Simulation of DC Link Capacitor Free BLDC Motor Drive using Different Current Controllers

A DC link capacitor is an integral component of every BLDC motor drive. It is rated for a lower number of operating hours in comparison to other components used in the circuit. In addition, the lifetime of electrolytic capacitors is severely affected by the ambient operating temperature. As such, the DC link capacitor is considered to be a frequent component of failure. Therefore, the inclusion of the capacitor reduces the durability of the motor drive, particularly in hot or cold environments. Excluding DC link capacitor from the drive yields additional advantages like cost reduction and overall reduction in the area of the printed circuit board. However such a setup gives rise to torque ripples, which causes vibrations and acoustic noise in the drive. This paper focus on a compensation method to reduce the ripples for smooth operation of the drive. Simulations using different controllers are done and their performances are compared.