基于高压直流断路器的多端直流输电系统可靠性差异化控制策略

Differentiation Reliability Control Strategy of Multi-terminal HVDC System Based on High Voltage DC Circuit Breaker

直流断路器是多端直流输电系统可靠性控制的关键设备,实际工程中不同区域、不同设备的故障各有特点,对直流系统的影响也不尽相同。基于一种具有限流功能的混合式直流断路器,首先描述了该直流断路器的分断和限流控制原理,而后针对实际工程中不同情形下的瞬时性故障和永久性故障,提出一种差异化可靠性控制策略,能够有效避免系统因瞬时故障而造成不必要的停运,在永久故障下也可以为其他设备动作以及控制策略的进行争取时间,增强系统运行的可靠性和稳定性。最后通过PSCAD/EMTDC仿真分析,验证了该控制策略对短路电流的有效控制和不同故障类型的处理效果。

The direct current(DC) circuit breaker is key equipment for DC reliability control. In practical projects, faults of different devices in different regions have their own characteristics, thus have different influence on DC system. Bases on hybrid DC circuit breaker with current limiting function, the breaking and current limiting principle of DC circuit breaker is introduced. Aimed at transient and permanent fault in different situations, a strategy for differentiation reliability control is proposed, which could avoid unnecessary outage owing to transient fault, and gain time for equipment to act or control strategy to be enforced. The reliability and stability of the system is enhanced. Finally, the simulation results in PSCAD/EMTDC show that the proposed control strategy is effective for current limiting and fault processing.