Electric Source Research Articles

Forensic Analysis of Electrical Injury Patterns: A Study of Electrocution Fatalities at SMS Medical College Jaipur

Objective: To provide an in-depth forensic analysis of the types and locations of electrical injuries observed in electrocution deaths, focusing on the presence of entry and exit wounds, the voltage involved, and associated burns. Methods: This hospital-based observational study examined 75 cases of electrocution fatalities autopsied at the mortuary of SMS Medical College Jaipur from June 2021 to June 2022. Data on demographics, injury types, wound locations, voltage levels, and burn patterns were collected and analyzed. Descriptive statistics were used to summarize the data, and chi-square tests assessed the significance of categorical variables. Results: Among the 75 cases, males accounted for 92% of the victims, with the majority aged 21-30 years (34.4%). Upper limb injuries were predominant (38.67%), and both entry and exit wounds were present in 48% of cases. Low voltage (65.33%) was the most common electrical source, and flame burns were observed in 44% of the cases. Shock – Septicaemia was the primary cause of death (58.66%). Conclusions: This study highlights the forensic significance of analysing injury patterns in electrocution deaths. Understanding these patterns aids in determining the cause and manner of death, emphasizing the need for preventive measures and public awareness to reduce such fatalities.

Holistic approach to energy storage management aspects in sustainable community

Energy management is nowadays key topic for synchronic operation of renewable sources of energy and their recipients. Contemporary national electrical power grid systems more often cannot supply efficiently electrical energy and cannot receive energy produced by renewable sources. The common approach to the problem is to meet energy demands supplying from electrical grid and renewable power sources with energy storage feature. From the other side, off-grid solutions based on the co-generation biogas plants are commonly aimed on small local communities as power supply supported by renewable energy systems like photovoltaic (PV) systems, wind power plants or small water plants with energy storage to support self-consumption of electrical energy. Integration of intermittent renewable power sources, such as solar, wind and biogas plant, increases the difficulty of managing the electricity grid and maintaining the balance of electricity supply and demand, especially in small communities. The holistic approach to the energy storage management takes all above aspects and presents the concept where municipal waste is used to produce energy in biogas plant supported by PV systems and community shared electrical energy storage to provide uninterrupted power supply. The study also presents how energy storage management can be used in whole process to adjust the size and manage energy supply and demand within the community based on energy self-consumption optimization. It is also shown that by utilizing municipal waste produced by the community we can meet the goals of circular economy and sustainable development of local communities as the waste will be used in full without necessity of recycling it outside the community. The novelty of the study is the foundation for energy storage capacity and renewable energy sources size evaluation to balance energy management process without the need of on-grid power supply and with use only municipal biodegradable waste for biogas fuel supply and solar energy for energy production.

Enhancement of cyclic spectral coherence map by statistical testing approach—application to bearing faults diagnosis in electric motors

Abstract Efficiency of fault detection in rolling element bearings is heavily influenced by the quality of data. In controlled environments, such as test rigs designed for bearing diagnostics, data quality is relatively good. Similarly, diagnosing bearings that support shafts in industrial machinery is relatively straightforward. However, diagnosing bearings in electric motors presents greater complexity due to the influence of additional cyclic components on vibration signals. These extra components, originating from mechanical or electrical sources, complicate frequency-based analysis.
This paper proposes a novel approach for diagnosing bearings in electric motors, utilizing statistical analysis within the bi-frequency domain through a cyclostationary framework. The method involves applying a statistical testing procedure to individual pixels on the Cyclic Spectral Coherence (CSC) map. The statistical significance of these pixels is assessed based on quantiles of CSC maps obtained from a dataset representing a healthy bearing. This process results in an enhanced or cleaned CSC map, facilitating the identification of fault-related components. Consequently, this approach enables the detection of defects in electric motor bearings, even when additional signal components unrelated to the defect, but characteristic of a healthy bearing, are present.

Comprehensive analysis of supervised learning methods for electrical source imaging

Electroencephalography source imaging (ESI) is an ill-posed inverse problem: an additional constraint is needed to find a unique solution. The choice of this constraint, or prior, remains a challenge for most ESI methods. This work explores the application of supervised learning methods for spatio-temporal ESI, where the relationship between measurements and sources is learned directly from the data. Three neural networks were trained on synthetic data and compared with non-learning based methods. Two distinct types of simulation, each based on different models of brain electrical activity, were employed to quantitatively assess the generalization capabilities of the neural networks and the impact of training data on their performances, using five complementary metrics. The results demonstrate that, with appropriately designed simulations, neural networks can be competitive with non-learning-based approaches, even when applied to previously unseen data.

