Rapid test structure and test method for loop resistance of high-voltage switch of transformer substation

Abstract

The invention relates to a transformer substation high-voltage switch loop resistance rapid test structure and test method. The transformer substation high-voltage switch loop resistance rapid test structure comprises a high-voltage switch loop resistance tester, a bus tie switch, a plurality of first-section high-voltage switches, an isolation switch, a filtering device and a plurality of second-section high-voltage switches. Three-phase power supply wire inlet ends of the bus tie switch and the plurality of first-section high-voltage switches are connected to a high-voltage side first-section bus, a three-phase output end of the bus tie switch is connected in series with a three-phase output end of the isolation switch, and three-phase power supply wire inlet ends of the isolation switch and the plurality of second-section high-voltage switches are connected to a high-voltage side second-section bus. The voltage sampling end of the high-voltage switch loop resistance tester is connected to the two ends of a loop to be tested through one filtering device, and the current sampling end of the high-voltage switch loop resistance tester is connected to the two ends of the loop to be tested through the other filtering device; according to the high-voltage switch cabinet, a test can be conveniently carried out at the feed-out end of the high-voltage switch cabinet, the working efficiency is greatly improved, and meanwhile, high-frequency interference brought by a high-voltage station during testing is also avoided.

Description

Technical Field

[0001] The invention relates to the technical field of transformer substations, and in particular to a transformer substation high-voltage switch loop resistance rapid testing structure and testing method. Background Art

[0002] High voltage switch is the main electrical equipment in the substation and plays a very important role, so various tests on it are particularly important. Figure 1 , the existing high-voltage switch loop resistance test connection structure, if the high-voltage switch loop resistance test is to be carried out, the high-voltage switch must be pulled out, and then sent back after the test is completed, which is time-consuming and laborious. In particular, the current high-voltage switches are all equipped with closing and locking electromagnets. After being pulled out from the high-voltage switch cabinet, they cannot be manually closed, and the high-voltage switch loop resistance test cannot be carried out; and because the high-voltage switch cabinets are all in the substation with a strong magnetic field, there are many devices in the substation that generate high-frequency interference, such as thyristor rectifier equipment, IGBT electronic switches, and frequent opening and closing of high-voltage equipment, which are all high-frequency interference sources. The generated harmonics will enter the test equipment along the current line and voltage line of the loop resistance tester, causing greater interference to the inside of the instrument, affecting the calculated resistance value, and even burning the chip; therefore, there is an urgent need for a structure and method that can quickly test the loop resistance of the substation high-voltage switch without pulling out the high-voltage switch, and avoid high-frequency interference in the substation. Summary of the invention

[0003] The present invention provides a structure and method for quickly testing the circuit resistance of a high-voltage switch in a transformer substation, which not only saves the time for withdrawing and returning the high-voltage switch, but also solves the difficulties of being unable to manually close the switch and being unable to perform a circuit resistance test on the high-voltage switch after the switch is withdrawn, and also avoids high-frequency interference in the transformer substation during the test.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A transformer substation high-voltage switch loop resistance rapid testing structure comprises a high-voltage switch loop resistance tester, a bus tie switch, a plurality of first-stage high-voltage switches, an isolating switch and a plurality of second-stage high-voltage switches; the bus tie switch is arranged in a bus tie cabinet, the first-stage high-voltage switch is arranged in a first-stage high-voltage switch cabinet, the isolating switch is arranged in an isolating cabinet, and the second-stage high-voltage switch is arranged in a second-stage high-voltage switch cabinet; and further comprises a filtering device, wherein the three-phase power supply inlet terminals of the bus tie switch and the plurality of first-stage high-voltage switches are all connected to a first-stage busbar on the high-voltage side, the three-phase output terminal of the bus tie switch is connected in series with the three-phase output terminal of the isolating switch, the three-phase power supply inlet terminals of the isolating switch and the plurality of second-stage high-voltage switches are connected to the second-stage busbar on the high-voltage side, the voltage sampling terminal of the high-voltage switch loop resistance tester is connected to the two ends of the circuit to be tested through a filtering device, and the current sampling terminal of the high-voltage switch loop resistance tester is connected to the two ends of the circuit to be tested through another filtering device.

[0006] Furthermore, the filtering device is an adjustable anti-interference electromagnetic filter, and the adjustable anti-interference electromagnetic filter includes a magnetic ring and two groups of coils, and the two groups of coils are wound on the magnetic ring in a common mode.

