【摘要】 针对多端直流系统的故障保护问题,首先分析了直流故障特性及多端直流系统保护难点,总结了现有多端直流系统故障保护方法。然后,基于一种典型的多端直流系统拓扑结构,以使用最少数量直流断路器为目标,提出了多端直流系统区域保护划分原则和分区保护策略。该方法将直流故障区域通过直流断路器与非故障区域进行隔离,从而使非故障区域可以继续维持正常运行,而故障区域则通过换流站交流侧断路器和直流侧开关进行保护和隔离。最后,通过MATLAB/Simulink仿真平台建模及仿真分析,验证了多端直流系统分区保护的有效性和经济性。更多还原

【Abstract】 In view of the problems of fault protection for the multi-terminal DC system,the DC fault characteristics and the challenges that multi-terminal DC system protection are facing are analyzed,and the existing fault protection methods for multi-terminal DC system are summarized. Based on a typical topology of the multi-terminal DC system,the partition principles of DC zones and a coordinated partition-based protection strategy are proposed,with the objective of using a minimum number of DC breakers. The method uses the DC breakers to separate the faulted DC zone from the healthy DC zones. Thus the healthy DC zones can be restored to normal operation quickly after the fault,and the faulted zone can be protected by AC breakers and DC switches which are already installed at the AC and DC side of modular multilevel converters( MMC). Finally,the simulation results based on MATLAB/Simulink platform show that the coordinated partition based protection strategy is effective and economical.更多还原