Flux Maps Spatial Harmonic Modeling and Measurement in Synchronous Reluctance Motors

This work proposes a novel identification test and post-processing procedure to measure the complete flux linkage model of a synchronous reluctance (SyR) machine, including its spatial harmonics. A novel space harmonic flux model is developed, capable of describing the machine behavior even under distorted current waveforms. This permits to characterize the machine by adopting standard and straightforward PI-based current vector control, avoiding the use of the resonant controllers normally adopted in similar tests procedures present in the literature. The flux ripple information is extracted by combining the space distortion in the stator current and voltage. The flux ripple measurement can be used for validating the FEA model of the SyR machine, thus improving the motor design stage, for experimentally estimating the motor torque ripple and for building accurate simulation models including the space harmonics. this is particularly critical for very low-speed applications, accurate position control, and sensorless drives. An experimental validation is carried out on a 4.4 kW SyR machine.