Superconductors in Electric-Power Technology

It is very important for the development of electric power big data technology to use the electric power knowledge. A new electric power knowledge theory model is proposed here to solve the problem of normalized modeled electric power knowledge for the management and analysis of electric power big data. Current modeling techniques of electric power knowledge are viewed as inadequate because of the complexity and variety of the relationships among electric power system data. Ontology theory and semantic web technologies used in electric power systems and in many other industry domains provide a new kind of knowledge modeling method. Based on this, this paper proposes the structure, elements, basic calculations and multidimensional reasoning method of the new knowledge model. A modeling example of the regulations defined in electric power system operation standard is demonstrated. Different forms of the model and related technologies are also introduced, including electric power system standard modeling, multi-type data management, unstructured data searching, knowledge display and data analysis based on semantic expansion and reduction. Research shows that the new model developed here is powerful and can adapt to various knowledge expression requirements of electric power big data. With the development of electric power big data technology, it is expected that the knowledge model will be improved and will be used in more applications.

The development of aircraft secondary power technology is moving from mechanical power, pneumatic power and hydraulic power to electric power. The trend toward electric power is known as More Electric Aircraft (MEA). Modern military aircraft are designed using 270VDC for electric power system. Today, some military aircraft still use 115VAC/400Hz for their electrical power system. If this type of aircraft need provides 270VDC electrical power, then they require Multi-Pulse Transformer Rectifier Unit (TRU). The development of this type TRU has not been aimed to comply with aircraft military standards. This research investigates the variation of the number of pulses (p) and firing angle (α) to the amplitude ripple voltage, output voltage, and distortion factor in order to comply with the MIL-STD-704F standards. The multi-pulse transformer rectifier unit being analyzed consists of 6-Pulse and 12-Pulse. The research shows that the amplitude ripple voltage and distortion factor of the 6-Pulse TRU do not comply MIL-STD-704F. The amplitude ripple voltage and distortion factor of 12-Pulse comply MIL-STD-704F with firing angle (α) ≤4°.Keywords: Transformer Rectifier Unit, thyristor, ripple voltage, distortion factor, firing angle

Superconductivity has the potential to bring a more fundamental change to electric power technologies than has occurred since electricity use became widespread nearly a century ago. The potential is for an energy revolution as profound as the impact fiber optics has had on communications. The fiber optic ‘information superhighway’ was constructed by replacing copper wires with a higher capacity alternative. Superconductivity provides an ‘energy superhighway’ that greatly improves efficiency and capacity. The economic and energy impacts of superconductors are predicted to be huge. Many challenges are being addressed in order for superconductivity to play this important role in the electric power system. The difficult challenge is underway in many countries to manufacture electrical wire from the ceramic high-temperature superconducting (HTS) materials, while in parallel, super-efficient power devices that use these wires are being designed and demonstrated in field trials. The benefits can be substantial: HTS wires that are a resistance-free alternative to conventional wires while carrying 100 times the amount of electricity; oil-free electrical equipment that is environmentally benign, with half the energy losses and half the size of conventional alternatives; and addressable markets estimated to exceed US$10 billion per annum within the next two decades. The savings due to increased efficiency of HTS electric power products may exceed 36 million metric tons of CO2 in Japan, and much higher numbers in the U.S. and Europe, if generation continues to rely upon fossil fuels.

Since the early 1990s, the United States Air Force has been successfully pursuing advancement in aircraft electrical power system technologies as a means of collectively establishing the capability to dramatically reduce or eliminate centralized hydraulics aboard aircraft and replace it with electrical power as the motive force for all aircraft functions. This overall approach (called the More Electric Aircraft, MEA) has been analytically determined to provide dramatic improvements in reliability, maintainability, supportability and operations/support cost as well as enhancements in aircraft weight, volume, and battle-damage reconfigurability. Advances in switched reluctance configuration electric machines and solid state power electronics has enabled demonstration of an MEA. This paper provides: (1) a brief historical treatment of technology milestones achieved which enabled the MEA approach; (2) a status of United States Air Force and Department of Defense research and development programs in electrical power generation, distribution, energy storage, systems integration and flight testing; (3) a description of some of the Air Force's planned demonstration activities in aircraft electrical power subsystems; and (4) the dual use nature of many of these technologies to enable a variety of electric and hybrid electrically-propelled military weapon systems and commercial vehicles.

