Analysis and clarification of vacuum degree reduction of vacuum switch dedicated for high-voltage reactive power compensation

Analysis and clarification of vacuum degree reduction of vacuum switch dedicated for high-voltage reactive power compensation

The reduction in vacuum degree will seriously endanger the overvoltage breaking ability of the vacuum switch dedicated to high-voltage reactive power compensation, which will then cause the service life of the isolation switch to drop sharply, and in obvious cases, it will cause the switch to explode. The vacuum degree in the vacuum interrupter tube generally needs to be maintained at 10-4~10-6Pa. With the rapid increase in the use time of the vacuum interrupter, the frequency of interruptions increases, and it is restricted by external conditions, and its vacuum degree gradually declines. , reduced to a certain extent, will affect its breaking capacity and pressure resistance level. Therefore, the high-voltage vacuum switch must regularly maintain the vacuum in the arc extinguishing chamber tube during use, and pay attention to safety inspections and observations of the action of the isolating switch at any time during actual operation.

For the laminated glass casing vacuum arc extinguisher, it can be estimated on time during inspection. Normally, the surface color of the internal anti-interference magnetic ring and other parts should be very bright, and light blue light will emit when the current is interrupted; when the vacuum degree is severely reduced, the color of the internal structure will also become dim, and when the current is interrupted, A deep red electric light emitted from the handle. When the above situation occurs during operation, it can be analyzed and judged that the vacuum degree of the arc extinguishing chamber of the vacuum switch dedicated for high-voltage reactive power compensation has decreased, and it needs to be clarified in time according to the experimental method. 

During inspections, operators need to pay attention to whether there is any discharge phenomenon outside the vacuum interrupter of the isolating switch. If there is discharge phenomenon, most of the vacuum degree test results of the vacuum bubble will not pass, and the power needs to be cut off and replaced in time. In order to ensure the safety of electrical equipment, electrical equipment must be maintained and tested regularly. Through a series of inspection technical means and by inspecting the overall working condition of the isolating switch, the safety hazard of reduced vacuum degree of the high-voltage vacuum switch can be clearly discovered in time. The vacuum degree of the vacuum switch dedicated for high-voltage reactive power compensation can generally be determined as follows: Experiment to check:

1. Special vacuum switch for reactive power compensation: Vacuum degree tester inspection: Use a vacuum degree tester to accurately measure the vacuum degree of the arc extinguishing chamber.

Ensure that the vacuum degree of the vacuum arc extinguisher is maintained within the range of 10-4~10-6Pa; if the vacuum degree drops beyond the above or the specified value in the product manual, further operate the isolating switch under the opening conditions of the vacuum arc extinguisher. Conduct a power frequency withstand voltage test on the fracture surface to confirm.

2. Special vacuum switch for reactive power compensation: Power frequency withstand voltage test: According to the relevant provisions of the "Preventive Test Regulations for Electric Power Equipment", high-voltage vacuum switches of 12Kv and below need to conduct power frequency withstand voltage at least once after 1 to 3 years. The experiment mainly includes the two colors of the isolating switch, the relative ground of the isolating switch, and the fracture surface of the isolating switch.

Among them, the AC withstand voltage test on the fracture surface of the isolating switch can, on the one hand, check whether the opening distance of the acoustic circuit breaker of the isolating switch meets the standard; on the other hand, it can judge whether the vacuum of the high-voltage vacuum switch has reduced auxiliary basis after being detected by the vacuum meter. When the high-voltage vacuum switch audible circuit breaker reaches the rated opening distance condition, if the pressure resistance is relatively low and cannot meet the required pressure resistance standards, it means that the vacuum degree of the vacuum interrupter has been significantly reduced and cannot be used normally.