[0007] Furthermore, the circuit under test includes a main bus switch circuit, multiple first-stage high-voltage switch circuits and multiple second-stage high-voltage switch circuits, and the voltage sampling end and current sampling end of the high-voltage switch circuit resistance tester are respectively connected to the main bus switch circuit, multiple first-stage high-voltage switch circuits and multiple second-stage high-voltage switch circuits.

[0008] Furthermore, in the bus tie switch circuit, the incoming terminal of the bus tie switch is the positive pole for testing, and the outgoing terminal of the bus tie switch is the negative pole for testing.

[0009] Furthermore, the one-section high-voltage switch circuit includes a connection circuit between a one-section high-voltage switch and a bus tie switch, and a connection circuit between a one-section high-voltage switch and a one-section high-voltage switch; in the connection circuit between the one-section high-voltage switch and the bus tie switch, the output terminal of the one-section high-voltage switch is a test positive electrode, and the output terminal of the bus tie switch is a test negative electrode; in the connection circuit between the one-section high-voltage switch and the one-section high-voltage switch, the output terminals of the two one-section high-voltage switches are respectively the test positive electrode and the negative electrode.

[0010] Furthermore, the two-stage high-voltage switch circuit includes a connection circuit between the two-stage high-voltage switch and the bus-tie switch, and a connection circuit between the two-stage high-voltage switch and the two-stage high-voltage switch; in the connection circuit between the two-stage high-voltage switch and the bus-tie switch, the output terminal of the two-stage high-voltage switch is the test positive pole, and the output terminal of the bus-tie switch is the test negative pole; in the connection circuit between the two-stage high-voltage switch and the two-stage high-voltage switch, the output terminals of the two two-stage high-voltage switches are the test positive pole and the negative pole, respectively.

[0011] A method for testing a fast test structure of a high-voltage switch loop resistance in a transformer substation comprises the following steps:

[0012] 1) Move all high-voltage switches including isolating switches to the working position and close them manually;

[0013] 2) The voltage sampling terminals U+ and U- of the high-voltage switch loop resistance tester are connected to the filter device and the output test terminal is U + , U － , the current sampling terminals I+ and I- of the high-voltage switch loop resistance tester are connected to the filter device and the output test terminal is I + ,I － ;

[0014] 3) Test the resistance of the bus tie switch circuit. Connect the A phase of the bus tie switch inlet to the filter device test terminal U + ,I + , the output port A of the bus tie switch is connected to the test port U of the filter device － ,I － , and conduct the loop resistance test of phase A of the bus tie switch, and then conduct the loop resistance test of phases B and C;

[0015] 4) The output port A of the first high-voltage switch Q11 is connected to the test port U of the filter device. + ,I + , the output port A of the busbar switch QM is connected to the test port U of the filter device － ,I － , and the A phase circuit resistance R 1母 Test the test, and then test the B-phase and C-phase loop resistance respectively;

[0016] The output port A of the first high-voltage switch of a section is connected to the test port U of the filter device. + ,I + , the output port A of the second high-voltage switch is connected to the test port U of the filter device － ,I － , and the loop resistance R of phase A 12 Test the test, and then test the B-phase and C-phase loop resistance respectively;

[0017] The output port A of the second high-voltage switch is connected to the test port U of the filter device. + ,I + , the output port A of the bus tie switch is connected to the test port U of the filter device － ,I － , and the loop resistance R of phase A 2母 Test test, and then respectively carry out the B phase and C phase loop resistance test test; then the A phase loop resistance R of the first high voltage switch A1 =(R 1母 +R12 -R 2母 ) / 2, and similarly calculate the resistance of the B and C phase loops;

[0018] 5) Connect the output port A of the second high-voltage switch to the test port U of the filter device. + ,I + , the output port A of the third high-voltage switch is connected to the test port U of the filter device － ,I － , and the loop resistance R of phase A 23 Test the test, and then test the B-phase and C-phase loop resistance respectively;

[0019] The output port A of the first high-voltage switch of a section is connected to the test port U of the filter device. + ,I + , the output port A of the third high-voltage switch is connected to the test port U of the filter device － ,I － , and the loop resistance R of phase A 13 Test test, and then respectively carry out the B phase and C phase loop resistance test test, then the A phase loop resistance R of the second high voltage switch A2 =(R 12 +R 23 -R 13 ) / 2, and similarly calculate the resistance of the B and C phase loops;

