Improved multilevel voltage source converters and systems

摘要

Nested neutral point clamped (NNPC) multilevel power converter stages (100) and systems (300) are presented, in which the converter stage includes an NPC inverter core circuit (110) with a flying (switched) capacitor nesting circuit (104), with the switches of the NPC core (110) and the switched capacitor circuit (104) being gated using selected redundant switching states to control the voltage of the switched capacitors to achieve a multilevel output voltage having equally spaced voltage step values. Multiple inverter stages (100) can meet cascaded or connected in various configurations to implement single or multiphase power conversion systems, and higher output voltages can be achieved by forming to converter stages (100) into an H-bridge configuration, and connecting multiple H-bridge stages in series with one another.