This standard specifies the terms, rated parameters, test methods and test reports for disconnectors breaking and closing busbar transfer currents. This standard applies to AC high-voltage disconnectors with rated voltages of 63 kV and above that have the ability to break and close busbar transfer currents. JB/T 6462-1992 AC high-voltage disconnectors breaking and closing busbar transfer current test JB/T6462-1992 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
Test of Bus Transfer Current for AC High Voltage Disconnectors 1 Subject Content and Scope of Application
JB/T6462-1992
This standard specifies the terms, rated parameters, test methods and test reports for disconnectors to open and close bus transfer currents. This standard applies to AC high voltage disconnectors with rated voltages of 63kV and above and capable of opening and closing bus transfer currents. Note: Disconnectors with rated voltages below 63kV may also open and close bus transfer currents, however, it is usually not required to take the disconnector opening and closing bus transfer current test as a type test. If the test is to be carried out, the user shall negotiate with the manufacturer. 2 Reference Standards
GB2900.1 Electrical Terminology Basic Terminology
GB2900.20 Electrical Terminology High Voltage Switchgear 3 Terminology
According to GB2900.1 and GB2900.20, and the following terms are supplemented. Bus transfer current of disconnector (hereinafter referred to as bus transfer current) 3.1
Bus transfer current is the current that the disconnector must open and close when it transfers the load from one bus system to another bus system.
Bus transfer voltage of disconnector (hereinafter referred to as bus transfer voltage) Bus transfer voltage is the working voltage that appears on the disconnector break after the disconnector breaks the bus transfer current or before closing the bus transfer current.
4 Rated value
4.1 Rated bus transfer current
The rated bus transfer current is the maximum current that the disconnector should be able to open and close under the rated bus transfer voltage. Regardless of whether it is a gas or air insulated disconnector, its rated bus transfer current is specified as 80% of the rated current, but the maximum value does not exceed 1600A. This value has nothing to do with the rated current of the disconnector. Note: When the rated bus transfer current exceeds 80% of the rated current or is greater than 1600A, the manufacturer can order it separately from the user. 4.2 Rated bus transfer voltage
The rated bus transfer voltage is the maximum power frequency voltage when the disconnector opens and closes the rated bus transfer current. The rated bus transfer voltage value is shown in Table 1.
Table 1 Rated busbar switching voltagewww.bzxz.net
Rated voltage
Air insulated disconnector
V (effective value)
Gas insulated disconnector
V (effective value)
Rated voltage
JB/T6462-1992
Continued Table 1
Air insulated disconnector
V (effective value)
Note: When the busbar switching voltage exceeds the rated value in Table 1, the user shall negotiate with the manufacturer. 5 Test method
5.1 Arrangement of the disconnector under test
Gas insulated disconnector
V (effective value)
The disconnector under test shall be installed on its own bracket or an equivalent bracket. Its operating mechanism shall be operated in the prescribed manner. For electric (pneumatic, hydraulic) operating mechanisms, the operating electric (gas, hydraulic) pressure during the test should be the specified minimum value. Before the opening and closing tests, no-load operation should be carried out and the operating characteristics of the disconnector, such as travel, speed, opening time and closing time, should be recorded.
For gas-insulated disconnectors, the gas density during the test should be the specified minimum value. For disconnectors equipped with manual operating mechanisms, power operation may be used for remote control during the test. In this case, the speed of power operation must be equivalent to that of manual operation.
If the following conditions are not more favorable during the single-phase test than the three-phase test, the three-pole disconnector can only be tested in a single-phase test: Closing speed;
1. Opening speed;
2. The influence of adjacent phases.
Note: The arcing time and arcing distance provided during the single-phase test can only indicate the breaking and closing performance of the disconnector, but the influence of adjacent phases is not assessed. Therefore, for some structures of disconnectors, three-phase tests are required or single-phase tests are performed using methods equivalent to three-phase tests. 5.2 Grounding of test circuits and disconnectors
The bracket of the disconnector should be grounded, and the test circuit should be grounded according to Figure 1: Either of the two test circuits can be used. See 5.6. 5.3 Test frequency
The disconnector should be tested at the rated frequency, and the frequency tolerance is ±10%. 5.4 Test voltage
The test voltage should ensure that the rated busbar conversion voltage meets the requirements of Table 1, and its tolerance is 0 to +10%. The test voltage should be measured immediately after the current is interrupted. The measuring point should be as close as possible to the two ends of the disconnector, and there should be no obvious impedance between the measuring point and the disconnector terminal. If a three-phase test is required, the test voltage should be the average value of the three-phase test voltage, and the difference between the test voltage of each phase and the average value should not exceed 10% of the average value.
After disconnection, the duration of power frequency recovery voltage should not be less than 0.3s. 5.5 Test current
The test current should be equal to the rated busbar conversion current, and its allowable deviation is 0~+10%. The test current should be measured before the disconnection operation of the disconnector.
The current to be disconnected should be a symmetrical current with minimal attenuation. The contacts of the disconnector should not be separated until the transient current caused by the closing circuit disappears.
If a three-phase test is performed, the test current should be the average value of the three-phase test current. The difference between the test current of each phase and the average value should not exceed 10% of the average value.
