Continuous-control-set Model Predictive Current Control of Asymmetrical Six-phase Drives Considering System Non-idealities

Finite-control-set model predictive control (FCS-MPC) of multiphase (n-phase, n is assumed to be an odd number for simplicity) drives is challenging because of the large number of actual/virtual voltage vectors and the need for current control in (n-1)/2 sub-spaces (or planes; multi-plane current control). Any sub-optimal design (poor or no current control in some of the (n-1)/2 planes) may result in high individual plane current ripples, due to the low reactance. This work therefore investigates continuouscontrol-set (CCS) MPC for constant switching frequency multiphase motor drives as another alternative. The highbandwidth CCS-MPC is designed to accurately account for system non-idealities, namely digital control and pulse width modulation delays, inverter dead time, and measurement noise. It will be shown that the CCS-MPC has the advantages of full voltage vector space access, regular switching characteristic, and improved cycle-by-cycle tracking control, while maintaining some of the known advantages of the FCS-MPC, e.g., intuitive cost function design, model-based control, and fast dynamics. The proposed control scheme is benchmarked experimentally against the classical, proportional-integral-based, fieldoriented control in conjunction with an asymmetrical sixphase induction motor drive

“Holographic Implementations” in the Complex Fluid Dynamics through a Fractal Paradigm

Assimilating a complex fluid with a fractal object, non-differentiable behaviors in its dynamics are analyzed. Complex fluid dynamics in the form of hydrodynamic-type fractal regimes imply “holographic implementations” through velocity fields at non-differentiable scale resolution, via fractal solitons, fractal solitons–fractal kinks, and fractal minimal vortices. Complex fluid dynamics in the form of Schrödinger type fractal regimes imply “holographic implementations”, through the formalism of Airy functions of fractal type. Then, the in-phase coherence of the dynamics of the complex fluid structural units induces various operational procedures in the description of such dynamics: special cubics with SL(2R)-type group invariance, special differential geometry of Riemann type associated to such cubics, special apolar transport of cubics, special harmonic mapping principle, etc. In such a manner, a possible scenario toward chaos (a period-doubling scenario), without concluding in chaos (nonmanifest chaos), can be mimed