Comparison of Electric Machine Types for Electrically Driven Engine Accessories Using Multiphysics Simulation Tools

With growing interest in electrification in automotive industries, the selection of suitable electric machine types based on application requirements is most important. In this article, three electric machine types, axial flux machine, interior permanent magnet (IPM) machine, and switched reluctance machine, are compared systematically to find the best candidate to drive engine accessories in a hybrid truck. These machine types are designed and optimized to meet the application-oriented design requirements and constraints. An extensive Pugh matrix is created where each machine type is scored based on efficiency range, cost, volumetric power density, gravimetric power density, acoustic noise and stress on the rotor, fault tolerance, heat rejection, and manufacturability. Each Pugh matrix component is assigned to a priority-based weighting, based on the application demand, to determine an accumulated score for each machine topology. A full-scale prototype of the best performing machine type is built and tested. Experimental results validate the multiphysics conclusions drawn in the work.

Automated summary

This study systematically compares three types of electric machines - axial flux machine, interior permanent magnet (IPM) machine, and switched reluctance machine - to find the most suitable candidate for driving engine accessories in a hybrid truck. A Pugh matrix is created to score each machine type based on various criteria, with the best performing machine type validated through a full-scale prototype and testing.