基于特征电压注入的UPFC接入线路三相自适应重合闸方案

输电线路自适应重合闸技术的难点在于故障性质的准确判别。针对统一潮流控制器(UPFC)接入线路的故障场景,利用UPFC灵活的可控性,文中提出基于特征电压注入的三相自适应重合闸方案。首先,通过切换UPFC串联侧模块化多电平换流器(MMC)控制方式,采用定U/f控制注入特征电压。在此基础上,通过判断线路是否产生特征电流识别永久性故障与瞬时性故障;针对高阻故障的特殊场景,进一步提出阶段性注入特征电流判据提高故障性质判别的可靠性。最后,利用PSCAD/EMTDC仿真平台验证了所提出的三相自适应重合闸方案的可行性和有效性。

Three-phase Adaptive Reclosure Scheme Based on Characteristic Voltage Injection for Transmission Line Equipped with Unified Power Flow Controller

The difficulty of adaptive reclosure technology for transmission line lies in the accurate identification of fault characteristics. Aiming at the scenario of fault on the line equipped with unified power flow controller (UPFC), a three-phase adaptive reclosure scheme based on characteristic voltage injection is proposed by using the flexible controllability of UPFC. Firstly, by switching the control mode of modular multilevel converter (MMC) on the series side of UPFC, the injection characteristic voltage is controlled by constant U/f. On this basis, permanent fault and transient fault are identified by judging whether the characteristic current is generated on the line. For the special scenario with high resistance fault, the staged injection characteristic current criterion is further proposed to improve the reliability of fault characteristic identification. Finally, the feasibility and effectiveness of the proposed scheme are verified by PSCAD/EMTDC simulation platform.