Magnetic circuit

About: Magnetic circuit is a research topic. Over the lifetime, 15707 publications have been published within this topic receiving 118099 citations.

Recent advances in the one- and two-dimensional magnetic measurement technique for electrical sheet steel

Abstract: The problems connected with measuring the magnetic properties of electrical sheet steel under the condition of one-dimensional (alternating) and two-dimensional excitation (circular, elliptic, and alternating with rotation of the direction) are surveyed. Regarding the classical case of one-dimensional excitation, the relationships between the SST (single-sheet tester) and Epstein results, and different types of SSTs and their peculiarities are considered. The main arguments in favor of the SST that determines the field strength from the magnetizing current (MC method) in comparison with that using the H procedure are greater simplicity and, therefore, greater reproducibility to be expected in practice. It is also shown that single-yoke construction is inadequate for accurate loss measurements on an electrical steel sheet. Various methods for the determination of rotational power loss are in use. The thermometric methods appear to be less effective than the more convenient and versatile field-sensing methods, which yield more information. Digital procedures are particularly useful for this kind of measurement. New magnetic circuits are under test. Standardization was deemed desirable, but a method for this purpose has not been agreed upon. >

Force Calculation in 3-D Magnetic Equivalent Circuit Networks With a Maxwell Stress Tensor

Abstract: Magnetic equivalent circuit (MEC) models are increasingly valuable for analysis and design of electromechanical devices, particularly electrical machines, because of their moderate computational effort and reasonable accuracy. Force and torque calculations in prior MEC implementations are almost exclusively based on the virtual work method (VWM) adapted to the specific device model. But VWM does not easily extend to a general MEC modeling approach. In this paper, the more direct Maxwell stress tensor (MST) method is applied to a general 3-D MEC modeling framework. MST theory and implementation are presented. Its application is discussed with the example of an electromagnet. Results are compared to both measurements and analytical and finite-element models.

Magnetic refrigeration device and magnetic refrigeration system

Abstract: A magnetic refrigeration device, which can be reduced in size and improve magnetic refrigeration efficiency, and a magnetic refrigeration system can be provided. The magnetic refrigeration device has a heat exchanger vessel of a helical structure filled with magnetic particles having a magnetocaloric effect, a magnetic circuit, a driving unit configured to relatively move the heat exchanger vessel and the magnetic circuit so that a magnetic field can be applied to and removed from the magnetic particles, a low temperature side heat exchanging unit, a high temperature side heat exchanging unit, a refrigerant flow device, and a refrigerant circuit formed by connecting the heat exchanger vessel, the low temperature side heat exchanging unit, the high temperature side heat exchanging unit, and the refrigerant flow device by a pipe for circulating a refrigerant. The magnetic refrigeration system is arranged to use the magnetic refrigeration device.

Analysis and performance of an ironless stator axial flux PM machine

Abstract: This paper presents the analysis, design and performance of an axial flux permanent magnet (AFPM) machine with an ironless stator. The topology has a large airgap length and zero core losses. A machine model that uses both lumped magnetic circuit and finite element method results is used with a multi-variable optimization algorithm to obtain the optimum machine dimensions. Special attention is given to the magnet interpolar gap to ensure a certain minimum plateau width for brushless DC operation. The large airgap length allows several approximations to be made that simplifies the machine model. A prototype machine is constructed and evaluated. Measured results of the armature reaction effect in the large airgap are given and discussed.