The growing demand for high-power-density electric and electronic systems has encouraged the development of energy-storage capacitors with attributes such as high energy density, high capacitance density, high voltage and frequency, low weight, high-temperature operability, and environmental friendliness. Compared with their electrolytic and film counterparts, energy-storage multilayer ceramic capacitors (MLCCs) stand out for their extremely low equivalent series resistance and equivalent series inductance, high current handling capability, and high-temperature stability. These characteristics are important for applications including fast-switching third-generation wide-bandgap semiconductors in electric vehicles, 5G base stations, clean energy generation, and smart grids. There have been numerous reports on state-of-the-art MLCC energy-storage solutions. However, lead-free capacitors generally have a low-energy density, and high-energy density capacitors frequently contain lead, which is a key issue that hinders their broad application. In this review, we present perspectives and challenges for lead-free energy-storage MLCCs. Initially, the energy-storage mechanism and device characterization are introduced; then, dielectric ceramics for energy-storage applications with aspects of composition and structural optimization are summarized. Progress on state-of-the-art energy-storage MLCCs is discussed after elaboration of the fabrication process and structural design of the electrode. Emerging applications of energy-storage MLCCs are then discussed in terms of advanced pulsed power sources and high-density power converters from a theoretical and technological point of view. Finally, the challenges and future prospects for industrialization of lab-scale lead-free energy-storage MLCCs are discussed.
Nowadays, wireless power transmission has many related applications in life, such as wireless charging of mobile phones and wireless charging of electric toothbrushes. Some electronic devices have achieved wireless charging. This paper focuses on wireless power transmission. Firstly, the basic knowledge of wireless power transmission is briefly introduced, including the classification of wireless power transmission, the most basic principle of wireless power transmission and its practical application. After that, this paper gives two examples of the two challenges facing the development of wireless power transmission: the distance limit of power transmission and the harm of electromagnetic fields to the human body. It also includes what would happen if these two problems were solved, and the need to solve them. At the end of this paper, the solutions that can be used to solve the above two problems are also listed, and the expectations and predictions for future wireless power transmission are also mentioned.
Our societies are ever more dependent on Global Navigation Satellite Systems (GNSS) like Galileo, GPS, Glonass or BeiDou. Navigation technology has penetrated so deeply into all sectors of society that one may argue that it constitutes critical infrastructure. The paper identifies and analyses the cross-sectoral dimensions of GNSS criticality, such as the high geostrategic and military importance, the dual-use character, the broad cross-sectoral application, the ubiquitous timing service of atomic clocks and the increasing sectoral requirements for availability and precision. Based on a synthetic literature review and an expert workshop, the paper also identifies numerous cross-sectoral spillover effects that could flow from a potential disruption of GNSS to other GNSS-dependent sectors including transport, telecommunications and the Internet, electric power generation and distribution, financial services and banking, agriculture, fisheries, emergency and security services, armed forces and defence, science, environmental and weather monitoring, construction, even space operations and various other applications.
K. Raghavendra, Kamran Zeb, Anand Muthusamy
et al.
Renewable Energy Sources (RES) showed enormous growth in the last few years. In comparison with the other RES, solar power has become the most feasible source because of its unique properties such as clean, noiseless, eco-friendly nature, etc. During the extraction of electric power, the DC–DC converters were given the prominent interest because of their extensive use in various applications. Photovoltaic (PV) systems generally suffer from less energy conversion efficiency along with improper stability and intermittent properties. Hence, there is a necessity of the Maximum power point tracking (MPPT) algorithm to ensure the maximum power available that can be harnessed from the solar PV. In this paper, the most important features of the DC/DC converters along with the MPPT techniques are reviewed and analyzed. A detailed comprehensive analysis is made on different converter topologies of both non-isolated and isolated DC/DC converters. Then, the modulation strategies, comparative performance evaluation are addressed systematically. At the end, recent advances and future trends are described briefly and considered for the next-generation converter’s design and applications. This review work will provide a useful structure and reference point on the DC/DC converters for researchers and designers working in the field of solar PV applications.
