Design, implementation, and application of 150-degree commutation VSI to improve speed range of sensored BLDC motor

Abstract

Permanent magnet brushless dc (BLDC) motors are very convenient for many applications such as industrial, medical, robotic, aerospace, small electric vehicles, and home applications because of their inherent satisfying dynamic characteristics. There are numerous studies about these motors and their control schemes such as sensorless control and different speed and torque control schemes. All electric motors need commutation in order to produce speed and torque. Commutation in brushed DC motors is performed by means of a brush and collector. In BLDC motors, commutation is provided electronically in contrast to the brushed dc motors. In BLDC motors, motor phase windings are energized according to the information of the rotor position by inverter transistors. Rotor position information is used for commutation. Therefore, rotor position information is required to produce speed and torque for BLDC motors. The easiest and cheapest way to obtain rotor position information is to use Hall-effect or optical sensors. BLDC motor manufacturers generally produce BLDC motors equipped with three Hall-effect position sensors. Having three position sensors on BLDC motors provides six-step commutation which ensures two phase windings are energized in each moment. The third phase is empty. In this study, all phase windings are energized in the same time. This commutation method is twelve-step or 150 degrees commutation. So that more speed can be achieved from the same BLDC motor by comparison with six-step commutation. In this paper, both six-step and twelve-step commutation methods applied to the same BLDC motor and obtained experimental results from this study were presented, examined, and discussed.

Analysis of the Effects of Three Various Current Control Methods on BLDC Motors

“…In BLDC motor drivers, if duty cycle is %100, the average phase voltage is expressed as follows (Ozgenel M. C., 2017); ℎ = 0.41.…”

“…A BLDC motor is a form of brushed direct current motor that is replaced its commutator and brushes with electronic commutation mechanism. While commutation is done via mechanical commutator and brushes in brushed dc motors, it is accomplished electronically in BLDC motors (Ozgenel M. C., 2017). In order to accomplish commutation in BLDC motors rotor position information is required.…”

“…BLDC motors have a good linear relationship between torque and speed; they don't need maintenance owing to absence of brushes and commutator, high power density and efficiency, fast dynamic response, easy speed control. Thanks to these superior features, BLDC motors have been a good choice in a wide range of applications (Pindoriya, R. M. et al, 2014;Ozgenel M. C., 2017). Although BLDC motors have these superior features, they have also some disadvantages such as they need a driver for running even at fixed speed and initial cost is relative expensive compared to brushed and induction motor for the same power (Sathyan A. et al, 2009;Pindoriya, R. M. et al, 2014;Lengade S.R.…”

Design, Producing and Testing of 12-Step Three-Phase Voltage Source Inverter with Flexible Independent PWM Current Control for Brushless Direct Current Motor

“…Brushless motors are used in wide areas in the industrial and domestic applications owing to their superior advantages over other type electric motors such as induction and brushed direct current motors. Some advantages of brushless motors are; they have small size compared to AC motors for the same power, good linear torque-speed characteristic, easy torque and speed control, noiseless operating, high efficiency, fast dynamic response (Ozgenel, 2017).…”

“…The first one is trapezoidal back electro motive force in the phase winding that is called brushless direct current motor and the second one is sinusoidal back electro motive force in the phase winding that is called permanent magnet synchronous motor (PMSM). While permanent magnet synchronous motors phase windings are fed by sinusoidal current, permanent magnet direct current motors phase windings are fed by trapezoidal currents via three-phase inverter (Ozgenel, 2017). Both PMSM and BLDC motors are need rotor position information to be made commutation properly.…”