中国电机工程学报
中國電機工程學報
중국전궤공정학보
Proceedings of the CSEE
2015年
11期
2822-2830,后插21
,共10页
公铮%伍小杰%王钊%戴鹏
公錚%伍小傑%王釗%戴鵬
공쟁%오소걸%왕쇠%대붕
模块化多电平变换器%载波移相%变频%电压平衡%低开关频率
模塊化多電平變換器%載波移相%變頻%電壓平衡%低開關頻率
모괴화다전평변환기%재파이상%변빈%전압평형%저개관빈솔
modular multilevel converter (MMC)%carrier phase-shift%variable frequency%voltage balancing%low switching frequency
模块化多电平变换器(modular multilevel converter, MMC)工作于低频工况时,子模块电容电压波动加剧导致输出电压畸变严重,制约了其在中高压大功率变频调速领域中的应用.针对这一问题,在分析MMC数学模型的基础上,从维持各相上、下桥臂功率动态平衡角度出发,设计一种基于注入高频共模电压及高频环流的电压波动抑制策略.为降低功率器件开关频率并减少系统损耗,将载波移相技术应用于MMC变频驱动,分别讨论输出N+1和2N+1电平相电压的实现方式.基于载波移相调制,结合低频工况子模块电容电压波动抑制方法,提出一种变频工况下MMC子模块电容电压控制策略,并设计相应控制系统架构及实现方式.该控制策略能在变频工况维持子模块电容电压平衡,保证调速过程中MMC和电动机正常平稳运行,并在低开关频率下获得良好的输出谐波特性.最后,通过搭建 Matlab/Simulink 仿真及实验样机,验证所提控制策略的正确性和有效性.
模塊化多電平變換器(modular multilevel converter, MMC)工作于低頻工況時,子模塊電容電壓波動加劇導緻輸齣電壓畸變嚴重,製約瞭其在中高壓大功率變頻調速領域中的應用.針對這一問題,在分析MMC數學模型的基礎上,從維持各相上、下橋臂功率動態平衡角度齣髮,設計一種基于註入高頻共模電壓及高頻環流的電壓波動抑製策略.為降低功率器件開關頻率併減少繫統損耗,將載波移相技術應用于MMC變頻驅動,分彆討論輸齣N+1和2N+1電平相電壓的實現方式.基于載波移相調製,結閤低頻工況子模塊電容電壓波動抑製方法,提齣一種變頻工況下MMC子模塊電容電壓控製策略,併設計相應控製繫統架構及實現方式.該控製策略能在變頻工況維持子模塊電容電壓平衡,保證調速過程中MMC和電動機正常平穩運行,併在低開關頻率下穫得良好的輸齣諧波特性.最後,通過搭建 Matlab/Simulink 倣真及實驗樣機,驗證所提控製策略的正確性和有效性.
모괴화다전평변환기(modular multilevel converter, MMC)공작우저빈공황시,자모괴전용전압파동가극도치수출전압기변엄중,제약료기재중고압대공솔변빈조속영역중적응용.침대저일문제,재분석MMC수학모형적기출상,종유지각상상、하교비공솔동태평형각도출발,설계일충기우주입고빈공모전압급고빈배류적전압파동억제책략.위강저공솔기건개관빈솔병감소계통손모,장재파이상기술응용우MMC변빈구동,분별토론수출N+1화2N+1전평상전압적실현방식.기우재파이상조제,결합저빈공황자모괴전용전압파동억제방법,제출일충변빈공황하MMC자모괴전용전압공제책략,병설계상응공제계통가구급실현방식.해공제책략능재변빈공황유지자모괴전용전압평형,보증조속과정중MMC화전동궤정상평은운행,병재저개관빈솔하획득량호적수출해파특성.최후,통과탑건 Matlab/Simulink 방진급실험양궤,험증소제공제책략적정학성화유효성.
Applying the modular multilevel converter (MMC) into medium-voltage/high-voltage high-power drive systems is an intrinsically challenging problem because the output voltage distortion is serious when the converter works at low frequency operation, as a result of the sub-module capacitor voltages fluctuations' aggravation. For this matter, a method of injecting the high frequency common mode voltages and the circulating currents was designed from the perspective of balancing the upper and lower arm powers dynamically based on the analysis of the mathematical model of a MMC. The carrier phase-shift technology was adopted in the drive system to reduce the switching frequency and losses. The implementations to make the phase voltage asN+1 and 2N+1 levels were discussed. By combining the carrier phase-shift modulation and low frequency operation sub-module capacitor voltage restraining method, a voltage control strategy along with its system architecture and implementation were presented for variable frequency operation. The proposed control strategy achieves the goal of balancing voltages in variable frequency operation and makes the MMC and motor work stably. At the same time, a satisfied output harmonic characteristic is acquired at low switching frequency. Finally, the constructed Matlab/Simulink simulation and experimental prototype verify the availability of the proposed control strategy at variable frequency operation.