Hasil untuk "Applications of electric power"

Zhen Zhang, Hongliang Pang, A. Georgiadis et al.

Due to limitations of low power density, high cost, heavy weight, etc., the development and application of battery-powered devices are facing with unprecedented technical challenges. As a novel pattern of energization, the wireless power transfer (WPT) offers a band new way to the energy acquisition for electric-driven devices, thus alleviating the over-dependence on the battery. This paper presents an overview of WPT techniques with emphasis on working mechanisms, technical challenges, metamaterials, and classical applications. Focusing on WPT systems, this paper elaborates on current major research topics and discusses about future development trends. This novel energy transmission mechanism shows significant meanings on the pervasive application of renewable energies in our daily life.

J. Jaguemont, L. Boulon, Y. Dubé

Jie Deng, Chulheung Bae, A. Denlinger et al.

Jie Deng is a research engineer in the Department of Electrification Subsystems and Power Supply at Ford Motor Company. He has extensive experience in computer-aided engineering analysis (structural, fluid, and thermal), battery simulations, and material characterization. He got his PhD in Mechanical Engineering from Florida State University and has published over 30 papers. His current research mainly focuses on battery array design and multi-physics modeling and testing of battery behaviors under various abuse conditions. Chulheung Bae is a high-voltage battery systems group supervisor at Ford Motor Company, where his research activities focus on lithium ion battery system development and validation for automotive applications. Dr. Bae has over 22 years of experience in advanced battery materials and various energy storage devices, including Lithium Ion, NiZn, Lead-Acid and redox flow batteries, and ultra-Capacitors. Dr. Bae has a Doctorate in Chemical Engineering from University of Manchester in the UK. Adam Denlinger is manager of high-voltage systems research and development at Ford Motor Company. Adam’s team is responsible for delivering high-voltage battery system innovations—including packaging, durability, thermal, management and controls, and EMC—as well as human-centered technologies targeting an enhanced electrified vehicle ownership experience. The team also leads multiple collaborations in this field with industry, university, and national lab partners. Adam has worked with Ford for 22 years, with experience delivering powertrain technologies, including Ford’s first Ecoboost engine application, industry-first hydrogen internal combustion engine vehicle fleet, and multiple high-voltage battery systems for battery electric (BEV) and plug-in electric (PHEV) vehicles. Ted Miller is manager of electrification subsystems and power supply research. His team is responsible for Ford global electrification subsystem and power supply research, delivering battery system design innovations in advanced cell technology, packaging, thermal, EDS, EMC, charging, power conversion, and energy management and modeling. They provide subject matter expertise from raw materials to end-of-life recycling. The team also leads collaboration with university, industrial, and National Lab partners. Mr. Miller is chairman of the United States Advanced Battery Consortium and a member of the Idaho National Laboratory Strategic Advisory Committee and the University of Michigan Energy Institute External Advisory Board.

Anurag Chauhan, R. Saini

A. Poorfakhraei, M. Narimani, A. Emadi

Traction inverter, as a critical component in electrified transportation, has been the subject of many research projects in terms of topologies, modulation, and control schemes. Recently, some of the well-known electric vehicle manufacturers have utilized higher-voltage batteries to benefit from lower current, higher power density, and faster charging times. With the ongoing trend toward higher DC-link voltage in electric vehicles, some multilevel structures have been investigated as a feasible and efficient option for replacing the two-level inverters. Higher efficiency, higher power density, better waveform quality, and inherent fault-tolerance are the foremost advantages of multilevel inverters which make them an attractive solution for this application. This paper presents an investigation of the advantages and disadvantages of higher DC-link voltage in traction inverters, as well as a review of the recent research on multilevel inverter topologies for electrified transportation applications. A comparison of multilevel inverters with their two-level counterpart is conducted in terms of efficiency, cost, power density, power quality, reliability, and fault tolerance. Additionally, a comprehensive comparison of different topologies of multilevel inverters is conducted based on the most important criteria in transportation electrification. Future trends and possible research areas are also discussed.

J. Zha, M. Zheng, Benhui Fan et al.

Juner Zhu, I. Mathews, Dongsheng Ren et al.

Summary E-mobility, especially electric cars, has been scaling up rapidly because of technological advances in lithium-ion batteries (LIBs). However, LIBs degrade significantly with service life cycles. With the current increase in the adoption of electric vehicles (EVs), a large volume of retired LIB packs, which can no longer provide satisfactory performance to power an EV, will soon appear. Various end-of-life (EOL) options are under development, such as recycling and recovery. Recently, stakeholders have become more confident that giving the retired batteries a second life by reusing them in less-demanding applications, such as stationary energy storage, may create new value pools in the energy and transportation sectors. In this perspective, we evaluate the feasibility of second-life battery applications, from economic and technological perspectives, based on the latest industrial reports and technical publications.

