The Importance of Torque/Speed-Points and Working Cycles in Designing Electric Motors

Abstract

Designing electric motors is a task, where various requirements and objectives have to be met simultaneously. To achieve this, different approaches to the design optimization problem of electric motors have been developed. Especially today, one of the most important properties of an electric motor is its efficiency. Therefore, it is important to include the efficiency into the design process since at this stage, gains in energy efficiency can be made very cost-effective. Typically, state of the art is to consider only distinct operational points and not the whole operational cycle in the design optimization.To demonstrate that the whole working cycle of an electric motor should be included into the design optimization, is subject of this paper. Based on a literature survey of recent design optimization methods the current state of the art will be presented. The main objective of this paper is dedicated to the design of a permanent magnet synchronous motor. Using genetic algorithms, the motor will be designed several times with varying operational points. As will be seen, for the sake of minimal energy requirement, the whole working cycle and not only distinct operational points have to be considered in the design optimization.