Control of brushless synchronous motor with a digital signal processor

Abstract

This paper deals with the development of a complete digital control for an electrical drive with a brushless synchronous motor. This control allows the power switches of the static convertor to work in pulse width modulation in order to have sinusoidal waveform of currents in the windings of the motor. Moreover, it is well adapted for the implementation of speed and position regulation loops. It is also easier to establish a dialogue with a computer which can directly determine references for torque, speed or position. The modularity of this control yields an easy adjustment to various cathegories of motors. The digital control is built round a digital signal processor : the ADSP 2100. This one has a small but sufficient environment to execute the different tasks such as the interface with a common bus with the host computer, the acquisition of phase currents, the measurement of the position and the generation of the different power switches orders. A fine modelisation of the behavior of the vaiatior and machine in addition make it possible to regulate corrctly controls.