评估新能源多场站送出系统静态电压稳定的裕度比指标研究

Study on Margin Ratio Index of Static Voltage Stability of Multiple Renewable Energy Stations Delivery System

风电、光伏等新能源场站远距离、大规模的并网,导致场站并网点电压稳定较弱,严重制约电力系统的安全稳定运行。为此,该文提出一种能够评估新能源多场站送出系统静态电压稳定性的裕度比(static voltage stability margin ratio,SVSMR)指标。该指标根据不同场站送出功率的分配对多场站送出系统进行电抗拆分,基于单点静态电压稳定极限公式,解析推导出多场站送出系统静态电压稳定功率极限,进而得到适应新能源多场站接入场景的SVSMR指标。该指标是多点静态电压稳定功率极限的解析表达,直观体现了短路容量、新能源功率和不同新能源间电气距离对静态电压稳定性的影响,同时能够反映系统不同功率增长方式下静稳极限的变化。最后,使用PSD-BPA对所提指标进行了时域仿真验证,算例结果表明SVSMR可以准确衡量新能源多场站送出系统的静态电压稳定性及稳定裕度变化。

The voltage stability often becomes weak at the grid connection points of the renewable energy stations with long-distance and large-scale grid connections,such as the wind power and photovoltaics stations,which seriously restricts the safe and stable operation of the power system.Therefore,this paper proposes a static voltage stability margin ratio(SVSMR)index that may evaluate the static voltage stability of the delivery systems of the multiple renewable energy stations.This index splits the reactance of a delivery system according to the distribution of the power from different stations.Based on the single point static voltage stability limit formula,the static voltage stability power limit of the sending system is analytically derived,and then the SVSMR index adapted to the access scenario of the multiple renewable energy stations is obtained.As an analytical expression of the power limit of the multi-point static voltage stability,the index directly indicates the influences of the short-circuit capacity,the new energy power and the electrical distance between different renewable energy sources on the static voltage stability,and also reflects the changes of the static stability limit under different power growth modes of the system.Finally,the PSD−BPA is used to verify the proposed index in the time domain simulation.The numerical results show that the SVSMR is able to accurately measure the static voltage stability and the stability margin changes of the delivery systems of the multiple renewable energy stations.