基于支路电压方程的在线电压稳定指标

提出一种基于支路电压方程的电压稳定指标,该指标具有显式表达式,可结合PMU量测实现在线计算和应用。首先,利用电压功率灵敏度在电压崩溃点趋于无穷大的特性,推导获得该指标。其次,通过分析静态负荷特性对该指标假设条件(即P-V曲线电压崩溃点处特性)的影响,揭示了该指标对静态负荷特性的适应性,并用单支路系统进行了仿真验证。进一步,采用多支路系统验证了该指标可有效表征支路电压的稳定性,且具有较高的适用性。最后,探讨了应用等效方法改进该指标,从而提升多节点系统中该指标准确性的方法,并用10节点系统验证了改进指标的有效性。

A New On-Line Voltage Stability Index Based on Voltage Equation of the Branch

This paper proposes a new on-line voltage stability index based on the voltage equation of the branch.The proposed index has an explicit expression,which can be calculated with the on-line PMU data,and is suitable for online applications.First,the paper derives the index with the characteristic that the sensitivity of voltage to power tends to be infinite at the voltage collapse point.Then,it discusses the impacts of load characteristic on the proposed index,and the simulation results with the single-branch system reveals the adaptability of the proposed index to the static load.Furthermore,it presents the simulation results in multi-branch system to verify the effectiveness of the proposed index.Finally,it discusses the improvement to the proposed index with the equivalence method,and the enhancement of the effect of the improved index is verified with the simulation results in a 10-bus system.