摘要
由于光伏场站的弱馈性,当送出线路发生经过渡电阻短路时,传统距离保护可能无法正确动作。而自适应距离保护方案在一定程度上解决了区内故障保护拒动的问题,但存在区外故障误动的可能。首先分析了区外故障时自适应距离保护误动的原因,进而提出了一种自适应距离保护的改进方案。在现有自适应距离保护的动作特性基础上,引入线路的短路阻抗,根据区内、外故障下线路短路阻抗的大小差异,构成保护的辅助判据,以甄别可能引起现有自适应距离保护误判的区外故障。该方法仅依靠光伏侧电气量近似求取线路短路阻抗值,与现有自适应距离保护相互配合实现区内、外故障正确判别。最后通过PSCAD仿真验证了改进方案的有效性。
When non-metallic faults occur on the outgoing line of the photovoltaic(PV) power station, the performance of traditional distance protection may be deteriorated due to the weak-infeed property of the PV power station. The existing adaptive distance protection scheme can improve the performance of the distance protection to some extent, but there is the possibility of mal-operation when the external fault occurs. Firstly, the reasons for mal-operation of adaptive distance protection are analyzed when the external fault occurs, and then an improved scheme for adaptive distance protection is proposed. Due to the defects of adaptive distance protection, the short-circuit impedance of the line is introduced. According to the difference of the short-circuit impedance under internal fault and external fault, the auxiliary criterion is formed to identify external faults which may result in the mal-operation of the existing adaptive distance protection. The new scheme only needs the PV side electric quantities to obtain the short-circuit impedance approximately, and cooperates with the existing adaptive distance protection to distinguish internal and external faults. Finally, the simulation based on the PSCAD verifies the proposed scheme.
作者
王峰渊
方愉冬
赵萍
郑远德
周再兵
郑涛
王铭灏
黄予园
WANG Fengyuan;FANG Yudong;ZHAO Ping;ZHENG Yuande;ZHOU Zaibing;ZHENG Tao;WANG Minghao;HUANG Yuyuan(State Grid Zhejiang Electric Power Company,Hangzhou 310007,China;Taizhou Power Supply Company,State Grid Zhejiang Electric Power Company,Taizhou 318000,China;State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources,North China Electric Power University,Beijing 102206,China)
出处
《电力系统保护与控制》
EI
CSCD
北大核心
2019年第20期127-134,共8页
Power System Protection and Control
基金
国家重点研发计划智能电网技术与装备重点专项资助(2016YFB0900600)~~
关键词
光伏场站
弱馈性
自适应距离保护
短路阻抗
辅助判据
PV power station
weak-infeed property
adaptive distance protection
short-circuit impedance
auxiliary criterion
