Electro-thermal Coupling Simulation Research Articles

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.

The Impact of Temperature on the Electromagnet and Structural Optimization of a Solenoid Valve

The mathematical model of the solenoid valve under varying temperatures is constructed to investigate itsperformance and enhance heat dissipation balance. The relationship between temperature and electromagnetic force isdetermined. Electrothermal coupling simulation using COMSOL is conducted, optimizing the outer diameter and lengthstructure parameters of the coil. It is established that the heat dissipation of the coil is influenced by its outer diameter.Subsequently, based on optimized coil structure parameters, an orthogonal experimental design method combinedwith Ansys Maxwell is employed for simulation solution analysis to study the impact of structural parameters such aslength, position, front and rear angles of the magnetic barrier ring in the iron core, armature length, and through-holesize on electromagnetic force. Optimal structural parameters are identified. Results indicate a decrease in steady-stateelectromagnet temperature by 3–4℃, an increase in the initial electromagnetic force by 32.63%, and a rise in the maximumelectromagnetic force by 27.10%.

Diagnosis Method of Decay-like Composite Insulators in a High-Humidity Environment Based on Characteristic Coefficient of Temperature Rise Gradient.

At present, the temperature rise in insulators is observed using infrared thermometry as a common method of diagnosing decay-like insulators. However, the original characteristic data obtained by infrared thermometry cannot effectively distinguish some of the decay-like insulators from those with ageing sheaths. Therefore, it is imperative to find a new diagnostic characteristic quantity. Based on statistical data, this article first explains that existing diagnostic methods have limited diagnostic effectiveness and a high false detection rate for insulators in a slightly heated state. A full-scale temperature rise test is carried out on a batch of composite insulators returned from the field under high-humidity conditions. Two different defective insulators with similar temperature rise profiles are identified, and an electro-thermal coupling simulation model is developed based on the dielectric characteristic parameters of the above insulators for both core rod defects and sheath ageing. A new infrared diagnostic feature, the temperature rise gradient coefficient, is then obtained to identify the source of abnormal heat in insulators using statistical analysis of an infrared image gallery of abnormally hot composite insulators obtained from field inspections and laboratory tests.

Data-driven early warning strategy for thermal runaway propagation in Lithium-ion battery modules with variable state of charge

Thermal runaway (TR) propagation is triggered in a battery pack by abnormalities such as a cell fire or explosion, which leads to severe consequences. Predicting the TR propagation is challenging due to the complex, high non-linearity, and uncertain disturbances of TR. This paper establishes an electro-thermal coupling simulation model of TR propagation to supplement experimental data and public datasets for model training and verification. Then, a data-driven fusion model named Multi-Mode and Multi-Task Thermal Propagation Forecasting Neural Network (MMTPFNN) is established quantitative advance multi-step prediction of TR propagation in Li-ion battery modules, and a temperature-based TR propagation grading warning strategy is proposed. The TR propagation is mainly influenced by the thermal characteristics of surrounding batteries, and the temperature distribution in the entire battery module is of great significance to the prediction of TR propagation. Herein, the model is presented by using the thermal image and the discrete operating data of cells. Furthermore, because TR is a small probability event, obtaining the thermal image of the battery module requires additional system memory and computational resources. A switching strategy of the prediction model is established to improve the applicability of the model with the temperature threshold of 60 °C. When the battery is in a safe temperature range (below 60 °C), the long short-term memory (LSTM) model is run to predict the battery temperature. Once the battery temperature is detected above 60 °C, the thermal image is captured, and the MMTPFNN model is run to predict the TR propagation. In the validation section, different network structures are discussed, and different time resolutions and different window settings of the MMTPFNN are compared. Finally, the early warning strategy with three alert levels is introduced, and the effectiveness of the warning strategy with different window settings and initial SoCs is further discussed.

Electrothermal Analysis of System in Package for Aerospace Application

Abstract Aiming at the failure problem of aerospace electronic product at the complex space environment, the electrothermal coupling method has been used to analyze the reliability of the ten channels independently adjustable voltage conversion system in package (SIP) module based on integrated forming package, which has supplied the voltage to the remote sensing camera detector. First, the electromagnetic model and thermal model have been made based on the SIP module; second, the electrothermal coupling simulation of three working conditions at normal environment have been made, and the maximum temperature of the SIP has been calculated; then, the maximum temperature of the SIP has been also calculated at vacuum and 45 °C to analyze the performance of this SIP in the space environment; at last, some test have been made of the SIP product. Compared with the measured results, the electrothermal coupling method has much more accurate than traditional thermal method. At normal environment, the simulated temperature relative error is 2.8%. At vacuum and 45 °C environment, the simulated temperature relative error is 9%. This method ensured the performance and accuracy of the design of the SIP, which has verified the reliability of aerospace SIP module at early stage.

