GB/T 25307-2010High-voltage direct current by-pass switches (English PDF)

3.15 Insulation level

[GB/T 1984-2003, definition 3.7.154]

3.16 Direct current withstand voltage

when the test is carried out under the specified conditions and the prescribed time, the DC voltage to which the bypass switch can withstand

3.17 Impulse withstand voltage

[GB/T 1984-2003, definition 3.7.156]

3.18 Short-time withstand current

[GB/T 1984-2003, definition 3.7.121]

3.19 Peak withstand current

[GB/T 1984-2003, definition 3.7.122]

3.20 DC transfer current

through the cooperation of converter bridge trigger angle, bypass switches, etc., the direct current transferred by the bypass switch to the converter bridge

3.21 Short-time DC current

under specified conditions of use and performance, the direct current to which the main circuit of by-pass switch can withstand within 30min

5.9

Rated pressure of compressed air source for insulation, operation and/or transfer of DC current 4.10 of GB/T 11022-1999 applies.

5.10 Rated DC transfer current

The rated DC transfer current of bypass switch is equal to the rated short-time DC current.

5.11 Transient recovery voltage (TRV) related to rated

DC transfer current According to 5.10, the transient recovery voltage associated with the rated DC transfer current is a reference voltage. It constitutes the limit value of the expected transient recovery voltage of the circuit to be tolerated by the by-pass switch during transfer DC operation.

5.11 of GB/T 11022-1999 applies.

5.12 Rated closing current

The by-pass switch's rated closing current is equal to the rated short-time DC current.

5.12 of GB/T 11022-1999 applies.

5.13 Rating operation sequence

The rating operation sequence of by-pass switch is related to the rating characteristics. The rating operation sequence of by-pass switch is as follow. Closing-t1-openning-t2-cloding-t1-opening, in which. t1<=0.06s, t2< 15s.

5.13 of GB/T 11022-1999 applies.

5.14 Rated time parameters

It shall specify rated values for the following time parameters.

- opening time (empty loaded);

- break time;

- closing time (empty loaded);

- opening-closing time (empty loaded);

- reclosing time (empty loaded);

- closing-opening time (empty loaded). The rated time parameters are based on.

6.10 Interlocking device

6.11 Location instructions

6.12 Protection rating of enclosure

6.13 Creepage distance

According to by-pass switch used pillar insulator antifouling performance and withstand mechanical requirements, insulators can be divided into porcelain insulator, ceramic surface coating insulator and composite insulator.

Valve room equipment recommended creepage ratio is 14 mm/kV. Indoor DC switching field recommended creepage distance is 25 mm/kV. Outdoor insulator shall be determined according to the insulator umbrella, converter station contamination conditions and the insulator material.

6.14 Gas and vacuum sealing

6.15 Liquid sealing

6.16 Flammability

6.17 Electromagnetic compatibility (EMC)

6.18 Dispersion requirements for opening operation

Opening time dispersion shall be less than 2 ms.

6.19 General requirements for operation

The bypass switch and its actuator shall be capable of completing its rated operating sequence within the entire ambient temperature range of the temperature class specified in Clause 2 of GB/T 11022-1999.

7.1.3 Information contained in type test report

7.2 Insulation test

7.2.1 Atmospheric conditions for test

7.2.2 Wet test program

The by-pass switch installed outdoors shall withstand the wet endurance test under the standard wet test procedure specified in GB/T 16927.1.

7.2.3 By-pass switch state in insulation test

7.2.4 Criteria for passing test

a) DC voltage withstand test If no destructive discharge occurs, the by-pass switch shall be considered to have passed the test.

During wet test, if a destructive discharge occurs on the external self-restoring insulation, the test shall be repeated under the same test conditions.

If no destructive discharges occur again, the by-pass switch shall be considered successfully passed the test. […]