This article aims at giving a contribution to the issue of accounting electrical energy sale and purchase agreements in accordance with the faithful representation principle. To this end, it must be ascertained whethe...This article aims at giving a contribution to the issue of accounting electrical energy sale and purchase agreements in accordance with the faithful representation principle. To this end, it must be ascertained whether electrical energy is bought/sold for an industrial use exclusively, so that the relevant transaction will be accounted as a normal purchase/sale, or through the lease of the relevant production plant, which would require the supply contract to be accounted in compliance with International Accounting Standards (IAS) 17 "Leasing". Alternatively, it must also be ascertained whether the relevant party is implementing financial trading strategies, as in such hypothesis, the supply contract is to be accounted as a financial instrument according to International Financial Reporting Standards (IFRS) 9/IAS 39 "Financial Instruments". Finally, the modalities used by a number of companies listed on European regulated markets to account such kind of contracts will be analyzed.展开更多
<span style="font-family:Verdana;">Today, energy is a vital component in the functioning of a hospital. Hospital technical facilities have several types of technologies, these include appliances for us...<span style="font-family:Verdana;">Today, energy is a vital component in the functioning of a hospital. Hospital technical facilities have several types of technologies, these include appliances for use;examination apparatus. So, for Quality Health Care in a hospital, there is</span><span style="font-family:Verdana;"> a</span><span style="font-family:Verdana;"> need to ensure the proper functioning of hospital equipment. In addition to the required maintenance as specified by the device manufacturer, </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">quality of the electrical energy across the device must be ensured. This article is an analysis of the quality of electric energy at the substation of National Hospital of Niamey. Thereby, the data collection, followed by the data processing and analysis revealed the parameters characterizing the quality of electrical energy across the substation. Our studies have shown that the substation is underutilized as the maximum inrush current is less than half the available current. </span><span style="font-family:Verdana;">The </span><span style="font-family:Verdana;">current </span><span style="font-family:Verdana;">was </span><span style="font-family:Verdana;">consumed by the three phases ha</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> resulted </span><span style="font-family:Verdana;">in</span><span style="font-family:Verdana;"> a strong current unbalance (230</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">A). However, the current unbalance and the voltage amplitude</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> are admissible according</span><span style="font-family:Verdana;">ly</span><span style="font-family:Verdana;"> base on EN50160 standard. Furthermore, the harmonics voltages present in this medium </span><span style="font-family:Verdana;">are</span><span style="font-family:Verdana;"> in the accepted range (1.8%) according to IEEE 519 standard. However, the fundamental frequency does not meet the standard, but the difference obtained has no adverse effect.</span>展开更多
The urgent need for sustainable energy choices, local sustainable value creation, and reduction of import dependencies and non-sustainable resource use in Namibia cannot be over emphasised. This study was conducted wi...The urgent need for sustainable energy choices, local sustainable value creation, and reduction of import dependencies and non-sustainable resource use in Namibia cannot be over emphasised. This study was conducted with the ultimate goal to provide the basis for accurate energy fuel mix and climate change monitoring, and reporting and planning for addressing a global problem at local/domestic level. The energy consumption and production data for the country were used with International Panel on Climate Change (IPCC) and International Energy Agency (IEA) conversions, and carbon footprint calculation tools to determine the GHG emissions and air pollutants per type of energy fuel;and the carbon footprint associated with each energy fuel option for the country. The study showed that: 1) there is no single energy fuel which is not associated with GHG emissions and/or other environmental implications;2) increase in population and energy consumption and production yields increase in GHGs and other major pollutants (SO<sub>x</sub>, NO<sub>x</sub>, Particulate Matter);and 3) the choice of fuel mix determines the success of GHG emissions reduction. A future energy mix dominated by renewable energy technologies;and a balanced view of the actual benefits of the Namibian energy supply choices was also recommended.展开更多
At present,the increasing consumption of electrical energy is accompanied by the increasing pressure on natural environment,excessive discharge of waste gas,and accelerated rate of global warming.Photovoltaic new ener...At present,the increasing consumption of electrical energy is accompanied by the increasing pressure on natural environment,excessive discharge of waste gas,and accelerated rate of global warming.Photovoltaic new energy plays an important role in reducing costs and improving resource utilization.The leading power industries should come up with new designs of equipment that is in line with the green concept,improve the utilization of photovoltaic energy,and realize sustainable economic development.In view of this,this paper mainly analyzes the application of photovoltaic new energy in electrical energy conservation.展开更多
