Single phase inverter control with capacitor current feedback

In this paper, single phase sinusoidal pulse width modulated (SPWM) inverter control with modified unipolar switching is presented. The two loops namely, capacitor current feedback as inner loop and output voltage feedback as outer loop were implemented. The mathematical model and state space analysis of power stage is derived and used to design the feedback compensators. The compensators for the two feedback loops are designed and verified using MATLAB and Simulink. The simulation results for a 1kVA SPWM inverter are presented. With the designed PI compensators, the system exhibits stable output voltage and good transient response for linear and non linear loads. For 700W load step, the output voltage recovers in a time less than 0.5ms.