A vacuum interrupter contact for switching capacitor banks and its control method

Abstract

The invention provides a vacuum interrupter contact for switching capacitor banks and a control method thereof, the contact includes a shield cover, a moving conductive rod, a static conductive rod, a first contact, a second contact and Limiting resistance; one end of the limiting resistance is fixedly connected to the first contact, and the other end is slidingly connected to the static conductive rod; one end of the moving conductive rod is fixedly connected to the second contact; the moving conductive rod, the static conductive rod, the second The first contact, the second contact and the limiting resistor are arranged inside the shielding case. The technical solution provided by the invention effectively limits the amplitude of the high-frequency inrush current generated when the capacitor bank is closed by installing a limiting resistor, reduces its welding damage to the contact surface, and limits the recovery voltage when the capacitor bank is opened, reducing the For the insulation withstand voltage assessment of the vacuum interrupter, reduce the probability of heavy 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, ...

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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

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