Control and efficiency analysis for a Lundell-alternator/active-rectifier system in automotive applications

This paper presents a control strategy for a conventional Lundell alternator and an active-rectifier. The control scheme focuses on the minimisation of the stator copper losses of the alternator in an effort to maximise its efficiency. The modulation scheme of the active-rectifier is being investigated with the introduction of three different modulation techniques in order to quantify the effect they have on the alternator's efficiency. Steady-state results from experimental measurements of the alternator rectifier system are compared against a standard passive rectifier. The comparison indicates that the modulation scheme of the active-rectifier is significant to the alternator's efficiency as well as to the overall system efficiency.