Capacitor voltage transformer insulation resistance test adapter and test method

Abstract

The present invention discloses a capacitor voltage transformer insulation resistance test adapter device and a test method. The test method places the capacitor voltage transformer insulation resistance test adapter device in a place where it can be operated without climbing an insulation ladder, such as flat ground, and connects it between the capacitor voltage transformer and an insulation resistance meter, so that the inter-electrode insulation resistance, the low-voltage end-to-ground insulation resistance, and the intermediate transformer primary-to-secondary and ground insulation resistance can be measured with only one climbing connection, avoiding repeated climbing and changing of wires, shortening the climbing operation time, reducing the climbing operation risk, and improving the operation efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of insulation resistance testing, and in particular to a capacitance voltage transformer insulation resistance test adapter and a test method. Background Art

[0002] Currently, capacitive voltage transformers (CVTs) are widely used as voltage signal acquisition devices in substations with voltages of 110 kV and above. However, some CVTs have potential defects such as manufacturing quality, water ingress, oil deficiency, and insulation aging, which often lead to failures during operation. Therefore, insulation resistance testing is required for CVTs before shipment, during delivery, and during operation.

[0003] In addition, the China Southern Power Grid's corporate standard "QCSG1206007-2017 Power Equipment Maintenance Test Procedure" stipulates that the insulation resistance test of the CVT during operation is as follows:

[0004] (1) The inter-pole insulation resistance test cycle for CVTs with voltage levels of 110 kV and below is 6 years; the inter-pole insulation resistance test cycle for CVTs with voltage levels of 220 kV and above is 3 years;

[0005] (2) The low-voltage end-to-ground insulation resistance test cycle for CVTs with voltage levels of 110 kV and below is 6 years; the inter-electrode insulation resistance test cycle for CVTs with voltage levels of 220 kV and above is 3 years;

[0006] (3) The test cycle for the primary-to-secondary and ground insulation resistance of intermediate transformers of CVT with voltage level of 110kV and below is 6 years; the test cycle for the primary-to-secondary and ground insulation resistance of intermediate transformers of CVT with voltage level of 220kV and above is 3 years.

[0007] However, the terminal box of the CVT that has been in operation is often installed at a higher position, which requires a test wiring personnel to wear a safety belt to climb the insulating ladder, hang and fix the safety belt primary protection and secondary protection ropes on the CVT support frame, and remove the terminal box cover. Taking the 110kV single-column structure CVT as an example, the CVT structure is as follows: Figure 1 In the figure, T is the intermediate transformer, C1 and C2 are high-voltage capacitors and low-voltage capacitors respectively, a, x, af, and xf are the secondary winding terminals, point X is the tail end of the intermediate transformer, point N is the tail end of the capacitor, and point A is the top of the lower section of the CVT.

[0008] The traditional CVT insulation resistance test method involves first disconnecting the grounding connections at points X and N, then connecting the insulation resistance meter to points A and X, respectively. After wiring is complete, the tester descends the ladder before applying pressure, allowing the meter to measure the insulation resistance between the C1 and C1 electrodes. After measuring the C1 insulation resistance, the tester removes the pressure, climbs the ladder again, and connects the insulation resistance meter to points N and X, respectively. After wiring is complete, the tester descends the ladder and applies pressure again, allowing the meter to measure the insulation resistance between the C2 electrodes. This process must be repeated multiple times to complete the insulation resistance test.

[0009] It can be seen that the traditional CVT insulation resistance test method requires repeated climbing of insulating ladders to perform high-altitude operations. High-altitude operations take a long time, are high-risk, and are time-consuming and labor-intensive. Summary of the Invention

[0010] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a capacitor voltage transformer insulation resistance test adapter, which can avoid repeated climbing of insulation ladders during CVT insulation resistance testing, reduce the risks brought by climbing, and save time and effort during the operation process.

[0011] To achieve the above objectives, the technical solutions provided by the present invention are:

[0012] Capacitive voltage transformer insulation resistance test adapter, including the connection area of ​​the object under test, the transfer switch, and the instrument connection area;

[0013] The measured object connection area includes an A-point terminal for connecting to point A of the capacitor voltage transformer, an N-point terminal for connecting to point N of the capacitor voltage transformer, an X-point terminal for connecting to point X of the capacitor voltage transformer, and a Ground terminal for grounding;

[0014] The instrument wiring area includes a positive terminal and a negative terminal for connecting to the positive and negative poles of the insulation resistance meter;

[0015] The transfer switch includes a rotary switch S1 connected to the negative terminal, a rotary switch S2 connected to the positive terminal and linked to the rotary switch S1, and a switch S3 linked to the rotary switch S1;

[0016] The rotary switch S1 and the rotary switch S2 both include OFF position, C1 position, C2 position, N position, and X position;

[0017] In the rotary switch S1, its C1 position is connected to the A point terminal, its C2 position and N position are connected to the N point terminal respectively, and its X position is connected to the A point terminal and the X point terminal respectively;

[0018] The switch S3 is connected between the X gear and the A point terminal;

[0019] In the rotary switch S2, its C1 position and C2 position are both connected to the X point terminal, and its N position and X position are both grounded.

