Abstract HVDC transmission systems using voltage source converters (VSC-HVDC) have been identified as an attractive solution for bulk power delivery over long distance. However if DC grids are to be built using this technology, fast DC circuit breakers are needed. This work proposes a new hybrid DC circuit breaker utilizing a series connected coupled inductor connected, which enables automatic current commutation from the mechanical switch to the semiconductor switch during a fault. The key advantage of the proposed DC circuit breaker is that the current in the mechanical switch automatically reduces to zero when a fault happens. This paper focuses on comparison of different mechanisms to commutate the current from the mechanical switch to the semiconductor switch and create a zero current for the mechanical switch. Three types of hybrid DC circuit breaker topologies including proactive hybrid DC circuit breaker, hybrid DC circuit breaker with commutation booster, and hybrid DC circuit breaker with coupled inductor for a 500 kV HVDC system are simulated and compared using Matlab/Simulink. A prototype hybrid DC circuit breaker with coupled inductor is designed and built. The prototype is capable of interrupting 200 A direct current within 4 ms. The automatic current commutation compensates for the fault detection and location time in the selective protection scheme, which provides faster fault current interruption.

中文翻译：

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带有耦合电感器的混合直流断路器，用于自动电流换向

摘要 使用电压源转换器 (VSC-HVDC) 的 HVDC 传输系统已被确定为长距离大容量电力传输的有吸引力的解决方案。但是，如果要使用该技术构建直流电网，则需要快速的直流断路器。这项工作提出了一种新的混合直流断路器，它利用串联的耦合电感器连接，在故障期间实现从机械开关到半导体开关的自动电流换向。所提出的直流断路器的主要优势在于，当发生故障时，机械开关中的电流会自动降至零。本文重点介绍将电流从机械开关换向至半导体开关并为机械开关创建零电流的不同机制的比较。使用 Matlab/Simulink 对 500 kV 高压直流系统的三种混合直流断路器拓扑结构进行了仿真和比较，包括主动式混合直流断路器、带换向升压器的混合直流断路器和带耦合电感的混合直流断路器。设计并制作了一个带有耦合电感的混合直流断路器原型。该原型能够在 4 ms 内中断 200 A 直流电。自动电流换向补偿了选择性保护方案中的故障检测和定位时间，从而提供更快的故障电流中断。设计并制作了一个带有耦合电感的混合直流断路器原型。该原型能够在 4 ms 内中断 200 A 直流电。自动电流换向补偿了选择性保护方案中的故障检测和定位时间，从而提供更快的故障电流中断。设计并制作了一个带有耦合电感的混合直流断路器原型。该原型能够在 4 ms 内中断 200 A 直流电。自动电流换向补偿了选择性保护方案中的故障检测和定位时间，从而提供更快的故障电流中断。