Yan Rongge

Direct Field-Circuit Coupled Analysis and Corresponding Experiments of Electromagnetic Resonant Coupling System

Based on electromagnetic (EM) field resonantly coupling technology, a novel contactless power transfer system is analyzed in this paper. A detailed field-circuit coupling model is proposed taking into account the influences of near field strength and circuit constraints simultaneously. Therefore, the distribution of magnetic field strength under different angular frequencies and spacing distances are calculated through direct field-circuit coupled method. In the experimental aspect, a resonantly coupling system contains planar disc resonators is designed. It is shown by measurement results that property of system is basically consistent with the results derived in article. Moreover, the solution accuracy is improved through this technology to recharge electrical devices or transfer power.

Investigation of current dependencies of displacement under variable load for giant magnetostrictive actuators

The dependencies of displacement on current under different variable loads for giant magnetostrictive actuators are computed by using the finite-element method and measured. It is found that the computed result is in agreement with the measured one. This indicates that the finite-element model is valid for computing the displacement for actuators under variable load, and it can be used to design actuators.

Reactor vibration reduction based on giant magnetostrictive materials

The vibration of reactors not only produces noise pollution, but also affects the safe operation of reactors. Giant magnetostrictive materials can generate huge expansion and shrinkage deformation in a magnetic field. With the principle of mutual offset between the giant magnetostrictive force produced by the giant magnetostrictive material and the original vibration force of the reactor, the vibration of the reactor can be reduced. In this paper, magnetization and magnetostriction characteristics in silicon steel and the giant magnetostrictive material are measured, respectively. According to the presented magneto-mechanical coupling model including the electromagnetic force and the magnetostrictive force, reactor vibration is calculated. By comparing the vibration of the reactor with different inserted materials in the air gaps between the reactor cores, the vibration reduction effectiveness of the giant magnetostrictive material is validated.

Research on Stress Characteristics of Shunt Reactor Considering Magnetization and Magnetostrictive Anisotropy

In order to reduce the vibration of shunt reactors with gapped iron-core structure, accurate stress computation should be carried out. The magnetization and magnetostrictive anisotropy should be considered in the calculation. In this paper, the magnetization and magnetostrictive properties of non-oriented silicon steel sheets along the rolling direction and the transverse direction are first measured by a magnetization and magnetostriction tester. Based on the measurement results, an electromagneto–mechanical coupled numerical model for shunt reactors, considering magnetization and magnetostrictive anisotropy, has been developed. Then, the stress distribution of the reactor core is calculated and that between isotropy and anisotropy numerical model is compared. From the computation results, it can be seen that magnetization and magnetostrictive anisotropy greatly influences the stress distribution of the reactor core.

Stress analysis of motor cores based on the measurement of magnetostriction of non-oriented silicon steel sheet

In order to control and reduce the electromagnetic vibration of motors, the stresses in motor cores, which are the inherent reasons of vibration, should be computed accurately. Electromagnetic stresses in motor cores are mainly generated from magnetostrictive effect of silicon steel and Maxwell electromagnetic force between the stator and the rotor. So far, stress analysis on motor cores, which is based on the finite element numerical method, did not consider the influence of stress on magnetostrictive and magnetic properties of the core material. Thus, this paper first measures multi-group magnetostrictive and magnetic characteristic curves of non-oriented silicon steel sheet under different stresses to support the computation. Then an electromagneto-mechanical coupled numerical model for motors considering anisotropy and the influence of stress on magnetic properties of the core material is proposed and stress distribution of motor cores is calculated. From the computed results, it can be seen that radial stress and circumferential stress show different characteristics in different parts of motor cores, which provides a theoretical basis for further analysis of vibration and noise reduction.

Research on stress of magnetically controlled saturable reactor under practical working conditions

Due to the special structure and working mode of AC and DC excitation, the vibration of magnetically controlled saturated reactors (MCSRs) is larger than that of the ordinary ones. In order to design an appropriate damping system or vibration isolation system for MCSRs, this paper studies the stress characteristic which is the inherent reason of vibration and noise. The multi-group magnetization and magnetostrictive curves of the silicon steel under different compressive forces with different DC bias excitations are tested in this paper. Based on the measured constitutive relations, an electromagnetic-mechanical coupled numerical model for MCSRs is established. Considering the electromagnetic force and magnetostriction force, the magnetic field and stress distribution under practical working conditions are calculated for MCSRs. During the calculation, the control circuit of MCSRs is coupled to the finite element model, which provides the theoretical basis for vibration and noise reduction of MCSRs.

