Thermal management of integrated motor drives

When reviewing technology related with integrated motor drives (IMDs), it is natural to look first at the most recent developments in high-specific-output and high efficiency electrified propulsion, on-board power generation and actuation. All of these have been recently receiving increased attention in the context of global efforts towards the net-zero emission and more sustainable society. Particularly, transportation (future mobility) has been undergoing dynamic transformative changes, with numerous technological challenges to be addressed [1,2]. Here, both system integration and thermal management have been identified as essential to development of the next-generation IMDs. Interestingly, when exploring the motor drive technology, it is evident that the concept of IMDs is not new. IMDs have been with us for much longer than one might think. The early examples of integrating electronics with electrical machines include both automotive and aerospace applications introduced in the 1960s [3,4]. Here, car alternators and aircraft generators were the first to combine both electrical machine and power electronics (three-phase full-wave discrete diode rectifiers) in a single package to provide a specific application driven, technologically competitive products. Figure 5.1 presents the early design solutions including the rotating rectifier assembly of an actively air-cooled brushless AC generator [3] and alternator assembly [5] for aerospace and automotive applications, respectively.