[0020] 6) Similarly, the N-1th high-voltage switch A phase loop resistance R A(N-1) =(R (N-2)(N-1) +R (N-1)N -R (N-2)N ) / 2, and similarly calculate the resistance of the B and C phase loops;

[0021] 7) The resistance R of the A phase loop of the Nth high voltage switch AN Similarly, the bus tie switch loop resistance is measured separately using a high voltage switch loop resistance tester;

[0022] 8) Multiple two-stage high-voltage switch loop resistance test The same process is used for multiple one-stage high-voltage switch loop resistance test.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1) The three-phase power supply inlet terminals of the bus tie switch and multiple one-stage high-voltage switches are all connected to a section of the high-voltage side bus, the three-phase output terminal of the bus tie switch is connected in series with the three-phase output terminal of the isolating switch, the three-phase power supply inlet terminals of the isolating switch and multiple two-stage high-voltage switches are connected to the two-stage bus on the high-voltage side, and then the high-voltage switch loop resistance tester is used to test at both ends of each loop to be tested, thereby avoiding the time of withdrawing and returning the high-voltage switch, and solving the problem that the high-voltage switch cannot be manually closed after being withdrawn, and the high-voltage switch loop resistance test cannot be performed;

[0025] 2) Moreover, whether the contact between the moving and static contacts is good can be judged according to the calculated loop resistance. The debugging method is simple and easy to master, and it is convenient to carry out testing at the feed end of the high-voltage switch cabinet, which greatly improves work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the high-voltage switch loop resistance test structure of the prior art of the present invention.

[0027] Figure 2 It is a structural schematic diagram of the high-voltage switch circuit described in the present invention.

[0028] Figure 3 It is a wiring diagram of the filter device described in the present invention.

[0029] Figure 4 It is a schematic diagram of the bus tie switch loop resistance test structure according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings:

[0031] See Figure 2, is a schematic diagram of the structure of the high-voltage switch circuit of the present invention. A fast test structure for the resistance of a high-voltage switch circuit of a substation of the present invention comprises a high-voltage switch circuit resistance tester TR, a bus tie switch QM, a first high-voltage switch Q11 of a section, a second high-voltage switch Q12 of a section, a third high-voltage switch Q13 of a section, an isolating switch QG, a second first high-voltage switch Q21 of a section, a second second high-voltage switch Q22 of a section, a second third high-voltage switch Q23 of a section and a filtering device; the bus tie switch QM is arranged in a bus tie cabinet, a first high-voltage switch is arranged in a first high-voltage switch cabinet, the isolating switch QG is arranged in an isolating cabinet, and the second high-voltage switch is arranged in a second high-voltage switch cabinet; the bus tie switch QM and a first high-voltage switch Q 11. The three-phase power supply inlet terminals of the first section second high-voltage switch Q12 and the first section third high-voltage switch Q13 are connected to a section busbar on the high-voltage side. The three-phase output terminal of the bus tie switch QM is connected in series with the three-phase output terminal of the isolating switch QG. The three-phase power supply inlet terminals of the isolating switch QG and the second section first high-voltage switch Q21, the second section second high-voltage switch Q22, and the second section third high-voltage switch Q23 are connected to the second section busbar on the high-voltage side. The voltage sampling terminal of the high-voltage switch loop resistance tester TR is connected to the two ends of the measured loop through a filtering device, and the current sampling terminal of the high-voltage switch loop resistance tester TR is connected to the two ends of the measured loop through another filtering device.

[0032] The circuit under test includes a bus tie switch QM circuit, three first-stage high-voltage switch circuits and three second-stage high-voltage switch circuits;

[0033] In the bus tie switch QM circuit, the incoming line terminal of the bus tie switch QM is the positive pole for testing, and the outgoing line terminal of the bus tie switch QM is the negative pole for testing;

[0034] The one-stage high-voltage switch circuit includes a connection circuit between a one-stage high-voltage switch and a bus tie switch QM, and a connection circuit between a one-stage high-voltage switch and a one-stage high-voltage switch; the outlet end of the one-stage high-voltage switch in the connection circuit between the one-stage high-voltage switch and the bus tie switch QM is a test positive electrode, and the outlet end of the bus tie switch QM is a test negative electrode; the outlet ends of the two one-stage high-voltage switches in the connection circuit between the one-stage high-voltage switch and the one-stage high-voltage switch are respectively a test positive electrode and a test negative electrode;

[0035] The two-stage high-voltage switch circuit includes a connection circuit between the two-stage high-voltage switch and the bus tie switch QM, and a connection circuit between the two-stage high-voltage switch and the two-stage high-voltage switch; in the connection circuit between the two-stage high-voltage switch and the bus tie switch QM, the output end of the two-stage high-voltage switch is the test positive pole, and the output end of the bus tie switch QM is the test negative pole; in the connection circuit between the two-stage high-voltage switch and the two-stage high-voltage switch, the output ends of the two two-stage high-voltage switches are the test positive pole and the negative pole respectively.

