While I doing some work this morning, It just occurred to me that one could replace the bipolar PWM switching algorithm with a Unipolar version.
Basically what this means is that instead of the battery Voltage producing Line to line voltage, one could produce twice the line voltage, using a unipolar switching PWM waveform
Notice how the PWM on the graph is referenced to GND rather than 1/2VCC
That would allow 415V motors to be operated from a 300V Battery with no conversion losses. Anyone interested in this?