Electromechanical Energy Research Articles

Mathematical Modeling of Mechanical Forces and Power Balance in Electromechanical Energy Converter

This article proposes a calculation method for mechanical (electromagnetic) forces arising in an electromechanical energy converter acting on current circuits in a magnetic field, or on capacitor plates in an electric one. Transformations were performed on the basis of the principle of possible displacements involving the apparatus of partial derivatives. It was found that the power converted into mechanical power is partially spent on changing the energy of the electromagnetic field, and the remaining power, determined by the co-energy, is converted into mechanical power. Expressions for the mechanical (electromagnetic) forces were obtained based on the power balance. The reliability of the obtained results was compared with the known results. Of these, one can observe the well-known 50/50 principle, which states that only part of the power associated with the movement of the circuits is converted into mechanical power, while the rest is intended for changing the energy of the magnetic field.

Control of Halogen Atom in Inorganic Metal-Halide Perovskites Enables Large Piezoelectricity for Electromechanical Energy Generation.

Regulating the strain of inorganic perovskites has emerged as a critical approach to control their electronic and optical properties. Here, an alternative strategy to further control the piezoelectric properties by substituting the halogen atom (I/Br) in the CsPbX3 perovskite (X = Cl, Br) structure is adopted. A series of piezoelectric materials with excellent piezoelectric coefficients (d33 ) are unveiled. Iodine-incorporated CsPbBr2 I demonstrates the record intrinsic piezoelectric response (d33 ≈47 pC N-1 ) among all inorganic metal halide perovskites. This leads to an excellent electrical output power of ≈ 0.375mW (24.8 µW cm-2 N-1 ) in the piezoelectric energy generator (PEG) which is higher than those of the pristine/mixed perovskite references with CsPbX3 (X = I, Br, Cl). With its structural phase remaining unchanged, the strained CsPbBr2 I retains its superior piezoelectricity in both thin film and nanocrystal powder forms, further demonstrating its repeatability and versatility of applications. The origin of high piezoelectricity is found to be due to halogen-induced anisotropic lattice strain in the unit-cell along the c-axis, and octahedral distortion. This study reveals an avenue to design new piezoelectric materials by modifying their halide constituents and paves the way to design efficient PEGs for improved electromechanical energy conversion.

System design, analysis, and experimental investigations of linear switched reluctance machines with double mover configuration

This paper proposes a new double mover configuration of a linear switched reluctance motor (LSRM). The proposed design is established for optimization of the motional forces and to ensure a high-grade electromechanical energy conversion process. The major drawback of the traditional linear machine is that its force densities within and throughout its area is produced in its radial direction of the yoke and does not contribute to its motion or twisting force of the rotor. If these normal forces happen to be in the direction of motion, a larger motional force profile for SRM is yielded. Based on these guidelines, a new LSRM is developed. In order to compare the energy conversion efficiency of LSRM with that of the conventional SRM, a finite element model is constructed. The proposed system is simulated using the FEM software and tested under four conditions. Further, an experimental prototype of the proposed machine is also developed and tested in the laboratory. The results obtained from the prototype indicate that the proposed geometry offers superior performance in terms of high-power density and higher percentage of the national forces.

Anisotropy free energy contribution of the ferroelectric domain dynamics in PMN‐PT and PIN‐PMN‐PT relaxor ferroelectrics

AbstractA direct correlation between the materials property behavior with its associated ferroelectric domain mechanisms and the anisotropic component of the Landau free energy is established for binary PMN‐PT (generation I) and ternary PIN‐PMN‐PT (generation II) relaxor ferroelectric single crystal material systems. In addition to their trade‐off in material properties, the observed ferroelectric domain dynamic and the determined free energy anisotropies, especially as approaching phase transition, provide direct insights into the materials field‐dependent behavior between the binary and ternary ferroelectric systems. Domain configuration features such as lamellar structures in binary PMN‐PT and concentric oval‐like structures in ternary PIN‐PMN‐PT result in different material responses to external stimuli. Compared to binary PMN‐PT, the concentric oval‐like domain structures of ternary PIN‐PMN‐PT result in a 20°C higher temperature range of field‐dependent linear behavior, 40% increase in coercive electric field higher elastic stiffness during ferroelectric domain switching, and lower electromechanical energy losses. Separation of the isotropic and anisotropic components in the Landau free energy reveals a higher anisotropic free energy contribution from the ternary system, especially at temperature for practical applications. The high anisotropic free energy found in the ternary PIN‐PMN‐PT system implies that the concentric oval‐like domain structure contributes to reduced electromechanical energy losses and enhanced stability under external applied fields.

