Periodic disturbance rejection of a PMSM with adaptive control algorithms

Permanent magnet synchronous motors (PMSMs) produce a parasitic oscillating torque due to several reasons. This contribution cancels the oscillating torque with adaptive control algorithms. Therefore a mathematical model of the PMSM is necessary. A model with nonlinear dynamics and a Fourier approach for the ripples is used as a mathematical description. Through comparisons between measured data and simulated data it is shown that the model assumptions are valid. The adaptive algorithm is implemented as an add-on controller to the already existing control system which consists of a feedforward part and a basis controller. The challenge is that the closed loop system has a resonant frequency and the algorithm should have the same performance for all frequencies. Experimental results show the performance and convergence of the adaptive algorithm at constant and non constant velocity.