Reluctance motor and actuator design: Finite-element model versus analytical model

Designing actuators or motors requires analysis of a lot of parameters such as length, temperature, efficiency, and weight. A global analysis to evaluate these parameters is possible. Three methods can be used: 1) an analytical method, allowing parametric study and parameter sensitivity analysis; 2) a finite-element model, which makes it possible to take into account nonlinearities, including the fringe effect; and 3) the analytical method, followed by a process of optimization, which makes it possible to reach an optimum based on an objective function and constraints. This paper describes each of these methodologies and compares them to help designers make a choice. Two examples to illustrate the three methods are a reluctance actuator and a brushless dc motor intended for a new intracardiac blood pump.