Common mode voltage reduction apparatus and method for current source converter based drive

A current source converter drive, comprising:

• a rectifier comprising an AC input having a plurality of AC input nodes to receive AC electrical input power, a DC output with first and second DC output nodes, and a rectifier switching network including a plurality of rectifier switching devices individually coupled between one of the AC input nodes and one of the first and second DC output nodes, the rectifier switching devices individually operative to selectively couple the AC input node with the corresponding DC output node according to a corresponding rectifier switching control signal;
• an intermediate DC circuit comprising first and second DC current paths and at least one inductance;
• an inverter comprising an AC output with a plurality of AC output nodes for supplying power to a load, and an inverter switching network comprising a plurality of inverter switching devices individually coupled between one of the DC current paths of the intermediate DC circuit and one of the AC output nodes, the inverter switching devices individually operative to selectively electrically couple the corresponding DC current path with the corresponding AC output node according to a corresponding inverter switching control signal to provide AC electrical output power to the load;
• and
• a switch control system, comprising a rectifier control component operative to provide the rectifier switching control signals to cause the rectifier to convert AC electrical input power to provide regulated DC power to the intermediate DC circuit, and an inverter control component operative to provide the inverter switching control signals to cause the inverter to selectively convert DC current from the intermediate DC circuit to provide AC electrical power to the AC output according to at least one setpoint signal or value, a first one of the rectifier control component and the inverter control component being operative to select one of a plurality of zero vectors for space vector modulation of a corresponding first one of the rectifier and the inverter at least partially according to a switching state of a second one of the rectifier and the inverter.