Air clearance test assembly and test method

Abstract

The present invention discloses an air clearance test assembly, comprising a first shielding cover assembly, a second shielding cover assembly, a third shielding cover assembly, a metal bar, a first insulating member, a second insulating member, and a third insulating member; one end of the metal bar is connected to the first shielding cover assembly, and the other end is connected to the third shielding cover assembly; one end of the third insulating member is fixed to the second shielding cover assembly, and the other end is fixed to the third shielding cover assembly; one end of the first insulating member is fixed to the first shielding cover assembly, and the other end is supported or suspended; one end of the second insulating member is fixed to the third shielding cover assembly, and the other end is supported or suspended; the second shielding cover assembly and the metal bar, the first shielding cover assembly, and the third shielding cover assembly form a gap. The present invention can realize the accurate measurement of the insulation discharge performance outside the interlayer gap of the converter valve, and accurately obtain the interlayer air clearance of the DC converter valves of different voltage levels and different altitudes.

Description

Technical Field

[0001] The invention relates to the field of power electronic equipment, and in particular to an air clearance test component and a test method. Background Art

[0002] As HVDC transmission technology develops towards higher voltage levels or is applied in high-altitude areas, the external insulation reliability of its core component, the thyristor DC converter valve, becomes the key to system safety. The DC converter valve consists of multiple valve layers. The air clearance between the valve layers determines its external insulation reliability. The size of the air clearance seriously affects the size of the converter valve and the valve hall. The increase in size will increase the land occupation and investment. In order to design a reasonable air clearance and ensure reliability without significantly increasing the size of the valve and valve hall, it is necessary to study the external insulation discharge characteristics of the gap between the converter valve layers, especially when the converter valve is used in UHV and high-altitude areas.

[0003] At present, there are many studies on the external insulation discharge characteristics of converter valves to the ground or to the wall, but there is no study on the external insulation discharge characteristics of the interlayer gap of the converter valve, nor on the altitude correction of the external insulation discharge characteristics applied in high-altitude environments.

[0004] Ji Daqian et al.'s "Operational impulse discharge characteristics of air gap in valve hall of ±800kV UHV DC transmission system" (High Voltage Technology, 2014, 40(6), 1864-1869) studied the discharge characteristics of the bottom shielding cover of the ±800kV UHV DC converter valve to the ground.

[0005] Wei Xiaoguang et al.’s “±1100kV UHV DC converter valve external insulation switching impulse discharge test and altitude correction research” (Proceedings of the CSEE, 2014, 34(12), 1996-2003) studied the switching impulse discharge characteristics of ±1100kV UHV DC converter valves to virtual walls and virtual grounds.

[0006] At present, the interlayer air clearance of converter valves is mainly calculated based on the discharge characteristics test results of typical gaps, and the altitude correction is determined according to the calculation formula of typical gaps specified in the national standard. This method has a large deviation and is not accurate enough to obtain the interlayer air clearance of converter valves, which seriously affects the size of converter valves. It is necessary to conduct targeted research on the external insulation discharge characteristics of the interlayer gap of converter valves, but if the interlayer gap external insulation discharge test is carried out using an actual valve tower, it is highly complex, the risk of equipment damage is high, and the interlayer air clearance cannot be adjusted.

[0007] In view of the shortcomings of the aforementioned existing methods, this case arises. Summary of the invention

[0008] The purpose of the present invention is to propose an air clearance test assembly, whose discharge characteristics are consistent with the actual interlayer gap discharge characteristics of the converter valve and is simple and easy to use. By conducting an external insulation discharge test on this gap assembly, the air clearance between the layers of the converter valves at different voltage levels and different altitudes can be accurately obtained, and then a valve tower with high external insulation reliability and reasonable size can be designed. The present invention also proposes a corresponding test method.

[0009] In order to achieve the above object, the present invention adopts the following technical solution:

[0010] An air clearance test assembly comprises a first shielding cover assembly S1, a second shielding cover assembly S2, a third shielding cover assembly S3, a metal row C, a first insulating member I1, a second insulating member I2, and a third insulating member I3; one end of the metal row C is connected to the first shielding cover assembly S1, and the other end is connected to the third shielding cover assembly S3; one end of the third insulating member I3 is fixed to the second shielding cover assembly S2, and the other end is fixed to the third shielding cover assembly S3; one end of the first insulating member I1 is fixed to the first shielding cover assembly S1, and the other end is supported or suspended; one end of the second insulating member I2 is fixed to the third shielding cover assembly S3, and the other end is supported or suspended; the second shielding cover assembly S2 and the metal row C, the first shielding cover assembly S1, and the third shielding cover assembly S3 form a gap G.

