A PFC Based BLDCM Drive for Low Power Household Appliances

This work presents a low cost PFC (Power Factor Correction) based BLDCM (Brush less DC Motor) drive targeting low power household appliances. Development of a highly efficient BLDCM drive with minimum amount of sensing requirement is the primary objective of this work. The switching losses in the VSI (Voltage Source Inverter) feeding BLDCM is reduced by electronically commutating the BLDCM and controlling its speed by controlling the voltage of the DC bus. A PFC buck-boost converter is used as a front-end converter due to its simplicity in design, minimum number of component count and its ability to buck and boost the voltage to control the speed over a wide range. The PFC buck-boost converter operating in DICM (Discontinuous Inductor Current Mode) is used for the control of DC bus voltage. An inherent PFC is achieved for variation of speed over a wide range at universal AC mains (90-265 V). The obtained PQ (Power Quality) indices are within the recommended limits of international PQ standards IEC 61000-3-2. The performance of proposed BLDCM drive is simulated in MATLAB/Simulink environment and validated experimentally on a developed prototype of the drive.