DSP-based integral variable structure control for permanent magnet AC and DC motor drivers

Abstract

This paper deals with the design, simulation and implementation of a digital signal processor (DSP)- based speed controller. The method applied is known as "integral variable structure model following control "(IVSMF)": which takes the error between the state of the model and the controlled plant, this error is to be minimized using the boundaries defined in the sliding mode plane. The control has been used to drive two types of permanent magnet motors, a PMDC motor and brushless AC motor, obtaining accurate speed regulation in both cases. The implementation is developed using two DSP's sharing a common memory, one is dedicated to implement the control algorithm and the other is devote to control the current controlled inverter (PWM), process the speed and current signals coming from the Hall effect current sensors and the position encoder. The control algorithm used is such if considers the variations from plant parameters, considering those parameters can have variations due to different factors such as core manufacture temperature, friction, etc. The results obtained show the robustness and the reliability of the controller when used with both the DC motor and the AC brushless motor.