[0020] To achieve the above object, the present invention further provides a method for testing the insulation resistance of a capacitor voltage transformer, comprising:

[0021] The capacitor voltage transformer insulation resistance test adapter device according to claim 1 is placed in a place where it can be operated without climbing an insulating ladder;

[0022] Connect the positive and negative poles of the insulation resistance meter to the positive and negative terminals of the capacitance voltage transformer insulation resistance test adapter respectively;

[0023] The test wiring personnel wear safety belts and climb the insulating ladder. They hang and fix the primary and secondary protection ropes of the safety belts on the support frame of the capacitor voltage transformer and remove the terminal box cover of the capacitor voltage transformer located at a high place.

[0024] Disconnect the grounding connections at points X and N of the capacitor voltage transformer;

[0025] Connect the A point, N point and X point of the capacitor voltage transformer to the A point terminal, N point terminal and X point terminal of the capacitor voltage transformer insulation resistance test adapter device respectively;

[0026] Ground the Ground terminal of the capacitor voltage transformer insulation resistance test adapter;

[0027] After the connection between the capacitor voltage transformer insulation resistance test adapter and the capacitor voltage transformer is completed, perform the pressure operation and adjust the corresponding gear of the rotary switch S1 to conduct all insulation resistance tests of the capacitor voltage transformer;

[0028] After all insulation resistance tests of the capacitor voltage transformer are completed, the test wiring personnel remove the pressurization operation and disconnect the capacitor voltage transformer insulation resistance test adapter from the capacitor voltage transformer and the insulation resistance meter;

[0029] Climb the ladder again, ground the X and N points of the capacitor voltage transformer, install the terminal box cover, and complete the insulation resistance test of the capacitor voltage transformer.

[0030] Furthermore, the linkage relationship between the rotary switch S1 and the rotary switch S2 is as follows:

[0031] When the rotary switch S1 is turned to OFF, the rotary switch S2 is also turned to OFF; when the rotary switch S1 is turned to C1, the rotary switch S2 is also turned to C1; when the rotary switch S1 is turned to C2, the rotary switch S2 is also turned to C2; when the rotary switch S1 is turned to N, the rotary switch S2 is also turned to N; when the rotary switch S1 is turned to X, the rotary switch S2 is also turned to X;

[0032] The linkage relationship between rotary switch S1 and switch S3 is as follows:

[0033] Switch S3 is closed only when the rotary switch S1 is turned to the X position, and is disconnected in other positions.

[0034] Furthermore, by adjusting the corresponding gear of the rotary switch S1, all insulation resistance tests of the capacitor voltage transformer are performed, including:

[0035] 1) When the rotary switch S1 is turned to the OFF position, the capacitor voltage transformer insulation resistance test adapter device is shut down;

[0036] 2) When the rotary switch S1 is turned to C1, the insulation resistance between the C1 poles can be measured;

[0037] 3) When the rotary switch S1 is turned to C2, the insulation resistance between the C2 poles can be measured;

[0038] 4) When the rotary switch S1 is turned to N, the insulation resistance of the low voltage end to the ground can be measured;

[0039] 5) When the rotary switch S1 is turned to the X position, the insulation resistance of the intermediate transformer from primary to secondary and to ground can be measured.

[0040] Compared with the existing technology, the principles and advantages of this technical solution are as follows:

[0041] This solution places the capacitor voltage transformer insulation resistance test adapter device in a place where it can be operated without climbing an insulating ladder, such as flat ground, and connects it between the capacitor voltage transformer and the insulation resistance meter, so that the inter-pole insulation resistance, the low-voltage end-to-ground insulation resistance, and the intermediate transformer primary-to-secondary and ground insulation resistance can be measured with only one climbing and wiring. This avoids repeated climbing and changing of wires, shortens the climbing operation time, reduces the climbing operation risk, and improves work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the services required for use in the embodiments or the prior art descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1 This is a structural diagram of a 110kV capacitor voltage transformer;

[0044] Figure 2 This is a schematic diagram of the appearance of a capacitor voltage transformer insulation resistance test adapter device of the present invention;

[0045] Figure 3 This is a schematic diagram of the switching principle of a capacitor voltage transformer insulation resistance test switching device of the present invention;

[0046] Figure 4 The present invention provides a flow chart of a method for testing the insulation resistance of a capacitor voltage transformer. DETAILED DESCRIPTION

[0047] The present invention will be further described below in conjunction with specific embodiments:

[0048] like Figure 2-Figure 3 As shown, the capacitance voltage transformer insulation resistance test adapter described in this embodiment includes a connection area for a test object, a transfer switch, and an instrument connection area;

[0049] The connection area of ​​the device under test includes a point A terminal for connecting to point A of the capacitor voltage transformer, a point N terminal for connecting to point N of the capacitor voltage transformer, a point X terminal for connecting to point X of the capacitor voltage transformer, and a ground terminal for grounding.