F. Zhou, H. Gong, M. Xiao et al.

Avalanche and surge robustness involve fundamental carrier dynamics under high electric field and current density. They are also prerequisites of any power device to survive common overvoltage and overcurrent stresses in power electronics applications such as electric vehicles, electricity grids, and renewable energy processing. Despite tremendous efforts to develop the next-generation power devices using emerging ultra-wide bandgap semiconductors, the lack of effective bipolar doping has been a daunting obstacle for achieving the necessary robustness in these devices. Here we report avalanche and surge robustness in a heterojunction formed between the ultra-wide bandgap n-type gallium oxide and the wide-bandgap p-type nickel oxide. Under 1500 V reverse bias, impact ionization initiates in gallium oxide, and the staggered band alignment favors efficient hole removal, enabling a high avalanche current over 50 A. Under forward bias, bipolar conductivity modulation enables the junction to survive over 50 A surge current. Moreover, the asymmetric carrier lifetime makes the high-level carrier injection dominant in nickel oxide, enabling a fast reverse recovery within 15 ns. This heterojunction breaks the fundamental trade-off between robustness and switching speed in conventional homojunctions and removes a key hurdle to advance ultra-wide bandgap semiconductor devices for power industrial applications.

M. Brenna, F. Foiadelli, C. Leone et al.

Many different types of electric vehicle (EV) charging technologies are described in literature and implemented in practical applications. This paper presents an overview of the existing and proposed EV charging technologies in terms of converter topologies, power levels, power flow directions and charging control strategies. An overview of the main charging methods is presented as well, particularly the goal is to highlight an effective and fast charging technique for lithium ions batteries concerning prolonging cell cycle life and retaining high charging efficiency. Once presented the main important aspects of charging technologies and strategies, in the last part of this paper, through the use of genetic algorithm, the optimal size of the charging systems is estimated and, on the base of a sensitive analysis, the possible future trends in this field are finally valued.

S. R. Hui, Yun Yang, Cheng Zhang

The first generation of wireless power transfer (WPT) standard Qi, launched in 2010, contains a wide range of transmitter and receiver designs with the aim of maximizing compatibility to attract many manufacturers to share the same standard. Such compatibility feature (i.e., interoperability) has not only attracted over 400 company members in the Wireless Power Consortium (WPC), but also facilitated a fast-growing wireless power market for a decade. The WPC is now expanding the scope of WPT applications to mid-power and high-power applications up to several kilowatts while the Society for Automobile Engineers (SAE) also set the SAE standard for wireless charging of electric vehicles (EVs) up to tens of kilowatts. Without compromising compatibility, the authors share in this article their views on the need for a paradigm shift from compatibility to optimal performance in terms of maximum energy efficiency for the entire charging process and minimum charging time. This paradigm change is imminent and important in view of the increasing power of WPT applications. Several enabling technologies essential to the paradigm shift will be addressed.

Weiqi Qin, Tiejun Ma, Xianhao Fan et al.

Gas-insulated equipment (GIE) plays a critical role in modern power systems, where reliable and accurate condition monitoring is essential for operational safety. Optical sensing technologies, benefiting from immunity to electromagnetic interference, high sensitivity, and adaptability to harsh environments, offer promising alternatives to traditional electrical sensors. This review presents a comprehensive survey of optical sensing technologies for GIE, including fiber Bragg gratings (FBG), fiber-optic interferometry, distributed acoustic and temperature sensing, gas absorption spectroscopy, and electric-field detection based on the electro-optic (EO) effect. The fundamental principles, implementation schemes, and typical applications of each method are systematically analyzed. Despite the demonstrated advantages, challenges remain in sensor packaging reliability, optical coupling efficiency, and long-term stability. Future research should focus on enhancing system robustness, spatial resolution, and integration with digital twins and intelligent diagnostic frameworks. This work seeks to bridge GIE and optical sensing technologies, facilitating the development and deployment of high-reliability optical sensing systems for the monitoring of next-generation GIE.

Fatjon Maxharraj, Karsten Voigt, Anton Werwein et al.

In various applications, including modern electric vehicles, the demand for batteries with high gravimetric and volumetric energy density is growing, driving the need for new production concepts to meet this requirement. Enhancing the energy and power density of lithium‐ion batteries is a crucial goal, as it refers to how much energy can be stored in a given volume or mass and how quickly that energy can be delivered, which are key factors determining the performance of batteries. In pursuit of higher energy density and fast‐charging capability, recent attention has been drawn toward strategies that emphasize optimizing the characteristics of composite electrode structures, such as porosity, conductivity, or tortuosity, achieved through restructuring the matrix composition of lithium‐ion battery electrode films. This review highlights the importance of structuring, explores recent advances in electrode design, and critically evaluates them in terms of energy and power density using a computational tool (Ragone calculator). Employing the Ragone calculator enables the evaluation of electrodes with different designs on the cell level. Various electrode designs created using different techniques, including laser, multilayer structuring, and interdigitated approaches are evaluated. The insights from this review can help the reader to assess the actual improvements from the structuring technique.

