Improved BLDC motor drive performance without electrolytic capacitor in DC link

Abstract

Todays, BLDC motors have been used in many industrial and non-industrial applications for reasons, such as high efficiency, easy control and reliability, and are being used in mass production applications, particularly in home appliances. But even in constant-speed applications, these motors require an electric drive. Commercialization of these drives by reducing prices and increasing their reliability is one of the main goals of researchers and manufactures. These have been partially achieved by reduction of power switches, the number of current or voltage sensors, elimination of position sensors by using sensorless control techniques. But according to statistics, electrolytic capacitors used to reduce the ripple voltage are both costly and potentially inherent in most drive failures. In this paper, with the aim of eliminating high-capacity electrolytic capacitors, a new control method based on simultaneous control of speed and torque is presented, which significantly reduces the torque ripple caused by voltage fluctuations in the DC link. The validity of the proposed method is verified using Simulink software.