基于同步相量测量装置(PMU)的电压失稳预测(VIP)指标是基于本地相量测量数据进行电压稳定性分析的方法,它利用最小二乘拟合技术来实时跟踪系统的戴维南等值参数。拟合技术的应用条件和静态电压稳定性的物理意义会对这种指标的使用构成一定限制,若输入的采样数据不满足适当的争件,拟舍得到的等值模型没有实际意义,可能造成误判。文中剖析了曲线拟合计算戴维南等值参数时出现参数漂移的原因,据此提出了VIP指标的正确工作条件和有效性判据,确保无效的VIP值不会对运行造成误判。根据实际系统运行数据所做的算例验证了该判据的可靠性。
Voltage instability predictor (VIP) based on PMU is a method for analyzing voltage stability using local measurements and it employs the least squares fitting method to track the Thevenin parameters. The application of VIP is limited by the application conditions of curve fitting technique and the real meaning of the static voltage stability. The equivalent model is invalid if the input data set cannot meet appropriate limitation, and as a result the voltage stability situation will be misestimated. In this paper the underlying cause of the parameter drifting is analyzed and validity criterion is set up to determine whether the result of VIP is significant. Tests based on real electrical network operation show that the criterion is reliable,