基于动态仿真的连锁故障分析

Cascading Outage Analysis Based on Dynamic Simulation

提出一种基于长期动态仿真的电力系统连锁故障模型。该模型不仅考虑了动态过程中机组保护、变压器励磁保护、低频/低压减载、线路过载与短路故障、解列等因素,而且充分考虑了随机因素对这些保护元件的影响,可较为准确、有效地模拟电力系统连锁故障。基于PSS/E,采用蒙特卡罗算法对实际电网予以仿真,结果表明,停电规模—频次基本符合幂率分布且存在临界点,当故障规模超过临界点时系统幂尾特性发生变化且停电规模及其概率迅速增大,临界点的提出对预防大停电有参考价值。

A cascading outage model based on dynamic simulation is developed and analyzed in this work together with its stochastic counterparts, such as stochastic characters of generator frequency/voltage protection, under-frequency/under-voltage protection, over-excitation, overload, short circuit and the tripping time. The model captures the fundamental dynamic characteristics of power systems and is valid for studying system cascading outage. Based on PSS/E platform and Monte Carlo method, a test on practical system is given which shows the curve of outage scale versus outage frequency obeys the exponential distribution and has critical points. When the critical point is exceeded, the outage size and its probability rise rapidly and the power law is changed. Detection of critical points can provide helpful information for blackout prevention.