Torque Ripple Reduction of Electrolytic Capacitor-less BLDC Motor Drive

Brushless DC motors called BLDC are used in many industrial and non-industrial applications today for reasons such as very high efficiency, easy control method and high reliability, and their use is increasingly used in mass production applications, especially home appliances. But these motors require the use of an electric drive, even in constant speed applications. Commercialization of these drives by reducing their price and increasing their reliability is one of the main goals of craftsmen and researchers. These goals have been achieved to some extent by using fewer power switches, reducing the number of current and voltage sensors, eliminating position sensors, and using sensorless control methods. But according to the electrolytic capacitors used to reduce DC voltage ripple are both significantly more expensive and, inherently, potentially cause the most damage to the drive. In this paper, with the aim of eliminating high-capacity electrolytic capacitor and using low capacity switched thin film capacitor in DC link, a new control method based on simultaneous control of speed and torque is presented, the use of which significantly causes torque ripple. Reduced voltage fluctuations in the DC link. The validity of the introduced method is checked using simulation in Simulink software and then a laboratory sample of the drive is tested and the results of theory and simulation are validated.