Modern electromagnetic and electromechanical devices have complex flux paths, often developing in three dimensions. Moreover, the supply frequency of electrical machines and transformers is increasing in order to reduce their dimensions. For these applications, the use of soft magnetic composite materials is advantageous. Soft magnetic composite cores may help reducing the eddy current loss in electric machines with complex MMF content. However, their performances must be carefully modelled and evaluated. A comparative study is made at room temperature and at cryogenic temperature. The torque density of axial flux machines with different soft magnetic composite cores is compared. Also, a linear tubular machine was specially built to assess the behavior of soft magnetic composite cores at cryogenic temperature. The increase of core loss of soft magnetic composite materials at cryogenic temperatures is limited as shown in Fig.1. Therefore they are suitable for use in cryogenic machines, like the HTS cold core transformers. Although many magnetic materials are used in key fields of applications, e.g. in special machines, superconducting machines, magnetic shields, particle accelerators in fusion energy, MRI magnets and other, a database of their characteristics is missing, as well as their modelling at a microscopic level. This presentation represents the starting point for a systematic study on the subject from the point of view of an application designer.
The behaviour of soft magnetic composite cores for Electrical Machines both in standard environmental conditions and in cryogenics
MARIGNETTI, Fabrizio
2017-01-01
Abstract
Modern electromagnetic and electromechanical devices have complex flux paths, often developing in three dimensions. Moreover, the supply frequency of electrical machines and transformers is increasing in order to reduce their dimensions. For these applications, the use of soft magnetic composite materials is advantageous. Soft magnetic composite cores may help reducing the eddy current loss in electric machines with complex MMF content. However, their performances must be carefully modelled and evaluated. A comparative study is made at room temperature and at cryogenic temperature. The torque density of axial flux machines with different soft magnetic composite cores is compared. Also, a linear tubular machine was specially built to assess the behavior of soft magnetic composite cores at cryogenic temperature. The increase of core loss of soft magnetic composite materials at cryogenic temperatures is limited as shown in Fig.1. Therefore they are suitable for use in cryogenic machines, like the HTS cold core transformers. Although many magnetic materials are used in key fields of applications, e.g. in special machines, superconducting machines, magnetic shields, particle accelerators in fusion energy, MRI magnets and other, a database of their characteristics is missing, as well as their modelling at a microscopic level. This presentation represents the starting point for a systematic study on the subject from the point of view of an application designer.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
