Electromagnetic Performance Analysis Research Articles

Electromagnetic tracking performance analysis and optimization.

The purpose of this study is to evaluate the uncertainties of an electromagnetic (EM) tracking system and to improve both the trueness and the precision of the EM tracker. For evaluating errors, we introduce an optical (OP) tracking system and consider its measurement as "ground truth". In the experiment, static data sets and dynamic profiles are collected in both relatively less-metallic environments. Static data sets are for error modeling, and dynamic ones are for testing. To improve the trueness and precision of the EM tracker, tracker calibration based on polynomial fitting and smooth filters, such as the Kalman filter, the moving average filter and the local regression filter, are deployed. From the experimental data analysis, as the distance between the transmitter and the sensor of the EM tracking system increases, the trueness and precision tend to decrease. The system's trueness and jitter errors can be modeled as the 3(rd) order polynomial error equations. After minimizing the positional error and applying smoothing filters, the mean value of error reduction is 36.9%. Our method can effectively reduce both positional systematic error and jitter error caused by EM field distortion. The method is successfully applied to calibrate an EM tracked surgical cautery tool.

Analysis of Electromagnetic Performance of Halbach PM Brushless Machines Having Mixed Grade and Unequal Height of Magnets

This paper proposes a permanent magnet machine having mixed high-cost NdFeB and low-cost ferrite magnets with modular unequal magnet height poles, i.e., the modular Hat- and T-type magnet poles, together with optimized Halbach magnetization. The investigation shows that the modular T-type magnet poles with mixed magnet grade and unequal side-magnet height exhibit significant potential to achieve low torque ripple, relatively large electromagnetic torque, and high magnet usage efficiency simultaneously.

Electromagnetic Performance Analysis of Claw-Pole Alternator with Changing Permeance

A changing air gap permeance model of the alternator and its influence were discussed in this paper. When the alternator was under high-speed operation, taking it into consideration that the claws getting deformation for rotating centrifugal force and electromagnetic exciting force, the alternator’s changing air gap permeance model was established. And the alternator’s Maxwell3D calculation model was built. The field magnetic distribution under the rated speed was obtained as well, also before the claws’ deformation was obtained. The harmonics of the air-gap flux were analyzed and compared. The changing air gap permeance model was proved to be reasonable. It would lead to air-gap magnetic field distortion of the generator, which affected the generator’s electromagnetic properties. Instruction was provided for more precise of air gap magnetic field analysis or vibration noise analysis of alternator.

Electromagnetic performance analysis of novel multi-band metamaterial FSS for millimeter wave radome applications

The electromagnetic design and performance analysis of dual/ multi-band metamaterial frequency selective surface (FSS) structures have been carried out for radome applications in microwave and millimeter wave frequency regimes. The proposed metamaterial FSS structure, consisting of cascaded MNG (mu-nega -tive) and DPS (double positive) layers, exhibits dual-band transmission responses at V-band and W-band. Excellent transmission efficiency (more than 95%) has been obtained over the frequency range 45.8-53.1 GHz at first resonance, and from 93.0-97.1 GHz at second resonance. The incorporation of additional DPS layer to the proposed metamaterial-FSS structure facilitates multiband bandpass characteristics at 30 GHz (in Ka-band), 64 GHz (in V-band), and 93.6 GHz (in W-band). The reflection and insertion phase delay characteristics are also analyzed at high incidence angles in view of streamlined airborne nosecone radome applications.

Control of the Flight Vehicle Cable over Wide Spectrum Radiation Effects Simulation Experiment Research

According to the aircraft is under complex work hard to electromagnetic environment performance analysis of the issue, a vehicle body and control lead in ultra-wideband high power microwave (UWS-HPM) under the irradiation of coupling effect and experimental study. Use back to lose signal simulator with the repetitive; the change control the length of the wire, radiation orientation, irradiation parts and other measures to make the experiment generality. The results of the study show that: aircraft in more than 25 kV/m of field UWS-HPM irradiation, interference and make its crash. Interference coupling mechanism is energy electromagnetic pulse through the control lead into the control box, and influence the formation of the control order. On the basis of experiment, this paper analyzes the interference with various factors coupling relation, which for electromagnetic protection equipment provides a theoretical basis.

