VSC-HVDC系统保护策略的研究

目的对基于电压源换流器的高压直流输电系统（VSC—HVDC）的保护策略进行分析，为保护装置的研究提供依据。方法通过在PsCAD／EMTDC软件环境下对系统中常见的两大类故障——破坏性故障和非破坏性故障进行仿真，从结果中提取了故障特征，并据此提出相应的保护策略。结果1）对于破坏性故障，由于控制失效，只能进行闲锁跳闸，并在适当位置安装熔断器；2）对于非破坏性故障，对故障端功率进行“软关断”。结论仿真实验结果表明，上述两种保护策略是有效可行的。

Study on the protection strategy in VSC-HVDC system

Objective--To analyze the protection strategy of VSC-HVDC system, and provide the basis for the research into protection device. Methods--The simulating model for VSC-HVDC is established under the environment of PSCAD/EMTDC, and two common faults-destructive malfunctions and non-destructive malfunctions-in voltage source converter are discussed. What＇s more, fault characteristics are extracted and relevant protection strategy is proposed. Results--I） For destructive faults, the impulse signal must be blocked and fuse should be erected; 2） As for non-destructive faults, ＂ soft turn-off＂ operation should be carried out. Conclusion--Simulation results testify the effectiveness of the protection strategy.