Neuromodel of an Eddy Current Brake for Load Emulation

The eddy current brake (ECB) is an electromechanical energy conversion device that can be used as a load emulator to load a motor according to the intended load scenario. However, conducting an analysis in the time domain is difficult due to its complex behavior involving mechanical, electrical, and magnetic phenomena. The challenges with the time domain analysis of the ECB require new modeling approaches that provide reliability, robustness, and controllability over a wide speed interval. If the ECB can be modeled with high accuracy, it can be controlled like a load emulator that can simulate nonlinear industrial loads. This paper describes a neuromodeling approach taken to develop an ECB. The nonlinear characteristic of the brake system was modeled with a high performance by using an artificial neural network (ANN), which is a potent nonlinear system identification tool. Several characteristics of a designed and optimized brake system undergoing various excitation currents in whole speed regions are described and verified experimentally. Eventually, an electromechanical brake system is proposed that aims to provide the required linear or nonlinear load model dynamics throughout an emulation process in line with the obtained neuromodel. To identify the most suitable ANN architecture for the problem, various ANN configurations, ranging from 1 neuron to 20 neurons in the hidden layer, as well as a statistical approach that differs from the existing literature, are presented. Additionally, the suggested model’s scalability is discussed.

A Review of Ultrathin Piezoelectric Films.

Due to their high electromechanical coupling and energy density properties, ultrathin piezoelectric films have recently been intensively studied as key materials for the construction of miniaturized energy transducers, and in this paper we summarize the research progress. At the nanoscale, even a few atomic layers, ultrathin piezoelectric films have prominent shape anisotropic polarization, that is, in-plane polarization and out-of-plane polarization. In this review, we first introduce the in-plane and out-of-plane polarization mechanism, and then summarize the main ultrathin piezoelectric films studied at present. Secondly, we take perovskite, transition metal dichalcogenides, and Janus layers as examples to elaborate the existing scientific and engineering problems in the research of polarization, and their possible solutions. Finally, the application prospect of ultrathin piezoelectric films in miniaturized energy converters is summarized.

IoT-Based Prepaid Energy Meter

Abstract: India uses electromechanical or electronic energy meters. The main problems with these energy meters are recovering the electricity bills and more manpower being used in billing processes. An IOT-based prepaid energy meter would be able to address some of the challenges currently available in the existing energy meter. Smart Metering with its unique performance with the Internet of Things (IoT) tends to be an efficient system for electricity management. This can reduce human errors and helps to retrieve the real-time meter value via IOT and send it to the customer’s mobile phone through IOT. This energy meter consists of ATMEGA328, a Current sensor, and a Wi-Fi module. It also consists of a mobile app through which consumers can monitor the electricity used by them.

Both network architecture and micro cracks effects on lacuno-canalicular liquid flow efficiency within the context of multiphysics approach for bone remodeling

When physical forces are applied to bone, its mechanical adaptive behaviors change according to the microarchitecture configuration. This leads to changes in biological and physical thresholds in the remodeling cell population, involving sensor cells (osteocytes) interacting with each other and changes in osteocyte shape due to variation in lacunar shape. The resulting alterations in fluid flow leads to changes in the membrane electrical potential and shear stress. Eventual creation of microcracks, may lead in turn to modify cell activity. In contrast, the redundancy in the lacuno canalicular network (LCN) interconnectivity maintains partial flow. Our goal was to investigate the role of fluid flow in LCN by proposing a model of electro-mechanical energy spread through inhomogeneous microarchitectures. We focused on mechano-sensitivity to changes in load-induced flow impacted by neighboring micro cracks and quantifying its critical role in changing, velocity, shear stress and orientation of liquid mass transportation from one cell to another. To enhance the concept of intricacy LCN micro-structure to fluid flow, we provide a new combined effects factor considered as osteocytes sensor efficiency. We customized an influence function for each osteocyte, coupling: in one hand, the spatial distribution within remodeling influence areas, conducting a significant fluid spread, leading hydro-dynamic behavior and impacted further by presence of micro cracks and; in other hand, the fluid electro kinetic behavior.As an attempt to fill the limitations stated by many of the recent studies, we reveal in numerical simulation, some results which cannot be measured in vitro/in vivo studies. Numerical calculations were performed in order to evaluate, among many others, how liquid flow conditions changes between lacunas, how the orientation and the magnitude of the governing flow in LCN can regulate osteocytes efficiency. In addition to be regulated by osteocytes, a direct effects of fluid flow are also acting on osteoblast activity. In summary, this new approach considers mechano-sensitivity in relation to liquid flow dynamic and suggests additional pathway for Osseo integration via osteoblast regulation. However, this novel modeling approach may help improve the mapping and design bone scaffolds and/or selection of scaffold implantation regions.

