直流分量时间常数对断路器非对称开断性能影响分析

Analysis of Direct Current Component Time Constant In?uence on Asymmetrical Breaking Ability of Circuit Breakers

从短路电流的有效值、燃弧时差、电弧能量等方面分析了直流分量时间常数对断路器非对称电流开断性能的影响,给出了非对称短路计算模型及计算方法。结果表明直流分量时间常数越大,短路电流中直流分量越大且衰减越慢,燃弧时差越大,电弧能量越大,电流过零时di/dt降低,TRV参数亦有所降低,且非对称电流开断时,直流分量时间常数增大将导致断路器的开断条件变得苛刻。

This paper analyzed the direct current (DC) component time constant influence on asymmetrical current breaking ability of circuit breakers fromthe aspects of effective value of short-circuit current, difference of arcing time, arc energy and so on, and gave the calculation model and method of asymmetricalshort-circuit. The results show that the bigger the DC component time constant is, the bigger the DC component in short-circuit current is, the slower theattenuation is, the bigger the difference of arcing time is , the bigger the arc energy is. When the current is zero, the parameters of di/dt and TRV are decreased.When the asymmetrical current cuts off, the increase of the DC component time constant will make the breaking conditions of circuit breakers more rigorous.