Alberto Dequino, Luca Bompani, Luca Benini et al.

Transformers have emerged as the central backbone architecture for modern generative AI. However, most ML applications targeting low-power, low-cost SoCs (TinyML apps) do not employ Transformers as these models are thought to be challenging to quantize and deploy on small devices. This work proposes a methodology to reduce Transformer dimensions with an extensive pruning search. We exploit the intrinsic redundancy of these models to fit them on resource-constrained devices with a well-controlled accuracy tradeoff. We then propose an optimized library to deploy the reduced models using BFLoat16 with no accuracy loss on Commercial Off-The-Shelf (COTS) RISC-V multi-core micro-controllers, enabling the execution of these models at the extreme edge, without the need for complex and accuracy-critical quantization schemes. Our solution achieves up to <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>220</mn><mo>×</mo></mrow></semantics></math></inline-formula> speedup with respect to a naïve C port of the Multi-Head Self Attention PyTorch kernel: we reduced MobileBert and TinyViT memory footprint up to ∼94% and ∼57%, respectively, and we deployed a tinyLLAMA SLM on microcontroller, achieving a throughput of 1219 tokens/s with an average power of just 57 mW.

Qiwen JING, Sipeng HAO, Siyuan LI

Exposed conductors in 10 kV distribution line are one of the major causes with operational faults in distribution lines, continuously affecting the safe and stable operation of the distribution network. Traditional manual inspection methods often fail to detect such defects in a timely manner. A detection method for exposed conductors in 10 kV distribution lines is proposd based on an improved YOLOv8 algorithm,which is designed to assist power grid maintenance personnel detecting conductor exposed defects quickly and efficiently. The algorithm replaces the original convolution with omni-dimensional dynamic convolution in the backbone network, enhancing the features of exposed conductors through multi-dimensional feature extraction. In the neck network, the connection between high-level and low-level features is enhanced by combining attention embedding module with the cross stage feature fusion module of the original network, thereby analyzing both the overall shape and local details of exposed conductors. For the loss function, distance intersection over union with normalized wasserstein distance is combined to increase focus on cases where targets are small or background interference exists in drone inspection photographs. The experimental results demonstrate that the improved algorithm achieves increases of 4.8 percentage points, 4.2 percentage points, and 5.2 percentage points in precision, recall, and mean average precision, respectively, compared to the original algorithm. This effectively enhances the detection capability for exposed distribution conductors, providing a new technical approach for ensuring the safe and stable operation of power systems.

XIE Weichen, GUO Jun, ZHENG Qunshuang et al.

Overhead transmission lines are the significant component of electric power system, where the over current can be coupled with the transient electromagnetic field or excitations (such as high-altitude electromagnetic pulse). As the coupling path of strong electro-magnetic interference, overhead transmission lines cause serious interference to the power system. Among the existing modelling methods, the classical transmission line theory may generate large error when dealing with the high-frequency coupling problem, where the cross dimension of the transmission line is not electrically small. Numerical full-wave method (such as moment of method) which relies on the grid subdivision with low efficiency when dealing with long transmission lines. Moreover, the number of cables is usually large in electric power system, and the ground are considered as the lossy ground. Therefore, to address the above mentioned problems, an asymptotic method is proposed to calculate the high-frequency coupling current along overhead transmission lines in electric power system. Based on the asymptotic theory with high calculation efficiency, the scattering and reflection process are introduced to quantify higher-order model components. In addition, the arbitrary number of wires, arbitrary parameters of the ground and different excitations are considered to derivate the current expression. Finally, the validity and reliability of the proposed method are tested using the full-wave simulation and antenna irradiation experiment. The proposed method can quickly calculate high-frequency coupling current, which can provide theoretical basis and data support for protection and electromagnetic effect study of overhead transmission lines.

Fatemeh Nasr Esfahani, Ahmed Darwish, Saud Alotaibi et al.

This paper presents a novel modular integrated on-board charger (MIOBC) topology and control scheme for dual-motor electric vehicle (EV) applications. Designed for effective power management across various operational states (driving, regenerative braking, and charging), the MIOBC modularises the HV battery and converters, improving fault ride-through (FRT) capability, system flexibility, safety, and efficiency. The architecture features a single-stage bidirectional isolated Cuk converter as its submodule (SM), providing inherent power factor correction (PFC), reduced current ripple, and enhanced power quality. The control strategy integrates finite control set model predictive control (FCS-MPC) with classical proportional-integral (PI) controllers in a hierarchical multi-loop framework. The FCS-MPC dynamically predicts and regulates switching states, minimising a defined cost function to achieve real-time current and voltage tracking while suppressing second-order harmonic components through an innovative capacitor-based energy buffering technique. The paper further explores the impact of the prediction horizon on stability, employing state-space modelling to analyse robustness under parameter variations. Experimental validation is conducted on a 20 kW dual-motor system controlled by a TMS28335fezdsp, demonstrating robust performance under normal and fault conditions, including mode switching and second-order harmonic suppression.

