A Bridgeless High Step Down Voltage Gain Based Power Factor Correction Rectifier Fed Low Voltage Low Power Switched Reluctance Motor Drive

A bridgeless modified SEPIC based front end PFC rectifier is presented for low voltage low power switched reluctance motor (SRM) drive. Using switched inductor in traditional SEPIC converter, output voltage is reduced to meet low voltage DC link requirement of asymmetric bridge converter (ABC) fed SRM drive. Unlike, diode bridge rectifier-based SEPIC, presented bridgeless converter is more efficient as prime requirement of low power applications. Discontinuous conduction mode (DCM) operation is selected for low power to reduce controller complexity and cost of drive. Two switches are used in this bridgeless topology and their gate triggering pulse is independent of supply voltage information. Single voltage sensor is sufficient for wide voltage control for SRM drive. Inductors are selected to operate in discontinuous current conduction mode (DICM) for grid side power quality management per international IEC 61000-3-2 standard. DC link voltage regulation involves adjusting voltage level within system to ensure proper control and operation of motor. Bridgeless converter is designed for 400 W, 48 V, three phase SRM drive for domestic/industrial appliances. Component design and validation of presented power factor correction (PFC) rectifier fed SRM drive are presented through MATLAB Simulink. Simulation results affirm reliability of converter in maintaining unity PFC across a wide range of SR motor speed, even in presence of fluctuations in supply voltage.