DESIGN AND PERFORMANCE COMPARISON OF PERMANENT MAGNET BRUSHLESS MOTORS AND SWITCHED RELUCTANCE MOTORS FOR EXTENDED TEMPERATURE APPLICATIONS

In-Service Inspection (ISI) plays a critical role in ensuring the safety and security of nuclear power plant and personnel. The limited access and high ambient temperature conditions impel the need for remote inspection techniques using semi automated vehicle. The electrical actuators driving the ISI robotic vehicle must satisfy the requirements of high operating temperature, high torque density, compact size and low weight. Currently, permanent magnet brushless motors are used due to its compact size and high efficiency. However, due to risk of demagnetization at high temperature as well as due to depleting resources of rare earth material alternate topologies without using permanent magnets shall be considered. This paper investigates the performance of Permanent Magnet (PM) brushless motor and Switched Reluctance (SR) motors for high temperature applications. SR motor is designed as per fundamental design equations satisfying the application requirements. Electromagnetic performance is verified by Finite Element Analysis (FEA) and thermal performance is verified by lumped parameter thermal analysis. Finally the performance of SR motor is compared with PM motor in terms of torque, efficiency, weight, cost and temperature rise.