Well I thought I would give a little update (I got a PM from an interested member) I was successful in building a VFD, but due to uni health and safety I couldnt use 340VDC in the labs and I built a low voltage prototype which drove a dummy RL load at 30VDC
I actually won an award for my work as it was pretty impressive (to me at least!)
A pic of the proto type complete with electrical isolation, gate drive circuitry three phase inverter and current measurement stage
Speed select electronics which I had to implement a LP RC filter to filter the 16kHz transients from the common leg switching
One of the phase currents
and a shot of both outputs showing the 90 degree phase shift
