Conference Agenda

A recently presented selective electromagnetic actuation technique allows vibrations of multiple tactile elements to be controlled using a single coil based on the individual mechanical resonance frequencies. This technique allows realization of many tactile elements in a smaller area. We present a new structure by transferring the design to a Multi-layer Printed Circuit Board (PCB) to show a wire wound coil capable of mass production in a scalable technology allowing for an affordable and lightweight portable device whilst miniaturizing the coil to increase the mechanical force generated and the spatial resolution over the same area. The finite element analysis (FEA) on multiphysics model developed for this transducer are in agreement with the optical vibrometry measurement results, which successfully validates the proposed method for transferring the design to Multi-layer PCB.

During the high-speed motion of the armature, the armature equivalent conductivity dynamically changes due to variations in intrinsic conductivity and contact conductivity caused by extreme electromagnetic and thermal shock conditions. Accurate modeling of dynamic armature conductivity and analyzing its impact on motion are essential to enhance the computational accuracy of numerical models. Real-time, in-situ measurement of armature conductivity under extreme conditions is highly challenging. Therefore, this paper proposes a method to analyze the motion characteristics of electromagnetic propulsion devices based on dynamic armature conductivity inversion. Firstly, the real-time velocity of the armature and the spatial magnetic field at the measurement point are obtained through electromagnetic propulsion experiments. The finite element model of magnetic flux density at the measurement point, considering different armature conductivities, is parameterized using a Deep Neural Network (DNN). Then, an inverse model for armature equivalent conductivity is established using the Gradient Descent method (GD). The computed values from the parameterized the finite element model are corrected in real time using the measured magnetic flux density at the measurement point to obtain its spatio-temporal characteristics. Secondly, the model of armature-rail for transient electromagnetic, thermal, and mechanical coupling is established to analyze the influence of dynamic armature conductivity on the motion. Finally, experiments confirm that considering dynamic armature conductivity significantly enhances the computational accuracy of the finite element model. This method provides theoretical guidance for reliability prediction and structural optimization of electromagnetic energy equipment and offers innovative solutions for real-time in-situ measurement of material properties under extreme conditions.

This paper propose a time-splitting pseudospectral method to investigate the dynamic of ultracold ion-ion quantum plasmas. The wave functions of positive and negative ions are modeled by the Gross-Pitaevskii equations coupled with the Poisson equation for electric potential. The time-splitting scheme on the Gross-Pitaevskii-Poisson system is explicit, unconditionally stable and massconserving, which is highly efficient for simulating the coupled system. Numerical examples validate the spectral convergence and unconditional stability, with an X-shape quantum plasma interaction demonstrated.

Transformer core noise primarily results from the magnetostrictive effect, where slight deformations during magnetization generate mechanical vibrations and noise. This study employs a multi-physics simulation, integrating magnetic field, structural mechanics, and acoustics, to analyze the vibration and acoustic field distribution in a 200 kVA laminated core transformer, focusing on noise generation mechanisms and their environmental impact. An active noise control (ANC) system is proposed to mitigate the noise, utilizing inverse frequency vibration to neutralize core-induced vibrations. Through simulation and comparative analysis, the ANC system effectively reduces noise, improving the transformer's acoustic performance and minimizing its environmental impact.

The optimization of heat dissipation performance during transformer operation directly affects the reliability and service life of the equipment. Traditional heat dissipation calculation methods have certain limitations in terms of accuracy and resource consumption. To address this, this paper proposes an optimized heat sink equivalent method that reduces the number of cooling fins and adjusts the oil width while ensuring the same amount of heat dissipation. First, a mathematical model for heat sink equivalence is established, and the variation law of heat transfer coefficient is discussed. Then, based on the equivalent parameters, a finite element simulation model of transformer overall temperature field is constructed, and the effectiveness of equivalent method under multiple working conditions is verified. Finally, through a comparative analysis of experimental tests and simulation results, the accuracy of method and its potential for engineering applications are evaluated. The research results show that the error between simulation and experimental results is within 5%, verifying the feasibility and reliability of method, and providing solid theoretical support and practical evidence for the optimization design of transformer cooling systems.

This paper presents an optimization method based on the pigeon-inspired optimization (PIO) algorithm to determine the optimal dimensions of self-shielding gradient coils suitable for a magnetically shielded cylinder (MSC). The coil set comprises inner and outer layers, with the internal region configured to generate a gradient magnetic field while the external region is maintained at near-zero field strength by appliying opposing currents. In the design of the coil using the target field method (TFM), the challenge of solving closed-form equations is transformed into a constrained nonlinear objectivite optimization problem. Consequently, a modified pigeon-inspired optimization algorithm is introduced to derive optimal parameters for coil size. This approach incorporates a collaborative and competitive mechanism between global and local populations, enabling the algorithm to effectively balance exploration and exploitation capabilities. As a result, it can swiftly identify global optimal solutions without converging to local optima.The final results demonstrate that the coil we designed can achieve a high linear gradient with a maximum spatial gradient magnetic field deviation below 2.36%, and it exhibits a significant self-shielding effect in the external region.

