直流超导限流器实用化的技术要求

Technical Requirement for Practical Application of DC Superconducting Current Limiter

直流系统发生故障后故障电流会迅速增加并达到峰值,由于直流系统没有电流过零点,给直流断路器切断故障断流带来了困难,且开断的暂态过程中系统内设备会承受较大电压应力。使用直流超导故障限流器(Superconducting Fault Current Limiter,SFCL)来限制故障电流可以缓解此问题。因此,首先介绍了不同类型的直流SFCL,然后分析了直流SFCL的限流要求。为了满足这些要求,提出了直流SFCL的一些基本技术指标。直流SFCL不仅应限制直流故障电流的峰值来降低对直流断路器的最大开断能力的要求,而且应限制故障电流的上升速率,以实现换流器、断路器和限流器之间的配合。此外,还应确保直流SFCL的响应时间,恢复时间和其他问题。

The fault current of DC system will increase rapidly and reach the peak value after the fault occurs.Because there is no current zero-crossing point in DC system,it is difficult for DC circuit breaker to cut off the fault current.This problem can be alleviated by using a DC superconducting fault current limiter(SFCL).In this study,different types of DC SFCL are introduced.Then the current limiting requirements of DC SFCL are analyzed.In order to meet these requirements,some basic technical specifications of DC SFCL are proposed.DC SFCL should not only limit the peak value of DC fault current to reduce the maximum breaking capacity of DC circuit breaker,but also limit the rising rate of fault current to realize the coordination among converter,circuit breaker and current limiter.In addition,the response time,recovery time and other issues of DC SFCL shall be ensured.