Electrothermal Analysis Research Articles

Electro-thermal dynamics in superconducting generators: An In-Depth investigation of AC losses and cooling techniques for a 10 MW rotor coil system

In the pursuit of optimizing superconducting generator systems, a comprehensive understanding of their electro-thermal behaviors is crucial. This study builds upon previous research on an 8-pole, 10 MW superconducting generator by Inanir et al. (2022, Journal of Superconductivity and Novel Magnetism, 35(11), 3189) and focuses on an in-depth electro-thermal analysis of the rotor coil system. The emphasis is on assessing the AC losses experienced during transitory current changes. By simultaneously solving Ampere's equation and the heat conduction equation under specific boundary conditions, the research provides a detailed insight into the interaction between electrical and thermal dynamics within the rotor coils. The paper highlights the importance of temperature dynamics in various cooling and current conditions. The results demonstrate that achieving an optimal balance in cooling, particularly with the use of liquid nitrogen, is critical for efficient operation. This study not only advances the understanding of superconducting generators but also highlights potential strategies for improving their reliability and efficiency.

Theoretical analysis for dynamic model of U-shaped electrothermal microactuator based on Chebyshev spectral method

Abstract This paper presents a largely and accurate analysis for dynamic model of U-shaped actuator that considers the material parameters dependent on temperature. The electro-thermal analysis for temperature distribution and thermo-mechanical analysis for deflection is carried out. The electro-thermal dynamic behaviour is described by piecewise one-dimensional (1D) heat transfer partial differential equations (PDE) for each beam of U-shaped actuator. A combination of Chebyshev spectral method for space domain and Euler forward difference method for time domain is used to solve these equations. The convergence test is first done to ensure the result convinced.

Electrothermal damage numerical analysis for overhead ground wire at terminal of armor rods under short-circuit current

Electrothermal damage numerical analysis for overhead ground wire at terminal of armor rods under short-circuit current

A modeling method for thermal steady-state simulation of the four-layer printed circuit board.

Thermal simulation of a Printed Circuit Board (PCB) can help identify potential overheating risks in the circuit. The proposed modeling method combines analytical temperature solutions and numerical approximations. Only Fourier-series analytical solutions related to the prepreg-layer surfaces need to be calculated, rather than the entire structure. Heat transfer through the lateral sides of a PCB is approximately considered as part of the compensated heat flux of the insulating-layer surface boundaries. Heat diffusion within or between metal layers is numerically approximated using the finite volume method. The core layer is treated as "thermally-thick". Temperature-dependent boundary conditions are considered through iterations. A test solver was developed based on the method. The modeling accuracy was validated by comparison with COMSOL Multiphysics for a four-layer structure with a moderate degree of discretization. Additionally, a PCB for generating DC 3.3V was designed, tested, and modeled, with the modeling results confirmed by the thermal images. The electro-thermal analysis of the distribution of electric potential and Joule heating in traces and vias was integrated into the PCB model. The layout maps of the PCB were further adjusted to reduce Joule heating in the output circuit, and the improvement on reducing the IR drop and hotspot temperature was examined.

A novel and fast electromagnetic and electrothermal software for quench analysis of high field magnets

Abstract High-field superconducting REBCO magnets contain several coils with many turns. For these magnets, electro-thermal quench is an issue that magnet designers need to take into account. Thus, there is a need for a fast and accurate software to numerically model the overall performance of full-scale magnets. High temperature superconductors can be modeled using different techniques for electro-magnetic and thermal (finite element method) analysis. However, it takes a lot of time to model the electro-magnetic and electro-thermal behavior of superconductors simultaneously, especially for non-insulated or metal-insulated coils. In addition, most of the available methods ignore screening currents, which are an important feature of REBCO magnets. We have developed a novel software programmed in C++, which performs coupled electro-magnetic and electro-thermal analysis using variational methods based on minimum electro-magnetic entropy production and finite difference, respectively. The developed software, which takes screening currents into account, is applied to axi-symmetric full scale magnets of more than 32 T field strength under the SuperEMFL project for thermal quench reliability during standard operation. We show that magnets incorporating non-insulated coils are more reliable against quench than metal insulated coils. Also, realistic cooling conditions at the boundaries are essential for such simulations. The model developed can be used for a quick and complete electro-magnetic and electro-thermal analysis of superconducting high field magnets.

