Research Of Sensorless Brushless DC Motor Control System

Brushless DC (BLDC) motor, which substitute the mechanical commutator configuration with electrical, avoid a series of problems with mechanical ones. BLDC motor is good at anti-jamming, reliability, and maintained expediently. Surely, BLDC motor preserves the excellent speed regulation performance. Lately years, BLDC motor is applied widely in many scopes.This paper introduces BLDC motor's developing situation in home and abroad at first. It's configuration and composing is done in detail, and build up whole mathematics equations and dynamic block diagram based on the relationships between the parameters. Then, the developing situation of sensorless technology is introduced, and two methods for rotor flux position, the traditional direct back-emf and third harmonic signal of back-emf, are discussed detailedly.For a better effect, the double closed loops control, with velocity and current, is adopted in this control system. The model reference fuzzy adaptive approach is present in velocity loop, and hysteresis loop control in current loop. The simulation results are illustrated to show very good static and dynamic performance. Then, aim at the question of torque ripples the improved compensate approaches of Commutation torque ripple are discussed. The simulation results are illustrated to show that, the compensate approaches come out well efficiency in torque ripple minimization.In the end, the design of hardware and software program of the BLDC motor's control system is introduced as well.