Converter system for powering an electrical load

A converter system for converting a multi-phase AC power signal having one or more phases at a line frequency from an AC power source to a desired power signal for powering a load, comprising:

• a DC bus for each phase of the AC power signal;
• a first at least two switching cells, each switching cell of the first at least two switching cells including a first at least two active switches coupled in series across the DC bus;
• a first AC pole formed between the first at least two active switches;
• a decoupling capacitor coupled directly across the first at least two active switches coupled in series;
• and an inductor coupled between the first AC pole and the AC power source for each phase;
• and
• a second at least two switching cells, each switching cell of the second at least two switching cells including a second at least two active switches coupled in series across the DC bus;
• and a second AC pole formed between the second at least two active switches, wherein the second AC poles for each of the second at least two switching cells are coupled together and form a flying neutral,
• wherein the first at least two switching cells are operative to switch at a first frequency at least an order of magnitude greater than the line frequency to convert AC to DC;
• and
• wherein the second at least two switching cells are operative to switch at a second frequency approximately equal to the line frequency to convert AC to DC.

A converter system for converting a three-phase AC power signal from an AC power source to a desired power signal for powering a load, comprising:

• a DC bus for each phase of the AC power signal;
• means for converting AC to DC at a first frequency at least an order of magnitude greater than the line frequency;
• and
• means for converting AC to DC at a second frequency approximately equal to the line frequency.