[0011] Preferably, the gap length of the gap G is changed by adjusting the length of the insulating member or the distance between the insulating members.

[0012] Preferably, the gap length of the gap G is adjusted in one of the following two ways:

[0013] Method 1: Adjust the horizontal distance between the first insulating member I1 and the second insulating member I2;

[0014] Method 2: Adjust the heights of the third insulating member I3 and the first insulating member I1.

[0015] Preferably, the first shielding cover assembly S1, the second shielding cover assembly S2 and the third shielding cover assembly S3 all include: a shielding cover, a metal beam, a shielding cover support, a lifting ear and an insulator fitting.

[0016] Preferably, the length of the first insulating member I1 and the second insulating member I2 is more than three times the length of the gap G.

[0017] Preferably, the first shielding cover assembly S1 and the second shielding cover assembly S2 represent the shielding cover assemblies on the left and right sides of the same valve layer in the converter valve, the third shielding cover assembly S3 is the shielding cover assembly of the next valve layer located below the second shielding cover assembly S2, the metal row C is a metal row across the valve layers that electrically connects the first shielding cover assembly S1 and the third shielding cover assembly S3, and the minimum air clearance between the converter valve layers is between the second shielding cover assembly S2 and the metal row C.

[0018] The present invention also provides a test method for an air clearance test assembly, comprising:

[0019] During the test, the second shielding cover component S2 is at the first potential, the metal bar C, the first shielding cover component S1 and the third shielding cover component S3 are at the second potential, one of the two potentials is the ground potential; the first insulating member I1 and the second insulating member I2 support or suspend the end at the ground potential;

[0020] An external insulation discharge test is performed on the gap G to obtain the external insulation discharge characteristics of the gap between the converter valve layers simulated by the test component; and the air clearance between the converter valve layers is obtained based on the external insulation discharge characteristics.

[0021] Preferably, the above test method further comprises:

[0022] At normal altitude, the gap length of the gap G is adjusted, and the external insulation discharge test of the test assembly at each gap length is performed to obtain the external insulation discharge characteristics of the interlayer gaps of different gap lengths at normal altitude; according to the external insulation discharge characteristics, the interlayer air clearance of converter valves of different voltage levels at normal altitude is obtained;

[0023] At high altitudes, the gap length of the gap G is adjusted, and external insulation discharge tests are performed on the test assembly at various gap lengths to obtain external insulation discharge characteristics of interlayer gaps with different gap lengths at high altitudes; and the interlayer air clearance of converter valves with different voltage levels at high altitudes is obtained according to the external insulation discharge characteristics;

[0024] The interlayer air clearance of converter valves at normal altitude and high altitude is compared to obtain the influence of altitude on the interlayer air clearance of converter valves.

[0025] The beneficial effects of the present invention are:

[0026] 1. The present invention studies the external insulation characteristics of the interlayer gap of the converter valve and designs a gap component that can be equivalent to the weak position of the external insulation of the interlayer gap. It can realize the accurate measurement of the external insulation discharge performance of the interlayer gap of the converter valve, avoids the problems of excessive design of the interlayer air clearance of the converter valve and unreasonable size of the valve tower that occur when using the existing method, and can accurately obtain the interlayer air clearance of DC converter valves of different voltage levels and different altitudes.

[0027] 2. It avoids the problems of high complexity, high risk of equipment damage, and inability to adjust the air clearance between layers that occur when using an actual valve tower for discharge testing.

[0028] 3. The present invention uses a simple gap component to simulate the gap between layers of the converter valve. The gap G is the weakest link in the external insulation performance between the layers of the converter valve. By adjusting the length of the insulating component, the influence of the ground potential on the gap discharge characteristics is effectively avoided, and the equivalence is high. The gap distance can be easily changed by adjusting the length of the insulating component or the distance between them. It is suitable for converter valves of different voltage levels and different altitudes and has strong versatility. The gap component is composed of metal and insulating components, and the discharge is air discharge. There is no risk of equipment damage and it is simple and easy to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to make the content of the present invention more clearly understood and facilitate the description of specific implementation methods, the following are the drawings related to the present invention:

[0030] Figure 1 This is a layout diagram of the support gap assembly of the present invention.