5.6 Test circuit
Field test or laboratory test can be carried out. The test circuit of the laboratory is shown in Figures 1A and 1B, and the power factor does not exceed 0.15. For the convenience of testing, any of the test circuits can be used. The characteristic parameters U and ZT of the components in the test circuit are selected according to the required test current and test voltage. If a three-phase test is required, each phase of the three-phase test circuit should contain the same components as the single-phase test circuit in order to meet the test current and test voltage requirements of JB/T6462-1992
. The neutral point of the power supply circuit should be grounded. Note: ① Other test circuits that can produce the required test current, test voltage and appropriate transient recovery voltage parameters can also be used. ② For gas-insulated disconnectors, there are generally no problems with the insulation of the live circuit to the ground during the opening and closing tests. If in doubt, the rated relative voltage of the screened switch can be applied to the housing of the isolation switch for testing. This requires an independent voltage source. In field tests, it is generally impossible to obtain the test voltage and test current required by the isolation switch. These requirements can be relaxed through negotiation between the user and the manufacturer.
Tested disconnector
A test circuit
Tested disconnector
B test circuit
Figure 1 Test circuit for busbar transfer current breaking and closing test Ur—test voltage
Isr——rated busbar transfer current
5.7 Transient recovery voltage
—impedance
Due to the influence of the wave impedance of the connected busbar system, the expected waveform of the transient recovery voltage should be a triangular waveform, and the wave impedance of air-insulated disconnectors and gas-insulated disconnectors is very different. However, for the convenience of testing, the transient recovery voltage waveform can adopt a (1-cos) waveform. Its oscillation frequency should not be less than 10kHz, and the expected amplitude coefficient should not be less than 1.5. Note: ④ A transient recovery voltage branch can be added to the test circuit. The arc voltage of the disconnector under test is relatively high compared with the test voltage, which will cause a rapid decrease in the recovery voltage and a phase shift of the current, making the phase of the test current closer to the phase of the test voltage. Therefore, the recovery voltage parameters (rate of rise and peak value) are not obvious and do not need to be specified in detail.
5.8 Number of tests
The number of tests is shown in Table 2.
Operation cycle
Close-break\Operation cycle (times)
JB/T6462-1992
Table 2 Number of tests
Air insulated disconnector
General
Performing high-frequency busbar switching
Operation
Gas insulated disconnector
General
Note: The number of "close-break" operation cycles does not represent the number of electrical life of the disconnector. The wear of the contacts should be provided. The breaking operation should be performed after the closing operation and after a certain delay, at least until the transient current disappears. During the test, maintenance of the disconnector is not allowed. 5.9 Performance of the disconnector during the closing and breaking test The disconnector should be successfully tested without mechanical or electrical damage. During the
test of the
operation of the frequency-purple busbar conversion, arcs or metal particles appearing on the disconnector that are ejected or splashed outward are allowed if they do not affect the insulation level of the disconnector and are guaranteed not to endanger the operator. 5.10 Status of the disconnector after the closing and opening test The mechanical and insulation properties of the disconnector should be basically the same as before the test, and the loop resistance should not exceed the value specified in the product technical conditions. If there is any doubt, a temperature rise test should be carried out to verify. If the mechanical operation and mechanical characteristics of the disconnector meet the requirements of the product technical conditions, it is considered that the burning and corrosion caused by the arc are acceptable.
Arc contacts or other specified replaceable parts can be burned; the performance of the arc extinguishing material will also be reduced to below the normal level due to arc burning; the surface of the insulator will also deposit arc extinguishing medium and decomposition products of the contact material. However, the insulation level between the disconnector breaks and relative to the ground should not be reduced, and the insulation level of the insulating parts adjacent to the disconnector breaks should meet the requirements of the disconnector in the relevant standards. Visual inspection and no-load operation of the disconnector are usually sufficient to verify whether the above requirements are met. If there is any doubt, additional relevant tests can be added for further verification.
For gas-insulated disconnectors, in order to facilitate the test, the withstand voltage test between the breaks and relative to the ground should be carried out at 80% of the rated power frequency withstand voltage or 80% of the rated operating impulse withstand voltage. 5.11 If the manufacturer has evidence that a disconnector with a given structural principle can meet the requirements of the opening and closing operation mode of the busbar transfer current, then other disconnectors of the same series with the same or smaller rated busbar transfer voltage and rated busbar transfer current do not need to be subjected to this type test. If there is any doubt, the test shall be carried out under the conditions agreed between the user and the manufacturer. 6 Type test report
All type test results shall be recorded in the type test report. The report shall include sufficient data to prove that the tested disconnector complies with this standard. The type test report shall also include sufficient information for the identification of the important components of the tested disconnector. The test report shall make a clear conclusion on whether it is qualified or not.
The test report should include the following information:
Typical oscillogram or similar record;
Test circuit;
Test voltage;
Test current:
Power frequency recovery voltage;
Expected transient recovery voltage:
Number of breaking and closing operations;
Provide the energization time of the trip coil (if any); Test power frequency,
Withstand voltage after test,
JB/T6462-1992
It should also include the general situation of the supporting structure of the disconnector, and the separation time, closing time and form of the dry-action mechanism of the disconnector should be recorded.
Additional remarks:
This standard is proposed and managed by the National Technical Committee for Standardization of High Voltage Switchgear. This standard is drafted by Shenyang High Voltage Switch Factory. The main drafters of this standard are Gao Yongwu, Zhong Baojiao, Jin Naifu and Ke Zili.
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