Regenerative undeland snubber circuit for half-arm of an inverter

A system for converting direct current into multiple phase alternating current comprising:

• at least one power module with each power module being associated with a different alternating phase current;
• each power module being configured for connection to a DC source for providing electrical energy to be converted from the DC source into the multiple phase alternating current, the DC source providing a non-reference voltage and a reference voltage, each power module including two switches connected in series and having an input and an output which are respectively connected to the voltages and a common connection between the switches which provides an output phase of the multiple phase alternating current, and the switches are switched to produce the output phase of the multiple phase alternating current;
• two diodes connected in series between the voltages, having an output providing energy recovery of switching losses from the switches and are coupled together at a common point;
• a first capacitor coupled between the reference voltage and the output of the two diodes which stores energy recovered from the switching losses of the switches;
• a second capacitor coupled between the common point of the switches and the common point of the diodes for producing voltage modulation of soft switching losses of the switches;
• and wherein
• each power module does not include a resistor coupled between the non-reference voltage and the output phase of alternating current.