Vacuum arc-extinguishing chamber contact for switching capacitor bank and control method thereof

Abstract

The invention provides a vacuum arc-extinguishing chamber contact for switching a capacitor bank and a control method thereof. The vacuum arc-extinguishing chamber contact includes a shielding cover, a movable conductive rod, a static conductive rod, a first contact, a second contact and a limiting resistor. One end of the limiting resistor is fixedly connected with the first contact and the other end of the limiting resistor is slidably connected with the static conductive rod. One end of the movable conductive rod is fixedly connected with the second contact. The movable conductive rod, the static conductive rod, the first contact, a second contact and the limiting resistor are disposed inside the shielding cover. The vacuum arc-extinguishing chamber contact reduces the amplitude of high-frequency inrush current generated when switching on the capacitor bank by using the limiting resistor, reduces welding damage of the high-frequency inrush current to the contact surface, restricts the recovery voltage when switching off the capacitor bank, reduces dielectric breakdown voltage withstand check of a vacuum arc-extinguishing chamber, and reduces the probability of repeated breakdown.

Description

technical field [0001] The invention relates to a vacuum interrupter contact, in particular to a vacuum interrupter contact for switching capacitor banks and a control method thereof. Background technique [0002] During the operation of the medium-voltage reactive power compensation system, due to frequent fluctuations in the grid load, in order to adjust the system power factor, reduce harmonics, stabilize voltage and reduce losses, capacitive loads will be frequently switched on and off. According to the operation experience of my country's power grid, 1.2kvar to 1.4kvar of reactive power is required for every 1kW of active power to maintain the normal working voltage of the power grid. According to foreign research and investigation, the application of vacuum circuit breakers in capacitive current operations can reach 300-700 times a year, that is, there are 1-2 opening and closing operations per day. For such frequent operating tasks, compared with other gas switches, ...

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the disadvantages of high re-breakdown probability, high cost, and difficult operation and control of vacuum interrupters in the prior art, a special physical phenomenon of switching capacitive loads in vacuum interrupters is proposed. The contact structure of the vacuum interrupter of the capacitor bank can effectively limit the amplitude of the high-frequency inrush current during the closing process, reduce its welding damage to the contact surface, and also effectively limit the recovery voltage during the opening process. Amplitude, reduce the insulation withstand voltage assessment of the vacuum interrupter, thereby reducing the probability of re-breakdown of the vacuum interrupter

Images