Complete position sensorless control of PMBLDC motor for variable speed applications

摘要

This paper presents a comprehensive control scheme for complete position sensorless operation of a Permanent Magnet Brushless DC Motor (PMBLDCM), for variable speed applications. An approach based on initial rotor alignment from any position is used along with an open loop speed up. During alignment of rotor, phase currents are controlled by pulse width modulation (PWM) of voltage source inverter (VSI). Thereafter, line back-EMF sensing based position sensorless control is used for running under speed control. To reduce the control complexity, speed control of PMBLDCM is performed by controlling the input dc voltage to VSI. The proposed position sensorless controller for PMBLDCM is designed, modelled and simulated in MATLAB/SIMULINK environment to demonstrate wide range speed control in position sensorless mode. The hardware setup results, obtained using a digital signal processor (DSP) TI-2812 for the developed position sensorless controller, are presented to validate the simulation results.