Control strategy for single-phase UPS inverters

A simplified control strategy is proposed for single-phase uninterruptible power supplies in continuous time. In this strategy the controller has command feedforward and feedback components. Only proportional controllers are employed in the inductor current and output voltage control loops. This controller yields zero output impedance of the UPS, provided that estimated filter parameters match their actual values. Robustness of the control system is investigated. Simulation and experimental results are presented for linear and nonlinear loads.