Research on PCB layout optimization of vehicle controller based on electrothermal hybrid simulation

Abstract With the rapid development of the electronic industry, electronic equipment is more and more widely used in automobiles. The integration of electronic components on the Printed Circuit board (PCB) is getting higher and higher, the size is getting smaller and smaller, and the power is getting larger and larger, which leads to a sharp increase in the heat flow density of the whole PCB. The surface temperature of the chip is too high when it is working, which leads to a series of thermal failure problems. In order to improve the thermal characteristics between PCB and electronic components and improve the heat dissipation capability and reliability of PCB, this paper designed a vehicle controller PCB. PowerDC was used to conduct an electrothermal hybrid simulation analysis, and the temperature distribution of the whole board was obtained. Meanwhile, the structural layout of the PCB was optimized by increasing the heat dissipation hole, floor copper foil, and wiring width. Thus, the temperature of PCB and electronic components is reduced, which provides a vital reference for the thermal design of PCB.

Multifunctional flexible carbon fiber felt@nickel composite films with core–shell heterostructure: Exceptional Joule heating capability, thermal management, and electromagnetic interference shielding

Flexible electrothermal materials with multifunctionality have gained paramount importance in both industrial and everyday settings. Nevertheless, achieving exceptional electrothermal performance at ultra-low actuation voltages remains an imposing challenge. This research addresses this challenge by introducing a novel core–shell heterostructure. The unique design incorporates carbon fiber felt (CFF) as the core and envelops it with nickel (Ni) particles through electroplating. The giant core–shell heterostructure endows CFF@Ni to achieve impressive heating temperatures of up to 146.7 °C at only 1.5 V. A proposed linear model offers precise thermal control by correlating saturation temperature with the square of applied voltages. CFF@Ni exhibits rapid heating rates up to 35.8 °C/s, surpassing previous reports, and also possesses robust bending durability and reliable electrothermal characteristics. The electrothermal mechanism analysis manifests that the synergy of enhanced electrical conductivity and the unique heterostructure enables efficient electricity-to-heat conversion. Versatility is demonstrated in diverse applications, from rapid liquid heating to de-icing and thermal therapy. Notably, CFF@Ni excels in microwave shielding and flame retardancy, marking it as an excellent multifunctional material. This research significantly advances the landscape of electrothermal materials, offering a promising avenue for practical, efficient, and durable electric heating solutions that can be applied across various fields.

Electro-thermal and mechanical property analysis of powder metallurgy processed, multi-stage ball milled aluminium-copper-multi walled carbon nanotube composite

Aluminium Metal Matrix Composite (Al-MMC) is a favourable option for industries like automotive, aerospace, sports equipment, electronic packaging and renewable energy because of its impressive strength-to-weight ratio, effective thermal and electrical conductivity, abundant availability and reasonable cost of aluminium. Carbon nanotube (CNT) reinforced Al-MMC is popular among researchers due to its impressive strength and stiffness. The electrical and thermal conductivity of Al-CNT is a less focused field with challenges like uniform dispersion and structural integrity of CNT depending on the manufacturing process. In this paper, a novel method of Multistage ball milling (MSBM) was introduced to develop a powder metallurgy processed Al-MMC, consisting of 5-weight percentage (5 wt%) of copper (Cu) and 0.5 to 1.5 volume percentage (0.5–1.5 vol%) multi-walled carbon nanotubes (MWCNT). In MSBM, mixing was done in two stages with two different rpms of the ball mill to add the advantages of flake powder metallurgy with lower chances of structural damage and the agglomeration of CNT. Mechanical, electrical, thermal, and microstructure characteristics of the fixed-speed single-stage ball milling (SSBM) process and the MSBM were compared. MSBM-processed Al-5Cu-0.5CNT composites showed higher electrical conductivity (15.03%), thermal conductivity (5.88%) and hardness (9.68%) than SSBM-processed composites. Al-5Cu-0.5CNT developed by the MSBM process achieved superior electrical and thermal conductivity, surpassing pure sintered Al by 138.45% and 9.39%, respectively.

