Active Output Voltage Regulation for an Ironless Axial-Flux PM Automotive Alternator with Electromechanical Flux Weakening

Aim of the paper is to present a solution for active output voltage regulation in PM automotive alternators, though mechanical flux weakening. An AFPM ironless machine is investigated, composed of two stators connected in series which can be shifted one with respect to the other, thus allowing a theoretically infinite constant power speed range. The paper focuses on the aspects related to layout, sizing and control of the shifting mechanism, which are critical for accurate output voltage regulation. Experimental tests on a 2 kW prototype will validate the capabilities of the proposed solution, both during steady-state and during transient operating conditions.

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