基于功角测量和等面积法则的发电机暂态稳定在线判别研究

Generator based on power angle measurement and equal area rule On line identification of transient stability

基于相量测量单元(PMU)的广域测量系统将电力系统的安全稳定监测提高到了动态水平,其中一个关键功能是发电机功角的直接测量。本文将功角测量和等面积法则相结合,用以快速判别电力系统的暂态稳定。该方法能够在线实时判别电网故障的发生和切除、根据实测功角数据计算加速面积、预测最大可能的减速面积,从而根据加速面积和减速面积的差值来判断暂态稳定性。该方法预测耗时短,可在故障切除后80ms内给出判断结果并提供稳定裕度信息。仿真结果一方面证明了其可行性;另一方面也表明,受PMU本身数据上传速率的影响,加速面积的预测值可能偏小,当加速面积和减速面积非常接近时,应采用其他辅助分析手段协助判别暂态稳定性。

The phasor measurment unit (PMU) based wide area measurement system (WAMS) pushes the monitoring and control of the power system into a dynamic level. One of the key functions of PMU and WAMS is rotor angle measurement. This paper proposed a transient stability detecting method by using measured rotor angle and equal area criterion. This method can on line detect the occurrence and abscission of the grid fault, can calculate the acceleration area in real time by measured rotor angle, can forecast the maximun deceleration area fastly atfer the fault abscission. This method can detect the transient stability and give the stability margin information within 80ms after the fault cleaned by comparing the dimensions of acceleration area and maximun deceleration area. The simulation result shows the effectiveness of this mehod. And it also shows that the maximun deceleration area may be reduced because of the data uploading interval of the PMU. Therefore, some other stability detecting method is suggested to be used to help making decision of transient stability when the dimensions of acceleration area and maximun deceleration area are very close.