[0036] See Figure 3The filtering device is an adjustable anti-interference electromagnetic filter, which includes a magnetic ring and two sets of coils. The two sets of coils are wound on the magnetic ring in a common mode. The two sets of coils of the adjustable anti-interference electromagnetic filter are synchronously linked when adjusting impedance.

[0037] A method for testing a fast test structure of a high-voltage switch loop resistance in a transformer substation comprises the following steps:

[0038] 1) Move all high-voltage switches including the isolating switch QG to the working position and close them manually;

[0039] 2) The voltage sampling terminals U+ and U- of the high-voltage switch loop resistance tester are connected to the filter device and the output test terminal is U + , U － , the current sampling terminals I+ and I- of the high-voltage switch loop resistance tester are connected to the filter device and the output test terminal is I + ,I － ;

[0040] 3) See Figure 4 , conduct the bus tie switch QM loop resistance test, the bus tie switch QM inlet port A is connected to the filter device test terminal U + ,I + , the output port A of the busbar switch QM is connected to the test port U of the filter device － ,I － , and carry out the loop resistance test of the QMA phase of the bus tie switch, and then carry out the loop resistance test of the B phase and the C phase.

[0041] 4) The output port A of the first high-voltage switch Q11 is connected to the test port U of the filter device. + ,I + , the output port A of the busbar switch QM is connected to the test port U of the filter device － ,I － , and the A phase circuit resistance R 1母 Test the test, and then conduct the B phase and C phase loop resistance test respectively.

[0042] The output port A of the first high-voltage switch Q11 is connected to the test port U of the filter device. + ,I + The output port A of the second high-voltage switch Q12 is connected to the test port U of the filter device. － ,I － , and the loop resistance R of phase A 12 Test the test, and then conduct the B phase and C phase loop resistance test respectively.

[0043] The output port A of the second high-voltage switch Q12 is connected to the test port U of the filter device.+ ,I + , the output port A of the busbar switch QM is connected to the test port U of the filter device － ,I － , and the loop resistance R of phase A 2母 Test test, and then test the B phase and C phase loop resistance respectively; then the A phase loop resistance R A1 =(R 1母 +R 12 -R 2母 ) / 2, and calculate the B and C phase loop resistances in the same way.

[0044] 5) Then connect the output port A of the second high-voltage switch Q12 to the test port U of the filter device. + ,I + The output port A of the third high-voltage switch Q13 is connected to the test port U of the filter device. － ,I － , and the loop resistance R of phase A 23 Test the test, and then test the B-phase and C-phase loop resistance respectively;

[0045] The output port A of the first high-voltage switch Q11 is connected to the test port U of the filter device. + ,I + The output port A of the third high-voltage switch Q13 is connected to the test port U of the filter device. － ,I － , and the loop resistance R of phase A 13 Test test, and then test the B phase and C phase loop resistance respectively, then the A phase loop resistance R of the second high voltage cabinet switch Q12 A2 =(R 12 +R 23 -R 13 ) / 2, and calculate the B and C phase loop resistances in the same way.

[0046] 6) The resistance of the A phase loop of the third high voltage switch R A3 Similarly, the bus tie switch loop resistance is measured separately using a high voltage switch loop resistance tester;

[0047] 7) Test the resistance of all high-voltage switches in the second stage. The output port A of the first high-voltage switch Q21 in the second stage is connected to the test port U of the filter device. + ,I + , the output port A of the busbar switch QM is connected to the test port U of the filter device － ,I － , and the A phase circuit resistance R 1母Test the test, and then conduct the B phase and C phase loop resistance test respectively.

[0048] The output port A of the first high-voltage switch Q21 of the second stage is connected to the test port U of the filter device. + ,I + The output port A of the second high-voltage switch Q22 of the second stage is connected to the test port U of the filter device. － ,I － , and the loop resistance R of phase A 12 Test the test, and then conduct the B phase and C phase loop resistance test respectively.

