多端柔性直流系统直流故障保护方案

DC Fault Protection Strategy for the Flexible Multi-terminal DC System

多端柔性直流系统直流故障保护是直流系统发展的关键技术之一,主要技术难点包括直流故障的可靠识别和快速隔离。该文从故障快速隔离和提高供电可靠性的角度出发,设计基于直流断路器和不基于直流断路器的直流故障保护方案。设计的直流故障保护方案无需通信,能可靠实现故障识别。同时与传统基于交流断路器的保护方案相比,所设计的方案在动作速度和供电可靠性方面均有显著改善。最后,在MATLAB/Simulink仿真平台上分别搭建基于直流断路器和不基于直流断路器的四端柔性直流系统,通过仿真测试验证所设计的保护方案的可行性以及与已有保护方案相比所具有的优越性。

Protection for the flexible multi-terminal dc system is one of the key techniques for the dc system, mainly including de fault identification and isolation. From the aspect of fast fault isolation and improving the supply reliability, this paper desiged the dc fault protection strategies based on the de circuit breaker and without the dc circuit breaker respectively. The proposed protection strategy could realize the fault identification without communication. Compared with the conventional de fault protection strategy based on the ac circuit breaker, the action speed and power supply reliability of the proposed strategy have been improved significantly. Finally, this paper built four-terminal de systems based on dc circuit breaker and without de circuit breaker respectively on the MATLAB/Simulink platform, verifying the feasibility and superiority of the proposed strategy.