Joule-Heated Interfacial Catalysis for Advanced Electrified Esterification with High Conversion and Energy Efficiency.

Esterification reactions are crucial in industries such as chemicals, fragrances, and pharmaceuticals but often face limitations due to high reversibility and low reactivity, leading to restricted yields. In this work, an electrified esterification pathway utilizing a Joule-heated interfacial catalysis (JIC) system is proposed, where a hydrophilic, sulfonic acid-functionalized covalent organic framework grown on carbon felt (COF─SO3H@CF) acts as the interfacial catalyst, and the carbon felt serves as the electric heat source. This approach achieves an acetic acid conversion of 80.5% at a heating power density of 0.49Wcm-3, without additional reagents by vaporizing reaction products, surpassing the theoretical equilibrium limit of 62.5% by 1.29 times. Comprehensive analysis indicates that the intimate contact between the electric heat source and the COF─SO3H catalyst enables efficient, localized Joule heating directly at catalytic sites, minimizing thermal losses and allowing precise control over reaction interfaces. This finding demonstrates that this JIC system not only enhances esterification efficiency but may also offer a sustainable, energy-efficient pathway for high-yield chemical processes.

Global floating PV status and potential

Abstract Floating photovoltaics (FPV) has been a rapidly growing source of renewable electricity for the past 15 years since first commercial systems were installed. In this work, the insights from SERIS FPV database are shared. This is likely the largest database of its kind and contains the information from 1142 FPV systems in operation, totalling 5.9 GWp, by the end of 2022. Mainland China has been leading FPV installation capacities since 2017 and comprises almost half of the cumulative installed capacity. Similar to land-based PV, FPV installation size has been increasing; the median size has grown from 0.09 MWp in 2013 to 1.40 MWp in 2022, while the median power density has increased from 82 Wp m−2 to 123 Wp m−2 in the same timeframe. The installation cost has fallen simultaneously – the lowest reported was 0.41 USD/Wp in India in 2021. Other pertinent insights from SERIS FPV database include float supplier market share, reported electricity price, water body types and characteristics, as well as its coverage ratio. Finally, the global FPV potential (capacity, energy production, and water saving), for different tilt angles, tracking configurations, and solar panel types are explored. By installing FPV on 10% of the area of 249 717 inland reservoirs, FPV capacity could reach up to 22 TWp and could fulfil the whole global electricity consumption and up to 5% of the world’s water demand. The use of trackers and bifacial panels are advantageous for energy generation in all locations, with trackers increasing specific energy yield of a typical fixed 10° tilt FPV by up to 50% for reservoirs within ± 40 ∘ latitude, while the bifacial gains reach up to 4.5% for all analysed configurations within ± 40 ∘ latitude. The insights from this global FPV market and potential analysis can serve as a reliable reference for FPV stakeholders, researchers, and regulators alike.

A Soft Start Method for Doubly Fed Induction Machines Based on Synchronization with the Power System at Standstill Conditions

Due to their exceptional operational versatility, doubly fed induction machines (DFIM) are widely employed in power systems comprising variable renewable energy-based electrical generation sources, such as wind farms and pumped-storage hydropower plants. However, their starting and grid synchronization methods require numerous maneuvers or additional components, making the process challenging. In this paper, a soft start method for DFIM, inspired by the traditional synchronization method of synchronous machines, is proposed. This method involves matching the frequencies, voltages, and phase angles on both sides of the main circuit breaker, by adjusting the excitation through the controlled power converter at standstill conditions. Once synchronization is achieved, the frequency is gradually reduced to the rated operational levels. This straightforward starting method effectively suppresses large inrush currents and voltage sags. The proposed method has been validated through computer simulations and experimental tests, yielding satisfactory results.

