Unwanted voltages in inverter
The driving scheme you are using is not good for the job. 

You can't leave the four MOS open in between the pulses otherwise magnetizing current build up will work against power supply through body diodes. Doing so you return the magnetic energy stored back into supply and get 2Vcc overvoltage.

During the pause you should instead leave a low drop mesh ON for current  freewheeling.

So you could have both lowside ON during pauses and then alternatively switch on two opposite MOS during drive phases.