Design of a switched reluctance sector motor for an integrated motor/propeller unit

Electrically powered thruster units are widely used for the propulsion of a variety of small vessels. In craft powered this way, one or more thrusters mounted externally to the vessel are employed to provide both propulsion and a means of steering. This paper describes some of the aspects of the design of a prototype switched reluctance motor for use in an integrated motor/propeller unit. The motor is a three phase sector design with a six pole stator and twenty pole rotor. The paper addresses the factors which influenced the choice of phase and pole numbers and considers some of the trade-offs between the mechanical and electromagnetic requirements. Motor control is also discussed.