500 kV整流型混合式高压直流断路器

直流断路器作为柔性直流电网故障元件的快速隔离装置,是构建直流电网的关键设备,能够大力支撑大规模新能源的高效并网和消纳。文中提出一种整流型混合式高压直流断路器电路拓扑,采用桥式换向阀组和单向开断阀组构成分断支路,与常规拓扑相比,使用一半数量的绝缘栅双极型晶体管(IGBT)即可实现电流双向开断,经济性好和可靠性高。文中详细介绍了整流型混合式高压直流断路器的拓扑结构及其开断工作原理,并提出预分闸控制策略和软合闸控制策略,以缩短分闸时间和减小合闸操作冲击。研制了一台额定电压500kV,额定电流3kA,最大开断电流25kA,开断时间小于3ms整流型混合式高压直流断路器样机。实验结果验证了整流型混合式高压直流断路器电路拓扑的可行性和有效性

500 kV Commutation-based Hybrid HVDC Circuit Breaker

As the fast fault isolating device of flexible high voltage direct current(HVDC)network, HVDC circuit breaker is becoming the essential device to construct the HVDC network, and can strenuously support the high-efficient large-scale renewable energy integration and consumption. In this paper, a novel commutation-based topology of hybrid HVDC circuit breaker is proposed. Compared with the existing topology, the proposed only needs half the insulated gate bipolar transistors(IGBTs)by applying H-bridge commutation modules and unidirectional breaking modules to achieve bidirectional breaking. Therefore, it is more economical and reliable. The topology and breaking principle of hybrid HVDC circuit breaker are introduced in detail, and a pre-breaking control strategy and a soft-closing control strategy are proposed to reduce the breaking time and closing-operation impact. Besides, a full-scale prototype with 500 kV rated voltage, 3 kA rated current, 25 kA breaking current, and less than 3 ms breaking time is developed to comprehensively test the performances of the proposed HVDC circuit breaker. The experiment results validate the feasibility and effectiveness of the proposed solution.