Current-sensorless control of an SPWM H-Bridge-based PFC rectifier designed considering voltage sag condition

This paper presents and details the H-Bridge PFC rectifier control scheme. This control is a step forward in sensorless current control schemes for performance improvements of single-phase bidirectional rectifiers. The H-Bridge PFC rectifier is designed based on a single PI controller loop fed by DC reference signals. Regarding dynamic operating conditions, the proposed control can maintain a regulated DC voltage under varying conditions at input (voltage sags) and output (load step changes) ports while maintaining an unitary power factor (PF) and constant THD current input at any of these conditions. Different to other investigations, this control proposal uses SPWM, does not require a variable transformation into the dq0 reference frame, and the complex compensators accompanying to the PI controller stage are no longer needed. Therefore, this proposal is aimed to reduce the complexity of the control scheme and to improve the overall dynamic response of the PFC rectifier. The experimental results obtained from the scaled-down prototype setup, which was built for research purposes, validate the control law, mathematical model and quantitative comparison between simulation and experiment, both considering the parasitic resistances of the inductor and semiconductor switches.