Methods for Optimal Design of Electric Motors
Electric motors are widely used in industrial and domestic fields. Important and significant reductions in energy consumption can be obtained by producing high-performance motors. Examples of characteristics to be improved as much as possible can be efficiency and / or torque. From a commercial point of view it is necessary that these new motors are made with low construction costs in order to make them competitive with traditional electric motors engines. These objectives (performance-costs) are in contrast with each other. The design of electric motors capable of making efficient compromises of these conflicting objectives needs the use of sophisticated and complex mathematical methodologies. In this context, various methods have been developed which, using simulation codes, make it possible to determine the values of the design parameters of various classes of electrical motors which ensure efficient trade-offs between the various conflicting objectives for new motors.
The first activity carried out in this area concerned the development of a new methodology for the optimal design of a 7.5 kW – 4 pole three-phase asynchronous motor. Traditional motors of this class had a real nominal efficiency of 84.2%. The use of the proposed methodology made it possible to obtain a new motor which, almost at the same cost, had a real nominal efficiency of 90.2%. In the most recent activity, an optimization code for the design of synchronous reluctance motors has been proposed. This new design tool has made it possible to identify a new motor of this class which has a significant improvement in torque compared to motors designed with more traditional methodologies. In fact, the torque of the new motor goes from 0.43 Nm to 0.71 Nm, while the other characteristics of the electric motor remain practically unchanged.
Some of the contributions proposed in this area are described together with the corresponding methodologies in the papers listed below.