Harmonic Injection Strategy Considering Multiplane Iron Loss Impact With Optimal Magnetizing Flux Distribution for Multiphase Induction Machines

Lagging orientation error detuning induced by iron losses for multiplanes of multiphase induction machines (IM) under nonsinusoidal supply control triggers error in the determination of calculated harmonic, fundamental air-gap flux advance angles, and harmonic slip frequency. This in-turn leads to inaccurate harmonic injected currents, which are dependent on a harmonic multiple of frequency for the corresponding plane with respect to the fundamental plane frequency. This article proposes the novel harmonic injection strategy considering the detuned impact of iron losses by keeping in view the complete iron loss modeling for both harmonic magnetizing flux orientation control (MFOC) and fundamental rotor flux orientation control (RFOC) planes. Furthermore, the satisfaction of complete optimal flux distribution constraints for multiphase IM is taken into account, which results in preserving optimal flux patterns throughout the mechanical loading, particularly at low and medium load conditions. Contrary to other traditional orientation schemes, this article adopts the MFOC and RFOC for harmonic and fundamental planes, respectively, for acquiring the aligned and synchronized control of harmonic and fundamental air-gap flux distribution. Detailed experimental results incorporating a seven-phase induction machine as a prototype are utilized to evaluate the harmonic injected currents, advance angles, slip frequencies, and induced electromotive force waveforms, which validate the effectiveness of the proposed scheme.

Automated summary

This article proposes a novel tuning strategy considering the impact of iron losses, by maintaining a complete iron loss model for both the harmonic magnetizing flux orientation control (MFOC) and the fundamental rotor flux orientation control (RFOC) planes. The strategy satisfies the optimal flux distribution constraints for multiphase induction machines and preserves optimal flux patterns throughout mechanical loading. Experimental results using a seven-phase induction machine prototype validate the effectiveness of this strategy.