Finite Element Analysis Of Magnetic Field Research Articles

The Efficiency Improvement of Track-Type Wireless Power Transmission Systems through Electromagnetic Finite Element Analysis

The original system, designed as a combination structure of a linear machine and a wireless power transmission transformer, was designed to overcome the limitations of the wired power supply method used for working robots and transportation equipment in existing smart factories, and improvements in magnetic coupling and power transfer efficiency are needed. In this work, we study the efficiency improvement of a system that can supply wireless power to track-type transportation equipment. For this purpose, electromagnetic properties such as magnetic equivalent resistance, inductance, magnetic coupling rate, and core loss are analyzed using the finite element method. In addition, the results of magnetic field finite element analysis are applied in electrical equivalent circuit modeling to analyze the voltage transfer ratio and input/output characteristics of a CLLC resonant converter designed for wireless power transmission. The efficiency improvements of the proposed model are verified through a comparison of experimental and simulation results after fabricating a prototype. From the results of this study, a more optimized wireless power transmission system design based on the analysis results from an electromagnetic perspective can be realized to improve the efficiency of wireless power transmission.

Conceptual Design of Scanning Magnets Using HTS Coils Wound With Spiral Copper-Plated Striated Coated-Conductor (SCSC) Cables for Carbon-ion Radiotherapy

When we reduce the size of a rotating gantry using high field superconducting bending magnets, we must also increase the magnetic field of scanning magnets. We conceptually designed scanning magnets using HTS coils wound with Spiral Copper-plated Striated Coated-conductor (SCSC) cable, which is a low-ac-loss, high current cable concept. The coils were designed to cooled at 65 K by using liquid nitrogen. We conducted the two-dimensional cross-sectional design of the HTS coils as well as warm iron yokes by finite element magnetic field analysis. AC losses in the HTS coils and iron losses in the yokes were calculated. Electrical power consumption to excite the magnets, liquid nitrogen consumption to cool the HTS coils, and the terminal voltages of the magnets were calculated to discuss the feasibility of the designed scanning magnets.

Study on the structural design and performance of magnetorheological (MR) valve with hybrid supply magnetic source and double annular channels

Valve plays an important role in achieving precise position control for the hydraulic lift system. In order to improve the performance of hydraulic lift in precise motion, this paper proposes an MR valve with hybrid supply magnetic source and double annular channels. In addition, a structural model was established to perform pressure drop analysis. According to its working principle, it is proposed that this MR valve has two channels that work separately. There are three working modes in which the two channels work together, and the pressure drop of the MR valve can be calculated in different ways. Therefore, the MR valve with hybrid supply magnetic source and double annular channel performance test system is constructed, and the magnetic field inside the valve is simulated by performing magnetic field finite element analysis. Finally, a test bench of vehicle maintenance elevators is built to analyze whether the MR valve with hybrid supply magnetic source and double annular channels can achieve accurate control on the vehicle maintenance elevators. According to the experimental and simulation results, the pressure drop of the MR valve with hybrid supply magnetic source and double annular channels is affected by the current and channel operating mode, while the load makes little difference to the pressure drop. The worse the rising response time performance increases with increasing current, but the response time performance decreases without being affected by current. When a current greater than 1.5A is applied to the coil, the response time of the lifting platform is basically maintained at 6 s with the increase of current. The position accuracy is ±1 mm for the experimental platform of the vehicle maintenance lift table based on the MR valve with hybrid supply magnetic source and double annular channel hydraulic system.

Research on the Transmission Performance of a High-Temperature Magnetorheological Fluid and Shape Memory Alloy Composite

To address the fact that the performance of magnetorheological fluid decreases with increasing temperature, a high-temperature magnetorheological fluid and shape memory alloy spring friction composite transmission method is proposed, and its transmission performance is shown to essentially maintain stability under high temperatures. We introduce a composite transmission method, performed a magnetic field finite element analysis, and present the equation of torque transmission of the composite. The results show that the amount of torque transferred by the magnetorheological fluid reached its maximum value at magnetic saturation, but decreased with increasing temperature, down to 33.41%, whereas the frictional torque generated by the shape memory alloy spring increased with increasing temperature. When the temperature reached 100 °C, the frictional torque effectively compensated for the decrease in the magnetorheological fluid’s performance.

Magnetic field finite element analysis of diverging stepped ferrofluid seal with a large gap and two magnetic sources

Magnetic field finite element analysis of diverging stepped ferrofluid seal with a large gap and two magnetic sources

Magnetic Circuit Design and Magnetic Field Finite Element Analysis of Converging Stepped Magnetofluid Seal with Small Clearance

The stepped magnetofluid seal is an effective method for improving the pressure ability of ordinary magnetofluid seals (OMS) with large clearance. At present, the research on stepped magnetofluid seal with less than 0.4 mm small clearance has not been carried out yet. The equivalent magnetic circuit design of converging stepped magnetofluid seal (CSMS) with small clearance has been carried out and verified by magnetic field finite element method based on the CSMS theory and magnetic circuit theory. The effects of the width of the axial seal position, the height of the radial seal position, the number of the pole tooth in the axial seal position, and the number of the pole tooth in the radial seal position on the theoretical pressure ability of the CSMS are investigated by numerical simulation. The calculation results are analyzed and discussed. The results show that the magnetic flux leakage at the junction of the permanent magnet and pole piece causes the higher pressure ability of the CSMS structure designed by the equivalent magnetic circuit method than that calculated by the magnetic field finite element method. When the width of the axial seal position is greater than the height of the radial seal position and the number of pole teeth in the axial seal position is less than the number of pole teeth in the radial seal position, the CSMS has the best effect. Compared with OMS with small clearance, CSMS has greater advantages.

