Improvement of IPMSM sensorless control performance by suppression of harmonics on the vector control using Fourier transform and repetitive control

In the case of the sensorless control for the PMSM that estimates position and velocity from EMF using the model of a synchronous motor with the voltage and current, it is desirable for the voltage and current to be perfect sine waves. However, in fact, various harmonic components are contained in the voltage and current, and they have bad influence on the estimation performance of a sensorless control. In this paper, we propose an improving method of sensorless control performance for the IPMSM by suppression of harmonic component in the current control loop of the vector control using Fourier transform and repetitive control. To suppress harmonic components, compensation signals are acquired using Fourier transform and repetitive control, and feedforward control is implemented with acquired compensation signals. To evaluate our proposed system, the sensorless control system for the IPMSM is taken for instance. The system is constructed on the basis of the extended EMF disturbance observer with the current and voltage command whose harmonic components are suppressed. As a result, we can have a margin in pole assignment of the disturbance observer, and the performance of sensorless control can be improved. The effectiveness of the proposed method is confirmed by experimental results.