This paper presents an improved and easy-to-use battery dynamic model. The charge and the discharge dynamics of the battery model are validated experimentally with four batteries types. An interesting feature of this model is the simplicity to extract the dynamic model parameters from batteries datasheets. Only three points on the manufacturer’s discharge curve in steady state are required to obtain the parameters. Finally, the battery model is included in the SimPowerSystems simulation software and used in a detailed simulation of an electric vehicle based on a hybrid fuel cell-battery power source. The results show that the model can accurately represent the dynamic behaviour of the battery.
Abstract Recently, implantable medical electronics (IMEs) have become essential for extending patient’s lives. Extending the lifespan of these devices has in turn become a main challenge for their development; thus, current research efforts on this topic are focusing on their power sources (e.g., generation of energy by body activity). In this respect, piezoelectric energy harvesters (PEHs) are ideal candidates for the capture and subsequnt conversion of biomechanical energy into electric energy to operate IMEs (e.g., energies created through muscle relaxation and contraction, body movement, blood circulation, lung motion, and cardiac motion). This paper reviews the recent developments in PEHs and associated biomedical devices. The materials and fabrication processes needed for the development of PEHs are also discussed along with their biomedical applications (e.g., cardiac pacemaker, active pressure sensors, direct stimulation of tissue, and living cells). The present limitation and future prospects of PEH technology are discussed finally.
Uwe Schröder, Falk Harnisch, Elizabeth Heidrich
et al.
Global wastewater production exceeds 359 billion m3 annually, of which only 52% is treated, mostly in expensive and resource-consuming processes. Microbial electrochemical technologies (METs) offer a transformative approach to sustainable wastewater management by converting waste into valuable resources such as energy, clean water, and nutrients. They present a viable solution to the United Nations’ Sustainable Development Goal 6 (to ensure access to water and sanitation for all) by enhancing both sanitation and resource recovery. METs, including microbial fuel cells (MFCs) and microbial electrolysis cells (MECs), harness electrogenic microorganisms to oxidize organic matter, generating electric energy or producing energy carriers like hydrogen and methane. METs also enable recovery of nutrients, such as ammonium and phosphates, which are essential for agriculture, thereby closing resource loops in a circular economy. Despite their potential, challenges remain in scaling up METs for widespread application. Pilot-scale MFCs and MECs have demonstrated feasibility, achieving up to 90% chemical oxygen demand removal and producing electric power, methane, or hydrogen from wastewater. However, high capital costs, material limitations, and energy efficiency barriers hinder commercialization. Innovations in electrode design, modular configurations, and integration with existing wastewater treatment processes (e.g., anaerobic digestion, membrane bioreactors, or constructed wetlands) are advancing METs toward higher technology readiness levels (TRLs 4–8). Field applications, like a system for urine-based electricity generation in underserved regions, highlight METs adaptability and societal impact. The transition from laboratory to real-world implementation requires scaling, process integration, and further optimization to reduce costs and improve performance. By aligning with circular economy principles, METs can transform wastewater into a resource, contributing to energy security, environmental sustainability, and global sanitation goals. Future research should focus on scalable designs, economic viability, and interdisciplinary collaboration alongside understanding and optimizing the microbial “black box” to enable METs to transform previously unused wastewater streams into valuable resources with targeted applications.
With the continued advancement of deep electrification across various industries, the demand for higher power density in electric machines is steadily increasing. However, realizing high power density remains a significant technical challenge and has become a major bottleneck in machine development. The design of such machines is inherently constrained by the strong coupling among electromagnetic (EM), thermal, and mechanical domains, while systematic analyses of these challenges remain insufficient. This paper clarifies the interdependent relationships among these domains during the machine design process. It reviews key enabling strategies, including machine design based on advanced electromagnetic theory, innovative thermal management techniques, cutting-edge material advancements, and state-of-the-art manufacturing technologies, that collectively enhance the performance and feasibility of high power density machines (HPDMs). The insights provided aim to support the development of next-generation machine systems with higher power density, compact size, and robust, sustainable performance across a wide range of industrial and technological applications.
Alper Yildirim, Samuel Bignardi, Christopher F. Barnes
et al.
Multi-view stereo techniques with traditional cameras have wide applications in robotics and computer vision for scene reconstruction. Their dependence on the visible spectrum, however, poses several limitations that radar sensing could overcome in obstructing conditions such as fog and smoke. We propose a new radar-based multi-view stereo method for scene reconstruction, which combines the power of multi-view stereo techniques with the advantages of radar sensing by extending upon our previous work in this direction, where we demonstrated a time-domain inversion approach by leveraging a set of independent radar echoes acquired at sparse locations to reconstruct the scene’s geometry. Here, we show how radar stretch processing can be incorporated into a similar geometric framework to leverage frequency-domain information. Our method fundamentally differs from classical radar imaging by utilizing an explicit geometric shape representation, allowing the imposition of shape priors and the ability to model visibility and occlusions, and a forward model based on the electric field strength density over the antenna range embedded within the deramped echo. An iterative scheme is then used to evolve an initial shape toward an optimal configuration to best explain the data. We conclude by showing the initial proof of concept for the success of this method through a set of simulated 2D experiments of increasing complexity.
