Model and Design of an Air-Cooled Thermal Management System for an Integrated Motor/Controller

Abstract

The use of a remote power supply for conventional induction-type electric motors requires that very high frequency, high power pulse-width modulated signals be transmitted through cables over a significant distance. There are losses inherent in this transmission process as well as problems related to the electro-magnetic interference generated by these cables and reliability issues associated with the cables and interconnects. In addition, the current thin lamination manufacturing method for induction motors results in geometrical restrictions, significant losses, and significant material wastes. The development of a modular permanent magnet machine that is constructed of identical, individual stator poles that are each closely integrated with their own power electronics module seeks to overcome the issues currently plaguing conventional induction- type electric motors. Combining the stator poles of a permanent magnet motor with their own integrated power electronics module-based drive unit within a motor housing has several advantages including increased reliability and improved efficiencies. However, this integrated approach is challenged by the mismatch in the thermal limits between the motor and IPEM. This thesis describes the development of computational models of the motor, air passages, and IPEM which are integrated in order to identify and design the most attractive thermal management system. An experimental verification follows the model results.