Novel Inhomogeneous Planar Layer Radome Design for Airborne Applications

In airborne radome applications, monolithic half-wave wall configuration is generally used to provide superior electromagnetic (EM) performance at the design frequency. However, the application of a monolithic half-wave wall is limited due to its very narrow bandwidth. In order to circumvent this problem, inhomogeneous planar layer (IPL) with exponential variation of complex permittivity is proposed here for the design of a radome wall. As compared to the conventional monolithic half-wave radome of identical thickness, the IPL-based radome wall offers superior EM performance both at the normal and high incidence angles. The EM performance analysis shows that the IPL wall configuration is a better choice for designing both the normal-incidence and the highly streamlined airborne nosecone radomes.

신재생 에너지 적용을 위한 고효율 영구자석 동기 전동/발전기의 해석 및 설계

In renewable energy system such as flywheel energy storage system, wind power and solar power, the motor/generator is the important key for offering the electric energy to the electric loads. For example, the heavy and large flywheel is rotated by electromagnetic torque of pemanent magnet synchronous motor (PMSM) and, in case of a breakdown of electric current, the PMSM used as generator supplies electric energy for the various electric utilities using mechanical rotation energy of the flywheel. Thus, design of a motor/generator should be performed in effort to reduce cogging torque and electromagnetic loss for high efficiency. In our paper, a slotless permanent magnet synchronous motor/generator (SPMSM/G) with output power 15kW at the rotor speed 18000rpm is designed from electromagnetic analysis and dynamic performance analysis. In analytical approach, design parameters such as back electro-motive force (back EMF), inductance and electromagnetic torque are derived from analytical method which is one of the electromagnetic analysis method. And using the design parameters, this paper deal with system design considering the driving characteristics and electric load in required power. Finally, the analytical results are verified by the experiment and finite element method (FEM).

Electromagnetic performance analysis and vector control of a flux‐controllable stator‐permanent‐magnet brushless motor with skewed rotor

PurposeThe purpose of the paper is to model, analyze and control a new flux‐controllable stator‐permanent‐magnet brushless (PMBL) motor with skewed rotor.Design/methodology/approachA new flux‐controllable stator‐PMBL motor with skewed rotor is presented. The key of the proposed motor is to incorporate both direct current field windings and permanent magnets in the stator. By using a 2D multi‐slice finite element model, the electromagnetic performances such as flux linkage, self‐inductance and back‐EMF are obtained. To minimize the torque ripple, a vector control strategy is applied to the stator‐PMBL motor drive for the first time.FindingsSome encouraging experimental results such as lower torque ripple and faster speed transients are achieved. It is shown that the three‐phase flux‐controllable stator‐PMBL motor, when properly designed and controlled, is an interesting candidate for traction drive systems especially for electrical vehicle operation.Originality/valueThe control method can also contribute the other type of stator‐PMBL machines to realize the low torque ripple.

A Precise Electromagnetic Modeling and Performance Analysis of a Three-Phase Squirrel-Cage Induction Motor under Mixed Eccentricity Condition

The aim of this paper is first calculating the airgap magnetic permeance in a mixed eccentricity condition. This is done by studying the governing geometric conditions of the airgap. A novel and precise distribution of the airgap permeance is introduced and compared with those available in the literature. Moreover, by reviewing and extending the winding function theory for a nonuniform airgap, the general equations for evaluating the inductances of a three-phase squirrel-cage induction motor with a mixed eccentricity condition is presented. Various inductances of the motor are then calculated using the airgap permeance distribution and inductance equations, which lead to precise and closed form analytical expressions. In this calculation, skewing of the rotor bars is taken into account. Finally, the performance of a three-phase squirrel-cage induction motor with a mixed eccentricity is simulated and analyzed.