Cyber-physical electrical energy systems(CPEES)combine computation,communication and control technologies with physical power system,and realize the efficient fusion of power,information and control.This paper summari...Cyber-physical electrical energy systems(CPEES)combine computation,communication and control technologies with physical power system,and realize the efficient fusion of power,information and control.This paper summarizes and analyzes related critical scientific problems and technologies,which are needed to be addressed with the development of CPEES.Firstly,since the co-simulation is an effective method to investigate infrastructure interdependencies,the co-simulation platform establishment of CPEES and its evaluation is overviewed.Then,a critical problem of CPEES is the interaction between energy and information flow,especially the influence of failures happening in information communication technology(ICT)on power system.In order to figure it out,the interaction is analyzed and the current analysis methods are summarized.For the solution of power system control and protection in information network environment,this paper outlines different control principles and illustrates the concept of distributed coordination control.Moreover,mass data processing and cluster analysis,architecture of communication network,information transmission technology and security of CPEES are summarized and analyzed.By solving the above problems and technologies,the development of CPEES will be significantly promoted.展开更多
Relaxor ferroelectric polymers display great potential in capacitor dielectric applications because of their excellent flexibility,light weight,and high dielectric constant.However,their electrical energy storage capa...Relaxor ferroelectric polymers display great potential in capacitor dielectric applications because of their excellent flexibility,light weight,and high dielectric constant.However,their electrical energy storage capacity is limited by their high conduction losses and low dielectric strength,which primarily originates from the impact-ionization-induced electron multiplication,low mechanical modulus,and low thermal conductivity of the dielectric polymers.Here a matrix free strategy is developed to effectively suppress electron multiplication effects and to enhance mechanical modulus and thermal conductivity of a dielectric polymer,which involves the chemical adsorption of an electron barrier layer on boron nitride nanosheet surfaces by chemically adsorbing an amino-containing polymer.A dramatic decrease of leakage current(from 2.4×10^(-6)to 1.1×10^(-7)A cm^(-2)at 100 MV m^(-1))and a substantial increase of breakdown strength(from 340 to 742 MV m^(-1))were achieved in the nanocompostes,which result in a remarkable increase of discharge energy density(from 5.2 to 31.8 J cm^(-3)).Moreover,the dielectric strength of the nanocomposites suffering an electrical breakdown could be restored to 88%of the original value.This study demonstrates a rational design for fabricating dielectric polymer nanocomposites with greatly enhanced electric energy storage capacity.展开更多
Hydrogen as an energy carrier represents one of the most promising carbon-free energy solutions.The ongoing development of power-to-gas(Pt G)technologies that supports large-scale utilization of hydrogen is therefore ...Hydrogen as an energy carrier represents one of the most promising carbon-free energy solutions.The ongoing development of power-to-gas(Pt G)technologies that supports large-scale utilization of hydrogen is therefore expected to support hydrogen economy with a final breakthrough.In this paper,the economic performance of a MW-sized hydrogen system,i.e.a composition of water electrolysis,hydrogen storage,and fuel cell combined heat and power plant(FCCHP),is assessed as an example of hydrogen-based bidirectional electrical energy storage(EES).The analysis is conducted in view of the Danish electricity spot market that has high price volatility due to its high share of wind power.An economic dispatch model is developed as a mixed-integer programming(MIP)problem to support the estimation of variable cost of such a system taking into account a good granularity of the technical details.Based on a projected technology improvement by 2020,sensitivity analysis is conducted to illustrate how much the hydrogen-based EES is sensitive to variations of the hydrogen price and the capacity of hydrogen storage.展开更多
The economics,infrastructure,transportation,and level of living of a country are all influenced by energy.The gap between energy usage and availabil-ity is a global issue.Currently,all countries rely on fossil fuels fo...The economics,infrastructure,transportation,and level of living of a country are all influenced by energy.The gap between energy usage and availabil-ity is a global issue.Currently,all countries rely on fossil fuels for energy genera-tion,and these fossil fuels are not sustainable.The hydrogen proton exchange membrane fuel cell(PEMFC)power system is both clean and efficient.The fuel delivery system and the PEMFC make up the majority of the PEMFC power sys-tem.The lack of an efficient,safe,and cost-effective hydrogen storage system is still a major barrier to its widespread use.Solid hydrogen storage has the large capacity,safety and good reversibility.As a hydrogen source system,the hydro-gen supply characteristics affect the characteristics of the PEMFC at the output.In this paper,a mathematical model of a hydrogen source reactor and PEMFC based on chemical absorption/desorption of solid hydrogen storage is established,and a simulation model of a PEMFC power system coupled with solid hydrogen storage is established using MATLAB/SIMULINK software,and the hydrogen supply of the reactor is analyzed in detail.The influence of prominent factors is evaluated.The research results show that the proposed method improved the system perfor-mance.At the same time,increasing the PEMFC temperature,increasing the area of the proton exchange membrane and the oxygen supply pressure can increase the output power of the power system.展开更多