Gioele Gregis, Luigi Piegari, Luca Raciti et al.

In recent years, the interest in DC systems has increased dramatically because of some key advantages, in terms of efficiency and reliability, that this technology can offer compared to AC systems in applications such as shipboard distribution, more electric aircrafts, DC microgrids, battery protection, and photovoltaics. In this context, DC circuit breakers based on power semiconductors, the so-called solid-state circuit breakers, are becoming a popular choice because of their fast intervention speed, which is typically on the order of microseconds. Unfortunately, power electronics are vulnerable to &#x201C;breakdown&#x201D;, which is a dangerous operating condition triggered by overvoltages. During current interruption, the energy stored in the inductive elements of the system must be dissipated, and this typically creates a very high voltage spike on the interrupting component, which is the breaker pole. This phenomenon, if not controlled, could lead to the premature failure of the semiconductor inside the solid-state circuit breaker. For this reason, suitable techniques aimed to control the voltage gradient and overshoot during interruption have been presented in the literature. This paper analyzes and compares the performances of the voltage-clamping solutions presented in the technical literature, which range from simple passive devices to more advanced solutions.

LÜ Jiawei, HUO Zhaoyi, LIU Feng et al.

ObjectivesThe advanced exergoeconomics analysis method based on exergetic analysis development can refine the economic costs of splitting system components and deeply explore the underlying reasons for the formation of economic costs.MethodsCombining advanced exergetic analysis, advanced exergoeconomics analysis method is used to split the costs of the components in the gas-steam combined cycle power generation system into endogenous, exogenous, avoidable and unavoidable costs, and calculate them.ResultsUnder the design conditions, the avoidable loss in the combustion chamber in the combined cycle power system is the largest, which is 28.41 MW, accounting for 26.55% of the combustion chamber loss. Based on the results of the analysis, different improvement measures are proposed for the turbine to reduce the endogenous and exogenous losses of the system. The largest share of the annualized cost of the system is the endogenous avoidable portion, and the bottom-cycle improvement is prioritized highest for the high-pressure cylinder, followed by the low-pressure cylinder. The exogenous share of annualized costs in the combined cycle power system is 80.59%, of which the exogenous avoidable portion is 40.04%.ConclusionsThe findings of the study can provide the system with a multifaceted energy efficiency evaluation perspective and an improvement direction to optimize the cost.

Ioannis Roditis, Michail Dakanalis, E. Koutroulis et al.

Distributed renewable energy sources in combination with hybrid energy storage systems are capable to smooth electric power supply and provide ancillary services to the electric grid. In such applications, multiple separate dc–dc and dc–ac converters are utilized, which are configured in complex and costly architectures. In this article, a new nonisolated multiport dc–ac power inverter is presented, which comprises less passive components and less high-frequency power semiconductors. The proposed grid-connected multiport converter (MPC) enables the integrated power management of a photovoltaic (PV) array, a battery unit, a supercapacitor bank, and the battery of an electric vehicle. The power circuit of the proposed MPC inverter is based on a new version of a split-source inverter topology to support bidirectional power flow and enables to connect the PV source directly to the dc link. The proposed design is accompanied by a specifically developed control method that enables to implement the maximum power point tracking process without the need of any extra power converter, regulate the power flow at each port independently, as well as to control the power flow between its ports. An experimental prototype of the proposed MPC inverter has been constructed and its operation has been validated experimentally under various power flow scenarios.

Paula B. Garcia-Rosa, Olav B. Fosso

New ancillary services and additional requirements for the grid integration of variable renewable energy (VRE) are being defined worldwide, in response to the technical challenges caused by increasing levels of VRE utilization in electric power grids. Currently, the use of wave energy is still limited to a few applications or demonstrations, where the level of penetration of wave power into the grid is not significant. To anticipate the future requirements for wave power integration, and the possibilities for provision of services, this paper considers the lessons being learned through the challenges caused by high penetration levels of other VRE sources into the grid, particularly wind power. On this basis, this paper presents an overview of grid support services that wave power plants can be expected to provide in power systems dominated by converter-interfaced generation, i.e. low inertia systems. Specifically, the focus is on services that support the active power balance in the power system. Then, the current capabilities and future perspectives for the provision of frequency support by wave farms are discussed.