap changer sample 4 are obtained. The test parameters include, but are not limited to, the test angular frequency and interstage voltage. The sample parameters include the rated current and transition resistance of the on-load tap changer sample 4. Based on the test parameters and sample parameters, the equipment parameters of the first converter assembly and the second converter assembly are adjusted so that the phasor difference amplitude between the first AC voltage of the first converter 2 and the second AC voltage of the second converter 3 is equal to the interstage voltage between the two stages of the on-load tap changer sample 4 or other desired voltage amplitude.

[0103] It should be noted that the equipment parameters include, but are not limited to, the firing angle and modulation ratio of the first converter 2, the firing angle and modulation ratio of the second converter 3, the bus voltage on the DC side of the first converter 2, the bus voltage on the DC side of the second converter 3, the inductance value of the converter reactor, the value of the first capacitor and the value of the second capacitor, etc.

[0104] Step 102: Adjust the inductance value of the compensation reactor L5 according to the test parameters and sample parameters;

[0105] In this embodiment of the invention, the inductance value of the compensation reactor L5 is adjusted according to the test parameters and sample parameters based on a preset compensation inductance function.

[0106] Step 103: Connect the first converter assembly, the second converter assembly, the compensation reactor L5, the on-load tap changer sample 4, and the DC power supply 1, and conduct load switching test and capacity test.

[0107] In this embodiment of the invention, in accordance with the relevant standards and guidelines for on-load tap changer switching tests, the first converter assembly, the second converter assembly, the compensating reactor L5, the on-load tap changer sample 4, and the DC power supply 1 are connected for testing. The on-load tap changer sample 4 is then embedded in the insulating medium used in actual operation. Simultaneously, the reliability and insulation performance of all connections are checked to ensure test safety. Load switching and capacity tests are conducted at specific frequencies of the on-load tap changer, and the voltage and current at relevant locations of the on-load tap changer sample 4 are monitored during the test using installed voltage and current transformers.

[0108] It should be noted that during the experiment, experimental data was recorded in real time and an experimental report was generated.

[0109] It is worth mentioning that the test power supply should be equipped with short-circuit protection, transient impact protection, and overheat protection to protect the test equipment from damage when the tap changer fails to switch. The tap changer switching test should be paused periodically, and the test equipment should be inspected to ensure there are no abnormalities before continuing the test.

[0110] In this embodiment of the invention, the DC voltage is converted into an adjustable frequency AC voltage through the first and second converter components, achieving flexible adjustment of the test frequency. This overcomes the technical problem that traditional on-load tap changer test devices mainly consist of power frequency power supplies, test transformers, and load reactors, but cannot perform on-load tap changer switching tests under non-power frequency conditions, thus reducing the reliability of on-load tap changer operation. Simultaneously, the on-load tap changer switching test device also includes a compensating reactor L5, which effectively reduces the output current and capacity requirements of the first and second converter components, reducing the cost and implementation difficulty of the test device and improving the reliability of on-load tap changer operation.

[0111] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0112] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between apparatuses or units, and may be electrical, mechanical, or other forms.

[0113] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An on-load tap changer switching test apparatus, characterized by, The first converter component, the second converter component, the compensation reactor, the on-load tap changer sample and the DC power supply are included. The first output end of the first converter component is connected with the first input end of the on-load tap changer sample, and the second output end of the first converter component is grounded. The first output end of the second converter component is connected with the second input end of the on-load tap changer sample, and the second output end of the second converter component is grounded. The positive pole of the DC power supply is connected with the first input end of the first converter component and the first input end of the second converter component respectively. The negative pole of the DC power supply is connected with the second input end of the first converter component and the second input end of the second converter component respectively. The output end of the on-load tap changer sample is connected with one end of the compensation reactor, and the other end of the compensation reactor is grounded.

2. The on-load tap changer switching test apparatus of claim 1, wherein, The first converter component includes a first converter, a first converter reactor, a second converter reactor and a first compensation capacitor. The first output end of the first converter is connected with one end of the first compensation capacitor through the first converter reactor. The second output end of the first converter is connected with the other end of the first compensation capacitor through the second converter reactor. The first input end of the first converter serves as the first input end of the first converter component. The second input end of the first converter serves as the second input end of the first converter component.

3. The on-load tap changer switching test apparatus of claim 2, wherein, One end of the first compensation capacitor serves as the first output end of the first converter component. The other end of the first compensation capacitor serves as the second output end of the first converter component.

4. The on-load tap changer switching test apparatus of claim 2, wherein, The second converter component includes a second converter, a third converter reactor, a fourth converter reactor and a second compensation capacitor. The first output end of the second converter is connected with one end of the second compensation capacitor through the third converter reactor. The second output end of the second converter is connected with the other end of the second compensation capacitor through the fourth converter reactor. The first input end of the second converter serves as the first input end of the second converter component. The second input end of the second converter serves as the second input end of the second converter component.

5. The on-load tap changer switching test apparatus of claim 4, wherein, One end of the second compensation capacitor serves as the first output end of the second converter component. The other end of the second compensation capacitor serves as the second output end of the second converter component.

6. The on-load tap changer switching test apparatus of claim 1, wherein, A controller is further included. The controller is connected with the first converter component and the second converter component through a communication interface respectively. The controller is configured to collect working condition parameters of the on-load tap changer switching test device through a current transformer and a voltage transformer, and to regulate and control the first converter component and the second converter component according to preset test parameters and the working condition parameters.

7. The on-load tap changer switching test apparatus of claim 4, wherein, The first capacitance value of the first compensation capacitor is equal to the second capacitance value of the second compensation capacitor. The first capacitance value and the second capacitance value are determined according to a preset test angular frequency and an inductance value of the compensation reactor.

8. The on-load tap changer switching test apparatus of claim 7, wherein, The first AC voltage amplitude of the first converter is equal to the second AC voltage amplitude of the second converter. The inductance value of the compensation reactor is determined according to the first AC voltage amplitude, the test angular frequency and the rated passing current of the on-load tap changer sample.

9. The on-load tap changer switching test apparatus of claim 4, wherein, The first converter and the second converter are full-controlled power electronic devices.

10. A test method applied to the on-load tap changer switching test device according to any one of claims 1 to 9, characterized in that, The method comprises: obtaining test parameters and sample parameters of the on-load tap changer sample, and adjusting device parameters of the first conversion assembly and the second conversion assembly according to the test parameters and the sample parameters; adjusting the inductance value of the compensation reactor according to the test parameters and the sample parameters; connecting the first conversion assembly, the second conversion assembly, the compensation reactor, the on-load tap changer sample and the DC power supply, and performing load switching test and capacity test.

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