252kV自能SF6断路器开断能力的研究和提高

Research and Improvement on the Breaking Capacity of 252 kV Self-energy SF_6 Circuit Breaker

提高电力系统元件的可靠性是提高电力系统可靠性的重要措施。笔者主要从优化断口间的绝缘结构、改善介质状况和增强热膨胀效应方面来提高断路器的开断能力。所研究的252 kV断路器总体设计方案采用双室+双动的自能式灭弧室结构和触头运动方式,并结合定型产品的设计经验进行了关键结构参数的设计优化:确定热膨胀室和压气室的容积及其配合问题,保证了大电流开断的可行性;利用电场分析软件,对断路器的关键部位的电场强度进行了计算、分析和优化;为了抑制由电弧引起的气体密度的下降,加强热气体的排放效率,进行了导气流通道的改进,改善了介质状况。所研制的断路器通过全部型式试验,并已投入生产,同时为后续产品的研发提供了技术平台。

By improving of the dielectric construct between the breakers, medium condition and thermal expansion effect, the breaking capacity of circuit breaker is increased. The main construct of the 252 kV circuit breaker is determined in which double chamber of interrupter construction ＋ dual-direction moving of contacts mode are introduced. The key structure design parameter has been optimized combined with the design experiences of the finalized product： The volume of thermal expansion chamber and puffer chamber as well as the coordination between them are determined which ensures feasibility of the high breaking current. Electric field analysis software is used to calculate, analyze and optimize the electric field strength between the circuit breaker contacts in some sensitive positions. Improving gas flow channel for the decrease of the gas density is restrained and the hot gas exhaust efficiency is increased. As a result, the medium condition is improved. ＇All the test verification has achieved for the researched and developed circuit breaker, and the product have been on stream. In the meantime, it provides the new technical foundation for the various following switchgears.