Bartosz Borkowski

Measurement of Core-Loss Distribution Using Thermography

In recent years, high-power electric motors have been mounted on mobile platforms such as electric vehicles. These motors are required to be compact, lightweight, and highly efficient. The reduction of core loss that occurs in electrical steels is an important factor in efficiency. Because core loss is ultimately converted into heat, it can be estimated by measuring the amount of heat generated. Methods for directly measuring the core loss in electrical steel sheets with thermistors and thermocouples have been proposed, but in these methods, many constraints complicate the measurements. In addition, the measurements are not suitable for a large number of sampling points. The aim of this study is to measure the distribution of core loss in electrical steel sheets by using thermography.

Construction of the Pulsed High Magnetic Field Generator up to 33T and the Enhancements of the Magnetic Coercivity in High Fields

M-Heff full curves up to 19T for the permanent magnets composed of Nd-Fe-B were very precisely observed by using specially designed magnetizer. The pulsed magnetic field directions were safely reversed with the same coil-end to ground side of coil positive and negative field directions. The coercivity enhancements were observed by 15% in high pulsed field applications.

Precise measurement of magnetization characteristics in high pulsed field

Permanent magnets, especially Nd-Fe-B magnets, are very important engineering elements that are widely used in many applications. The detailed design of electrical and electronic equipment using permanent magnets requires the precise measurement of magnetization characteristics. High pulsed magnetic fields can be used to measure the magnetization characteristics of permanent magnets in the easy and hard magnetization directions. Errors influencing the measurements stem from the relationship between the tested material, pick-up sensor configuration, and excitation coil. We present an analysis of the effect of the sensor construction on the accuracy of the measurements of the material’s magnetic properties. We investigated the coaxial and series types sensor configurations.