Improved performance alternator with fully integrated Switched-Mode Rectifier

Abstract

The use of Power Electronic circuits has helped to advance the technology of automotive alternators. The use of a Switched-Mode Rectifier (SMR) allows the alternator to run at a load-matched condition, optimizing power and efficiency over all operating speeds. However, the use of SMR's has largely been focused on designs for 42 V alternators. This thesis presents the design, build, and characterization of an SMR-based alternator that provides improved power and efficiency at the present automotive standard of 14 V. The SMR-based machine was built from commercial electronic devices and packaged such that it could be fully integrated into the alternator housing without impacting the physical structure or reliability. The SMR-based alternator was characterized in a laboratory environment (25°C ambient temperature) over the standard operating range of 1500 rpm (idle speed) to 6000 rpm (cruising speed). The alternator operated in a load-matched condition, achieving maximum power output up to 2400 rpm and achieved cruising speed output power of 2178 W at full field current of 4.3 A.