BLDC Motor Ceiling Fan Using a Bridgeless Isolated PFC SEPIC Converter

The bridgeless isolated power factor corrected (PFC) SEPIC converter based ceiling fan with DC link voltage of 48V, shows the better power quality and less power consumption. It consists of an electromagnetic interference (EMI) filter, high frequency isolation transformer in series with a voltage source inverter and a permanent magnet brushless DC (PMBLDC) motor. This topology is designed in discontinuous inductor current mode (DCIM) of operation with input power of 30W. This ceiling fan is taking power one third of a single phase induction motor. The power quality performances are found good for this topology based ceiling fan. This topology for the ceiling fan is simulated with simple voltage follower control technique. To control the speed of PMBLDC motor, DC link voltage is sensed and it varies up to 48V. The turn’s ratio of high frequency transformer and inductor are selected such a manner that the switch stress of the converter switches should be minimum. The MATLAB simulation results are shown to validate the design of a bridgeless isolated PFC SEPIC converter based ceiling fan.