Fundamental study for a fractional order repetitive control using Generalized Repetitive Control for high precision motor control

Abstract

Interior Permanent Magnet Synchronous Motors (IPMSMs) are widely used for industrial applications. IPMSMs has a lot of advantages, such as high efficiency, high torque density and so on. In such a drive system, harmonic current appears inevitably and harmonic current control technique is used for the compensation. Repetitive control is known as a useful harmonic current compensation method and realized by adding a specific number of a sampling period according to the frequency of repetitive disturbance. Such a discrete delay must be an integer of sampling period. However, it has fractional term in a specific frequency region of the disturbance. This paper proposes a novel fractional order repetititve control using Generalized Repetititve Control (GRC),which is based on Generalized KYP lemma proposed by S. Hara. GRC is compared with Lagrange interpolation method, which is used for fractional order repetitive control conventionally. The effectiveness of the proposed designing method is verified through simulations and the experiments.