直流断路器的研发现状及展望

可靠有效的电力供应以及开发利用可再生资源对于改进电力传输模式提出了巨大的挑战。基于低损耗、远距离、大功率输电以及更有效地连接可再生能源入网和便于灵活操作的优点，高压直流输电(HVDC) 得到了新的重视。特别是电压源换流器(VSC)技术的出现使得多端高压直流(MTHVDC)电网的筹建发展成为可能并越来越具吸引力。目前，多端高压直流电网技术上的主要挑战，如网络结构的拓扑设计、大容量电缆、保护和开断短路电流的直流断路器等成为热门话题。对于多端高压直流电网，具有快速开断直流故障电流和隔离故障功能的直流断路器是必不可少和至关重要的。只有应用高压直流断路器，才有可能采用多端高压直流实现多个节点连接的可再生能源入网或退网、及时快速分离故障并可保证系统的安全可靠运行。 虽然目前市场已有高压直流断路器，且有一些已在超高电压系统运行，但它们直接开断短路故障电流的开断能力较低，且都是作为转换开关将故障电流从一个电路转换到另一电路，最后由交流断路器完成开断，其开断时间较长，系统欠稳定。故具有高开断能力的高压直流断路器仍然是MTHVDC的发展的一个瓶颈，限制着MTHVDC的发展。因此，一场研发高压直流断路器的激烈竞争在ABB、西门子和阿尔斯通等国际电力设备制造商之间正在悄然进行。本文着重介绍了高压直流断路器的发展及其研发的必要性和迫切性，介绍了目前高压直流断路器的最新发展状况、现存的挑战和未来展望。

R&D Status and Prospects of HVDC Circuit Breakers

Effective and reliable supply of electricity as well as the development and utilization of renewable resources for improving power transmission mode have presented a huge challenge. Based on its advantages of low losses, long distance, high power transmission, efficient connection of renewable energy network and flexible operation, high voltage direct current (HVDC) transmission has been a new emphasis. Particularly, the emergence of the voltage sourced converter (VSC) technology makes the development and build of multi-terminal HVDC (MTHVDC) grids become possible and increasingly attractive. Technical challenges faced by the MTHVDC, such as the topology of the network structure design, high capacity cable, protection and DC circuit breakers with fast fault clearance and isolation capabilities have become hot topics, the DC circuit breakers are essential and vital for the MHVDC grids. Only when suitable HVDC circuit breakers with fast fault clearance and isolation capabilities have been developed, individual HVDC line can be quickly tripped to isolate faults, especially to allow multiple entry or exit points.Although there are HVDC breakers commercially available on the market and have been running in the ultra-high voltage system, their capabilities of directly breaking short circuit current are low and mainly used as transfer switches, i.e. transferring short circuit current from one circuit to another circuit and finally the current is interrupted by an AC circuit breaker. Normally the operation is complicate and interrupting time is long potentially leading to system instability. Therefore, HVDC circuit breaker with high breaking capacity remains a bottleneck of MTHVDC development which limits the development of MTHVDC. Thus a fierce competition of research and development of HVDC circuit breakers is among power equipment manufacturers of ABB, Siemens, Alstom etc. This paper focuses on the necessity and urgency of the development of research and development of HVDC circuit breakers and briefly. introduces the latest development current challenges and future prospects of the HVDC circuit breakers.