Built-in modular multilevel converter and power conversion system

摘要

Modular Multilevel Converter Built-in and Power Conversion System is a Modular Multilevel Converter (MEMC) (104) that includes a first phase portion (a, b, c) and a second phase portion (a, b, ç). the first phase portion includes a first stack of switches (206, 208, 210; 312) operable to couple a first phase branch (234, 236, 238; 300) between a positive dc bus (314; 404) and a midpoint node (212; 318; 402). the second phase portion includes a second stack of switches (206, 208, 210; 312) operable to couple a second phase branch (234, 236, 238; 300) between the midpoint node and a negative dc bus ( 316; 406). a dc voltage between the positive dc bus and the negative dc bus can be distributed between the arranged switching units (s1, s2, s3, s4, s5, s6, s7, s8, s9, s10, s11, s12) in the first phase branch and the second phase branch. A dc voltage distribution is controlled by regulating a dc voltage at the midpoint node to balance the power between the switching units.