定转子电阻对同步电机瞬态时间常数影响

Influence of stator and rotor resistances on transient time constant of synchronous machine

采用忽略部分定转子电阻影响的瞬态时间常数传统解析表达式计算同步电机瞬态特性时会产生一定的误差。为解决该问题,推导了计及定子电阻的直轴瞬态时间常数改进解析表达式和计及转子电阻的定子非周期瞬态时间常数改进解析表达式,通过7.5 kW模型机试验及时步有限元方法验证了该解析表达式的正确性。采用该解析表达式计算了瞬态时间常数随定转子电阻变化的规律,发现不同定转子电阻下,利用改进表达式计算瞬态时间常数的精度明显高于传统方法。

When the traditional analytical expression of transient time constants is adopted to calculate the transient performance of synchronous machine,if the influences of stator and rotor resistances are partly neglected,the calculative results may be inaccurate. An improved analytical expression of direct transient time constant considering the stator resistance and an improved analytical expression of stator aperiodic time constant considering the rotor resistance are deduced. Their correctness is verified by the 7.5 kW prototype test and time step finite element method. The variation laws of transient time constant vs. the stator and rotor resistances are calculated by the improved analytical expressions and it is found that,the accuracy of transient time constant calculated by the improved analytical expressions is higher than that by the traditional method under different stator and rotor resistances.