基于预充电换相电容的直流故障限流器

DC Fault Current Limiter Based on Precharge Commutation Capacitor

直流电网在电力系统中所占的比重越来越高,而直流电网中故障清除一直是研究的热点和难点。该文提出一种基于预充电换相电容的直流故障限流器,该限流器通过预充电换相电容实现限流电阻和限流电感的投入,合理利用电路原理和元器件特性实现限流器投入电网。同时,通过创新拓扑结构实现双向限流。该文对该限流器的拓扑结构、工作原理、控制模式和电气应力进行研究,阐明故障电流在限流器作用下发展的整个过程。并利用PSCAD/EMTDC仿真验证方案的可行性。研究结果表明,该文所提限流器能够有效抑制故障电流增长,减缓故障电流上升速度,并具有较好的经济性,适用于高压直流输电。

The proportion of DC power grid in the power system is increasing,and fault current clearance in DC power grid is always the hot and difficult point in research.This paper presented a new type of DC fault current limiter(FCL)based on precharge commutation capacitor.The fault current limiter realized the input of resistor and reactor through precharge commutation capacitor and the fault current limiter was inserted into the power grid by reasonable utilization of circuit principle and component characteristics.At the same time,bidirectional fault flow limiting was realized by innovating topological structure.The topological structure,working principle,control method and electrical stress were studied in this paper,and the whole process of fault current development under the action of current limiter was explained.PSCAD/EMTDC simulations were used to verify the feasibility of the scheme.The results show that the fault current limiter proposed in this paper can effectively restrain the fault current growth and slow down the fault current rising speed,and has good economy,which is suitable for HVDC transmission.