Sensorless Single-Switch PFC Converter Fed Brushless Direct Current Motor Ceiling Fan

This paper presents the reduction in total harmonics distortion, power input, and a supply power factor correction (PFC) of permanent-magnet brushless direct-current motor (PMBLDCM) ceiling fan (CF) to get reduced bills for the consumers. To address these supply power-quality issues in the existing PMBLDCM-CF, a single-stage, single-switch boost-fly back power-factor-correction-converter (S4BF-PFCC) is employed at the front-end. The front-end PFCC is designed in discontinuous conduction mode, which offers inherent supply PFC. The high-frequency-transformer (HFT) auxiliary-voltage is utilized as a feedback to get the controlled PFCC voltage output (VDC), and with this controlled VDC, CF speed is controlled. This method eliminates the required DC-link sensor or sensing circuitry. Moreover, the back-EMF sensor less-control is used to eliminate the Hall sensors and their auxiliary supply. The speed control with a variable output voltage of front-end PFCC allows an inverter to work at a commutation frequency, which offers low switching losses and improves CF efficiency. This CF system is modelled and simulated in MATLAB/Simulink.

Keywords: Single-Stage Single-Switch Boost-Flyback Power Factor Corrected Converter (S4BF-PFCC), unity power factor, PMBLDCM, ceiling fan, and power quality (PQ).