A computational model is proposed to consider the magnetic-thermal bidirectional coupling (MTBC) phenomenon in permanent magnet motors, based on the electromagnetic subdomain method and three dimensional (3D) thermal network. Compared with the traditional finite element (FE) and analytical methods, this model has the advantage of fast calculation speed and high precision. Firstly, independent models are established for the motor electromagnetic and thermal fields based on the subdomain method and 3D thermal network, respectively. Then, the remanent flux density of the permanent magnet (PM) is changed from a constant value in the independent electromagnetic subdomain model to a variable determined by the thermal network temperature in the coupled model. In this way, the interaction between the motor electromagnetic field and node temperatures of 3D thermal network can be realized. The steady-state temperature rises of the arc linear flux switching permanent magnet motor(AL FSPM) is calculated to verify the effectiveness of the MTBC model.

At present, the simulation of the magnetic characteristics of transformer cores generally adopts the constitutive model of the basic magnetization curve. However, the hysteresis effect of silicon steel sheets can not be reflected by this constitutive model. As a result, there will be relatively large errors in the excitation current and the internal magnetic field of the core, which will lead to inaccurate calculation of magnetostrictive force.In this paper, the hysteresis model is used to reasonably represent the hysteresis effect of silicon steel sheets, and the finite element hysteresis constitutive model is constructed by applying the measured hysteresis loops. Taking an 800 kVA power transformer model prototype as the research object, the electromagnetic simulation calculation is carried out first. Subsequently, based on the electromagnetic structural coupling method, the vibration caused by the magnetostrictive effect of the core is solved. For the vibration conditions of the core under different degrees of looseness, the internal relationship and variation law between the core looseness fault and the vibration characteristics are analyzed. Finally, the simulation results are verified by means of the vibration test of the model prototype to ensure the accuracy of the simulation calculation.

Motor drive systems are widely used in various industries, and improving their efficiency is essential for energy conservation. This paper presents a variable switching frequency control method for motor drive systems to enhance overall system efficiency. By employing a coupled model that captures the interdependent characteristics of the inverter and motor, the proposed method accurately evaluates losses under different operating conditions. The optimal switching frequencies are identified and compiled into a lookup table embedded in the drive program. Real-time adjustments to the inverter’s switching frequency based on system conditions enable the method to achieve optimal efficiency with reduced computational complexity compared to conventional strategies, validated through both simulation and experimental results.

Trajectory calculation of electron beams is the basis of parametric evaluation of vacuum electron devices. The interaction between electron trajectory and electric field makes the calculation of trajectory a complicated electro-magnetic particle coupling problem. This paper proposes a physics-driven calculation method for electro-magnetic particle coupling process in vacuum electron devices. The physics-driven calculation method for electromagnetic field incorporating space charge effect can be utilized repeatedly after training, and the node-based computation approach eliminates the node mapping between coupling fields, providing a novel approach to avoid redundant mesh regeneration and recalculations.

Electrical fire hazards due to arc faults are critical to the safety of more-electric aircraft (MEA)/all-electric aircraft (AEA). In this study, the damage behavior to the electrical wiring interconnection system (EWIS) caused by AC series arc fault is carried out. For this purpose, a 2D axis symmetric magnetohydrodynamics (MHD) model is implemented for a single defective insulation cable. The thermal field, flow field, and electromagnetic field are numerically coupled for the computation of the distribution of the temperature. Furthermore, to evaluate the damage effect to a proximal cable, a 3D MHD model is constructed for a typical two-wire bundle system. The influences of central distance and the properties of the insulation materials are taken into account. The results reveal that the high temperature caused by arc fault leads to heavy damage to the faulty cable and an adjacent one.

Conductivity will have an effect on the inductance gradient and thus change the magnitude of electromagnetic force, in order to investigate the effect of conductivity on the armature motion characteristics, a finite element model of electromagnetic energy equipment propulsion device considering dynamic conductivity is proposed to consider the electromagnetic-thermal multi-physical field coupling and the dynamic change of internal parameters, in order to improve the accuracy and realism of the model simulation calculation. By taking the rail current obtained from the experiment as the input parameter, a high-precision numerical calculation model is established. The sequential coupling method is adopted to calculate and obtain the dynamic electromagnetic force during the launching process. The armature muzzle velocity is used as the output result and verification parameter. On this basis, the change of armature speed under the consideration of high-speed movement of armature and change of conductivity is obtained. The accuracy of the proposed model is verified by comparing the experimental data with the simulation data results. The work in this paper provides theoretical support and valuable reference for further reliability prediction and optimal design of electromagnetic propulsion devices.