一种改进串联谐振型限流器

An Improved Series-Resonant Type Fault Current Limiter

串联谐振型限流器(Series-Resonant type Fault Current Limiter,SRFCL)实现故障限流的关键是电容器的旁路(或短路)操作。本文通过引入双分裂电抗器,改变了电容器的旁路方法,实现了对串联谐振型限流器拓扑的改进。在理论上,分析了改进型串联谐振型限流器工作原理,并详细研究了限流过程中双分裂电抗器的电感变化特点。研究了电网稳态时双分裂电抗器绕组自感对限流电抗器和电容器的谐振关系的影响,和故障限流过程中绕组漏感对限流器的限流能力的调节作用和对电容器过流的抑制作用。通过建模仿真,分析了双分裂电抗器的漏感和电容器振荡电流的频率和幅值关系,研究了避雷器(MOV1和MOV2)残压与线路电流和电容器电流的关系。最后,在参数优化的基础上,设计和研制了一台400V改进型串联谐振型限流器样机,测试结果表明了双分裂电抗器能够提高串联谐振型限流器的可靠性和限流能力。

The principal technological of series-resonant type fault current limiter(SRFCL) to limit short-circuit current is bypassing the capacitor. In this paper, by introducing double-splitting reactor to change the bypassing method of capacitor,the topology of SRFCL is improved. Firstly, the working principle of improved SRFCL is analyzed theoretically, and the impedance variation characteristics of the double-split reactor is also studied in detail. For double-splitting reactor, the self-inductance of the winding can effect on the series-resonant relationship in steady state, the leakage inductance of the winding can enhance the limiting capability of SRFCL and suppress the over-current of capacitor in fault current limiting process. Through the modeling and simulation, the relationship between the leakage inductance of the winding and the current frequency and amplitudeis studied, and the relationship between the residual voltages of MOV1 and MOV2, and the currents of line and the capacitor are also studied. At last, based on the parameter optimization, a 400 V prototype of SRFCL is designed and manufactured. Test results show that double-split reactor can enhance the reliability and fault current limiting capability of SRFCL.