[0049] The output port A of the second high-voltage switch Q22 of the second stage is connected to the test port U of the filter device. + ,I + , the output port A of the busbar switch QM is connected to the test port U of the filter device － ,I － , and the loop resistance R of phase A 2母 Test test, and then test the B phase and C phase loop resistance respectively; then the A phase loop resistance R of the second section first high voltage cabinet switch Q21 A1 =(R 1母 +R 12 -R 2母 ) / 2, and calculate the B and C phase loop resistances in the same way.

[0050] 8) Then connect the output port A of the second high-voltage switch Q22 of the second stage to the test port U of the filter device. + ,I + The output port A of the second stage third high voltage switch Q23 is connected to the filter device test port U － ,I － , and the loop resistance R of phase A 23 Test the test, and then conduct the B phase and C phase loop resistance test respectively.

[0051] 9) The output port A of the second stage first high voltage switch Q21 is connected to the test port U of the filter device + ,I + The output port A of the second stage third high voltage switch Q23 is connected to the filter device test port U － ,I － , and the loop resistance R of phase A 13 Test test, and then conduct B phase and C phase loop resistance test respectively, then the A phase loop resistance R A2 =(R 12 +R 23 -R 13 ) / 2, and calculate the B and C phase loop resistances in the same way.

[0052] 10) The resistance of the A phase loop of the 3rd high voltage switch of the second stage R A3 Similarly, the main tie switch loop resistance is measured separately using a high-voltage switch loop resistance tester.

[0053] When there are N high-voltage switch loop resistance tests, the A phase loop resistance R of the N-1 high-voltage switch A(N-1) =(R (N-2)(N-1) +R (N-1)N -R (N-2)N ) / 2, and similarly calculate the resistance of the B and C phase loops; the resistance of the A phase loop of the Nth high-voltage switch is R AN Similarly, the main tie switch loop resistance is measured separately using a high-voltage switch loop resistance tester.

[0054] When there are N two-stage high-voltage switch loop resistance tests, the second-stage N-1 high-voltage switch A phase loop resistance R A(N-1) =(R (N-2)(N-1) +R (N-1)N -R (N-2)N ) / 2, and similarly calculate the B and C phase loop resistances; the second section N high voltage switch A phase loop resistance R AN Similarly, the main tie switch loop resistance is measured separately using a high-voltage switch loop resistance tester.

[0055] The above embodiments are implemented based on the technical solution of the present invention, and detailed implementation methods and specific operation processes are given, but the protection scope of the present invention is not limited to the above embodiments. The methods used in the above embodiments are conventional methods unless otherwise specified.

Claims

1. A transformer substation high-voltage switch loop resistance rapid test structure, comprising a high-voltage switch loop resistance tester, a bus tie switch, a plurality of first-stage high-voltage switches, an isolating switch and a plurality of second-stage high-voltage switches; the bus tie switch is arranged in a bus tie cabinet, the first-stage high-voltage switch is arranged in a first-stage high-voltage switch cabinet, the isolating switch is arranged in an isolating cabinet, and the second-stage high-voltage switch is arranged in a second-stage high-voltage switch cabinet; characterized in that, It also includes a filtering device, the three-phase power supply input terminals of the bus tie switch and multiple single-stage high-voltage switches are all connected to a single-stage bus on the high-voltage side, the three-phase output terminal of the bus tie switch is connected in series with the three-phase output terminal of the isolating switch, the three-phase power supply input terminals of the isolating switch and multiple two-stage high-voltage switches are connected to the two-stage bus on the high-voltage side, the voltage sampling terminal of the high-voltage switch loop resistance tester is connected to the two ends of the circuit to be tested through a filtering device, and the current sampling terminal of the high-voltage switch loop resistance tester is connected to the two ends of the circuit to be tested through another filtering device.

2. A substation high-voltage switch loop resistance rapid test structure according to claim 1, characterized in that: The filtering device is an adjustable anti-interference electromagnetic filter, which includes a magnetic ring and two groups of coils, wherein the two groups of coils are wound on the magnetic ring in a common mode.

3. A substation high-voltage switch loop resistance rapid test structure according to claim 1, characterized in that: The circuit under test includes a bus-tie switch circuit, multiple single-stage high-voltage switch circuits and multiple second-stage high-voltage switch circuits. The voltage sampling end and the current sampling end of the high-voltage switch circuit resistance tester are respectively connected to the bus-tie switch circuit, multiple single-stage high-voltage switch circuits and multiple second-stage high-voltage switch circuits.

4. A substation high-voltage switch loop resistance rapid test structure according to claim 3, characterized in that: The bus tie switch inlet terminal in the bus tie switch circuit is the test positive pole, and the bus tie switch outlet terminal is the test negative pole.