Investigation of Energy Harvesting Capabilities of Metglas 2605SA1

In the framework of electromechanical energy conversion devices for vibrational energy harvesting, magnetostrictive materials are an attractive alternative solution to the brittleness of piezoelectric materials. Electromagnetic systems have low voltage output at a low frequency while magnetostrictive materials are suitable for a larger frequency bandwidth. In this work, a special experimental emphasis is placed on Fe80Si9B11 (also known as Metglas 2605SA1) alloy. The ultimate energy conversion abilities are investigated by performing experimental Ericsson cycles as well as through theoretical predictions using a dedicated model for the magnetic curves at the material scale. Typical output magnetic energy densities ranged between 0.1 and 1 mJ/cm3/cycle under moderate stress (<100 MPa) and magnetic excitation (up to 4 kA/m). Apart from its energy conversion abilities, Metglas 2605SA1 also features attractive characteristics for realistic applications in microgenerators, such as a low price, which is an important advantage for the mass production and cost-effectiveness of the harvester. Furthermore, its soft magnetic property reduces the need for high magnetic fields and yields a well-adapted solution from a system point of view. It is therefore shown that this material is a suitable conversion material according to the available stress and magnetic excitation magnitudes, in addition to economic considerations.

Bending Energy of Electric Dipole using Geometric Orientation Method

Abstract: Heat is the lower form of energy and work is the higher one. In every electrical, mechanical or electro-mechanical circuits energy is assumed to be conserved. Similarly, in magnetic and electrical circuits charge and potential difference are tried to be conserved. In this paper, we will analyse the different propagations of electro-static charges so that the main component of electric energy field (i.e. electric dipole moment) can be quantified for every orientation & trajectory of electric charge couple. A general formula for bending of the magnet is derived using direct geometric method. In this the magnetic dipole of a solide ferromagnetic within the Curie temperature is represented.

Linear contracting and air-stable electrochemical artificial muscles based on commercially available CNT yarns and ionically selective ionogel coatings

Artificial muscles, or soft actuators, that could exhibit contractile stroke and operate in open-air, would be crucial for many applications, such as robotics, prosthetics, or powered exoskeletons. Amongst the different artificial muscle technologies, electrochemical carbon nanotube (CNT) yarn muscles, transducing capacitively ionic accumulation at the electrochemical double layer into linear contraction, are amongst the most promising candidates. However, their performances are either limited by an undesired bipolar behaviour or short lifetime due to the inevitable drying of water-based electrolytes. In this paper, we present here the fabrication of air-operating contractile linear artificial muscles from commercially available CNT yarns exhibiting outstanding performance. The synthesis and the junction of two ionogels based on cationic and anionic polyelectrolyte have been designed for the coating process on CNT yarns, and for selectively orienting the ionic flow allowing optimal electromechanical energy conversion. The dual-electrode CNT yarn actuators showed air-stable unipolar contractile stroke, reaching 9.7% without loss of performances after 2000 cycles.

