Low-Speed Output Power Improvement of an Automotive Interior Permanent Magnet Alternator

Abstract

This paper examines a means for improving the low-speed output power of an interior PM automotive alternator with a switched-mode rectifier (SMR). Previous studies have shown that an SMR is a low cost alternative to an inverter, for achieving high output power and wide constant power speed range in conventional wound-field alternators and interior PM alternators. In both types of alternators, the low-speed output power is limited compared with the power available at high speeds. This paper takes an SMR modulation scheme which has been used to improve the low-speed output power of wound-field alternators, and applies it to a 6 kW interior PM alternator, and investigates its performance through both simulation and experimental tests.