一种基于高耦合分裂电抗器的500 kV限流器拓扑

A Topology of 500 kV Fault Current Limiter Based on a High Coupling Split Reactor

为限制500 kV及以上电压等级电网90 kA级别的短路电流,提出一种基于高耦合分裂电抗器的限流器拓扑。其中高耦合分裂电抗器一臂电感串联一组快速开关,与另外一臂电感并联,由快速开关控制限流器的投入。首先,对限流器的拓扑结构及工作原理进行了详细分析及改进,并通过小样机试验验证了其拓扑原理的有效性。然后,根据电网实际参数搭建了500 kV系统侧等值模型,通过限流器参数配置原则确定了500 kV、90 kA级别短路电流下的限流器参数,仿真得到此拓扑对90 kA级别短路电流限流深度超过40%,限流过程中过电压不会超过本体的绝缘要求。最后,为降低限流器对线路主断路器的影响,在限流器单模块两端并联1500 nF电容,给出了500 kV系统并联电容选取原则,验证了并联电容不会对限流器内部绝缘造成影响。

In order to limit the 90 kA-level short-circuit current of power grids where the voltage class is equal to or greater than 500 kV,a current limiter topology based on high coupling split reactor is proposed.The inductance of one arm of the high coupling split reactor is in series with a group of quick switches,and the inductance of the other arm is in parallel.The input of the current limiter is controlled by quick switches.Firstly,the topology structure and working principle are analyzed and improved in detail,and the validity of the topology principle is verified by small prototype tests.Then,a equivalent model of the 500 kV system on the basis of the actual power grid parameters is set up.Through the configuration principle of current limiter parameters,the parameters of current limiter of 500 kV-90 kA-level short-circuit current are determined.The simulation results show that this topology has a current limiting depth of over 40%for the 90 kA short-circuit current,and the over-voltage in the limiting process will not exceed.Finally,in order to reduce the influence of current limiter on the main circuit breaker,the 1500 n F capacitance is in parallel at both ends of the single module of the current limiter.The selection principle of the parallel capacitance of 500 kV system is given.And it is verified that the parallel capacitance will not impair the internal insulation of the current limiter.