Methodological approaches to carbon footprint assessment and certification of low carbon hydrogen

The article reviews existing approaches to low-carbon hydrogen certification and offers recommendations for their improvement based on an assessment of the carbon footprint across the entire life cycle. A comprehensive assessment of the carbon footprint of hydrogen produced from water and methane during steam reforming is presented. The assessment concluded that approximately 50% of hydrogen is produced from water, meets the requirements of low-carbon hydrogen (emission levels in the range of 4.2–4.5 kg CO2eq/kg H2) and can be considered for certification as renewable hydrogen. The results of estimating the carbon footprint of hydrogen from hydrogen sulfide demonstrate that for hydrogen sulfide methane reforming and thermal decomposition of hydrogen sulfide, carbon dioxide emissions will be on the order of 1.842 and 2.244 kg CO2/kg H2, respectively. Taking into account associated emissions from natural gas production, the total greenhouse gas emissions for the processes under consideration are 4.649 and 6.129 kg CO2eq/kg H2, respectively, when using grid electricity. When using electricity from hydropower, the total greenhouse gas emissions from hydrogen production through hydrogen sulfide methane reforming and thermal decomposition of hydrogen sulfide will be 2.33 and 2.78 kg CO2/kg H2, respectively, and for an alkaline electrolyzer they are about 2.60 kg CO2/kg H2. Thus, when using low-carbon sources of electricity to power processes, hydrogen sulfide technologies perform comparable to water electrolysis processes, and in some cases even show lower emissions.Additionally, the impact of hydrogen leaks on the greenhouse effect is considered and analyzed, which allows us to conclude that hydrogen is an indirect greenhouse gas.

The macro view of solar policy: The case for supporting utility-scale power

New solar energy generation is drastically needed as a source of clean electricity as the U.S. and the globe make the transition away from fossil fuels. Yet, even as solar costs have dramatically declined, solar sources still provide less than 5% of global electricity. We examine issues in solar policy leading to this low adoption rate. Examining the variables of cost, baseload power and intermittency, and land use, we evaluate the tradeoffs among policy support for utility-scale, commercial and residential solar systems. We argue that utility-scale solar power makes far more sense if there is adequate grid integration, so that such installations can be placed in locations that minimize land use tradeoffs. By focusing policy support on a few large solar installations, governments can vastly increase the solar contribution to electricity generation.

Optimizing energy-efficient grid performance: integrating electric vehicles, DSTATCOM, and renewable sources using the Hippopotamus Optimization Algorithm

The rapid increase in renewable energy integration and electric vehicle (EV) adoption creates significant challenges for the stability and efficiency of power distribution networks. This study addresses the need for optimized placement and sizing of Electric Vehicle Charging Stations (EVCSs), photovoltaic (PV) systems, and Distribution Static Compensators (DSTATCOMs) to enhance grid performance. The motivation for this work arises from the fluctuating nature of renewable energy generation and the unpredictable demands of EV charging, which strain existing infrastructure. To address these challenges, we propose a novel optimization framework that introduces the Renewable Distributed Generation Hosting Factor (RDG-HF) and Electric Vehicle Hosting Factor (EV-HF) as key metrics. These metrics, combined with the Hippopotamus Optimization Algorithm (HO), enable strategic planning within the IEEE 69-bus system. Simulation results demonstrate that the integrated placement of EVCSs, PVs, and DSTATCOMs reduces power losses by up to 31.5% and reactive power losses by up to 29.2%. An economic analysis further reveals payback periods ranging from 2.7 to 10.4 years and potential profits of up to $1,052,365 over 25 years. These findings highlight the importance of optimized integration in improving both technical performance and long-term economic benefits for distribution networks.

Room-Temperature Formate Ester Transfer Hydrogenation Enables an Electrochemical/Thermal Organometallic Cascade for Methanol Synthesis from CO2.

