三端星型柔性直流配电系统的启停、协调控制

为实现三端星型柔性直流配电系统定直流电压端、定功率端、直流变压器端有序启动,首先设计了系统的启动控制策略,同时设计了功率可控端功率按既定斜率下降的停运控制策略。其次,提出了柔性直流配电系统的协调控制策略,在直流变压器低压侧的不同元件投切时,利用储能装置抑制功率波动,以实现元件的平滑投退。最后,通过RTDS仿真,结果表明所提控制策略能实现柔性直流配电系统的有序启动、协调运行和平滑停运。

Start, stop and coordinated control of three-terminal flexible DC distribution systemusing star-type structure

To realize the orderly start of the fixed DC voltage terminal, the fixed power terminal and DC Solid State Transformer (DCSST) terminal of three-terminal Flexible DC Distribution System (FDCDS) using star-type structure, the start control strategy of the DC distribution system is designed, and the stop control strategy that power of the power controllable terminal decreases according to the set slope is designed. A coordinated control strategy for the FDCDS is proposed. When the different components on the low-voltage side of the DCSST are switched, the energy storage device is used to suppress the power fluctuation to achieve smooth switching of the components. Finally, through RTDS simulation, the results show that the proposed control strategy can achieve the orderly start, coordinated running and smooth stop of FDCDS. This work is supported by National Natural Science Foundation of China (No. 51777077).