Modified Single Switch Bridgeless PFC Converter based Sensorless PMSM Drive for Exhaust Fan

This paper presents sensorless control of the exhaust fan’s permanent magnet synchronous motor (PMSM) using a power factor correction (PFC) converter. The fan initially has an inefficient single-phase induction motor, which is replaced with an energy-efficient PMSM to reduce energy consumption. To address power quality issues, a modified single switch bridgeless PFC SEPIC (S
²
BL SEPIC) converter is employed. This converter design enhances efficiency by minimizing component count, and conduction losses and eliminating the circulating current. The control strategy prioritizes robustness and simplicity over high-speed performance, using a sensorless approach based on flux estimation to determine the PMSM’s rotor position. The S
²
BL SEPIC PFC operates in discontinuous mode, further streamlining the control structure. The upgraded fan operates effectively across a wide input voltage range.