The reduction of CO2 to synthetic fuels is a valuable strategy for energy storage. However, the formation of energy-dense liquid fuels such as methanol remains rare, particularly under low-temperature and -pressure conditions that can be coupled to renewable electricity sources via electrochemistry. Here, a multicatalyst system pairing an electrocatalyst with a thermal organometallic catalyst is introduced, which enables the reduction of CO2 to methanol at ambient temperature and pressure. The cascade methanol synthesis proceeds via CO2 reduction to formate by electrocatalyst [Cp*Ir(bpy)Cl]+ (Cp* = pentamethylcyclopentadienyl, bpy = 2,2'-bipyridine), Fischer esterification of formate to isopropyl formate catalyzed by trifluoromethanesulfonic acid (HOTf), and thermal transfer hydrogenation of isopropyl formate to methanol facilitated by the organometallic catalyst (H-PNP)Ir(H)3 (H-PNP = HN(C2H4PiPr2)2). The isopropanol solvent plays several crucial roles: activating formate ion as isopropyl formate, donating hydrogen for the reduction of formate ester to methanol via transfer hydrogenation, and lowering the barrier for transfer hydrogenation through hydrogen bonding interactions. In addition to reporting a method for room-temperature reduction of challenging ester substrates, this work provides a prototype for pairing electrochemical and thermal organometallic reactions that will guide the design and development of multicatalyst cascades.

RISC Fault of Non‐Salient Wound‐Rotor Synchronous Generator: A Detection Method and Effect Analysis of Insulation

Rotor interturn short circuit (RISC) fault is one of the most prevalent fault types in the non‐salient wound‐rotor synchronous generator (WRSG). In the paper, the theoretical mechanism of the RISC fault is studied in detail. Building upon this understanding, from the fault detection and harm consequences, the further work of this article includes proposing a RISC detection method and analyzing the influence of RISC on the insulation thermal damage. On the one hand, a new detection for RISC fault is first proposed based on the phase voltage. The proposed detection method innovatively allows for accurate determination of both the severity and location of RISC faults. On the other hand, the loss and the temperature of the stator core‐winding system are comprehensively investigated with varied RISC degrees and positions. The thermal responses of the winding insulation are obtained under the joint action of the external magnetic heat source and the internal electric heat source. The study identifies critical points of insulation vulnerability, particularly noting areas prone to noise and connection joints. This research contributes to the timely online identification of RISC faults and supports preventive maintenance strategies for protecting winding insulation. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.

Comprehensive study of rapid capacity fade in prismatic Li-ion cells with flexible packaging

Prismatic lithium-ion batteries (LIBs) are considered promising electric energy sources in electromobility applications due to their efficient space utilization. However, their sensitivity to external and internal influences and reduced durability lead to inflation risk and potential explosions throughout their lifecycle. These critical processes are strongly influenced by the inner construction of the cell, especially concerning the coating and mechanical fixation. This study subjects a commercially available prismatic LIB cell to comprehensive, correlative analysis employing various imaging techniques. The inner structure of the entire cell is visualized non-destructively by X-ray computed tomography (CT), enabling the identification of critical design flaws prior to electrochemical cycling. Electrochemical cycling simulates the battery lifecycle, and the cell is subsequently disassembled in the fully charged state. The usage of the inert-gas transfer system allowed the preparation of Broad Ion Beam (BIB) electrodes cross-sections in a fully native state and for the first time to observe the tearing of graphite particles due to over-lithiation. Established region labeling system allowed to use CT and scanning electron microscopy (SEM) correlatively to identify critical regions. After 100 cycles, a 40% capacity loss was observed and event diagram describing deagradation mechanisms, related both to the cell design and to the processes occurring at high load, was created.

Hierarchically Structured Catalysts Toward Sustainable Hydrogen Economy: Electro- and Thermo-Chemical Pathways.

Hydrogen, as an important clean energy source, plays a more and more crucial role in decarbonizing the planet and meeting the global climate challenge due to its high energy density and zero-emission. The demand for sustainable hydrogen is increasing drastically worldwide as driven by the global shift towards low-carbon energy solutions. Thermochemical catalysis process dominates hydrogen production at scale given its relatively mature technology and commercialization status, as well as the established manufacturing infrastructure. While due to its environmentally friendly nature and growing abundant sources of renewable electricity, the electrochemical path for hydrogen production is rising as a major alternative to the thermochemical means. Nevertheless, hierarchically structured catalysts and devices have gradually taken the center stage toward replacing the traditional counterparts, especially with the rapid advancement of the design and manufacture of such ordered nanostructure assemblies toward high activity, efficient mass transport, and superb stability. In this review, the latest progress of the hierarchically structured catalysts for hydrogen production have been surveyed on electro- and thermo- chemical pathways comparatively. It covers the structure designs of atomic dispersion, nanoscale surfaces and interfaces for achieving highly active and durable catalysts, components, and devices. Both electrochemical and thermochemical approaches are reviewed in terms of the vast design details, engineered benefits, and understandings of various Pt-group metal (PGM) and non-PGM based transition metal catalysts for hydrogen production. As the growing trend, brief discussions are also presented toward the high-level assembly and manufacture of complexly structured components and devices at scale in the electrochemical and thermochemical energy systems.