The electric power system's seasonality would mitigate the problem of the energy volatility crisis. Seasonal identification is important in energy usage analysis to make a better an organization's energy performance. Identification of the seasonal component in a time series data is essential since it defines a fluctuation within an interval of time. This seasonal component can be identified as a periodic phenomenon. Signal processing models can be used in analyzing periodic data in the representation of sinusoidal function. Seasonal variations are an important factor influencing the behavior of an electric power and energy load. This paper introduces the application of deterministic functions in the Ornstein\textendash Uhlenbeck process as a sinusoidal signal processing model in identifying seasonal components represented in periodic terms. We conducted extensive experiments to validate the model on three datasets in electric power and energy systems namely electricity load, household electric power consumption, and power consumption of the three source stations. Further, it can be obtained that the periodic continuous-time-inhomogeneous signal of Ornstein\textendash Uhlenbeck model can be used to identify the seasonal term of the very short to medium horizon forecast of the electric power and energy system. Seasonal changes in energy consumption can be used in energy management in the scope of energy efficiency connected to renewable energy plans.

An electric power system (EPS) with high-power-delivery and low-system-mass is required for wide body all electric aircraft (AEA). Cables are an essential component of this future EPS. At the cruising height of a wide-body aircraft the pressure is about 16.8 kPa. At that pressure, heat transfer to the ambient air by convection is strongly limited, so the distribution of temperature field across the aircraft cables is expected to be different from atmospheric pressure. The temperature field across the cable depends on the velocity field of the ambient air, which depends on the pressure and temperature. Also, to obtain the electric field of DC cables in the electric aircraft power system, the conductivity of the insulation, a function of temperature and electric field, should be calculated. In this paper, a 5 kV DC cable is studied at 16.8 kPa pressure to compare the cable's electric field and temperature field at low pressure to the atmospheric pressure. In our earlier research, we suggested novel EPS topologies for wide body AEA, and 5 kV DC is the voltage level that was taken into consideration. Moreover, the maximum permissible flowing current of the cable is investigated at the pressure of 16.8 kPa regarding the thermal limits of the cable. It is shown that at low pressures the temperature of the cable is highly increased compared to atmospheric pressure, so permissible current is lower than rated current.

International Conference on Hydrodynamics, Energy and Electric Power System (HEEPS) is an annually held conference, it aims to provide a forum for participants to exchange their experiences, share research results in all aspects about Hydrodynamics, Energy and Electric Power System and discuss the encountered practical challenges and the adopted solutions. The 2024 8th International Conference on Hydrodynamics, Energy and Electric Power System (HEEPS 2024) was held in Beijing, China from June 28th to 30th, 2024. This esteemed conference, as the eighth in its series, continues to serve as a premier platform for researchers, scholars, and industry professionals to converge, share insights, and collaborate on the latest advancements in hydrodynamics, water resources and hydropower engineering, energy systems, and electric power technologies. HEEPS 2024 was organized with the aim of fostering interdisciplinary dialogue and innovation within the rapidly evolving fields of fluid mechanics, energy systems, and power engineering. Building upon the success of the previous seven editions, this conference attracted a diverse and vibrant community of participants from around the world. The event was hosted with the support of esteemed institutions such as the University of Chinese Academy of Sciences and Universiti Putra Malaysia, further enhancing its international reach and impact. HEEPS 2024 was an outstanding three-day conference and a reference that attracted many remarkable keynote speakers, including: Professor Jizhong Zhu (South China University of Technology, China), Professor Ishak Bin Aris (Universiti Putra Malaysia, Malaysia), Professor Lin Chen (Chinese Academy of Sciences, China), Associate Professor Sohrab Mirsaeidi (Beijing Jiaotong University, China), as well as Assistant Professor Jianxiao Wang (Peking University, China). The program kicked off with a series of keynote lectures delivered by renowned experts in their respective fields, setting the tone for an intellectually stimulating conference. These presentations covered a broad spectrum of topics, ranging from fundamental research in hydrodynamics and fluid mechanics to the latest developments in energy systems and power grid technologies. Besides, during all parts of the conference, the attendees actively interacted with the speakers and each other on specific topics. The conference’s Proceedings of HEEPS 2024 contains the papers accepted and presented at this great conference. All these contributions were carefully reviewed by program committee members and took into consideration the breadth and depth of the research topics that fall into HEEPS scope. On behalf of the conference organizers, we would like to take this opportunity to express our sincere thanks to all the editors and reviewers for their tremendous efforts and dedication to the conference. We also wish to thank all the authors and speakers for their great contributions to this conference and the conference’s Proceedings. And we believe that with such earnest support and contributions, the future HEEPS conferences will also scale new heights. The Committee of HEEPS 2024 List of Committee Member are available in this pdf.

