基于稳定域及条件概率的暂态稳定不确定性分析

Non-deterministic Analysis for Transient Stability Based on Transient Stability Domain and Conditional Probability

以随机变量可信区间内最严重的取值为基本工况,利用稳定裕度及其灵敏度分析技术计算连续参数空间中的稳定域边界;根据概率分布密度函数,计算不确定工况处于该稳定域内(或其外)的联合概率,得到系统稳定(或失稳)的概率。在分析不同的2维参数稳定域的基础上,给出由负荷水平、故障位置与故障切除时间构成的3维参数稳定域。同时,采用条件概率方法处理电网拓扑、故障元件和故障类型等离散型随机变量。将条件概率方法与稳定域方法相结合,计算电力系统的失稳概率。定义新的风险指标来评估失稳风险。对IEEE 39节点和山东500kV系统的仿真表明该方法具有较好的实用价值。

Taking the most serious value within the credible region of each stochastic variable as the basic operating condition, the transient stability domain （TSD） in continuous parameter space is estimated by using stability margin and its sensitivity analysis technologies. The probability of the non-deterministic condition that is inside （or outside） the TSD is calculated by using the joint probability density function, namely the stability （or instability） probability. The 3-dimension TSD consisting of load level, fault location on a line and fault clearing time is estimated. Meanwhile, discrete random variables including system configuration, faulted element and fault type are handled with conditional probability. The whole instability probability is then computed. A new risk index is also defined to evaluate the instability risk. Simulations on IEEE 39-bus system and 500 kV Shandong system show that the proposed method is effective and practical.