The use of iron-nickel and iron-cobalt alloys in electrical engineering, and especially for electrical motors

Abstract

Today, one of the most important challenges for electrical motors is increasing the efficiency to obtain more power with the same electrical energy consumed. The use of iron-nickel and iron-cobalt alloys can significantly reduce the magnetic losses, and then increase the efficiency. At the same time, electrical motors are increasing their rotating speed thanks to the progress made in power electronics. The supply to the motors is not only limited to a frequency of 50 or 60 Hz, but will now be hundreds of hertz. Due to this, the magnetic field applied to the material in the stator is a high frequency and then induces high magnetic losses. The use of iron-nickel alloy and iron-cobalt alloys can reduce significantly the magnetic losses The magnetic sensitivity of iron-nickel alloys can not be reached by any other alloy. An example of sensor is presented in this paper. Induction at saturation of iron-cobalt is the highest known. This parameter can be directly linked to the size of the magnetic device. Using iron-cobalt alloys allows a 30% volume reduction.