Title: A pulse-width modulation technique for BLDC motor drive system to reduce commutation time
Authors: Shabanali Gol; Gholamreza Ardeshir; Ahmad Ale Ahmad; Mohammadreza Zahabi
Addresses: Faculty of Electrical and Computer Engineering, Babol Noshirvani University of Technology, Babol, Mazandaran, Iran ' Faculty of Electrical and Computer Engineering, Babol Noshirvani University of Technology, Babol, Mazandaran, Iran ' Faculty of Electrical and Computer Engineering, Babol Noshirvani University of Technology, Babol, Mazandaran, Iran ' Faculty of Electrical and Computer Engineering, Babol Noshirvani University of Technology, Babol, Mazandaran, Iran
Abstract: Commutations occurring in brushless DC motor (BLDCM) drive system cause failure of a sensorless drive based on zero-crossing detection of back-electromotive force (BEMF) when the commutation angle reaches or exceeds 30°. On the other hand, increasing the load on the motor slows down falling process of outgoing phase current during commutation. This paper presents a new method for complete vanishing of outgoing phase current before BEMF zero-crossing point, using a pulse-width modulation (PWM) mode in which an adaptive pattern is inserted to H-PWM_L-ON mode synchronously with commutation time. The proposed PWM mode can be used for sensorless drive based on direct BEMF zero-crossing detection method. The proposed method is applied to a 14 kW/220 V BLDCM with constant v/f control, and the results show that as the duty cycle of PWM is reduced, commutation time becomes shorter and the transferred power to motor is increased compared to H-PWM_L-ON mode.
Keywords: BLDCM; brushless DC motor; commutation time; direct back-EMF zero-crossing detection; drive system; pulse-width modulation; sensorless.
DOI: 10.1504/IJPELEC.2017.085078
International Journal of Power Electronics, 2017 Vol.8 No.3, pp.249 - 265
Received: 08 Sep 2016
Accepted: 30 Jan 2017
Published online: 10 Jul 2017 *