Asymmetric T‐Type PFC Converter With Sensorless Current Control Strategies Based on Different Pulse Width Modulation Techniques

This paper proposes a sensorless control strategy for a single‐phase asymmetric T‐type power factor correction (PFC) converter. Unlike traditional multi‐loop control methods, which require measurement of input AC voltage, output DC voltage, and inductor current, the proposed control algorithm relies solely on feedback signals from the input and output voltages. This method effectively regulates the output voltage and achieves power factor correction of the input current while eliminating the impact of inductor current sampling errors on system performance, reducing the number of sensors, and simplifying controller design. The control strategy utilizes hybrid unipolar and bipolar pulse width modulation (PWM) techniques to accommodate varying input AC voltage requirements. Simulation results show that the proposed control strategy successfully achieves power factor correction and output voltage adjustment while reducing the total harmonic distortion (THD) of the current in the circuit.