Magnetic circuit

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

Transient Analysis of a Magnetic Gear Integrated Brushless Permanent Magnet Machine Using Circuit-Field-Motion Coupled Time-Stepping Finite Element Method

Abstract: In this paper, a novel magnetic gear integrated brushless permanent magnet machine is studied. The main merit of the machine is that the torque produced by the stator windings can be transmitted between the low-speed rotor and the high-speed rotor through the modulation of ferromagnetic pole pieces; hence it can output a large torque at a low speed. The operating principle of the machine is discussed and its steady-state and transient performances are analyzed using circuit-field-motion coupled time-stepping finite element method. Detailed analysis about its gear ratio, cogging torque, core losses, and power factor are reported. Theoretical analysis agrees well with the FEM computation results.

A digital method for the determination of the magnetic characteristic of variable reluctance motors

Abstract: A digital method is proposed for the measurement of the magnetic flux, starting from the digital integration of the induced electromotive force (EMF). The method features sensitivity and accuracy greater than, or at least as high as, that of other methods, and is applied to the determination of the flux-linkage-versus-current diagrams of a variable-reluctance (VR) motor. Two different methods are proposed to determine flux variations in the motor magnetic circuit, and the results of the experimental work carried out on a typical 4-kW switched reluctance (SR) motor, show that the methods are in good agreement. The methods allow quicker and more accurate determination of the flux-linkage characteristics than other proposed methods, and allow the measurement of flux-linkage values for any value of the excitation current and of the rotor position. For this reason, the methods are useful for the determination of flux-linkage characteristics to be used in the analytical prediction of VR motor performance. >

Design and analysis of a tubular linear oscillating motor for directly-driven EHA pump

Abstract: This paper investigates a novel tubular DC linear oscillating motor (DLOM) for the application of directly-driven hydraulic servo pump in electro-hydrostatic actuator (EHA) A hollow mover structure is used to mount Halbach PM arrays, which not only reduces the mover mass for improvement of system dynamics, but also leaves space for installment of resonance springs It helps to shorten the motor length, simplify the structure and improve the power density Closed slot stator structure is used to reduce the cogging force The performance is compared with that of semi-closed slot with finite element method (FEM) Employment of multiple windings helps to reduce the flux leakage, and increases the flux density Air-gap flux density and thrust force are formulated with lumped magnetic circuit method analytically The influence of design parameters on output performance is investigated with analytical model and FEM Design optimization is conducted to improve the thrust and its stability with respect to displacement A research prototype is developed for experimental purpose Both FEM and experimental results validate the analytical models of air-gap flux density and thrust output The working principle is also verified with resonance experiment without external load

Open Circuit Performance Analysis of a Permanent Magnet Linear Machine Using a New Hybrid Analytical Model

Abstract: This paper presents the analysis of open circuit performance of a permanent magnet linear machine using a new hybrid analytical model (HAM). The goal is to show the capabilities offered by this new modeling approach. The new HAM is based on a strong coupling of magnetic equivalent circuits method and analytical models. The analytical model, based on the formal solution of Maxwell’s equations, is established because of the separation of variables method. The open circuit performance are: 1) cogging force; 2) electromotive force; and 3) open circuit iron loss, obtained from the HAM are compared with corresponding results obtained from a finite-element analysis. A very good agreement has been obtained.

A fully integrated micromagnetic actuator with a multilevel meander magnetic core

Abstract: To generate and to confine a magnetic flux in the magnetic core and at the same time minimize coil series resistance, low-resistance meander conductors located in a single plane were interwoven with multilevel meander magnetic cores. This 'wrapped' solenoid (with the core wrapped around the conductor) was fabricated in a fully integrated fashion. A micromagnetic actuator was realized by incorporating a surface micromachined nickel-iron cantilever beam as part of the magnetic circuit of the core. The nickel-iron cantilever beam was 2.5 mu m thick, 25 mu m wide and 780 mu m long, and the magnetic circuit contained 17 turns of meander type solenoid coils. Tip deflection of 4 mu m in the vertical direction was achieved when a DC voltage less than 1 V (and resulting drive current of 600 mA) was applied to the coils. This fully integrated multilevel topology offers a variety of micromagnetic applications, which can be fabricated on the same substrate with an integrated circuit and actuated with low voltages. >