CAJ | 학술논문

电网电压不平衡是VSC-HVDC系统实际运行时无法避免的问题，由于常规控制下的电压源换流器在电网电压不平衡时会将直流侧二倍频波动通过传输电路传播到相邻换流站，引起传输功率发生波动，进而影响直流输电系统的稳定运行，针对这一问题，本文对VSC行功率分析并研究其不平衡控制方案。同时采用了VSC侧与交流侧复合功率控制方法，设计了αβ静止坐标下自适应变结构滑模内环控制器。最后，在电磁暂态仿真软件PSCAD/EMTDC环境下搭建VSC-HVDC模型，仿真结果验证了该方案的有效性。
전망전압불평형시VSC-HVDC계통실제운행시무법피면적문제，유우상규공제하적전압원환류기재전망전압불평형시회장직류측이배빈파동통과전수전로전파도상린환류참，인기전수공솔발생파동，진이영향직류수전계통적은정운행，침대저일문제，본문대VSC행공솔분석병연구기불평형공제방안。동시채용료VSC측여교류측복합공솔공제방법，설계료αβ정지좌표하자괄응변결구활모내배공제기。최후，재전자잠태방진연건PSCAD/EMTDC배경하탑건VSC-HVDC모형，방진결과험증료해방안적유효성。
Grid voltage imbalance is an inevitable problem for voltage source converter based high voltage direct cur-rent transmission (VSC-HVDC) system. Due to the voltage source converter in conventional control would spread the second order fluctuation in DC voltage from one station to the other via the DC cables and further affect the system operation stability when the AC voltage unbalance appears, This paper takes both the VSC power and system side pow-er into account, and adopts the adaptive variable structure sliding-mode controller whose model is derived inαβrefer-ence frame based on the study of unbalanced control strategy of VSC. Finally, the detailed model of VSC-HVDC is set up in the environment of PSCAD/EMTDC, and the effectiveness of the proposed control strategy is verified by sim-ulation results.