发电机出口断路器选型分析

Type selection analysis of generator circuit breaker

针对大机组发电机出口断路器选型中校验开断短路电流的技术难点,通过对某大型机组发电机出口短路电流的计算,对于计算中出现的发电机出口断路器无法分断系统源非对称短路电流的问题,根据电弧电阻试验结果分析了动静触头分离时刻和电弧电阻对断路器分断短路电流的能力和灭弧性能的影响,为设备选型提供依据。

In view of the technical difficulties in verifying the breaking short-circuit current in the generator circuit breaker selection of large units, the outlet short-circuit current of large generating unit is calculated. In the calculation, there is a problem that the generator circuit breaker（GCB） cannot break the asymmetrical short-circuit of the power system. According to the results of the electric arc resistance test, the influence of the separation time of the dynamic and static contacts and the electric arc resistance on the ability of breaking the short-circuit current by GCB and the arc extinguishing performance are analyzed, which provided the basis for the equipment selection.