Comparison of electrical machines for use with a high-horsepower marine engine turbocharger

This paper compares in detail electrical machine technologies for an electrically-assisted turbocharger used with a high-horsepower marine engine. The machine is required to be used both as a motor to improve engine transient characteristics and as a generator for recovering energy (turbocompounding). The application translates to machine operation at high-power(150kW), and high-speeds with a constant power-speed range (CPSR) of 2 (25–50krpm). In this research Permanent Magnet Machines (PMSM), Induction Machines (IM) and Switched Reluctance Machines are compared in detail over a number of considerations, including the thermal performance, size, torque quality, kVA rating, and cost with the aim of identifying the most appropriate technology. In light of the technical and market requirements, an induction machine including novel materials is proposed and prototyped for the application.