[0031] Figure 2 It is a layout diagram of the suspended interlayer components of the present invention.

[0032] Figure 3 The present invention provides a flow chart of a test method for an air clearance test assembly according to an embodiment of the present invention.

[0033] Figure 4 It is a flow chart of a test method for an air clearance test assembly provided in another embodiment of the present invention. DETAILED DESCRIPTION

[0034] The following is a preferred embodiment of the present invention, and the present invention will be further described below in conjunction with the accompanying drawings.

[0035] An air clearance test assembly provided by an embodiment of the present invention includes a first shielding cover assembly S1, a second shielding cover assembly S2, a third shielding cover assembly S3, a metal row C, a first insulating member I1, a second insulating member I2, and a third insulating member I3; one end of the metal row C is connected to the first shielding cover assembly S1, and the other end is connected to the third shielding cover assembly S3; one end of the third insulating member I3 is fixed to the second shielding cover assembly S2, and the other end is fixed to the third shielding cover assembly S3. One end of the first insulating member I1 is fixed to the first shielding cover assembly S1, and the other end has two fixing methods, one is supported on the ground, i.e., supported type, such as Figure 1 As shown, the other is the suspension type, such as Figure 2As shown; one end of the second insulating member I2 is fixed to the third shielding cover assembly S3, and the other end is also supported and suspended. The second shielding cover assembly S2, the metal bar C, the first shielding cover assembly S1, and the third shielding cover assembly S3 form a gap G that is used to equal the gap with the weakest insulation performance between the layers of the converter valve. Each insulating member can be a general insulator.

[0036] The first shielding cover assembly S1 and the second shielding cover assembly S2 represent the shielding cover assemblies on the left and right sides of the same valve layer in the converter valve. The third shielding cover assembly S3 is the shielding cover assembly of the next valve layer located below the second shielding cover assembly S2. The metal row C is a metal row across the valve layers that electrically connects the first shielding cover assembly S1 and the third shielding cover assembly S3. The minimum air clearance between the converter valve layers is between the second shielding cover assembly S2 and the metal row C.

[0037] In a preferred embodiment, in order to more accurately reflect the interlayer insulation performance of the converter valve, the gap shape is consistent with the actual converter valve, and the shielding cover assembly in the gap G includes the shielding cover and also includes metal beams, shielding cover supports, lifting ears and other metal parts, which are consistent with the actual converter valve.

[0038] In a preferred embodiment, the lengths of the first insulating member I1 and the second insulating member I2 are more than three times the length of the gap G, so as to reduce the influence of the ground potential on the discharge characteristics of the gap G.

[0039] In a preferred embodiment, the gap length of the gap G is changed by adjusting the length of the insulating member or the distance between the insulating members. Specifically, one of the following two methods is adopted:

[0040] Method 1: Adjust the horizontal distance between the first insulating member I1 and the second insulating member I2;

[0041] Method 2: Adjust the heights of the third insulating member I3 and the first insulating member I1.

[0042] The embodiment of the present invention also provides a test method for an air clearance test assembly, comprising the following steps:

[0043] S11: During the test, the second shielding cover component S2 is at the first potential, the metal bar C, the first shielding cover component S1 and the third shielding cover component S3 are at the second potential, one of the two potentials is the ground potential; the first insulating member I1 and the second insulating member I2 support or suspend the end at the ground potential;

[0044] S12: performing an external insulation discharge test on the gap G to obtain external insulation discharge characteristics of the gap between converter valve layers simulated by the test assembly;

[0045] S13: Obtaining the air clearance between converter valve layers according to the external insulation discharge characteristics.