Numerical and experimental investigation of the energy harvesting performance of electromechanically coupled piezoelectric prestressed beams subjected to nonlinear vibrations

Τhe piezoelectric energy harvesting from nonlinear vibrating structures has greatly attracted the attention of scientific community over the last decades, as it seems to provide one of the more promising ways for high electromechanical energy conversion. Current study deals with the development of a robust and accurate numerical tool capable of modelling and designing piezoelectric structures undergoing severe nonlinear vibrations. Specifically, a coupled multi-field generalized nonlinear mechanics framework for piezoelectric beams subjected to initial stresses and large rotations, extended to include passive external electric circuits in order to predict the dynamic response of the structure and the power generated at the external resistive load. An experimental setup was also developed providing great correlations with the numerical results in case of a vibrating axially prestressed composite beam under the prebuckling regime. At the end, a computational investigation was performed studying the complex dynamic behavior of the piezoelectric beam, in the postbuckling regime. The model successfully captures the measured energy harvesting response of the beam including additional effects induced by the asymmetric configuration of the piezoelectric film.

Multilevel Fully Integrated Electromechanical Property Modulation of Functionally Graded Graphene‐Reinforced Piezoelectric Actuators: Coupled Effect of Poling Orientation

AbstractThis article explores the coupled static and dynamic electromechanical responses of single and multilayered functionally graded (FG) graphene platelet (GPL)‐reinforced piezoelectric composite (GRPC) plates by developing a 3D finite‐element model. The bending and eigenfrequency of piezoelectric FG composite plates are investigated, wherein an active behavior is proposed to be exploited in terms of the functional design of poling angle for a more elementary level property modulation. The numerical results reveal that the mechanical behavior concerning deflection and resonance frequency of FG‐GRPC plates can be significantly enhanced and modulated due to the influence of piezoelectricity and a small fraction of GPLs along with the consideration of poling angle in a multiscale fully integrated computational framework. The notions of on‐demand property modulation, actuation, and active control are established here by undertaking a comprehensive numerical analysis considering the coupled influences of poling orientations, different distributions, patterns, and weight fractions of GPLs along with different electromechanical loadings. Against the backdrop of the recent advances in microscale manufacturing, the current computational work will provide necessary physical insights in modeling piezoelectric multifunctional FG composites for active control of mechanical properties and harvesting electromechanical energy in a range of devices and systems.

Magnetic Material Modelling of Electrical Machines

As Guest Editors of this Special Issue, it was our responsibility to ensure that the contributions to the issue related to the extensive field of electromechanical energy conversion, with a special focus on the design, materials, and modeling of electrical machines [...]

Probabilistic approach of pre-estimating life-cycle costs of road tunnels

Conceptual pre-estimation of road tunnel costs is a vital yet challenging process during feasibility studies due to the prevailing underground uncertainties and risks. Most existing cost estimation approaches are deterministic, probabilistic methods are limited to a single cost examination. This paper introduces a probabilistic model for pre-estimating road tunnels life-cycle costs. It aims to capture their inherent uncertainty holistically, thus enabling more reliable decision-making at a project’s early stages. The proposed model is developed in three steps: multiple regression analysis, fitting distribution, and Monte-Carlo simulation. The first step unveils the correlations between independent and dependent variables, while the other two steps return the probabilistic descriptions of cost drivers and life-cycle costs. Civil engineering, electromechanical works costs, energy consumption, and operation & maintenance costs are determined as the model’s output variables. A real-world database of 32 dual-bore road tunnels with a total length of 55 km is used to develop probability distributions within reasonable confidence intervals and a sensitivity analysis was performed utilizing tornado charts. The results can assist public authorities and managers in estimating the probability of a specific life-cycle cost and making appropriate decisions in accordance with their risk tolerance.

Deep Learning Based Design Methodology for Electric Machines: Data Acquisition, Training and Optimization

This paper presents an automated deep learning-based design methodology to facilitate the design and optimization processes in electro-mechanical energy conversion devices. To validate the generality of the model, a complex machine structure with hybrid Permanent Magnets (PMs) is selected as the case study. First, the machine’s geometrical topology and the respective design variables are described in the cylindrical coordinate system and programmed into a Finite Element (FE) software package. Next, the program sweeps through the predefined ranges of selected design variables and captures corresponding air-gap flux distribution through an automated FE-based parametric analysis. The air-gap flux density data is post-processed and fed into a deep neural network (DNN) training algorithm. In particular, 10,000 data sets are utilized for training the DNN model. The trained model successfully predicts the machine’s performance for any random set of parameters, as confirmed via FE. Finally, by leveraging the trained model, the structural parameters of the machine are optimized to limit higher-order spatial flux harmonics and the cogging torque.