Electrothermal Coupling Methodologies and Their Influence on the Optimization of Aircraft Electric Motors

This work presents a fully coupled electrothermal motor analysis and optimization framework, where the motor’s electromagnetic performance depends on its temperature distribution, and the temperature distribution simultaneously depends on its electromagnetic performance. Notably, we analytically compute derivatives through this nonlinear, multidisciplinary analysis using coupled adjoints, which enables the exploration of high-dimensional design spaces. We demonstrate the framework on a series of optimization problems that investigate the effect of feedback coupling and serve to highlight the framework’s utility and flexibility. Furthermore, our results indicate that modeling the motor’s electrothermal coupling is critical to accurate performance prediction. We show that designs optimized using a feedforward-coupled model are found to be either infeasible or nonoptimal under the fully coupled feedback analysis; both conditions are unacceptable for aircraft applications, in which performance is critical.

Electric-driven shape memory deformation control and verification of composite films based on PVA/WPU/SCFs

Based on the research of Polyvinyl alcohol (PVA)/Waterborne Polyurethane (WPU)/Short Carbon Fibers (SCFs) novel electrochemically shape memory composites, this study delved into an exploration of factors influencing the shape memory deformation of shape memory film samples when subjected to voltage stimulation. These main affecting factors encompassed sample thickness, activation voltage, and wire layout. Subsequently, based on the above conclusions, the viscoelastic constitutive model of PVA/WPU/SCFs composite was established based on Maxwell model and the deformation deflection of the composite film was predicted by shape memory recovery, and the electrothermal coupling simulation analysis and shape memory recovery and deformation simulation verification were carried out. Finally, based on the shape memory recovery performance of the composite film, a new reciprocating moving deformation structure was conceptualized, characterized by distinct cycles of motion, each analyzed individually.

Design and analysis of novel microelectromechanical system based microgripper for manipulating microbiological species and micro objects

Design and analysis of a pair of novel microelectromechanical system (MEMS) microgrippers having single and multiple sets of jaws respectively, incorporated with displacement amplification mechanism and electrostatic force sensor is presented in this research work. The novelty of the proposed microgrippers is their unique and efficient designs, having the versatility of gripping ranges. The size of the microgripper is 3.2 × 3.7 mm2 in both cases and has one and three sets of jaws with gripping ranges of 30–64 µm, 175–200 µm, and 350–380 µm respectively. The three jaw sets are application-specific to the multicellular small organism, eukaryotic cells, and microcells, respectively. The microgrippers are being actuated by an optimized V-shaped thermal chevron actuator whose input is amplified by using a pantograph displacement amplification mechanism with an amplification factor of 54. The force applied to the gripping object is sensed by a rotary comb electrostatic force sensor. Special attention has been paid to the structural design, and detailed stress analysis has been discussed. This research work includes static, electrostatic, parametric, and electrothermal analysis carried out using Finite Element Method (FEM) techniques and analytical modeling. The results show that the operating voltage range of the devices is from 4 to 9.25 V, having a maximum operational temperature of 380 °C with a factor of safety of 1.026. The maximum capacitance change with the full operational range of microgrippers is 0.63 µf, having a capacitive sensitivity of 19.6 nf/µm. The microgrippers can be used as an instrument to grip not only the microbiological species but also can be beneficial to carry out manipulations at the micro-level like micro-assembly. The proposed microgripper has a substantial structural stability, has a high amplification factor and accommodates manipulation of a wide range of microorganism.

