Predictive Control of Permanent Magnet AC motor Drive

A predictive control algorithm for PMAC motor drives is presented in the paper. The proposed approach, implemented in rotor coordinates, allows to impose the reference values of d and q current components using recursive algorithms. The output of the digital control system directly imposes the timing control of the inverter by means of on/off state of the switches. Due to the time required for the execution of the algorithm, the vector control can be imposed with a delay of one sampling time. By introducing in the recursive algorithm the observed quantities instead of the measured ones, allows to impose the vector control without the delay. The state observer requires to introduce sampled data of two sampling time before the actual one and, hence, to employ a more powerful computing unit. The drive controlled by the proposed algorithms is simulated using Matlab Simulink tool. The results are compared with that obtained by simulating the traditional drive, where the d-q components of the current are controlled by PI regulators and PWM technique. The comparison highlights the better performance of the proposed direct digital control algorithm with respect to the traditional one.