Coulomb screening and weak interactions in a hot, magnetized plasma are investigated. Coulomb screening is evaluated in a relativistic thermal plasma in which electrons and positrons are in equilibrium. In addition to temperature effects, effects on weak screening from a strong external magnetic field are evaluated. In high fields, the electron transverse momentum components are quantized into Landau levels. The characteristic plasma screening length at high temperatures and at high magnetic fields is explored. In addition to changes to the screening length, changes in weak interaction rates are estimated. It is found that high fields can result in increased β-decay rates as the electron and positron spectra are dominated by Landau levels. Finally, the effects studied here are evaluated in a simple r-process model. It is found that relativistic Coulomb screening has a small effect on the final abundance distribution. While changes in weak interaction rates in strong magnetic fields can have an effect on the r-process evolution and abundance distribution, the field strength required to have a significant effect may be larger than what is currently thought to be typical of the r-process environment in collapsar jets or neutron star mergers. If r-process sites exist in fields G, effects from fields on weak decays could be significant.

Hybrid power systems are a combination of electric power generation technologies configured to meet specific customer needs such as reliable electric power, low cost, or portable power. If the power generation uses renewable sources such as wind, geothermal, solar, biomass, and waste, then the result is rightly considered a renewable system-of-systems. This is because each of the power systems can operate separately, but when combined, individual subsystems and components can be shared. In addition, the combined systems provide functionality that is not possible from any one of the sources. The discipline of systems engineering offers methods and techniques that can be applied to the engineering of hybrid renewable electric power generation. In this work, we apply systems-of-systems methods developed by systems engineering to develop a hybrid renewable electric power system. We examine customer needs for a specific renewable energy source. We then develop concepts that will meet that need by exploring multiple alternatives and their combinations. The concepts are subject to trade study against the customer needs. We then show the baseline design of a system that combines Concentrated Solar Power (CSP) with waste processing such as biomass and Pyrolysis. We conclude with a summary and suggestions for other hybrid electric power systems that can benefit from systems engineering techniques.

<div class="htmlview paragraph">A lot of electric components have been installed in a vehicle today for comfort, safety and environment. This tendency is said to be continued in the future. Therefore, additional power supplies such as exhaust gas electricity generation system and thermal electricity generation system have been developed in the world to supply additional electricity as well as an enlargement of an alternator. However, if these new electricity supply systems are installed in a present electric power system that is controlled based on a voltage feedback, each supply system cannot be controlled effectively, because it is difficult to control output power of each system independently. An electric power based control system, <u><b>V</b></u>ehicle <u><b>E</b></u>lectric power <u><b>F</b></u>low management system (<b>VEF</b>), has been developed to avoid this problem.</div> <div class="htmlview paragraph">Sum of required electric power is calculated based on electric loads power and battery charging power. This required power is allocated to each power supply system. This assignment is performed according to an index, a running cost of electricity. This index is called <b>DENPI</b> (<u><b>D</b></u>esign of <u><b>E</b></u>lectric <u><b>N</b></u>etwork with <u><b>P</b></u>ower <u><b>I</b></u>ndex). For example, <b>DENPI</b> of the alternator changes according to an engine torque, a rotational speed and efficiency. Therefore, electric power system can supply electricity more effectively by selecting power system according to <b>DENP</b>. <b>VEF</b> automatically allocates each power supply system according to <b>DENPI</b> of each power supply system. As this function has a unique structure, it can be extensively applied to new electricity generation systems in various categories of vehicles.</div> <div class="htmlview paragraph"><b>VEF</b> has been evaluated with a test vehicle, and the results show that this structure is applicable to a real vehicle and the running cost of electricity is improved 30% compared to a conventional system.</div>

This report is the second in a series of Electrification Futures Study (EFS) publications, a multi-year research project to explore widespread electrification in the future energy system of the United States. The report presents scenarios of electric end-use technology adoption and resulting electricity consumption in the United States. The scenarios are used to characterize changes to end-use sectors under futures with increased electrification and to quantify how those changes might impact the amount and shape of electricity consumption. These scenarios were developed primarily using expert judgment and an energy system accounting framework. Of course, technology adoption will ultimately depend on a set of complex considerations that are not fully assessed using our methodology, but which are discussed extensively throughout the report. These interacting factors include technology and fuel cost trade-offs, infrastructure needs, environmental policies, and consumer preference. Within each of these factors are barriers that might challenge increased electrification - such as higher upfront costs or unfamiliarity with new electric technologies - but also opportunities that could yield greater adoption - such as increased productivity or expanded value streams enabled by electric and/or grid-connected technologies. Understanding and quantifying these factors are needed to both evaluate the implications of a potential increased electrification future and to influence the degree of future electrification. Overall, the report represents an initial step to inform researchers and decision-makers with data and context to plan for a potential future in which electricity powers an expanded share of the U.S. energy economy.This report is the second in a series of Electrification Futures Study (EFS) publications, a multi-year research project to explore widespread electrification in the future energy system of the United States. The report presents scenarios of electric end-use technology adoption in all major sectors - transportation, commercial and residential buildings, and industry - and resulting electricity consumption in the United States. The scenarios are used to characterize changes to end-use sectors under futures with increased electrification and to quantify how those changes might impact the amount and shape of electricity consumption. These scenarios were developed primarily using expert judgment and an energy system accounting framework. Of course, technology adoption will ultimately depend on a set of complex considerations that are not fully assessed using our methodology, but which are discussed extensively throughout the report. These interacting factors include technology and fuel cost trade-offs, infrastructure needs, environmental policies, and consumer preference. Within each of these factors are barriers that might challenge increased electrification - such as higher upfront costs or unfamiliarity with new electric technologies - but also opportunities that could yield greater adoption, such as increased productivity or expanded value streams enabled by electric and grid-connected technologies. Understanding and quantifying these factors are needed to both evaluate the implications of a potential increased electrification future and to influence the degree of future electrification. Overall, the report represents an initial step to inform researchers and decision-makers with data and context to plan for a potential future in which electricity powers an expanded share of the U.S. energy economy.