5. A substation high-voltage switch loop resistance rapid test structure according to claim 3, characterized in that: The one-section high-voltage switch circuit includes a connection circuit between a one-section high-voltage switch and a bus tie switch, and a connection circuit between a one-section high-voltage switch and a one-section high-voltage switch; in the connection circuit between the one-section high-voltage switch and the bus tie switch, the output end of the one-section high-voltage switch is a test positive electrode, and the output end of the bus tie switch is a test negative electrode; in the connection circuit between the one-section high-voltage switch and the one-section high-voltage switch, the output ends of the two one-section high-voltage switches are respectively a test positive electrode and a negative electrode.

6. A substation high-voltage switch loop resistance rapid test structure according to claim 3, characterized in that: The two-stage high-voltage switch circuit includes a connection circuit between the two-stage high-voltage switch and the bus tie switch, and a connection circuit between the two-stage high-voltage switch and the two-stage high-voltage switch; in the connection circuit between the two-stage high-voltage switch and the bus tie switch, the output end of the two-stage high-voltage switch is the test positive pole, and the output end of the bus tie switch is the test negative pole; in the connection circuit between the two-stage high-voltage switch and the two-stage high-voltage switch, the output ends of the two two-stage high-voltage switches are the test positive pole and the negative pole respectively.

7. A method for testing a fast test structure for high-voltage switch loop resistance in a transformer substation according to any one of claims 1 to 6, characterized in that: The steps include: 1) Move all high-voltage switches including isolating switches to the working position and close them manually; 2) The voltage sampling terminals U+ and U- of the high-voltage switch loop resistance tester are connected to the filter device and the output test terminal is U + , U － , the current sampling terminals I+ and I- of the high-voltage switch loop resistance tester are connected to the filter device and the output test terminal is I + ,I － ; 3) Test the resistance of the bus tie switch circuit. Connect the A phase of the bus tie switch inlet to the filter device test terminal U + ,I + , the output port A of the bus tie switch is connected to the test port U of the filter device － ,I － , and conduct the loop resistance test of phase A of the bus tie switch, and then conduct the loop resistance test of phases B and C; 4) The output port A of the first high-voltage switch Q11 is connected to the test port U of the filter device. + ,I + , the output port A of the busbar switch QM is connected to the test port U of the filter device － ,I － , and the A phase circuit resistance R 1母 Test the test, and then test the B-phase and C-phase loop resistance respectively; The output port A of the first high-voltage switch of a section is connected to the test port U of the filter device. + ,I + , the output port A of the second high-voltage switch is connected to the test port U of the filter device － ,I － , and the loop resistance R of phase A 12 Test the test, and then test the B-phase and C-phase loop resistance respectively; The output port A of the second high-voltage switch is connected to the test port U of the filter device. + ,I + , the output port A of the bus tie switch is connected to the test port U of the filter device － ,I － , and the loop resistance R of phase A 2母 Test test, and then respectively carry out the B phase and C phase loop resistance test test; then the A phase loop resistance R of the first high voltage switch A1 =(R 1母 +R 12 -R 2母 ) / 2, and similarly calculate the resistance of the B and C phase loops; 5) Connect the output port A of the second high-voltage switch to the test port U of the filter device. + ,I + , the output port A of the third high-voltage switch is connected to the test port U of the filter device － ,I － , and the loop resistance R of phase A 23 Test the test, and then test the B-phase and C-phase loop resistance respectively; The output port A of the first high-voltage switch of a section is connected to the test port U of the filter device. + ,I + , the output port A of the third high-voltage switch is connected to the test port U of the filter device － ,I － , and the loop resistance R of phase A 13 Test test, and then respectively carry out the B phase and C phase loop resistance test test, then the A phase loop resistance R of the second high voltage switch A2 =(R 12 +R 23 -R 13 ) / 2, and similarly calculate the resistance of the B and C phase loops; 6) Similarly, the N-1th high-voltage switch A phase loop resistance R A(N-1) =(R (N-2)(N-1) +R (N-1)N -R (N-2)N ) / 2, and similarly calculate the resistance of the B and C phase loops; 7) The resistance R of the A phase loop of the Nth high voltage switch AN Similarly, the bus tie switch loop resistance is measured separately using a high voltage switch loop resistance tester; 8) Multiple two-stage high-voltage switch loop resistance test The same process is used for multiple one-stage high-voltage switch loop resistance test.

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