Salient pole generators for belt-driven automotive alternator applications

Of all the electric machine types, conventional automotive belt-driven Lundell generators, and electrically-excited or hybrid permanent magnet-electrically excited synchronous salient pole generators are the only types that can utilize inexpensive control electronics consisting of a passive three-phase diode bridge and a simple, one power switch voltage regulator. In this paper, the replacement of Lundell automotive generators with either electrically-excited or hybrid permanent magnet-electrically excited synchronous salient pole generators is investigated on the basis of their better efficiency and the ability to provide output power beyond the 6 kW level. The design considerations and the test results are presented for a 42 V, 3.5 kW electrically-excited salient pole generator and for a 42 V, 3.5 kW hybrid permanent magnet-electrically excited salient pole generator. Specific design criteria, design simulations/analyses, and test results are presented and compared with a belt-driven automotive generator performance.