A Reduced Sensor Power Factor Corrected Bridgeless Flyback Converter Fed Brushless DC Motor Drive

Abstract

This article presents the design and control of a power factor corrected bridgeless flyback converter based voltage source inverter fed brushless DC motor drive. In place of a conventional method of speed control using a pulse width modulation based voltage source inverter, a new approach for brushless DC motor speed control is proposed by controlling the DC-link voltage of the voltage source inverter using a single voltage sensor. This scheme utilizes a fundamental frequency switching of voltage source inverter (electronic commutation of brushless DC motor) and thus offers low switching losses. The proposed bridgeless converter topology offers an advantage of low conduction losses due to the absence of diode bridge rectifier. This bridgeless flyback converter is operated in a discontinuous conduction mode to utilize a voltage-follower scheme for voltage control using a single voltage sensor. The proposed brushless DC motor drive is designed to operate over a wide range of speed control with a near-unity power factor and improved power quality at AC mains as recommended by international power quality standards, such as IEC-61000-3-2.