一种基于连续潮流的在线静态稳定综合评估方法

An On-line Voltage Stability Composite Assessment Method Based on Continuation Power Flow

基于负荷裕度计算的电力系统静态电压稳定评估已经成为现代能量管理系统中的一个基本任务。传统方法大多没有考虑负荷的静态电压特性,没有计及有载调压变压器分接头与并联电容器的自动投切、低压减载等动作的作用,也没有计及线路热约束及其继电保护动作造成的开断对于负荷裕度的影响。因此,电压稳定评估得出的功率裕度与实际脱节,无法满足安全预警与预防控制的需求。文中提出一种基于连续潮流技术的在线静态稳定综合评估方法,计及了负荷的静态电压特性,考虑了自动装置和线路保护动作的作用。对中国某省网系统的实际应用表明,该方法比传统方法更具有实用价值。

On-line voltage stability assessment （VSA） of power system based on load margin computation has been a basic module in modern EMS. However,the static load voltage characteristics,OLTC,switchable shunt capacitor,under-voltage load shedding are not considered in most VSA tools. Furthermore,the thermal limit violation induced branch outage is not considered either. Therefore,the maximal power limits obtained in VSA are not of practical significance,and not meet the security alarming and preventive control requirement. A novel on-line static VSA method based on continuation power flow technique is proposed. The effects of load voltage characteristics,automatic devices and relays of transmission lines are considered. The proposed method has been tested on a practical system in China. The numerical results show that the proposed method is more suitable for on-line voltage stability assessment.