simulation of 180 degree inverter

Three phase 180 degree inverter can be used for v/f control in electric machines.

It consists of three legs with two MOSFETs in each leg and gate signal for each MOSFET is provided though individual pulse generator to each MOSFET. The top switches are 120 degree out of phase to each other and the bottom switches are 180 degrees out of phase to the top switches. V/f control can be obtained foe induction motor by this, as we change the frequency in inverter the voltage also gets changed proportionally. For example in this project at 50Hz output of inverter is 440 volts for 100 volts of dc at input to inverter, on changing the frequency to 25Hz output of inverter comes to be 220 volts, thus the V/f ratio remains constant.