Study on operation voltage monitoring and electrothermal coupling simulation of electric multiple unit (EMU) roof arrester

The roof arrester of electric multiple units (EMU) can efficiently limit the overvoltage, and ensure the safe operation of the EMU electrical equipment. In the process of high-speed operation, the traction power supply system is often affected by overvoltage. In addition, roof arrester explosion accidents occasionally occur. In this paper, the on-line voltage measurement system of the EMU arrester is developed. By analysing a large number of voltage waveforms, the abnormal voltage is divided into three categories: over-phase voltage, high harmonic voltage and steep impulse overvoltage. The characteristics of abnormal voltage waveforms are then summarised. The electrothermal coupling simulation model of the arrester is developed, and the current response and temperature distribution of the arrester under abnormal voltage are calculated. The impact of the impulse voltage energy on the arrester temperature is studied by applying a triangular wave voltage to the model. Finally, some suggestions are proposed for the operation and maintenance of the roof arrester.

Optimization Of The Measurement Precision Consistency Of Single-Phase Smart Electricity Meters In Full Temperature Range

With the development of smart power grids, smart electricity meters are widely applied to industrial production and the life. For interests of the power supply and consumption parties, electricity meters are required to have high quality, precision and consistency. As temperatures vary considerably in south and north of China and electricity meters work in complex temperature environments, studies on the effects of temperature on power metering are of significant importance. In this paper, an optimization method considering the effects of temperature is proposed for the consistency of electricity meters. The precision consistency of electricity meters is optimized in full temperature range through means such as electrothermal coupling simulation, orthogonal test, cost calculation, etc., and the design scheme of electricity meters with maximum cost performance can be delivered for their manufacturers.

Inner insulation structure optimization of UHV RIP oil-SF6 bushing using electro-thermal simulation and advanced equal margin design method

The iso-margin method based on the classical analytical equations is widely used in the development of extra high voltage (EHV) bushing. Therefore, its effectiveness and feasibility have been fully validated. However, with the theoretical formula, it is difficult to evaluate the influence of stray capacitance and temperature on the internal electric stress of the ultra high voltage (UHV) bushing. It's necessary to further improve the traditional iso-margin method. Firstly, the basic principle of iso-margin method has been briefly described. After that, the E-field distribution of condenser bushing was investigated on the Finite Element Method (FEM) computing platform. Then, the mathematical model of the advanced equal margin design method was established. Furthermore, this paper presents the program flow of optimization which combines the simulation of electro-thermal coupling process and the particle swarm optimization (PSO) algorithm. The proposed methodology was applied to the design of the prototype of the UHV resin impregnated paper (RIP) oil-SF 6 bushing, which realizes the uniform axial E-field distribution of the bushing condenser. Meanwhile, the partial discharge margin between adjacent foils can be equal. Moreover, the hot-spot temperature is lower than the operation limiting temperature of the RIP material. The bushing condenser was fabricated according to the optimal structure design. The prototype of bushing has passed through all the type tests. In this paper, the FEM electro-thermal coupling simulation and the advanced equal margin design method were applied to the inner insulation structure optimization of the UHV RIP oil-SF 6 bushing. Meanwhile, the proposed methodology provides some theoretical guidelines for the future research and development of other types of bushing on the UHV level.

Capability of Electrothermal Simulation for Automotive Power Application Using Novel Laterally Diffused Metal Oxide Semiconductor Model

This paper describes a methodology that enables the consistent simulation of electrothermal coupling using HiSIM_HV. HiSIM_HV is an extension of HiSIM, which is a surface-potential-based compact model, and it is expected that HiSIM_HV can realize stable and high speed circuit simulations. Evaluation of the HiSIM_HV model is performed on three aspects in this study. Firstly, the stability of the electrothermal coupling simulation on SPICE3 with long simulation time was evaluated. Next, a comparison of calculation speed between HiSIM_HV and MOS Level 3 on SPICE3 was performed. Finally, the calculation speed between HiSIM_HV on SPICE3 and the power metal oxide semiconductor field effect transistor (MOSFET) model on another simulator were compared. The results have verified that the methodology provides stable and fast simulation for real automotive applications with power devices where thermal interference occurs.