Increasing power and torque capability of brushless direct current motor by employing 150-degree conduction mode...

With the reduction of magnet costs and the production of high-energy magnets in small sizes, permanent magnet brushless motors are used widely in various applications from household to medical, industrial, and automation applications. Furthermore, permanent magnet brushless motors have some significant advantages over the other conventional motors such as induction and brushed motors. Due to the popularity of brushless motors, they have become the focus of interest of researchers. From the past 30 years to today, the researchers have carried out numerous studies in relation to brushless motors. These studies are generally sensorless control, adaptive control, different Proportional Integral and Derivate (PID) applications, fuzzy control, PI-fuzzy and PID-fuzzy control and different Pulse Width Modulation applications and to eliminate torque ripple and other control algorithms. Permanent magnet brushless motors can be divided into two main groups. One is the permanent magnet synchronous motor and the other one is the permanent magnet brushless direct current motor (BLDCM). BLDC motors are the most preferred in applications due to their low cost and relatively simple drivers. BLDC motors are run with the classical 120-degree conduction mode voltage source inverter (VSI). Because BLDC motors run with 120-degree conduction mode inverters, power and torque produced by BLDC motors are less than their capacity, whereas BLDC motors can provide a better dynamic response, higher power, and torque by employing 150-degree conduction mode controlled VSI. In this experimental study, it is aimed to design and manufacture a versatile VSI which can control the BLDC motor in both 120 and 150-degree conduction modes. Then, BLDC motor is run in two conduction modes employing the purposed inverter under various loads, and the torque, power, and speed performance of the motor were analyzed to demonstrate the effect of the two commutation methods on BLDC motor performance. The results of this comparative experimental study have shown that the 150-degree conduction mode-controlled inverter provides with the BLDC motor generating higher power, torque, and speed than the inverter with 120-degree conduction mode.