[0046] In a preferred embodiment, a test method for an air clearance test assembly includes:

[0047] S21: at a normal altitude, adjusting the gap length of the gap G, performing an external insulation discharge test on the test assembly at each gap length, and obtaining external insulation discharge characteristics of interlayer gaps with different gap lengths at a normal altitude; obtaining interlayer air clearances of converter valves with different voltage levels at a normal altitude according to the external insulation discharge characteristics;

[0048] S22: at high altitude, adjusting the gap length of the gap G, performing external insulation discharge tests on the test assembly at various gap lengths, and obtaining external insulation discharge characteristics of interlayer gaps with different gap lengths at high altitude; obtaining interlayer air clearances of converter valves with different voltage levels at high altitude according to the external insulation discharge characteristics;

[0049] S23: Compare the interlayer air clearance of the converter valves at normal altitude and high altitude to obtain the influence of the altitude on the interlayer air clearance of the converter valves.

[0050] The above embodiments are only for illustrating the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the present invention.

Claims

1. An air clearance test assembly, characterized in that: It includes a first shielding cover component S1, a second shielding cover component S2, a third shielding cover component S3, a metal row C, a first insulating member I1, a second insulating member I2, and a third insulating member I3; one end of the metal row C is connected to the first shielding cover component S1, and the other end is connected to the third shielding cover component S3; one end of the third insulating member I3 is fixed to the second shielding cover component S2, and the other end is fixed to the third shielding cover component S3; One end of the first insulating member I1 is fixed to the first shielding cover assembly S1, and the other end is supported or suspended; One end of the second insulating member I2 is fixed to the third shielding cover assembly S3, and the other end is supported or suspended; the second shielding cover assembly S2 and the metal row C, the first shielding cover assembly S1, and the third shielding cover assembly S3 form a gap G; the gap length of the gap G is changed by adjusting the length of the insulating member or the distance between the insulating members.

2. An air clearance test assembly according to claim 1, characterized in that: The gap length of the gap G is adjusted in one of the following two ways: Method 1: Adjust the horizontal distance between the first insulating member I1 and the second insulating member I2; Method 2: Adjust the heights of the third insulating member I3 and the first insulating member I1.

3. An air clearance test assembly according to claim 1, characterized in that: The first shielding cover assembly S1, the second shielding cover assembly S2, and the third shielding cover assembly S3 all include: a shielding cover, a metal beam, a shielding cover support, a lifting ear, and an insulator fitting.

4. The air clearance test assembly according to claim 1, characterized in that: The lengths of the first insulating member I1 and the second insulating member I2 are more than three times the length of the gap G.

5. The air clearance test assembly according to claim 1, characterized in that: The first shielding cover assembly S1 and the second shielding cover assembly S2 represent the shielding cover assemblies on the left and right sides of the same valve layer in the converter valve. The third shielding cover assembly S3 is the shielding cover assembly of the next valve layer located below the second shielding cover assembly S2. The metal row C is a metal row across the valve layers that electrically connects the first shielding cover assembly S1 and the third shielding cover assembly S3. The minimum air clearance between the converter valve layers is between the second shielding cover assembly S2 and the metal row C.

6. A test method for an air clearance test assembly according to any one of claims 1 to 5, characterized in that: include: During the test, the second shielding cover component S2 is at the first potential, the metal bar C, the first shielding cover component S1 and the third shielding cover component S3 are at the second potential, one of the two potentials is the ground potential; the first insulating member I1 and the second insulating member I2 support or suspend the end at the ground potential; An external insulation discharge test is performed on the gap G to obtain the external insulation discharge characteristics of the gap between the converter valve layers simulated by the test component; and the air clearance between the converter valve layers is obtained based on the external insulation discharge characteristics.

7. A test method for an air clearance test assembly according to claim 6, characterized in that: Also includes: At normal altitude, the gap length of the gap G is adjusted, and the external insulation discharge test of the test assembly at each gap length is performed to obtain the external insulation discharge characteristics of the interlayer gaps of different gap lengths at normal altitude; according to the external insulation discharge characteristics, the interlayer air clearance of converter valves of different voltage levels at normal altitude is obtained; At high altitudes, the gap length of the gap G is adjusted, and external insulation discharge tests are performed on the test assembly at various gap lengths to obtain external insulation discharge characteristics of interlayer gaps with different gap lengths at high altitudes; and the interlayer air clearance of converter valves with different voltage levels at high altitudes is obtained according to the external insulation discharge characteristics; The interlayer air clearance of converter valves at normal altitude and high altitude is compared to obtain the influence of altitude on the interlayer air clearance of converter valves.

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