[0050] The instrument wiring area includes positive and negative terminals, which are used to connect to the positive and negative poles of the insulation resistance meter;

[0051] The transfer switch includes a rotary switch S1 connected to the negative terminal, a rotary switch S2 connected to the positive terminal and linked to the rotary switch S1, and a switch S3 linked to the rotary switch S1;

[0052] The rotary switch S1 and the rotary switch S2 both include OFF position, C1 position, C2 position, N position, and X position;

[0053] In the rotary switch S1, its C1 position is connected to the terminal at point A, its C2 position and N position are connected to the terminal at point N respectively, and its X position is connected to the terminal at point A and the terminal at point X respectively;

[0054] Switch S3 is connected between the X gear and point A terminals;

[0055] In the rotary switch S2, its C1 position and C2 position are both connected to the X point terminal, and its N position and X position are both grounded.

[0056] In this embodiment, the linkage relationship between the rotary switch S1 and the rotary switch S2 is as follows:

[0057] When the rotary switch S1 is turned to OFF, the rotary switch S2 is also turned to OFF; when the rotary switch S1 is turned to C1, the rotary switch S2 is also turned to C1; when the rotary switch S1 is turned to C2, the rotary switch S2 is also turned to C2; when the rotary switch S1 is turned to N, the rotary switch S2 is also turned to N; when the rotary switch S1 is turned to X, the rotary switch S2 is also turned to X;

[0058] In this embodiment, the linkage relationship between the rotary switch S1 and the switch S3 is as follows:

[0059] Switch S3 is closed only when the rotary switch S1 is turned to the X position, and is disconnected in other positions.

[0060] like Figure 4 As shown, the specific process of using the above capacitor voltage transformer insulation resistance test adapter device for capacitor voltage transformer insulation resistance test is as follows:

[0061] S1. Place the capacitor voltage transformer insulation resistance test adapter on flat ground;

[0062] S2. Connect the positive and negative terminals of the insulation resistance meter to the positive and negative terminals of the capacitance voltage transformer insulation resistance test adapter respectively;

[0063] S3. The test wiring personnel wear safety harnesses and climb the insulating ladder. They hang and secure the primary and secondary safety ropes of the safety harnesses to the capacitor voltage transformer support frame and remove the terminal box cover of the capacitor voltage transformer located at a high position.

[0064] S4. Disconnect the grounding connections at points X and N of the capacitor voltage transformer;

[0065] S5. Connect points A, N, and X of the capacitor voltage transformer to the A-point terminal, N-point terminal, and X-point terminal of the capacitor voltage transformer insulation resistance test adapter device, respectively;

[0066] S6. Ground the Ground terminal of the capacitor voltage transformer insulation resistance test adapter;

[0067] S7. After the capacitor voltage transformer insulation resistance test adapter device and the capacitor voltage transformer are connected, pressurize the capacitor voltage transformer and adjust the corresponding gear of the rotary switch S1 to conduct all insulation resistance tests of the capacitor voltage transformer.

[0068] The test process includes:

[0069] 1) When the rotary switch S1 is turned to the OFF position, the capacitor voltage transformer insulation resistance test adapter device is shut down;

[0070] 2) When the rotary switch S1 is turned to C1, the insulation resistance between the C1 poles can be measured;

[0071] 3) When the rotary switch S1 is turned to C2, the insulation resistance between the C2 poles can be measured;

[0072] 4) When the rotary switch S1 is turned to N, the insulation resistance of the low voltage end to the ground can be measured;

[0073] 5) When the rotary switch S1 is turned to the X position, the insulation resistance of the intermediate transformer from primary to secondary and to ground can be measured.

[0074] S8. After all insulation resistance tests of the capacitor voltage transformer are completed, the test wiring personnel remove the pressurization operation and disconnect the capacitor voltage transformer insulation resistance test adapter from the capacitor voltage transformer and the insulation resistance meter;

[0075] S9. Climb the ladder again, ground the X and N points of the capacitor voltage transformer, install the terminal box cover, and complete the insulation resistance test of the capacitor voltage transformer.

[0076] In this embodiment, the linkage between the rotary switch S1, the rotary switch S2 and the switch S3 is controlled by a PLC.

