CAJ | 학술논문

为更大程度地提升电网输电能力，缓解潮流拥塞问题，提出了将现有交流线路改造成多端直流系统的想法。通过对三极直流系统的分析，指出了其对多端直流系统的不适用性，进而提出了一种采用三线双极结构的扩展式多端直流系统。首先对扩展式多端直流系统的结构进行了描述，然后针对三线双极结构的运行原理、扩容机理和其核心设备---电流调节控制器的运行特性和可行拓扑结构进行了阐述和分析。最后，通过PSCAD/EMTDC下的仿真分析，验证了三线双极结构在多端直流系统应用中的可行性及相应控制策略的有效性。同时，仿真结果还确立了全桥模块化多电平换流器作为电流调节控制器的可行性。
위경대정도지제승전망수전능력，완해조류옹새문제，제출료장현유교류선로개조성다단직류계통적상법。통과대삼겁직류계통적분석，지출료기대다단직류계통적불괄용성，진이제출료일충채용삼선쌍겁결구적확전식다단직류계통。수선대확전식다단직류계통적결구진행료묘술，연후침대삼선쌍겁결구적운행원리、확용궤리화기핵심설비---전류조절공제기적운행특성화가행탁복결구진행료천술화분석。최후，통과PSCAD/EMTDC하적방진분석，험증료삼선쌍겁결구재다단직류계통응용중적가행성급상응공제책략적유효성。동시，방진결과환학립료전교모괴화다전평환류기작위전류조절공제기적가행성。
In order to improve the transmission capability of power grids and mitigate the congestion of power flow,an idea about conversion of existing alternating current (AC) lines to multi-terminal direct current (MTDC)system is proposed. According to an analysis of the tripole high voltage direct current(HVDC)system,it is indicated that the tripole HVDC is not suitable for the MTDC system.Then,the three-wire bipole structure based extended MTDC system is proposed.Firstly,the structure of the extended MTDC system is described.Secondly,the operating principle and mechanism of power expansion of the three-wire bipole structure are analyzed in particular,as is its key equipment,the current regulation controller,whose operating characteristics and feasible topologies are elaborated.Finally,by use of the PSCAD/EMTDC simulation software, the designed model is simulated.The simulation results verify the feasibility of the application of three-wire bipole structure in the MTDC system,and the effectiveness of the corresponding control strategies.Meanwhile,the feasibility of the full-bridge modular multilevel converter acting as the current regulation controller is established.