基于连锁故障模型的感应电动机连锁堵转分析

Analysis on Induction Motor Cascading Stall Based on CASCADE Model

以包含感应电动机群的单负荷无穷大系统为对象,提出了适当假设条件下电动机群连锁堵转宏观规律的分析方法。该方法利用CASCADE模型的公式直接计算堵转规模的概率密度函数(PDF),避免了蒙特卡洛仿真,算例表明所述方法在中度连锁堵转条件下具有较好的精度。堵转规模影响因素的研究显示:刻画连锁堵转发生和传播的参数与负荷水平有较好的线性关系,从而在临界条件下,不发生连锁堵转的概率随负荷的增长而呈幂律下降;同期望堵转规模等值线间的间距反映了连锁堵转的传播状况,间距越小,堵转越易于传播,从而发生大规模连锁堵转的概率就越大;电动机群初始功率的分布和各电机初始功率的差异对堵转规模的PDF影响很小。

In the context of single load infinite bus system with load containing a group of induction motors,an analysis method for the macro law of induction motor cascading stall is proposed under certain assumptions.The method calculates the probability density function（PDF） of cascading stall directly using formula from CASCADE model and hence Monte Carlo simulations are no longer needed.Cases study verifies that the method can achieve good accuracy when cascading stall happens moderately.Studies of impact factors of cascading stall reveal that ①good linear relationship exists between load level and parameters for system initial shock and cascading propagation,and hence at critical condition,the probability of zero stall drops exponentially as load increases;②the space between contours of same expected stall number reflects the extent of cascading stall propagation,the smaller the space is,the easier cascading propagates,and hence,the bigger the probability of large scale of cascading stall is;and ③distribution of motor＇s initial power and differences among motors＇ initial power have little impact on PDF of cascading stall scale.