Enhanced Power Quality BLDCM Ceiling Fan

The power quality problems at the supply input are the significant concerns for the existing permanent magnet brushless direct current motor (PMBLDCM) ceiling fan (CF). The enhanced power quality sensorless PMBLDCM driven CF with an improved efficiency is presented here. The front-end switched-capacitor power factor corrected converter (PFCC) is designed to operate in the discontinuous conduction mode (DCM) to get inherent PFC at the supply input. The PFCC is utilized to take care of supply voltage fluctuation and to manage the wide-speed operating modes, which helps the inverter to operate at commutation frequency. This technique is used to control speed, minimizes inverter losses, and improves fan efficiency. Moreover, the high-frequency transformer (HFT) is designed to provide an isolation in the fan, and its auxiliary winding voltage is used as a feedback voltage to the controller. It reduces the sensing arrangement and reduces the cost of the CF. The CF system is simulated in MATLAB, and results are given to validate the design of the PFCC.