多端直流输电系统直流侧故障的控制保护策略

A Control and Protection Scheme of Multi-terminal DC Power System for DC Line Fault

在多端直流输电系统中使用直流断路器有利于故障的快速切除,但目前直流断路器的制造工艺尚不成熟,难以在工程中推广应用。文中在直流输电系统直流侧采用常规交流断路器作为直流断路器的替代方案,提出了一种针对多端直流输电系统直流侧故障的控制保护策略。利用PSCAD/EMTDC软件建立了±800kV双极四端直流输电系统仿真模型,并进行了仿真。仿真结果表明,基于常规交流断路器的多端直流输电系统控制保护策略能够实现系统故障后的快速恢复,较好地满足功率输送要求,有效提高所连交流系统的稳定性。

In the multi-terminal DC power transmission system,DC circuit breakers contribute to the fast fault clearing,but the immature manufacturing process leads to the difficulty of its engineering application.This paper uses AC circuit breakers on the DC side of the DC transmission system instead of DC circuit breakers,and a scheme of multi-terminal DC power system control and protections for the DC line fault is proposed.Using PSCAD/EMTDC,a ±800 kV bipolar four-terminal DC transmission system module is built and simulated.The simulation result shows that the system under the fault can achieve fast recovery by using the control and protection scheme based on AC breakers.The demand of power transmission is satisfied and the stability of the connected AC system is enhanced effectively.