直流断路器在短路电流下稳定性分析

Stability analysis of the DC breaker at short-circuit current

当电力系统发生短路故障时,断路器主回路触头会产生很大的电动斥力,可能会造成断路器触头机械变形或熔焊,从而无法切断短路电流实现保护功能。本文以某型直流断路器为研究对象,提出了一种具有电动力补偿功能的触头结构,分析了其在短路电流下动稳及热稳定性,并对其电动斥力及瞬态温升进行有限元仿真计算,最后断路器通过了短时耐受短路电流试验,验证了仿真计算方法的可行性。

When a short circuit fault occurs in the power system,contact of the main circuit breaker will produce great electric repulsion,which may cause mechanical deformation or melt welding of the contact.Thus,it is impossible to cut off the short circuit current to achieve protection function.This paper studies a certain DC breaker,proposes a contact structure with electrodynamic force compensation,analyzes its dynamic stability and thermal stability under short-circuit current,and performs finite element simulation of electric repulsion and transient temperature rise.Finally the breaker passes the short-term tolerant short-circuit current test to verify the feasibility of the simulation calculation method.