含STATCOM输电线路的故障选相方法

Faulty Phase Selection of Transmission Line With STATCOM

含静止同步补偿器(static synchronous compensator,STATCOM)的线路发生故障时,若并补元件未退出运行,仍然向系统中注入无功补偿电流,会使故障相电压和部分非故障相电流升高,也会使突变量选相元件的部分故障特征发生变化,从而影响到现有的基于稳态量和突变量的故障选相。针对此种问题,提出一种基于STATCOM补偿度突变量时差特征的故障选相方法。利用回归分析得到STATCOM的补偿度在实测量中的模型,通过分析故障时各相补偿度突变量之间的时差特征,得出故障选相的判据。大量PSCAD仿真验证了方法的正确性,该方法能简单、快速、有效地实现并补线路故障选相和故障类型的判别。

In the situation that fault occurs in transmission line with STATCOM when the STATCOM is not out of service and still injects reactive compensating current into power grid, it makes the voltage of fault phase and the current in partial non-fault phase increased as well as partial fault feature of sudden change based fault phase selecting element changed. In allusion to it, a fault phase selection method based on the time difference characteristics of compensation degree sudden change of STATCOM is proposed. Using regression analysis a model of STATCOM compensation degree in measured quantity is put forward, and through analyzing the time difference characteristics among the sudden change of compensation degree in each phase during the fault a criterion for fault phase selection is obtained. The correctness of the proposed method is validated by a lot of PSCAD based simulation results, using the proposed method the fault phase determination of transmission line with STATCOM and the discrimination of fault type can be implemented simply, fast and effectively.