Modeling and simulation of brushless dc motor control system for EPS applications

Abstract

This paper presents an advanced model of a brushless dc motor(BLDCM) control system for the electric power steering(EPS) applications considering the suppression of torque ripples. All modules of the EPS system with a BLDCM are modeled under the Matlab/Simulink environment. Among them, the DSP module and the back-EMF module are achieved by the C MEX S-function. The DSP module can output six PWM signals and commutation logic is just considered as a real DSP chip. Furthermore, all six PWM signal ports can be controlled independently, which is convenient in the suppression of commutation torque ripples. The back-EMF module can realize any waveform of back-EMF and the ADC module performs a sample-and-hold function. The model with all the modules considered highlights the consistency with the actual system, which can be used to study the suppression of the torque ripple of the BLDCM, as well as to provide an effective platform for the development of an EPS system with a BLDCM.