Investigation Into the Effect of Joint Clearance on the Dynamics of a Biomechanical Energy Harvesting System

The existing clearance in the mechanical joints plays a crucial role in the assembly of mechanical systems, allowing the mobility of its components. However, few studies have explored models that consider joint clearance in the case of electromechanical energy harvesting systems. This paper examines the effect of existing clearance in an electromagnetic energy harvester attached to the human lower limb. The dynamic response of the system and an estimate of its generated power are obtained by developing a lumped model, in which clearance is included by adding a dead band and assigning a stiffness coefficient during contact between elements. The natural motion of the lower limb is the input to the formulated model, which takes into account the nonlinear interaction of the electromagnetic device and the power conditioning circuit. Central composite design is used to study the influence of two selected factors on the dynamics of the system; joint clearance size and contact stiffness. The results suggest that the presence of clearance between the clamping mechanism and the human body positively affects the performance of the analyzed electromagnetic energy harvesting system. It was revealed that an increase of around 27% of output power could be intentionally achieved by adding larger clearance sizes.

УПРАВЛЕНИЕ ПЛАВАНИЕМ КОМПОЗИТНОГО ЭЛЕКТРОМЕХАНИЧЕСКОГО МИКРОРОБОТА

Relevance Currently, underwater robotics is one of the most important areas of development of robotic complexes. Their foundation and control are based on an electromechanical basis. The creation and research of electromechanical systems are one of the promising areas of development of electromechanics and electrical engineering. Equipped with a wide range of sensors, unmanned underwater vehicles are widely used to solve tasks such as studying the seabed relief, monitoring and servicing oil and gas pipelines and cable lines, collecting biological and geological samples of liquids, developing offshore oil and gas fields, conducting underwater rescue operations. The increasing popularity of such devices is explained by the fact that the use of manned vehicles can be very dangerous for the life of the pilots themselves and incur high costs during their operation. Research conducted by various engineering groups in the field of modeling and control of underwater robots is ultimately aimed at achieving full automation of processes. Achieving this aim seems to be an extremely difficult task, since it requires knowledge and understanding of a large volume of theoretical and practical problems that are subject to comprehensive research. Aim of research To carry out theoretical calculations on the study of electromechanical and mechanical parameters of underwater robot control and compare them with experimental data. Research methods The theory of electromechanical energy conversion and control of electrical equipment, methods of mathematical and physical modeling were used in the work. Results The results of constructing an algorithm and a mathematical model of the device of an electromechanical composite robot are presented. A system of equations of mechanics and electrodynamics was used to describe its power characteristics. By solving this system of equations, a theoretical analysis of the operation of its engine was carried out. With the help of the mechatronic approach, its swimming and coordination of its functional modules are studied. The results of this article will be useful for engineers involved in the design and operation of robots using robotic systems in the fields of biotechnology and biomechanics.

A Novel Wireless Energiser Based on HTS Electromechanical Energy Conversion

A Novel Wireless Energiser Based on HTS Electromechanical Energy Conversion

Исследование изменения электромагнитных параметров в управляемых асинхронных специальных электрических приводах

The article researches the changes in the electromagnetic parameters of controlled asynchronous special electric drives. Special asynchronous electric drives are controlled cascade electric drives of cylindrical and axial designs. The study of the dynamics of parameter changes is carried out on the basis of the method of electromagnetic energy conversion and the theory of electromagnetic circuits. As a result, for new mathematical models of the electromagnetic system of the studied asynchronous electric drives, the parameters of the electromagnetic field of a closed coil of one coil of an electric winding with electric current in a homogeneous medium are determined. The solved problem is spatial, since the distribution of electromagnetic induction in a coil of a given shape of an electromagnetic coil is determined. The obtained conclusions for determining the electromagnetic parameters of cylindrical and axial motors of special electric drives allow us to correctly solve the problems of modeling, designing and improving the efficiency of the studied electric drives and electromechanical energy converters of cylindrical and axial designs. The results of the study are applicable to create a computer-aided design system for the research asynchronous electric drives and solve modeling and design problems. The conducted research allows creating electric drives with optimal weight, size and energy indicators.