Power quality improvements in permanent magnet brushless DC motor drives for home appliances

High efficiency, high power density, compact size, silent operation, high reliability and low wear and tear of the magnet brushless DC (PMBLDC) motor, makes it a suitable choice in many low and medium power applications. Due to these features, PMBLDC motors are widely used in household equipments, industrial tools, heating, ventilation and air conditioning (HVAC), robotics, automation and medical applications. This seminar aims to present power factor correction (PFC) converters for feeding PMBLDC motor drives as a cost effective solution for low power household appliances. The selection of suitable PFC converter for particular application depends upon various aspects such as total number of components of PFC converter, voltage and power rating of BLDC motor, requirement of galvanic isolation, cost and efficiency of the overall system. This work presents various configurations of the PFC converters, which are classified into five different categories of non-isolated PFC converters, bridgeless non-isolated PFC converters, isolated PFC converters, bridgeless isolated PFC converters and integrated and high quality rectifiers. A PFC converter operating in discontinuous conduction mode (DCM) is used to control the PFC converter via an approach of voltage follower; which requires a single voltage sensor for PFC and DC link voltage control. Analysis, design and control of these PFC converters for improvements in power quality at AC mains of the PMBLDC motor drive is presented in this seminar. The speed of PMBLDC motor is controlled by adjusting the DC link voltage of the VSI feeding PMBLDC motor which allows the VSI to operate in fundamental frequency switching for reducing the switching losses in VSI. The other major aspect of the seminar includes simplicity in control, reducing the number of sensors and cost and increasing the overall efficiency of the system.