基于关键支路受扰轨迹凹凸性的暂态稳定判别及紧急控制

Transient Stability Identification and Emergency Control Based on the Convex Characteristic of the Key Branch's Disturbed Trajectory

基于局部受扰信息,判别大扰动冲击下互联电网暂态功角稳定性,具有本地量测信息量少、实时响应实时判别、稳定判别计算量小等突出技术优点。该文首先分析了稳定与失稳两种情况下,发电机相轨迹与网络交流支路相轨迹几何特征的一致性;提出了基于临界断面中交流关键支路受扰相轨迹凹凸性的暂态稳定判别新方法;通过与快速失步解列装置整定参数的协调配合,获得了具备工程实施条件的时间裕度,在防控暂态稳定的第二道防线失效时,可作为避免失稳的紧急追加控制措施;交直流混联外送电网和特高压跨大区互联电网仿真结果,均验证了稳定判别方法和紧急追加控制的有效性。

Identifying the transient stability with local disturbance information has such technical advantages as less information,faster computing,and more reliability.The consistency of geometric characteristics of the generator＇s phase trajectory and ac branches＇ phase trajectory were analyzed under stable and unstable occasion.A new transient stability assessment approach was put forward based on the characteristic concave or convex of the key ac branch＇s disturbed phase trajectory.On this basis,coordinating with the setting parameters of fast out-of-step separation device,the sufficient time margin can be obtained for the stable control of engineering implement.When the second defense line failed to prevent power system losing stability,it can be implemented the supplemental emergency control to restore the stability.Simulation results got from AC/DC hybrid sending system and UHVAC interconnected power system verify the effectiveness of the stability identified method and the supplemental emergency control.