Sensorless control of a wound rotor synchronous belt-driven starter-alternator

The main purpose of this work is to achieve a low-cost sensorless drive for wound rotor synchronous belt-driven starter-alternator (StARS). These electrical machines manufactured by automotive suppliers are intended to equip light cars. Classically, the self-commutation operation of the StARS is controlled by electromechanical position sensors. However, these last suffer from complex wiring and reliability issues. To overcome these problems, authors propose a sensorless control method which deals with initial rotor position detection and motor parameter identification at stand-still. A back-emfs estimation method suitable for non-zero speeds is presented as well as a DSP implementation of the suggested sensorless technique. Experimental results verify the good operation of the proposed solution.