Challenges and Opportunities for Wound Field Synchronous Generators in Future More Electric Aircraft

Electrical machines and drives keep moving away from traditional technologies such as brushed machines and wound field machines toward lighter, 'easier to maintain' machines. A very interesting aspect is that certain transport applications, especially the aerospace industry, still favor the classical wound field machine for its main generating system such as Boeing 787. This article focuses on investigating this particular trend by presenting a detailed overview of the historical power-generation systems on aircraft. This article compares the current state of the art of wound field machines with other generator families. The results of this analysis are then projected into the needs of the electrical power generation and distribution system on aircraft. Although power density is a major objective for any aerospace application, however, the extra benefits associated with wound field systems are still essential in modern aircraft. This article then focuses on the main challenges for improving the power density of wound field machines. Recommendations, opportunities, and improvements related to wound field machines are discussed. In conclusion, if robust designs for higher speed wound field generators were consolidated, it would be very probable that these classical machines might still be implemented on future More Electric Aircraft (MEA) platforms.