Arbitrary Current Harmonic Decomposition and Regulation for Permanent Magnet Synchronous Machines

This article contributes a novel solution for the regulation of arbitrary current harmonics in a permanent magnet synchronous machine (PMSM) system by introducing a virtual three-phase system. The inverter nonlinearity, back electromotive force harmonics, and the asymmetry among phases, are considered to derive a comprehensive electrical model of PMSMs. Compared to the conventional harmonic analysis, the derived model indicates that more new current harmonics can exist in the PMSM system. To regulate the current harmonics with arbitrary orders, a virtual three-phase system is established. By properly shifting the spatial and time phase angles between the virtual three-phase system and the original physical three-phase system, the selected current harmonics can be decomposed from the phase current. A simple proportional-integral regulator with adjustable phase compensation angle is designed based on the proposed model to regulate the decomposed current harmonics in the corresponding harmonic synchronous reference frame. The implementation details and experimental results are provided to illustrate the feasibility and correctness of the proposed control strategy.