[0077] The embodiments described above are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. Therefore, any changes made based on the shape and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. Capacitive voltage transformer insulation resistance test adapter, characterized in that: Including the wiring area of ​​the object under test, transfer switch, and instrument wiring area; The measured object connection area includes an A-point terminal for connecting to point A of the capacitor voltage transformer, an N-point terminal for connecting to point N of the capacitor voltage transformer, an X-point terminal for connecting to point X of the capacitor voltage transformer, and a Ground terminal for grounding; The instrument wiring area includes a positive terminal and a negative terminal for connecting to the positive and negative poles of the insulation resistance meter; The transfer switch includes a rotary switch S1 connected to the negative terminal, a rotary switch S2 connected to the positive terminal and linked to the rotary switch S1, and a switch S3 linked to the rotary switch S1; The rotary switch S1 and the rotary switch S2 both include OFF position, C1 position, C2 position, N position, and X position; In the rotary switch S1, its C1 position is connected to the A point terminal, its C2 position and N position are connected to the N point terminal respectively, and its X position is connected to the A point terminal and the X point terminal respectively; The switch S3 is connected between the X gear and the A point terminal; In the rotary switch S2, its C1 and C2 positions are both connected to the X-point terminal, and its N and X positions are both grounded; The linkage relationship between rotary switch S1 and rotary switch S2 is as follows: When the rotary switch S1 is turned to OFF, the rotary switch S2 is also turned to OFF; when the rotary switch S1 is turned to C1, the rotary switch S2 is also turned to C1; when the rotary switch S1 is turned to C2, the rotary switch S2 is also turned to C2; when the rotary switch S1 is turned to N, the rotary switch S2 is also turned to N; when the rotary switch S1 is turned to X, the rotary switch S2 is also turned to X; The linkage relationship between rotary switch S1 and switch S3 is as follows: Switch S3 is closed only when the rotary switch S1 is turned to the X position, and is disconnected in other positions.

2. Capacitor voltage transformer insulation resistance test method, characterized in that, include: The capacitor voltage transformer insulation resistance test adapter device according to claim 1 is placed in a place where it can be operated without climbing an insulating ladder; Connect the positive and negative poles of the insulation resistance meter to the positive and negative terminals of the capacitance voltage transformer insulation resistance test adapter respectively; The test wiring personnel wear safety belts and climb the insulating ladder. They hang and fix the primary and secondary protection ropes of the safety belts on the support frame of the capacitor voltage transformer and remove the terminal box cover of the capacitor voltage transformer located at a high place. Disconnect the grounding connections at points X and N of the capacitor voltage transformer; Connect the A point, N point and X point of the capacitor voltage transformer to the A point terminal, N point terminal and X point terminal of the capacitor voltage transformer insulation resistance test adapter device respectively; Ground the Ground terminal of the capacitor voltage transformer insulation resistance test adapter; After the connection between the capacitor voltage transformer insulation resistance test adapter and the capacitor voltage transformer is completed, perform the pressure operation and adjust the corresponding gear of the rotary switch S1 to conduct all insulation resistance tests of the capacitor voltage transformer; After all insulation resistance tests of the capacitor voltage transformer are completed, the test wiring personnel remove the pressurization operation and disconnect the capacitor voltage transformer insulation resistance test adapter from the capacitor voltage transformer and the insulation resistance meter; Climb the ladder again, ground the X and N points of the capacitor voltage transformer, install the terminal box cover, and complete the insulation resistance test of the capacitor voltage transformer.

3. The capacitance voltage transformer insulation resistance test method according to claim 2, characterized in that: The linkage relationship between rotary switch S1 and rotary switch S2 is as follows: When the rotary switch S1 is turned to OFF, the rotary switch S2 is also turned to OFF; when the rotary switch S1 is turned to C1, the rotary switch S2 is also turned to C1; when the rotary switch S1 is turned to C2, the rotary switch S2 is also turned to C2; when the rotary switch S1 is turned to N, the rotary switch S2 is also turned to N; when the rotary switch S1 is turned to X, the rotary switch S2 is also turned to X; The linkage relationship between rotary switch S1 and switch S3 is as follows: Switch S3 is closed only when the rotary switch S1 is turned to the X position, and is disconnected in other positions.

4. The capacitance voltage transformer insulation resistance test method according to claim 3, characterized in that: By adjusting the corresponding position of the rotary switch S1, all insulation resistance tests of the capacitor voltage transformer are carried out, including: 1) When the rotary switch S1 is turned to the OFF position, the capacitor voltage transformer insulation resistance test adapter device is shut down; 2) When the rotary switch S1 is turned to C1, the insulation resistance between the C1 poles can be measured; 3) When the rotary switch S1 is turned to C2, the insulation resistance between the C2 poles can be measured; 4) When the rotary switch S1 is turned to N, the insulation resistance of the low voltage end to the ground can be measured; 5) When the rotary switch S1 is turned to the X position, the insulation resistance of the intermediate transformer from primary to secondary and to ground can be measured.

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