ABSTRACT Recently, wireless power transfer (WPT) effectively meets the demands for distance, transfer power level, system efficiency and safety, making it highly promising for various applications. In practical applications, system performance is sensitive to the coil coupling, making reliability against coupling fluctuations a real challenge. This article focuses on the coil modelling for coils for wireless power transfer systems, of which the self‐inductance, mutual inductance, B field are all taken into consideration. Besides the accurate modelling, the coil optimization is conducted for better anti‐misalignment to achieve a robust stable performance. Finally, an experimental prototype is implemented, and the results validate the accuracy of the proposed model.
Jia Di Yang, Paul R. Shearing, Jason Millichamp
et al.
As we enter the age of electrochemical propulsion, there is an increasing tendency to discuss the viability or otherwise of different electrochemical propulsion systems in zero-sum terms. These discussions are often grounded in a specific use case; however, given the need to electrify the wider transport sector it is evident that we must consider systems in a holistic fashion. When designed adequately, the hybridisation of power sources within automotive applications has been demonstrated to positively impact fuel cell efficiency, durability, and cost, while having potential benefits for the safety of vehicles. In this paper, the impact of the fuel cell to battery hybridisation degree is explored through the key design parameter of system mass. Different fuel cell electric hybrid vehicle (FCHEV) scenarios of various hydridisation degrees, including light-duty vehicles (LDVs), Class 8 heavy goods vehicles (HGVs), and buses are modelled to enable the appropriate sizing of the proton exchange membrane (PEMFC) stack and lithium-ion battery (LiB) pack and additional balance of plant. The operating conditions of the modelled PEMFC stack and battery pack are then varied under a range of relevant drive cycles to identify the relative performance of the systems. By extending the model further and incorporating a feedback loop, we are able to remove the need to include estimated vehicle masses a priori enabling improving the speed and accuracy of the model as an analysis tool for vehicle mass and performance estimation.
Production of electric energy or power. Powerplants. Central stations, Renewable energy sources
The magnetic circuit has been a popular and powerful tool to analyze the magnetic field in electromagnetic devices for a long history. However, in the conventional magnetic circuit there is only one kind of component namely reluctance, which cannot analyze the phase shift or the amplitude attenuation of the alternating flux in electromagnetic devices. In this article, a new physical concept of magnetic-inductance is proposed, based on which the alternating-flux magnetic circuit theory including two kinds of components namely reluctance and magnetic-inductance has been developed. Furthermore, the virtual magnetic power is defined as the analogue of electric power, and the magnetoelectric power law is derived for magnetic circuits. Using the proposed magnetic circuit theory with magnetic-inductance, the relationship between the electric power and the virtual magnetic power is revealed and the long-lasting confusions in previous magnetic circuit methods, i.e., power calculation and phase shifts of magnetic variables, are clarified. By experiments, the magnetic-inductance and the magnetoelectric power law are validated, and their applications in eddy current loss analysis and B-H curve estimation in magnetic materials are demonstrated.
Abstract Huge regenerative braking (RB) energy is generated in the AC traction power supply system (TPSS) which is related to safe operation and comprehensive energy utilisation. For the RB energy utilisation, the authors propose a railway regenerative braking power conditioner (RBPC) with no energy storage system (ESS) integrated which is located at the end of the power sections between adjacent traction substations (TSSs). First, the RB characteristics are studied based on a large amount of measured data, and the load power states are classified according to the load powers of adjacent power sections. Then, the RB energy utilisation scheme, transferring the RB power to the adjacent power section where traction power exists, has been studied. Moreover, a dual closed‐loop control strategy for a back‐to‐back converter is adopted to achieve RB energy utilisation. Finally, a case study and an engineering application are carried out. The results have verified the feasibility of this method, which can illustrate that more than half of the RB energy can be mutually utilised in adjacent power sections.
The power balance of the new power system mainly based on new energy is facing an important technical challenge, and the participation of flexible load in power system regulation is an important way to enhance the active balance capability of the new power system. In view of the obvious seasonal and temporal characteristics of the electric and thermal loads, the new energy sources are “extremely cold and hot without wind” and “late peak without light”, and the thermoelectric loads in the new power system show the trend of anti-peak regulation. To address this problem, this paper analyzed the spatial and temporal characteristics and energy-use characteristics of electric and thermal loads, explored their regulation potential, focused on the control scenarios of electric and thermal controllable loads, and systematically gave a flexible scheduling strategy for electric and thermal loads to complete the flexible control and regulation of electric and thermal loads. The results realize the network-load cooperative optimization and flexible scheduling on the whole time scale, and thus verify the feasibility of the real-time participation of telectric and thermal loads in the scheduling of the grid.
Applications of electric power, Production of electric energy or power. Powerplants. Central stations
The characteristics of overvoltage are closely related to the system grounding mode, which is of great significance to the selection and design of key equipment. However, the research on grounding mode selection combined with overvoltage analysis in DC distribution network is still imperfect. Firstly, the mechanism of overvoltage generation is analyzed for ±10 kV dual-terminal DC distribution network based on modular multi-level converter (MMC), and the overvoltage peak values at key positions of the system under three typical grounding modes are compared by fault simulation in PSCAD/EMTDC. Then, the fault recovery ability, economy, voltage stability and overvoltage peak value are proposed as the indexes for the comprehensive selection of grounding mode. Grounding by resistance through neutral point of the transformer in AC side and ungrounding in DC side is evaluated as the preferred grounding mode of the studied system. Finally, the arrester parameters and configuration scheme are determined based on the chargeability calculation design method, and the validity is verified by simulation. References for the selection of grounding mode and insulation configuration of DC distribution network are supplied by the research.