Electrothermal Instabilities in Barium-Titanate-Based Ceramics

An electrothermal analysis for barium-titanate-based ceramics is presented, combining the Heywang–Jonker model for the electric resistivity with a heat dissipation mechanism based on natural convection and radiation in a one-dimensional model on the device level with voltage as the control parameter. Both positive-temperature-coefficient (PTC) and negative temperature coefficient (NTC) effects are accounted for through the double Schottky barriers at the grain boundaries of the material. The problem formulated in this way admits uniform and non-uniform multiple-steady-state solutions that do not depend on the external circuit. The numerical bifurcation analysis reveals that the PTC effect gives rise to several multiplicites above the Curie point, whereas the NTC effect is responsible for the thermal runaway (temperature blowup). The thermal runaway phenomenon as a potential thermal shock could be among the possible reasons for the observed thermomechanical failures (delamination fracture). The theoretical results for the NTC regime and the thermal runaway are in agreement with the experimental flash sintering results obtained for barium titanate, and 3% and 8% yttria-stabilized zirconia.

Electrothermal Reliability Analysis of Electromigration in 3-D TSV-RDL Interconnects

Electrothermal Reliability Analysis of Electromigration in 3-D TSV-RDL Interconnects

Electrothermal Distortion Analysis and Structural Strain Assessment of Vehicle Cable Terminals Under Bending Stresses

Electrothermal Distortion Analysis and Structural Strain Assessment of Vehicle Cable Terminals Under Bending Stresses

Enhanced Electrothermal Analysis for Acetone Gas Detection Based on PolyMUMPs MEMS Sensor

Enhanced Electrothermal Analysis for Acetone Gas Detection Based on PolyMUMPs MEMS Sensor

DEVELOPMENT OF A MATHEMATICAL MODEL OF THE THERMAL FIELD OF AN INTEGRAL STRUCTURE IN THE IMPLEMENTATION OF SENSORS FOR BIOMEDICAL RESEARCH

The paper deals with the implementation of a complex technique for electrothermal modeling of measuring transducers of thermal flow sensors, which combines the synthesis of the impulse temperature relaxation substitution circuit and the method of forming the I-V converters in the mode of their self-heating by the supply current. The issue of assessing the instability of iteration processes in the analysis of I/V measuring converters with negative differential resistance, which is caused by self-heating of these converters, is considered. An express method for determining the limits in which correct electrothermal DC analysis is provided for use in biomedical devices and systems has been developed.

Electro-thermal analysis of hybrid fluid through wavy divergent channel

In the bio-medical domains, the transportation of physiological fluids within the human body like chyme movement in the gastrointestinal tract, bolus through the esophagus, blood circulation in the small vessels and heart chambers etc., where the channels are nonuniform in nature. Due to diverse applications of nonuniform channel, in the current mathematical analysis the peristaltic flow of hybrid fluid (containing particular nanoparticles) under an applied axial electric field through the nonuniform channel is presented. To observe hybrid fluid performance, a set of modified hybrid fluid that comprise nanoparticles of titanium dioxide, aluminum trioxide and copper with water as a base fluid is considered in the analysis. Taking into consideration the long wavelength and low Reynolds number assumptions. Poisson-Boltzmann equations are linearized by the Debye-Hückel approximation. Solutions for the axial velocity, average flow rate, pressure gradient, pumping phenomena, heat transfer phenomena and volumetric fraction are obtained analytically. The physical impacts of numerous embedded parameters on the above-mentioned features are argued through graphs which are plotted by Mathematica 11.0 Software. Additionally, the influence of porous medium and nonuniform nature of flow geometry are also discussed in detail. The study could be useful in medical as well as the industrial domains since the electro-osmotic phenomenon is observed throughout the human body where through the osmosis, the body absorbs the nutrients from the food and toxins are removed from the blood stream. Also the nanofluids are widely used in medicines for drug delivery. Also in industries, electro-osmosis has many applications in microchips, biophysics, microfluidics, gas and oil manufacture and separations through the membranes etc.

