Flux-Linkage Based Fundamental and Harmonic Current Control of Saturated Salient AC Machines

Harmonic current injection is one of the common techniques used in interior mounted permanent magnet synchronous machines (IPMs) for applications like torque ripple minimization and self-commissioning. This requires high-performance current controllers to regulate the fundamental and harmonic current components. The performance of the current controllers is dependent on non-linear magnetic saturation effects, low sampling to fundamental ratios, and effects due to discretization and associated delays in the system. In this paper, a high-performance flux-linkage based discrete-time method to control the fundamental and harmonic current components is proposed. The proposed controller is accurate, capable of high bandwidth, robust against parameter mismatches, well suited for high magnetic saturation levels, simple to tune, and retains high performance for low sampling to fundamental ratios.