Sensorless BLDCM Ceiling Fan using a Single Switch and Single Stage PFC Converter

Here, a single switch and single-stage power factor corrected converter (S4PFCC) fed sensorless BLDCM (brushless direct current motor) based fan is presented. Here, the PFCC is designed in the discontinuous conduction mode (DCM) of operation with 48V output, and it provides a natural PFC at the input mains. This paper aims to produce a low-cost sensorless BLDCM fan with improved power quality indices and efficiency. The ceiling fan system contains an AC-DC S4PFCC cascaded with a three-phase voltage source inverter (VSI) fed BLDCM. The commutation frequency is used to keep minimum switching losses of the VSI. Moreover, the PFCC output voltage sensor is avoided using the auxiliary winding voltage as feedback to the DSP controller to handle the supply voltage fluctuations and controls fan speed. The performance of the BLDCM fan is simulated in MATLAB/Simulink to confirm the PFCC design.