Effect of lattice heating on the switching performance of a silicon‐gate all around dielectric window spaced‐multi‐channel MOSFET

AbstractIn this article, analysis of heating effect for a range of thermal resistance () and different ambient temperatures on the DC parameters of the proposed Silicon‐Gate All Around Dielectric Window Spaced‐Multi‐channel (Si‐GAA‐DWS‐multi‐channel) MOSFET is carried out. The performance of the device is examined through 3D‐ATLAS TCAD simulator, by performing the numerical and electrothermal analysis. Due to cylindrical dimension, the nanowire FETs undergoes undesirable self/lattice‐heating. The lattice heating of the device is calculated with respect to various device parameters such as channel length, drain‐source voltage, thermal resistance, ambient temperature, on‐current , and off‐current . The proposed device parameter has been compared with the existing devices, mainly with Silicon‐Nanowire‐Dielectric Pocket Packed MOSFET (Si‐NW‐DPP FET) and Silicon‐Nanowire MOSFET (Si‐NW FET). The Si‐GAA‐DWS‐multi‐channel FET is found to be as the better device than the other two structures, as the leakage current of the device is improved by 1 and 2 decades, drain current increases by 1 and 1 decade, a minimum SS of 63.271 mV/dec and a minimum DIBL of 26.172 mV/V, respectively. The lesser the SS, the faster will be the device; hence the proposed structure can be considered as the finest prospect for VLSI/ULSI electronic chips.

Electro-Thermal Analysis of a Pouch–Type Lithium–Ion Battery with a High Discharge Rate for Urban Air Mobility

The dynamic behavior and thermal performance of a high-power, high-energy-density lithium-ion battery for urban air mobility (UAM) applications were analyzed by using an electro-thermal model. To simulate the behavior of pouch-type nickel-cobalt-manganese (NCM) lithium–ion batteries, a battery equivalent circuit with a second order of resistance–capacitance (RC) elements was employed. The values of the RC models were determined by using curve fitting based on experimental data for the lithium-ion battery. A three–dimensional model of the lithium-ion battery was created, and a thermal analysis was performed while considering the external temperature and flight time under a 20 min load condition. At an external temperature of 20 °C, the heat generation increased proportionally to the square of the current as the C–rate increased. For 3C, the reaction heat source was 45.5 W, and the average internal temperature of the cell was 36 °C. Even at the same 3C, as the external temperature decreased to 0 °C, the increase in internal resistance led to a greater reaction heat source of 58.27 W, which was 36.9% higher than that at 20 °C. At 5C, the maximum operating time was 685.6 s. At this point, the average internal temperature of the cell was 59.8 °C, which allowed for normal operation. When the C–rate of the battery cell reached 8, which was the momentary maximum high-discharge condition, the temperature sharply rose before the state of charge (SoC) reached 0. With an average internal cell temperature of 80 °C, the maximum operating time became 111.9 s. This met the design requirements for urban air mobility (UAM) in this study.

Bi-level modeling and multi-energy flow calculation of main grid and microgrid cluster based on electro-thermal coupling analysis

In this study, considering the characteristics of multi-energy coupling and multi-level interconnection, a bi-level steady-state physical model is developed. Both decomposed and unified solution methods are employed for the energy flow calculation under the bi-level and multi-energy coupling structure. A numerical study is executed to examine the validity of the algorithms. In addition, the load change within the microgrid and the system operation state under both on-grid and off-grid modes are examined. According to the simulation results, compared with the unified solution method, the decomposed method has faster solution speed and higher data privacy protection, and is more adaptive to the further expansion of the scale of the interconnected microgrids. The microgrids can realize energy interaction and energy mutual aid through grid-connecting operation or inter-network interconnection.