A switch-controlled metal oxide arrester

Abstract

The invention provides a switch control type metal oxide lightning arrester. A high-voltage end of the lightning arrester is connected with a circuit breaker by a power transmission line, a low-voltage end of the lightning arrester is connected with the ground, the circuit breaker is used for performing breaking and closing operation under control of a control system, the lightning arrester comprises unit sections which are sequentially connected in series in a vertical direction, each unit section comprises an external insulation sleeve and a metal oxide resistance sheet, the metal oxide resistance sheet is arranged in the insulation sleeve, two ends of a bottom unit section of the lightning arrester are connected in parallel with a control unit, the control unit comprises a rapid switch and a controller, the controller is connected with the rapid switch, the control system is used for sending a control signal to the controller before sending a closing or breaking command to the circuit breaker, so that the controller triggers the rapid switch to be switched on, and the bottom unit section is short-circuited after the rapid switch is switched on. With the lightning arrester provided by the invention, the residual voltage of the lightning arrester can be reduced on the basis of maintaining a performance parameter of the metal oxide resistance sheet for an existing lightning arrester unchanged, the protection level and the shock-resistant performance of the lightning arrester are improved, the closing resistance of the circuit breaker is omitted, and the cost is reduced.

Description

technical field [0001] The invention relates to a lightning arrester, in particular to a switch-controlled metal oxide lightning arrester. Background technique [0002] Starting from the ultra-high voltage (330kV ~ 750kV) power transmission system, the operating overvoltage has already played a controlling role in the insulation level of the power transmission and transformation equipment. The limit is getting lower and lower. In EHV and UHV transmission systems, the operating impulse discharge voltage of the air gap presents a saturation characteristic, and the operating overvoltage level has a greater impact on the cost and manufacturing difficulty of power transmission and transformation equipment. Therefore, it is necessary to deeply reduce the operating overvoltage multiple and select equipment reasonably Insulation level is very necessary. [0003] Surge arresters are the main devices for overvoltage protection in power systems. The arrester resistor has developed f...

AI Technical Summary

Problems solved by technology

Since the 1980s, researchers at home and abroad have discussed and studied the situation of the series and parallel discharge gaps of metal oxide arresters, but it is difficult to solve the dispersion of the gap discharge voltage, and the reliability of the arrester is poor.

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