Magnetic Field Finite Element Analysis of a Novel Diverging Stepped Magnetic Fluid Seal

In order to improve the anti pressure capability of magnetic fluid seal under the large gap condition, a novel diverging stepped magnetic fluid seal was designed and set the pole teeth on the stepped shaft. The magnetic field distribution in the gap of diverging stepped magnetic fluid seal were numerical simulations by the finite element method of magnetic field. The effects of axial pole teeth number, radial pole number, radial sealing gap height and axial sealing gap on the anti pressure capability of a novel diverging stepped magnetic fluid seal were studied. The results show that the anti pressure capabilities of magnetic fluid seal increase with the increase of axial pole teeth numbers. The anti pressure capabilities of magnetic fluid seal firstly decrease and then increase with the increase of radial pole teeth numbers. The anti pressure capability of magnetic fluid seal firstly decreases and then increase with the increase of radial sealing gap height. The anti pressure capabilities of magnetic fluid seal decrease with the increase of axial sealing gap width.

Development and Analysis of the Magnetic Circuit on Double-Radial Permanent Magnet and Salient-Pole Electromagnetic Hybrid Excitation Generator for Vehicles

With the improvement of vehicles electrical equipment, the existing silicon rectification generator and permanent magnet generator cannot meet the requirement of the electric power consumption of the modern vehicles electrical equipment. It is difficult to adjust the air gap magnetic field of the permanent magnet generator. Consequently, the output voltage is not stable. The silicon rectifying generator has the problems of low efficiency and high failure rate. In order to solve these problems, a new type of hybrid excitation generator is developed in this paper. The developed hybrid excitation generator has a double-radial permanent magnet, a salient-pole electromagnetic combined rotor, and a fractional slot winding stator, where each rotor pole corresponds to 4.5 stator teeth. The equivalent magnetic circuit diagram of permanent magnet rotor and magnetic rotor is established. Magnetic field finite element analysis (FEA) software is used to conduct the modeling and simulation analysis on double-radial permanent magnet magnetic field, salient-pole electro-magnetic magnetic field and hybrid magnetic field. The magnetic flux density mold value diagram and vector diagram are obtained. The diagrams are used to verify the feasibility of this design. The designed electromagnetic coupling regulator controller can ensure the stable voltage export by changing the magnitude and direction of the excitation current to adjust the size of the air gap magnetic field. Therefore, the problem of output voltage instability in the wide speed range and wide load range of the hybrid excitation generator is solved.

Magnetic field finite element analysis of concentric biaxial stepped ferrofluid seals

Magnetic field finite element analysis of concentric biaxial stepped ferrofluid seals

Loss Simulation by Finite-Element Magnetic Field Analysis Considering Dielectric Effect and Magnetic Hysteresis in EI-Shaped Mn–Zn Ferrite Core

Loss Simulation by Finite-Element Magnetic Field Analysis Considering Dielectric Effect and Magnetic Hysteresis in EI-Shaped Mn–Zn Ferrite Core

Input and Output Power in Finite-Element Analysis of Electric Machines Taking Account of Hysteretic Property

This paper used a finite-element magnetic field analysis (FEA) to investigate the instantaneous and average power in a single phase transformer and a three-phase rotating machine. We examined the influence of the hysteretic properties of the magnetic materials on the instantaneous power in FEA using the isotropic vector play model. We applied post-correction to estimate the accuracy of the average power from their equivalent circuits.

パーミアンス分布のモデル化手法による交流励磁同期発電機の磁束密度分布解析

We describe a method for analyzing the harmonics components of the air-gap magnetic flux density distribution of doubly-fed generators that takes into consideration the influence of the circumference slot arrangement and winding pattern. The proposed method is based on an analytical equation of the permeance and the magnetomotive force (mmf) distributions. This method is applied to analyze quantitatively the harmonic components of the air-gap magnetic flux density distributions of a doubly-fed generator under different driving conditions. The analytical results obtained using the proposed method are in agreement with those of finite element magnetic field analysis (FEA). Thus, this method is shown to be an appropriate and useful method for quantitatively estimating magnetic flux density for doubly-fed generator.

