基于无迹变换法的配电网电压稳定指标概率分析及应用

Probability Analysis and Application of Voltage Stability Index of Distribution Network Based on Unscented Transformation

针对含间歇性分布式电源的配电网提出一种电压稳定指标概率分析方法,可对配电网电压稳定性进行合理分析且能帮助分析系统薄弱节点。首先,计及负荷功率和可再生电源出力的随机性建立配电网概率模型;然后,建立配电网电压稳定指标概率模型,通过电压稳定指标的均值和标准差分析电压稳定性的概率特征,利用无迹变换法将概率分析问题转化为确定性问题进行快速求解。以接入风机的配电网为例,采用中国西北实际风速数据和IEEE 33节点配电网系统进行算例分析,以蒙特卡洛模拟的计算结果为基准,验证了该文方法的准确性和高效性。最后,基于所提电压稳定指标概率分析方法对配电网电压稳定性进行改善,结果表明该文方法可以正确指导储能的优化配置,改善配电网电压稳定性。

A probabilistic analysis method of voltage stability index was proposed for the distribution network with intermittent distributed power,which could analyze the voltage stability of the distribution network reasonably and help to analyze the weak nodes of the system.First,considering the randomness of load power and renewable power output,a probability model of the distribution network was established;then,a probability model of the voltage stability index of the distribution network was established,and the probabilistic characteristics of voltage stability were analyzed by means and standard deviations of the voltage stability index.The probabilistic analysis problem was transformed into a deterministic problem for fast solution by the unscented transformation method.Taking the distribution network connected to the wind turbine as an example,the actual wind speed data of Northwest China and the IEEE 33 node distribution network system were used to analyze the examples.Based on the calculation results of Monte Carlo simulation,the accuracy and efficiency of this method were verified.Finally,the voltage stability of the distribution network was improved with the proposed voltage stability index probability analysis method.It was showed that the optimal configuration of energy storage could be guided correctly to improve the voltage stability of the distribution network by this method.