具备潮流控制功能的组合式高压直流断路器

针对直流电网目前面临的2个关键性问题:直流潮流控制自由度不够和直流线路故障,文中提出了一种适用于直流电网的具备潮流控制功能的组合式高压直流断路器。首先,介绍了模块化多电平潮流控制器和混合式高压直流断路器的基本结构和工作原理。然后,提出了一种组合式高压直流断路器,介绍了它的基本结构、配置原则、控制方式和工作原理;基于单换流器直流侧故障分析模型,分析了组合式高压直流断路器处理直流线路故障的可行性。最后,在PSCAD/EMTDC仿真平台搭建了四端柔性直流输电系统,分别对组合式高压直流断路器的直流潮流控制能力和直流故障处理能力进行了仿真。仿真结果表明:组合式高压直流断路器能够很好地控制直流潮流,并具有处理直流线路故障的能力。

Integrated HVDC Circuit Breaker with Power Flow Control Capability

Two key problems faced by meshed DC power grids are insufficient freedom of DC power flow control and DC line faults. In view of the above two problems, this paper proposes an integrated high voltage direct current (HVDC) circuit breaker with current flow control capability for DC power grid. Firstly, the basic structure and the working principle of the modular multi-level power flow controller (MMPFC) and hybrid HVDC circuit breaker are introduced. Then, the integrated HVDC circuit breaker is proposed, and the basic structure, the configuration principle, control mode and operation principle are introduced, respectively. Based on the analysis model of DC fault for single inverter, the capability to isolate the DC fault by integrated HVDC circuit breaker is analyzed. Finally, a four-terminal flexible HVDC grid is built on the PSCAD/EMTDC simulation platform to verify the current regulation capability and DC fault handling capability of integrated HVDC circuit breaker. The simulation results show that the integrated HVDC circuit breaker can control the DC power flow effectively and has the ability to deal with DC line faults.