Apply the gate pulse to IGBTs T1, T2 in positive half-cycle and T3, T4 in negative half-cycle. The on period ton is varied to get the variable output rms output voltage. The triangular signal vcar is compared with constant dc voltage vc to generate the PWM gate signals to the IGBTs T1, T2.
Similarly, the triangular signal -vcar is compared with control dc signal –vc to generate the PWM gate signals to the IGBTs T3, T4. By varying the dc signal up and down the ton period is decreased and increased respectively.
Observe the waveforms across each element of the power circuit with R and RL loads.
The output voltage and current can be observed for different values of Ro, Lo, Vdc, Vc1, Vc2 or fo.
Main Circuit Diagram
Circuit Diagram With Voltmeters And Ammeters At Various Points
For R Load
Ro =10 Ω
For RL Load.
Ro =1 Ω, Lo = 15 mH