Modular embedded multi-level converter with midpoint balancing

摘要

A modular embedded multi-level converter (MEMC) includes a first phase portion and a second phase portion. The first phase portion includes a first switch stack operable to couple a first phase branch between a positive DC bus and a midpoint node. The second phase portion includes a second switch stack operable to couple a second phase branch between the midpoint node and a negative DC bus. A DC voltage between the positive DC bus and the negative DC bus is distributable among switching units disposed in the first phase branch and the second phase branch. A distribution of the DC voltage is controlled by regulating a DC voltage at the midpoint node to balance energy among the switching units.

主权项

1. A modular embedded multi-level converter (MEMC) comprising:
a first phase portion comprising a first switch stack and a first phase branch, wherein said first switch stack is configured to couple said first phase branch between a positive direct current (DC) bus and a midpoint node; a second phase portion comprising a second switch stack and a second phase branch, wherein said second switch stack is configured to couple said second phase branch between said midpoint node and a negative DC bus, wherein a DC voltage between said positive DC bus and said negative DC bus is distributable among switching units disposed in said first phase branch and said second phase branch, and wherein a distribution of said DC voltage is controlled by regulating a DC voltage at said midpoint node to balance energy among said switching units; a third phase portion comprising a third switch stack and a third phase branch, wherein said third switch stack is configured to couple opposing ends of said third phase branch to said midpoint node; and wherein said first switch stack in combination with said third switch stack is configured to form an alternating current (AC) loop among said first phase branch and said third phase branch.