REDUCTION OF HARMONIC DISTORTION IN BLDC DRIVE USING BL-BUCK BOOST CONVERTER BLDC DRIVE

Conventional dc motors have many attractive properties such as high efficiency and linear torque speed characteristics. The main drawback of the dc motor is the need of periodic maintenance. The brushes of the mechanical commutator eventually wear out and cause undesirable effects such as sparks and acoustic noise. Brushless dc motors (BLDC) in many cases replace conventional dc motors . This paper presents the simulation of a PFC bridgeless (BL) buck-boost convertor fed brushless direct current motor drive and compares its performance with a conventional boost converter drive. The speed control the BLDC motor is done by controlling the dc link voltage of the voltage source inverter (VSI). A BLDC motor when fed by a diode bridge rectifier (DBR)with a high value of DC link capacitor draws peaky current which causes total harmonic distortion (THD) of the supply current in the order of 65% and power factor as low as 0.8 . A BL configuration of the buck-boost converter offers the elimination of DBR reducing the conduction losses. The performance of the proposed model is simulated in MATLAB/Simulink environment.