ABSTRACT This paper presents an enhanced robust filtering algorithm designed for integrated SINS/GNSS navigation systems operating under nonGaussian noise conditions. To address the challenges posed by heavy‐tailed noise distributions, a novel noise modelling framework based on Student's t‐distribution is developed, which provides superior outlier resilience compared to conventional Gaussian assumptions. Furthermore, a Gaussian mixture model representation is employed for both the one‐step predicted and likelihood probability density functions, enabling more accurate quantification of uncertainty. Additionally, a variational Bayesian‐based adaptive mechanism is employed for dynamic scale matrix optimisation, effectively mitigating the impact of process noise outliers. Extensive experimental validation, including Monte Carlo simulations and vehicular tests, demonstrates the algorithm's superior performance in SINS/GNSS integration scenarios. Comparative results indicate significant improvements in positioning accuracy and robust convergence characteristics relative to a decent number of iterations.
Lohith Kumar Pittala, Andrii Chub, Georgios I. Orfanoudakis
et al.
In many practical applications, such as electric vehicle charging and smart transformers, reverse power flow is significantly lower than forward power flow. Designing a full-rated bidirectional DC/DC converter in such cases leads to increased hardware costs. To address this, recent research has explored isolated topologies that support asymmetrical bidirectional power flow at reduced cost. This manuscript investigates an asymmetrical bidirectional DC/DC (AB-DC/DC) converter that integrates a partial-scale active bridge and a partial-scale diode bridge connected in parallel on the secondary side. Passive power sharing between these bridges is controlled by selecting appropriate coupling inductors, but practical magnetic tolerances cause power imbalances. To mitigate this, a novel modulation technique is proposed to enable active power sharing, allowing power transfer from the diode bridge to the active bridge. The study covers various operating regions, including discontinuous conduction mode (DCM), continuous conduction mode (CCM), dual-active-bridge (DAB) mode, and two hybrid regions, where the diode bridge operates in DCM and the active bridge in CCM. Closed-form power expressions and boundary conditions are derived for all modes. The proposed strategy is validated through simulations and experimental measurements on a hardware prototype, demonstrating consistent waveform behavior and confirming the feasibility of active power transfer from the diode bridge to the active bridge.
ObjectivesAs an important support for the new power system, hydrogen gas turbines can help reduce carbon emissions and are conducive to grid peak regulation. They are the focus of technological innovation in the global future strategic emerging industries. Many key issues faced by hydrogen blending gas turbine power generation technology from demonstration to commercialization, need to be solved.MethodsH-class gas turbines were taken as the research object, and the strategic planning and demonstration projects of hydrogen blending gas turbine power generation in China and abroad were introduced, and the technology routes of H-class gas turbines of major gas turbine manufacturers were compared. The analysis and suggestion was made from four aspects for the scale application of future hydrogen blending gas turbine power generation technology, including hydrogen source, system transformation, emission impact and hydrogen blending power generation cost.ResultsRenewable energy electrolysis of water to produce hydrogen will be the main source of hydrogen blending gas turbine power generation. In addition, the development of new dry low nitrogen oxide burners, which are suitable for unstable combustion of hydrogen blending, will be the key direction for future hydrogen blending gas turbine system transformation. The higher the hydrogen volume percentage is, the greater the CO2 emission reduction is. However, the NOx emission is on an upward trend. Moreover, there is a risk of exceeding the standard value, and the future cost of hydrogen blending gas turbine power generation can reach the same level as the cost of natural gas power generation.ConclusionsWith the reduction of the cost of large-scale renewable energy hydrogen production, and the implementation of carbon tax and the maturity of hydrogen blending power generation technology, the gas turbine hydrogen blending power generation will gradually enter large-scale application.
Applications of electric power, Production of electric energy or power. Powerplants. Central stations
As the “dual carbon” goal has been upgraded to a national strategy, coal-fired power plants are the top priority for carbon reduction in the power generation industry, and coal-fired power plants are facing a huge challenge in limiting carbon emissions. Using the method of bi-level programming model, this paper established a low-carbon coal blending optimization model for thermal power units by considering the combination of carbon emission quotas for regulatory agencies and coal blending in power plants. The upper layer is the goal of the government management department, which seeks to minimize the cost of emission reduction of power plants under the given total carbon emissions. The lower layer is the goal of the power plant sector, pursuing the minimization of coal blending cost and carbon emission cost. The chaotic particle swarm optimization (CPSO) algorithm was used to solve the model. The calculation provides a certain reference for the allocation of carbon emission quotas for regulatory agencies and coal blending for power plant operators, and has good application value and guiding role.
