An improved simulation model of a brushless DC motor drive systemfor industrial applications

摘要

An accurate and simplified model of a brushless DC motor drive(BLMD) system is presented as a simulation tool for performance relatedstudies in industrial drive applications and for system identificationin controller design. The model relies on the single Fourier seriesexpression for pulsewidth modulation (PWM), which includes the effectsof inverter dead time as a substantial part of the switching period T_s, in the current control loop. This simplified approachobviates the need for very small time steps (~0.5% T_s), inthe search of PWM edge transitions within a switching interval, foraccurate simulation. Substantial improvement in simulation speed isachieved (up to fiftyfold) with a beneficial saving in computation (CPU)resources. Model integrity is validated when simulation results arechecked against actual BLMD test data for coherence. Subsequent modelsimulations illustrate the effect of inverter delay on the reduction ofgenerated torque and power transfer