为研究直流电网的潮流控制器配置问题,首先,分析了直流电网潮流控制器的工作原理及其对直流电网潮流分布的影响,根据直流电网潮流控制器接入前后,系统潮流的变化及支路载流量的限值要求,提出直流电网潮流控制器的配置原则,并在此基础上分别构造函数用于直流电网潮流控制器接入位置的判断;其次,以系统潮流均衡分布为目标对直流电网的潮流分布进行优化;最后,分别在N-1和正常工作2种运行状态下,以六端柔性直流电网为例,进行系统潮流计算和潮流控制器的配置,通过直流电网潮流控制器接入前后系统潮流的变化验证了所述方法的正确性与有效性。
DC grid is the development direction for future power grid. Comparing with multi-terminal HVDC, DC grid has meshes and redundancies improving system flexibility and reliability greatly but also bringing new challenges for the network control. This paper analyzes the operating principle of power flow controllers for DC grid and their effects on system's power flow in detail and proposes a collocating method and principle of power flow controllers for DC grid based on operation space of power flow before and after power flow controller for DC grid and line load flow, the paper then constructs functions to judge whether the position is proper for power flow controller and takes the most balanced power flow as example to optimize the system's power flow. The paper takes a six-terminal DC grid as example to explain the configuration of DC grid power flow controller in normal operation and N-1 state and verify the correctness and effectiveness of the configuration method by the change of the power flow before and after the power flow controller. The conclusion of this paper provides theoretical foundations for configuration of the power flow controller for future DC grids.