CAJ | 학술논문

模块化多电平换流器(MMC )的启动是 MMC 柔性直流输电系统工程应用首先需要面临的问题，针对采用MMC结构的两端或者多端柔性直流输电系统，提出了一种新型的有序解锁启动方法，以减少传统充电方式下换流阀解锁瞬间的直流电压跌落和桥臂电流冲击。该方法在传统不控充电过程后，先解锁定直流电压换流站，再对其他换流站进行远端充电，期间其他换流站的桥臂按其子模块电容电压高低顺序逐步减少投入充电的子模块个数，以此不断抬高子模块电容电压，在电容电压到达一定数值后再解锁换流站。通过理论分析计算了本方法最大的电压跌落，并通过PSCAD/EMTDC仿真验证了该方法的有效性和优越性。此外，新的远端启动控制策略对多端柔性直流系统的定功率换流站启动顺序和启动时刻没有特殊要求，并针对单桥臂进行设计，可以重复应用于各桥臂，因此，其适用于实际工程中的多端柔性直流系统远端启动和交流系统故障造成无源端闭锁后的在线重启动。
모괴화다전평환류기(MMC )적계동시 MMC 유성직류수전계통공정응용수선수요면림적문제，침대채용MMC결구적량단혹자다단유성직류수전계통，제출료일충신형적유서해쇄계동방법，이감소전통충전방식하환류벌해쇄순간적직류전압질락화교비전류충격。해방법재전통불공충전과정후，선해쇄정직류전압환류참，재대기타환류참진행원단충전，기간기타환류참적교비안기자모괴전용전압고저순서축보감소투입충전적자모괴개수，이차불단태고자모괴전용전압，재전용전압도체일정수치후재해쇄환류참。통과이론분석계산료본방법최대적전압질락，병통과PSCAD/EMTDC방진험증료해방법적유효성화우월성。차외，신적원단계동공제책략대다단유성직류계통적정공솔환류참계동순서화계동시각몰유특수요구，병침대단교비진행설계，가이중복응용우각교비，인차，기괄용우실제공정중적다단유성직류계통원단계동화교류계통고장조성무원단폐쇄후적재선중계동。
Modular multilevel converter (MMC) start-up is a primary problem confronted by MMC-high voltage direct current (HVDC) engineering applications.Based on the modular multilevel converter HVDC,a new ordered charging method is proposed for the remote start-up of a proj ect to decrease the DC voltage drop of the converter valve and bridge arm current impact the instant it”s unlocked the traditional way.After the process of traditional uncontrolled charging,the DC voltage station is unlocked,then other converter stations are uncontrollably charged by bypassing the sub-module according to the voltage level.Finally,the stations are unlocked until the voltage of the sub-module is sufficiently high.The method has greatly reduced the DC voltage drop and bridge arm shock current for the passive converter station during start-up.Theoretical analysis has been made to obtain the largest voltage drop using this method,and simulation has been done to verify the feasibility of the method.The method can effectively reduce voltage drop,while making no particular requirements on the boot sequence and moment for unblocking.And single-arm design enables it to be reused for all arms,making it applicable to the multi-terminal flexible DC system for remote start-up and post-locking restart online because of AC faults.