Stationary Reference Frame Control of UPF AC-DC Converter without PLL

An increasing number of applications like motor drives, battery chargers, wind electric generators, telecom etc require high power, highly efficient sinusoidal input current rectifiers. Thus rectification of ac to dc at unity power factor has become mandatory in present scenario. Switched converters offer a variety of solution in this regard. The paper proposes controlling a three phase bidirectional switch mode bridge converter using stationary reference frame PQ closed-loop voltage oriented control where control loops are working with time varying αβ quantities; the need for PLL is eliminated. This method reduces computational complexities, requirement of additional hardware for phase estimation etc with improved sampling rate of variables. The mathematical model of the control scheme is realized. The scheme is tested using MATLAB/ Simulink and simulation results are analysed.