一种基于电阻型超导限流器的高压直流断路器拓扑

A High Voltage DC Circuit Breaker Topology Based on Resistive Superconducting Current Limiter

针对传统高压直流断路器在开断故障过程中反应速度慢、短路电流上升速度快和峰值高等问题,结合超导技术和直流开断技术,提出一种基于电阻型超导限流器的高压直流断路器拓扑.该拓扑利用超导限流器的自动触发、快速响应以及失超后高阻值等优势,有效抑制了短路电流的上升率和峰值;在拓扑结构中加入电容自充电回路,有效解决了换流电容充电问题;合理配置全控和半控电子器件,使得断路器更加灵活可控;增加换向电容和限流电感等元件,加快了换流速度.在PSCAD/EMTDC平台上搭建320 kV/1.6 kA直流接地系统模型,仿真得出断路器故障分断电流峰值为3.5 kA,避雷器吸收能量为0.75 MJ,分断故障总用时5.9 ms,表明所提拓扑有更好的故障分断特性.

Aiming at the problems of slow response,fast rise of short-circuit current and high peak value of traditional high-voltage DC circuit breaker in the process of breaking fault,a high-voltage DC circuit breaker topology based on resistance type superconducting current limiter is proposed by combining superconducting technology and DC breaking technology.The topology effectively suppresses the rise rate and peak value of short-circuit current by taking advantage of the automatic triggering,fast response and high resistance after quench of superconducting current limiter.A capacitor self charging circuit is added to the topology so as to effectively solve the charging problem of the converter capacitor;Fully controlled and semi controlled electronic devices shall be reasonably configured to make the circuit breaker more flexible and controllable;The commutation speed is accelerated by adding commutation capacitors,current limiting inductors and other components.A 320 kV/1.6 kA DC grounding system model is built on PSCAD/EMTDC platform.The simulation results show that the peak fault breaking current of the circuit breaker is 3.5 kA,the absorbed energy of the arrester is 0.75 MJ,and the total breaking fault time is 5.9 ms,which proves that the proposed topology has better fault breaking characteristics.