Applications of electric power, Production of electric energy or power. Powerplants. Central stations
Farhad Rezaee‐Alam, Abbas Nazari Marashi, Abolfazl Dehafarin
et al.
Abstract A new hybrid analytical model (HAM) based on conformal mapping (CM) method and magnetic equivalent circuit (MEC) model is presented in this paper for electromagnetic modelling of cage rotor induction motors (CRIMs) used in electric submersible pumps (ESPs). For every operating point, the iron parts are modelled with a non‐linear MEC model to calculate the equivalent virtual currents, which represent the influence of magneto motive force (MMF) drops and MMF sources in stator and rotor cores. The effects of the equivalent virtual currents on the air‐gap magnetic field are then considered using the CM method and Hague's solution. This approach for calculating the air‐gap field is also used to prepare a 3‐D lookup table (3‐D LUT) for each element of inductance matrix and derivative of inductance matrix in terms of rotor position. These LUTs are then used for transient modelling and analysis of CRIM under no‐load and loading conditions. The accuracy of proposed HAM is validated by comparing the results obtained through HAM with corresponding results obtained from finite element method and experiment set‐up.
Electric double layer capacitors (EDLCs) are a type of high-power and long-cycle energy storage device with wide operating temperature range. EDLCs have promising applications in transportation, microgrids, and the internet of things. Activated carbon, which is characterized by its high nanoporosity, high surface area, and high tap density, is the most widely applied electrode material for EDLCs. Plants, owing to the abundance, diversity, and renewability, have been considered as the most promising precursors for producing activated carbon. In this work, plant-derived activated carbon for EDLCs has been reviewed. First, the merits and operating mechanism for EDLCs have been briefly presented, and the plant-based precursors for activated carbon have been divided into four categories: agriculture & forestry plants, aquatic plants, fruit shells, and plant-derived molecules. Second, the basic requirements on activated carbon have been discussed, as well as the methods and mechanisms for preparing activated carbon. Third, the research progress of activated carbon prepared from plants has been reviewed, as well as the catalytic graphitization of the activated carbon derived from plants. Fourth, conclusions are presented, and the prospect for the promising applications in EDLCs and further research direction of plant-derived activated carbon have been delivered.
Chemical engineering, Materials of engineering and construction. Mechanics of materials
Morsy Nour, Jose Pablo Chaves-Avila, Alvaro Sanchez-Miralles
Blockchain technology applications in the electricity sector are getting considerable attention from both academia and industry. It is expected that blockchain will play an important role in the transition to the smart grid. The blockchain applications in the electricity sector can be classified to optimizing existing processes like metering and billing or grid management and using blockchain for emerging applications such as creating new platforms for value exchange like peer-to-peer (P2P) energy trading. This paper briefly introduces the fundamentals of blockchain technology, such as different types of blockchain networks and consensus mechanisms, in addition to introducing a few blockchain platforms that are widely used in current studies, projects, and startups or may have future potential in the electricity sector applications. The contribution of this paper is to provide a review of potential applications of blockchain in many electricity sector use cases, and they are categorized into eight categories such as P2P energy trading, wholesale markets, retail markets, metering and billing, trading of renewable energy certificates (RECs) and carbon credits, electric mobility, enhancement of power system cyber security, investments in renewable energy sources (RESs), and power system operation and management. Moreover, examples of research studies, pilot projects, industrial projects, startups, or companies investigating the blockchain capabilities at each potential application are introduced. Furthermore, the studies presented in each use case are compared to clarify and highlight the blockchain functions and involved actors. Finally, the paper discusses the challenges that blockchain technology is facing that obstruct large-scale adoption in different sectors and in the electricity sector specifically and potential solutions to these challenges that are being developed.