CAJ | 학술논문

模块化多电平换流器(modular multilevel converter， MMC)传统的电压均衡控制需要对电容电压排序，占用了大量计算资源。设计了一种无需排序的均衡控制策略。该策略通过比较前后控制周期中投入子模块的个数以及判断各桥臂子模块的电容电压与其平均值的偏差是否越界，来决定是否重新计算触发脉冲。选取桥臂电容电压的平均值作为基准值，各子模块由其电容电压与该基准值比较来确认投入与否：当桥臂处于充电状态时，优先投入低于基准值的子模块；当桥臂处于放电状态时，优先投入高于基准值的子模块。在PSCAD/EMTDC 平台上搭建了 MMC 模型，对设计的均衡控制策略的有效性进行了验证。结果表明该策略可以在较低频率下实现电容电压的均衡控制。
모괴화다전평환류기(modular multilevel converter， MMC)전통적전압균형공제수요대전용전압배서，점용료대량계산자원。설계료일충무수배서적균형공제책략。해책략통과비교전후공제주기중투입자모괴적개수이급판단각교비자모괴적전용전압여기평균치적편차시부월계，래결정시부중신계산촉발맥충。선취교비전용전압적평균치작위기준치，각자모괴유기전용전압여해기준치비교래학인투입여부：당교비처우충전상태시，우선투입저우기준치적자모괴；당교비처우방전상태시，우선투입고우기준치적자모괴。재PSCAD/EMTDC 평태상탑건료 MMC 모형，대설계적균형공제책략적유효성진행료험증。결과표명해책략가이재교저빈솔하실현전용전압적균형공제。
Excessive computation was required in the controller of MMC if typical voltage balancing control based on voltage sorting was adopted. A new voltage balancing control method without sorting was presented in this paper. The number of on-state SMs of the previous and the present control cycle were compared and the deviation between capacitor voltages and their average value in bounds was detected to determine whether to recalculate the trigger pulse. The average voltage was selected as reference value, the sub module whose capacitor voltage was lower than the reference value should be switched on prior in charging status, the sub module whose the capacitor voltage was upper than the reference value should be switched on prior in a state of discharge. A MMC model was set up on the PSCAD/EMTDC, the effectiveness of the design control method was verified. The results show that this voltage balancing method can be realized effectively under low frequency.