Comparative Performance Evaluation of Hall Effect Sensorless Control Options in Permanent Magnet Brushless DC Motor Drives

The objective of this paper is to present a comparative and quantitative study on three hall effect sensorless circuit configurations in permanent magnet (PM) brushless dc motor drives, along with four practical pulse width modulation (PWM) techniques. PM brushless direct current (BLDC) motor mathematical model, principles of operation, measurement circuit and logic configurations for three back electromotive force (EMF) zero crossing detection methods, as well as theoretical analysis on various PWM patterns are described. Their performance evaluation on waveform quality, rotor position tracking capability, and torque ripple impact are quantified as functions of motor speed and load variation. Digital time domain simulation models are established with the closed current and speed loops for the evaluation. Experimental results without using any hall effect sensors fully validate the theoretical and simulation findings.