基于主动控制的换流器与直流断路器的协调控制

针对采用直流断路器隔离故障的直流电网，提出了双极短路故障下的直流断路器与换流器协调控制策略。首先经理论推导，建立了双极短路故障时的故障电流表达式，根据表达式中影响故障电流的关键因素，提出了换流器的主动控制策略以减小故障电流。在换流器主动控制策略的基础上，提出了直流断路器与换流器之间的协调控制策略，用以提升直流电网的稳定性。最后在PSCAD/EMTDC仿真平台中搭建了四端直流电网仿真模型，仿真结果表明所提出的换流器主动控制策略可以有效减小故障电流，直流断路器与换流器之间的协调控制策略可以在断路器动作后快速提升直流电压，进而提高直流电网的稳定性。

Coordinated Control of Converter and DC Breaker Based on Active Control

Point at the bipolar short-circuit fault in the DC grid using DC breaker to isolate faults, a coordinated control strategy between the DC breaker and the converter is proposed. Firstly, a fault current expression of the bipolar short-circuit fault is established by theoretical derivation. According to the key factors affecting the fault current in the expression, the active control strategy of the converter is proposed to reduce the fault current. On the basis of the strategy, a coordinated control strategy between the DC breaker and converter is proposed to improve the stability of the DC grid. Finally, a simulation of the four-terminal DC grid model is built in the PSCAD/EMTDC simulation platform. The simulation results show that the proposed active control strategy of the converter can effectively reduce the fault current, and the coordinated control strategy between the DC breaker and converter can rapidly increase the DC voltage after the DC breaker is operated, thereby improving the stability of the DC grid.