Stress analysis of magnetically controlled reactor

To provide technique references for vibration reduction of magnetically controlled reactors (MCRs), stress, which is the inherent reason of vibration and noise, should be investigated. Stresses in reactor cores are produced due to the magnetostriction deformation of silicon steel and electromagnetic force between the core discs. So far, stress analysis on reactor cores was based on one-way coupled numerical method, which did not consider the influence of the stress on magnetic properties of the core material. Thus, multi-group magnetization and magnetostriction characteristics curves of silicon steel under different tensile stresses are measured firstly to support the computation. From the experiment results, it can be seen that magnetic properties of silicon steel change with stress. Then an electromagneto-mechanical two-way coupled numerical model for MCRs considering magnetostrictive effect and electromagnetic force effect is proposed. Stress distribution of MCR cores under the combination excitation o...

Magnetically controlled saturable reactor core vibration under practical working conditions

In order to seek new vibration reduction method for magnetically controlled saturable reactors (MCSRs), this paper studies the stress characteristic which is the inherent reason of vibration and noise. Under the practical working condition, dc and ac excitations make iron cores work in a magnetic saturation state. Meanwhile, the stress in reactor cores always exists and influences on magnetic properties of the core material. Because the core material shows different magnetization and magnetostrictive properties under dc bias and stress, a database of magnetization and magnetostrictive curves of silicon steel under different tensile stresses with different dc bias excitations is tested. Based on the measured constitutive relations, an electromagneto-mechanical two-way coupled numerical model for MCSRs is presented. Vibrations considering magnetostrictive effect, electromagnetic force effect, and the combination of them are calculated to compare the influence of the two forces on MCSR vibration. From the computation results, it can be seen that the total vibration stress is not a simple superposition of electromagnetic stress and magnetostrictive stress. Finally, vibration stress of an MCSR prototype under working conditions is tested to prove the validity of the proposed model.

Optimal design based on genetic algorithm and characteristic test for giant magnetostrictive actuator

This paper presented the optimization design model of giant magnetostrictive actuator (GMA) and applied the multi-object genetic algorithm for the optimization design of its solenoid coil and enamelled wire, and tested the static characteristic and dynamic characteristic of GMA here. The optimal objects of the model included: the structure design of GMA, the method building of producing bias magnetic field, study for the magnetic field distribution along the axis and maximization for magnetic field density of coil, from which the solenoid coil parameter was optimally designed. The optimization variables included: the size of GMM rod, the structure parameter of coil, the power consumption of solenoid coil and the enamelled wire parameter. The domain of optimal variables was determined according to the demand for application. The fittest parameters of coil were obtained using non-dominated sorting genetic algorithm (NSGA) combining with BP neural network (BPNN) by the search in multi-objective parameters space. The result of experiment incarnates fine static and dynamic characteristic of GMA and consistency between design parameter and experimental value, which shows the rationality of the optimal design.

Design and implementation of numerical calculation software package for new high performance materials applied to electrical engineering

A software package, modeling for new high performance materials applied to electrical engineering, for one, two or three dimensional electrostatic and magnetostatic field analysis has been developed. This software package is designed based on the FEM method, element-free method, boundary element method and so on for the solution of 2D or 3D electromagnetic problems. The package allows us to solve many kinds of problems such as static and dynamic characteristics application characteristics, weak and strong coupling, etc. The package includes three parts: the pre-processing for generating mesh automatically and displaying it, computing 2D or 3D electromagnetic field with the method of the vector potential and the two scalar potentials based on isoparametric elements, the post-processing. In this paper, application of electro-rheological technology on electro-hydraulic braking control system is taken as an example given to show how the program helps the designer to improve the design of the product. The results show the software package could bring advantages to the producers and designers.