Magnetic circuit

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

Development of passive fault current limiter in parallel biasing mode

Abstract: So far literature reports on the magnetic fault current limiter (FCL) are based on the series biasing mode in which the flux due to line current flows through the permanent magnet. As a result there is a high possibility of demagnetization of the permanent magnet. A passive fault current limiter is a combination of passive elements such as permanent magnet and saturable core. The permanent magnet is used to bias the core. In order to avoid severe demagnetization of the permanent magnet, we have investigated the performance of passive fault current limiters based on permanent magnet and saturable core in parallel biasing mode. The functional characteristics have been analyzed by Tableau approach and the simulation results are presented, The experimental results for a small scale prototype model are also presented for verification.

Permanent magnet flux-biased magnetic actuator with flux feedback

Abstract: The invention is a permanent magnet flux-biased magnetic actuator with flux feedback for adjustably suspending an element on a single axis. The magnetic actuator includes a pair of opposing electromagnets 11' and 12' providing bi-directional forces along the single axis to the suspended element. Permanent magnets in flux feedback loops from the opposing electromagnets establish a reference permanent magnet flux-bias to linearize the force characteristics of the electromagnets to extend the linear range of the actuator without the need for continuous bias currents in said electromagnets.

A new approach for iron losses calculation in voltage fed time stepping finite elements

Abstract: A methodology allowing one to include iron losses in voltage fed time stepping finite elements simulations is presented in this paper. Hysteresis, eddy currents and anomalous losses models are introduced in the 2D field formulation based on the magnetic vector potential. The influence of the losses on the behavior of an Epstein frame is given. Comparison between simulated and measured results shows the validity of the proposed methodology.

Development of a Novel Magnetic Circuit Model for Design of Premium Efficiency Three-Phase Line Start Permanent Magnet Machines With Improved Starting Performance

Abstract: This paper presents challenges in an ongoing project related to the design of a premium efficiency three-phase line start permanent magnet synchronous motor (LSPMSM) and proposes an exclusive solution through development of a novel magnetic circuit model. Since the LSPMSM is rapidly replacing the conventional induction motors in industrial applications such as pumps, fans and conveyors which require the machine to operate under both frequent start-stop and steady-state conditions for a wide range of time, a trade-off has to be reached between their starting performance and efficiency post-synchronization. Until now this has only been possible with time consuming FEA based design methodology. Hence, understanding the need and scanty availability of literature on simplistic and yet precise magnetic circuit based design of three-phase LSPMSM, this manuscript proposes exclusively a novel magnetic circuit model to design LSPMSM with improved starting performance. Firstly, the aforementioned design issues have been illustrated using different machine configurations developed. Further, a detailed procedure to deal with the design issues with the help of the developed magnetic circuit model is discussed and validated by developing a machine where the trade-off has been reached.

Design and Analysis of a New Enhanced Torque Hybrid Switched Reluctance Motor

Abstract: In this paper, a new 6/10 hybrid switched reluctance motor (HSRM) is proposed. This original topology deploys permanent magnets (PMs) between adjacent stator poles of a divided teeth SRM. The function of the PMs is to weaken the magnetic saturation in stator poles, which is a major obstacle of torque improvement for divided teeth SRMs. Besides, the magnetic flux in the airgap increases as well. Hence, the output torque can be increased significantly. The flux distribution of the topology is analyzed by using an equivalent magnetic circuit. The topology is optimized by using the genetic algorithm for the best torque performance. Additionally, the characteristics of the proposed topology are compared with a 12/10 SRM, a 6/10 two-teeth SRM, a 12-slot, 10-pole three-phase six-state PM brushless DC motor, and a flux switching permanent magnet motor of the same dimension. A prototype of the proposed topology is built for experimental verification. The simulation and experimental results indicate that the proposed topology can achieve high torque density and high PM utilization factor simultaneously.