大电网失步解列难点问题及隔离策略初步构想

Difficulties and Preliminary Conception of Isolation Strategy on Power Grid Out of Step Islanding

为了提高失步解列措施在大电网条件的适应性基于大量实际电网稳定破坏事故和大电网仿真分析结果,总结梳理了稳定问题耦合出现、失稳模式复杂、隔离断面复杂、振荡中心跃迁情况复杂、电网解列装置配置复杂、故障暂态冲击严重等6类大电网失步解列难点问题;结合我国未来规划电网严重故障下稳定特征的一些新变化,引入广域信息,提出了基于广域信息的失步振荡解列和隔离措施及策略;并通过实际电网的仿真对所提控制措施的有效性进行了验证。结果表明:针对失稳模式复杂问题提出的基于机组受扰轨迹同调分群的多解列措施配合策略、针对多稳定问题耦合出现提出的综合故障抑制策略、针对电磁环网带来的隔离断面复杂问题提出的广义规划隔离措施以及故障冲击严重提出的切机措施均能实现失步振荡的有效隔离和抑制。研究结果可为大电网的稳定性研究提供参考。

In order to enhance the adaption of out of islanding measure under large grid circumstance, by analyzing a plenty of power system instability incidents and grid simulation result, we summarized difficulties of power grid out of step islanding with different instability problems such as coupling occurrence, various instability modes, complicated iso- lation interface structure, unexpected oscillation center migration, multiple islanding device coordination, and serious transient impact due to grid failure. Considering some new stability characteristics of China planning power grids, we proposed the corresponding islanding and isolation measures against oscillation in which wide-area information were in- troduced. The simulation results verified the validity of the presented measure. The results show that, aiming at some complex islanding difficulties, such as complex instability mode, multiple instability failure, intricate isolation interface caused by electromagnetic looped network, and severe grid fault impact, the presented measures are effective that the multi-splitting measure coordinated strategy, comprehensive failure control strategy, the generalized planning islanding and isolation measure and generator tripping are included. The research results can provide a reference for the study of grid stability.