Changes in Farm Supply Voltage Caused by Switching Operations at a Wind Turbine

Renewable electricity sources are now widely used worldwide. Currently, the most common sources are those that use energy contained in biomass, water, sun, and wind. When connected to a medium-voltage grid, individual wind power plants must meet specific conditions to maintain electricity quality. This article presents field study results on the impact of switching operations (turning the power plant on and off) at a 2 MW Vestas V90 wind turbine on the voltage parameters at the connection point of a farm located 450 m from the source. The analysis showed that the wind turbine under study significantly affects customers’ voltage near the source, causing it to increase by approximately 2.5%. Sudden cessation of generation during the afternoon peak causes a 3% voltage fluctuation, potentially affecting equipment sensitive to rapid voltage changes.

Efficient Hybrid Electric Vehicle Power Management: Dual Battery Energy Storage Empowered by Bidirectional DC–DC Converter

ABSTRACTThis work offers a fuel cell power system with the ability to distribute power to the load from the electrical source and charge an auxiliary battery utilizing regenerative power flows created by the load. The approach is established on a bidirectional closed‐loop DC converter. A bidirectional DC–DC converter is presented as a means of achieving extremely high voltage energy storage systems (ESSs) for a DC bus or supply of electricity in power applications. This paper presents a novel dual‐active‐bridge (DAB) bidirectional DC–DC converter power management system for hybrid electric vehicles (HEVs). The proposed system makes it possible to charge an additional battery with regenerative power flows and distributes power from the electrical source to the load efficiently. The two main stages of the DAB converter, which are the focus of this work, are an interleaved buck/boost converter on the battery and a three‐phase wye‐wye series resonating converter on the DC bus. Each switch's current stress is greatly reduced by this design, which lowers transmission losses and enhances thermal performance. The interleaved buck conversion on the battery allows for lesser current stress in each switch, resulting in lower transmission loss. The increasing complexity and power of automotive embedded electronic systems have made the use of more potent power electronic converters in automobiles necessary. In recent years, many dual volt (42 V/14 V) bidirectional inverter topologies for automotive systems have been presented. However, the majority of them are either inefficient or use a huge number of transistors and magnetic devices in both parallel and series arrangements. As a result, in this study, a bidirectional high‐efficiency inverter with fewer components is provided. The design, modes of operation, and performance metrics of the DAB converter are examined, emphasizing its ability to achieve zero‐voltage switching (ZVS) and zero current switching (ZCS) throughout its operating range. The suggested system seeks to maximize EV power management, guaranteeing high dependability and efficiency. To test all of the aforementioned qualities, an evaluation version was created, with an average efficiency of 97.5%. This research could have a substantial impact on the advancement of power electronic converters for automotive applications, leading to better EV power management, increased system reliability, and increased overall efficiency.

Effect of electrode size and distance to tissue on unipolar and bipolar voltage electrograms and their implications for a near-field cutoff

Characteristics of electrograms depend on the electrode design and distance to the electric source. Our aim was to assess the impact of electrode design and distance from the myocardial electric source on the unipolar and bipolar electrograms to deduce a far-field cut-off. We retrospectively analyzed left atrial electroanatomical maps of 25 patients acquired using an ablation catheter with a 4.5 mm tip-, mini- and 2 mm ring electrodes. The unipolar and bipolar electrograms were characterized based on peak-to-peak amplitude, signal duration, maximal slope, and relative power of the high frequency spectrum above 50 Hz (HF_rel). The unipolar electrograms of ring electrodes showed an increased amplitude (140%), slope (150%) and HF_rel (16% vs. 11%) compared to the tip- and mini-electrodes. The median amplitude, slope, and HF_rel for the ring electrodes followed a power-law decay with distance with a steep decline up to 4 mm. This near-field cut-off can be identified based on a HF_rel above 10% in unipolar electrograms. In conclusion, we observed a higher unipolar amplitude for small ring-electrodes compared to larger tip-electrodes. The rapid decay of the amplitude, slope, and HF_rel up to a distance of 4 mm is suggestive for near-field cut-off identified based on HF_rel above 50 Hz.Clinical Trial Registration: NCT04095559.

