Implementation of LC Filter in Torque Ripple Minimization of Sensorless BLDC Motor

This paper presents the analysis, design and implementation of cost effective sensorless control scheme of Brushless DC Motors (BLDCM). There are several methods proposed in BLDC motor drives to obtain optimum current and torque control with minimum torque pulsation. But while coming to industrial applications, BLDC motor voltage contains harmonics which are caused because of high speed switching circuits resulting in high electromagnetic interference problems. During commutation pulsation torque is produced in the motor which are occurred by trapezoidal current pass through each phase. Here a cost effective methodology is implemented to reduce high frequency harmonics components and torque ripple using a LC filter. Here LC filter is connected at the input of the motor and hence the current waveforms are smoothened by the filter during the operation. Keywords—Brushless DC Motor (BLDCM), ElectroMagnetic Interference (EMI), Zero Volt Switching (ZVS), Zero Current Switching (ZCS), Total Harmonic Distortion (THD).