For the research on crucial technologies of range-extended electric vehicle, the first problem to be solved is parameter matching and efficiency optimization for range-extended electric vehicle power and transmission system. Parameter matching and optimization of range-extended electric vehicle power and transmission system are multi-objective optimization problem. Evaluation and analysis of multi-objective optimization problem should be mutually independent and balanced. With the aim of guaranteeing vehicle’s comprehensive performance, a parameter matching and optimization method for range-extended electric vehicle power and transmission system is proposed in this paper. First, the house of quality model of range-extended electric vehicle is established to determine weight coefficient of vehicle performance indicator based on market requirements instead of experience. Based on co-simulation control model which is established in Matlab-Simulink and AVL-Cruise, 40 groups of orthogonal tests are performed, and the sensitivity of characteristic parameters is analyzed to explore the coupling law among vehicle performance indicators, so as to clarify the entry point for parameter matching and optimization. The simulation results show that the characteristic parameters not only have a significant influence but also have a coupling effect on the vehicle performance indicators. The analysis of variance shows that there is a limitation in optimal level combination of various factors only by range. Then, particle swarm optimization algorithm is selected to optimize the parameters of range-extended electric vehicle power and transmission system based on sensitivity analysis results obtained above. The study reveals that it is more efficient and reasonable to match the range-extended electric vehicle power and transmission system with a smaller battery capacity and a “medium-sized” auxiliary power unit which can achieve adequate dynamic performance, lower purchase cost, longer driving range and less energy consumption. Finally, a comparative simulation between the range-based analysis and particle swarm optimization-based analysis is conducted, the simulation results indicate that the optimized design parameters solution can significantly improve the technical indicators of the vehicle.

This dissertation contributes to our understanding of how plug-in hybrid electric vehicles (PHEVs) and plug-in battery-only electric vehicles (EVs)—collectively termed plug-in electric vehicles (PEVs)—could be successfully integrated with the electric power system. The research addresses issues at a diverse range of levels pertaining to light-duty vehicles, which account for the majority of highway vehicle miles traveled, energy consumed by highway travel modes, and carbon dioxide emissions from on-road sources. Specifically, the following topics are investigated: (i) On-board power electronics topologies for bidirectional vehicle-to-grid and grid-to-vehicle power transfer; (ii) The estimation of the electric energy and power consumption by fleets of light-duty PEVs; (iii) An operating framework for the scheduling and dispatch of electric power by PEV aggregators; (iv) The pricing of electricity by PHEV aggregators and how it affects the decision-making process of a cost-conscious PHEV owner; (v) The impacts on distribution systems from PEVs under aggregator control; (vi) The modeling of light-duty PEVs for long-term energy and transportation planning at a national scale.

As an example of estimating the environmental impact of hydrogen energy, we have estimated the emission of CO/sub 2/ from the energy system using hydrogen. For the analyses, electric power and natural gas (city gas) systems are compared. For longer period of utilization the hydrogen system may result in the less emission, while new facility construction may be necessary. Estimation results on the energy transportation using hydrogen pipeline is also summarized, which indicates that for the longer distance the pipeline has the advantage over the electric power system from the view point of CO/sub 2/ emission and also the energy loss if adequate pipes and initial pressures are selected.

Due to the increasing penetration of gas-fired units and power to gas facilities, the electrical power system and natural gas system are more and more bi-directionally coupled. To tackle the challenges on the optimal scheduling operation of an integrated gas and power systems (IGPS), this article focuses on developing a novel approach to build a continuous spatial-temporal optimal operation schedule model. In the light of different time constants of the electrical power and natural gas systems, the continuous spatial-temporal optimal operation schedule model of IGPS is formulated in function space. Additionally, Bernstein polynomials are used to reformulate the continuous spatial-temporal optimization problem of IGPS to mixed-integer linear programming. In the study cases, the simulation results of a simple integrated system and a combined IEEE 39-bus power system and Belgian natural gas network demonstrate the accuracy and effectiveness of the proposed model.