基于改进戴维南等值方法的电压稳定裕度研究

Study of Voltage Stability Margin Based on the Improved Thevenin Equivalent Method

为了更好的应用电力系统同步相量测量装置(phasor measurement unit,PMU)测量数据评估系统的电压稳定性,本文提出利用戴维南等值参数求取电压稳定裕度的改进方法。加入初值优选环节,全面考虑戴维南等值参数和节点电压电流不断变化的关系,把每一时刻求出的戴维南等值参数作为下一时刻的计算初值,逐步迭代求解。基于单个电压稳定裕度指标估算的局限性,根据系统本身的特性,求出了阻抗模裕度指标和角度裕度指标的加权平均值表征电压稳定裕度。通过对IEEE39节点系统的仿真分析,证明了其准确性和有效性。该研究能准确的反应系统的电压稳定性,提高表征的精度和准确性,具有一定的实际应用价值。

The existing algorithm based on thevenin equivalent differential on initial value is highly dependent on the initial value selection,adding links.Considering the constant change of thevenin equivalent parameters and the change of node voltage and current,the Thevenin equivalent parameter at each moment is calculated as the initial value of the next time,and then solved iteratively.In order to better use power system phasor measurement unit(phasor measurement unit,PMU)to evaluate voltage stability of measurement data of the system,the thevenin equivalent parameters are adopted to obtain improved.This method can not only track thevenin equivalent parameters quickly and accurately but also avoid the equivalent parameter instability.According to the operating characteristics of the system,we calculate the weighted thevenin equivalent impedance modulus margin index and angle margin index average value of voltage stability margin based on characterization.According to the operating characteristics of the system,we calculate the weighted thevenin equivalent impedance modulus margin index and angle margin index average value of voltage stability margin based on characterization.The simulation and analysis of the IEEE39 node system show its accuracy and effectiveness.