Multiple-receptor wireless power transfer for magnetic sensors charging on Mars via magnetic resonant coupling

This paper proposes a new idea for magnetic sensors charging on Mars, which aims to effectively transmit energy from Mars Rover to distributed magnetic sensors. The key is to utilize wireless power transfer (WPT) to enable multiple receptors extracting energy from the source via magnetic resonant coupling. Namely, the energy transmitter is located on the Mars Rover, whereas the energy receptor is installed in the magnetic sensor. In order to effectively transfer the power, a resonator is installed between the transmitter and the receptors. Based on the proposed idea, the system topology, operation principle, and simulation results are developed. By performing finite element magnetic field analysis, the output power and efficiency of the proposed WPT system are evaluated. It confirms that the Mars Rover carrying with the energy transmitter is capable of loitering around the resonator, while the magnetic sensors on the receptors can be simultaneously charged according to energy-on-demand.

Magnetic Field Finite Element Analysis of Generator with Rotor Inter-Turn Short-Circuit Fault

Rotor inter-turn short-circuit is a common fault in generator and it is a research hotspot to identify the fault at its early stage. Considering the disadvantage of circuit analytical method, this paper establishes a 2D transient finite element electromagnetic-circuit coupling model, and calculates the magnetic field at normal and fault situations through the powerful post-processing function of ANSOFT, then magnetic flux density cloud pictures and air-gap magnetic flux density curves of different operating conditions are got. Using MATLAB to analyze and deal with the air-gap flux density cures, we can get the differences of faults in different levels and different positions, which provide a basis for further study of rotor inter-turn short-circuit fault.

Core Loss Computation in a Permanent Magnet Transverse Flux Motor With Rotating Fluxes

This paper presents the core loss computation in a permanent magnet transverse flux motor (TFM) with soft magnetic composite stator core and mild steel rotor yoke, in which the magnetic fluxes rotate. The computation is based on modified core loss models and finite element magnetic field analysis (FEA). The coefficients for the core loss models are obtained by curve-fitting measurements on samples, and the magnetic flux density patterns in the motor are obtained by time-stepping FEA while operating conditions are considered. The computations of the motor core losses agree with the measured values on the TFM prototype. Index Terms—Core loss, finite element analysis, rotating magnetic flux, soft magnetic composite, transverse flux motor.

Loss Calculation Method Considering Hysteretic Property With Play Model in Finite Element Magnetic Field Analysis

This paper proposes a novel estimation method for iron loss considering hysteretic property. In the proposed method, iron loss considering hysteretic property is estimated with play model as a postprocessing of usual finite element magnetic field analysis based on ordinary magnetization curve. Numerical results are compared with measured results to demonstrate the effectiveness of the proposed estimation method for iron losses.

Performance Analysis of a Linear Motor with HTS Bulk Magnets for Driving a Prototype HTS Maglev Vehicle

This paper presents the performance analysis of a linear synchronous motor which employs high-temperature superconducting (HTS) bulk magnets on the mover and normal copper windings on the stator. The linear motor is designed to drive a prototype HTS maglev vehicle in which the mover is suspended by the levitation force between HTS bulks on the mover and permanent magnets on the ground. Finite element magnetic field analysis is conducted to calculate the major parameters of the linear motor and an equation is derived to calculate the electromagnetic thrust force. Theoretical calculations are verified by the measured results on the prototype.

A fault-tolerant triple-redundant voice coil motor for direct drive valves: Design, optimization, and experiment

A direct drive actuator (DDA) with direct drive valves (DDVs) as the control device is an ideal solution for a flight actuation system. This paper presents a novel triple-redundant voice coil motor (TRVCM) used for redundant DDVs. The TRVCM features electrical/mechanical hybrid triple-redundancy by securing three stators along with three moving coils in the same frame. A permanent magnet (PM) Halbach array is employed in each redundant VCM to simplify the system structure. A back-to-back design between neighborly redundancies is adopted to decouple the magnetic flux linkage. The particle swarm optimization (PSO) method is implemented to optimize design parameters based on the analytical magnetic circuit model. The optimization objective function is defined as the acceleration capacity of the motor to achieve high dynamic performance. The optimal geometric parameters are verified with 3D magnetic field finite element analysis (FEA). A research prototype has been developed for experimental purpose. The experimental results of magnetic field density and force output show that the proposed TRVCM has great potential of applications in DDA systems.

Finite Element Analysis and Experimental Study for MWD Hybrid Excitation Generator

To obtain the stable output voltage, a new type of MWD hybrid excitation generator is designed in which magnetic flux can be regulated from -2% to 22%. In the generator, hybrid excitation part and permanent magnet part work in parallel. This article introduces the working principle and structure of this generator. In addition, finite element analysis, magnetic field and regulation characteristics analysis for this generator is addressed to illustrate the variation of magnetic flux with pole length and excitation current changing. Experiments verify the design and finite element analyses.

The Study of 3-D Magnetic Field Finite Element Analysis for Giant Magnetostrictive Actuator

Based on the structure and working principle of our giant magnetostrictive actuator (GMA), the properties of the driving magnetic field were researched. A 3-D nonlinear magnetic field model of the GMA was established with the finite element analysis method, and the magnetic field distribution of the GMA was obtained with the software ANSYS. Then the 3-D model helped us to find the effects about the distribution of magnetic field of the GMA from the structure. The 3-D magnetic field finite element analysis model can give us a new tool of GMA design and analysis.