Study on carbon emissions of a small hydropower plant in Southwest China

Hydropower plants with a small installed capacity, which are widely distributed in mountainous areas with abundant rainfall and steep rivers, play an important role in resolving energy problems in remote rural areas. These plants are a crucial source of clean electricity generated from water power. Harnessing local water resources not only helps alleviate energy shortages, but also reduces reliance on fossil fuels, contributing significantly to China’s national goals of achieving peak carbon emissions and carbon neutrality. This study investigates the carbon footprint of the Huangshadong Reservoir Project in Chongqing, China. The entire life cycle of the hydropower plant is assessed, including the preparation, construction, operation and maintenance, and demolition phases. The uncertainty was evaluated using the error propagation method. Following analysis, suggestions for carbon footprint reduction measures were proposed. Results showed that the total carbon footprint and the carbon intensity of the Huangshadong Reservoir Project over its entire life cycle are 33,148.29 t CO2e and 417.75 g CO2e/kWh, respectively. Of the total carbon footprint, the preparation phase, construction phase, operation and maintenance phase, and demolition phase account for 0.04%, 67.06%, 26.2%, and 6.7%, respectively. It means that the requirement for cement during the construction phase represents an important contribution to the entire life cycle carbon footprint of a small hydropower plant. As an integrated water conservancy project, the carbon intensity of the Huangshadong Reservoir Project is higher than that of medium-sized and large hydropower plants. However, its carbon intensity is lower than the emission factor of fossil power plants. The research results provide reference for both planning and construction of small hydropower plants and low-carbon development of rural hydraulic engineering.

Coordinated planning for offshore wind and electricity–hydrogen system based on SDDP: A case study of coastal provinces in China

The coordinated development of offshore wind and electricity–hydrogen systems (OW-EHS) has the potential to enhance the utilization of renewable energy sources and achieve carbon neutrality. This article presents a case study of nine coastal provinces in China and designs four scenarios to analyze the economic benefits and potential hydrogen production capacity of OW-EHS. A multi-stage stochastic dual dynamic programming based approach is proposed for integrating OW-EHS, exploring offshore wind energy as both a primary electricity source for coastal regions and a clean, sustainable energy source for electrolyzers. It accounts for variations in hydrogen demand, wind uncertainty, load profiles, and electricity price dynamics, offering a holistic perspective on the feasibility and benefits of collaborative offshore wind and electricity–hydrogen systems. A comparative analysis highlights the effectiveness of the proposed planning approach, demonstrating its capacity to maximize the overall system benefits, encompassing both the optimal levelized cost of energy and hydrogen production. The new discoveries elucidate the unique attributes and advantages of each coastal province in OW-EHS. This research provides a tailored blueprint for coastal provinces in China to harness their offshore wind potential and accelerate progress towards carbon neutrality.

Ocean energy enabling a sustainable energy-industry transition for Hawaiʻi

Global transitions to highly sustainable energy-industry systems imply shifts to high shares of variable renewable energy sources. While onshore solar photovoltaics and wind power can be expected to be the lowest cost electricity sources around the world, land-constrained regions and islands may have limited onshore renewable potential. Thus, offshore energy technologies, including floating solar photovoltaics, offshore wind turbines, and wave power, may become essential. Furthermore, for Hawaiʻi, offshore energy may provide increased supply diversity and avoid land conflicts as electricity generation is expected to increase. The LUT Energy System Transition Model was employed to investigate the techno-economic implications of high technological diversity through integration of offshore energy technologies compared to full cost-optimisation under both self-supply and electricity-based fuel import scenarios. Limiting solar electricity leads to 0–2.3 GW of offshore electricity and 0–4.1 GW of wave power by 2050, but at 3.5–28.0% increased system costs. Under self-supply conditions and an 80% solar photovoltaics limit, a novel interaction between the key offshore technologies was identified with 0.6–1.1 GW of offshore floating photovoltaics, which contribute 12.3% of all electricity generation by 2050. Due to the limited land availability in Hawaiʻi and island regions, ocean energy technologies may significantly contribute to energy-industry system defossilisation.