The energy bandgap is an intrinsic character of semiconductors, which largely determines their properties. The ability to continuously and reversibly tune the bandgap of a single device during real time operation is o...The energy bandgap is an intrinsic character of semiconductors, which largely determines their properties. The ability to continuously and reversibly tune the bandgap of a single device during real time operation is of great importance not only to device physics but also to technological applications. Here we demonstrate a widely tunable bandgap of few-layer black phosphorus (BP) by the application of vertical electric field in dual-gated BP field-effect transistors. A total bandgap reduction of 124 meV is observed when the electrical displacement field is increased from 0.10 V/nm to 0.83 V/nm. Our results suggest appealing potential for few-layer BP as a tunable bandgap material in infrared optoelectronies, thermoelectric power generation and thermal imaging.展开更多
The on-site inspection of high-power DC chargers results in new DC high-current measurement and DC energy traceability system requirements.This paper studies the traceability technology of electric energy value for au...The on-site inspection of high-power DC chargers results in new DC high-current measurement and DC energy traceability system requirements.This paper studies the traceability technology of electric energy value for automotive high-power DC chargers,including:(1)the traceability method of the built-in DC energy meter and shunt of the charger;(2)precision DC high current and small precision DC voltage output and measurement technology.This paper designs a 0.1 mA∼600 A DC high current measurement system and proposes a 0.005 level DC powermeasurement traceability system.The uncertainty evaluation experiment of theDC powermeasurement calibration system and the high-power DC charger’s on-site calibration experiment results verify the method’s effectiveness and feasibility in this paper.The experimental results show that the combined standard uncertainty of the DC power metering verification system can be 0.0451%.展开更多
The high consumption of electricity and issues related to fossil energy have triggered an increase in energy prices and the scarcity of fossil resources.Consequently,many researchers are seeking alternative energy sou...The high consumption of electricity and issues related to fossil energy have triggered an increase in energy prices and the scarcity of fossil resources.Consequently,many researchers are seeking alternative energy sources.One potential technology,the Microbial Fuel Cell(MFC)based on rice,vegetable,and fruit wastes,can convert chemical energy into electrical energy.This study aims to determine the potency of rice,vegetable,and fruit waste assisted by Cu/Mg electrodes as a generator of electricity.The method used was a laboratory experiment,including the following steps:electrode preparation,waste sample preparation,incubation of the waste samples,construction of a reactor using rice,vegetable,and fruit waste as a source of electricity,and testing.The tests included measuring electrical conductivity,electric current,voltage,current density,and power density.Based on the test results,the maximum current and voltage values for the fruit waste samples were 5.53 V and 11.5 mA,respectively,with a current density of 2.300 mA/cm^(2) and a power density of 12.719 mW/cm^(2).The results indicate the potential for a future development.The next step in development involves determining the optimum conditions for utilizing of rice,vegetable,and fruit waste.The results of the electrical conductivity test on rice,vegetable,and fruit waste samples were 1.51,2.88,and 3.98 mS,respectively,with the highest electrical conductivity value found in the fruit waste sample.展开更多
The presented circular current loop model reveals that charged fundamental particles such as the electron consist essentially of electric and magnetic energy. The magnetic properties have the same order of magnitude a...The presented circular current loop model reveals that charged fundamental particles such as the electron consist essentially of electric and magnetic energy. The magnetic properties have the same order of magnitude as the electric ones. The electromagnetic field energy is the origin of the inertial mass. The Higgs boson, existing or not, is not needed to “explain” particle mass. The magnetic moment of fundamental particles is not anomalous! The “anomaly” indicates the existence of a small additional amount of kinetic energy. Thus, fundamental particles are not purely field-like such as photons and not (essentially) mass-like such as atoms, they represent a special kind of matter in between. Their kinetic energy is obviously not due to any relativistic effect but is related to an independent physical law that provides, together with the magnetic energy, the angular momentum exactly to be ħ/2. Fundamental particles are (at least) two-dimensional. In the simplest case their core consists of two concentric, nearly identical current loops. Their relative design details, the “anomaly” factor, and the rotational velocity of the uniformly distributed elementary charge follow from the stability condition, i.e. electric and magnetic force balance, and do not depend on the particle’s rest mass! Fundamental particles are objects of classical physics. Their magnetic forces are the true origin of the weak and strong nuclear interactions. For their explanation bosons and gluons are not needed.展开更多
A good quality Environmental Impact Statement (EIS) is key for the effectiveness of Environmental Impact Assessment (EIA) processes and consequently to the acceptability of projects subject to EIA. The international l...A good quality Environmental Impact Statement (EIS) is key for the effectiveness of Environmental Impact Assessment (EIA) processes and consequently to the acceptability of projects subject to EIA. The international literature has contributed to the understanding of the essential aspects to be verified regarding the quality of EIS, offering a wide spectrum of good practice examples related to the content of the studies. Even so, there is a need for empirical studies that allow the identification of specific aspects related to the context of application of the EIS, which could lead to the identification of opportunities to improve both the quality of the reports and also the effectiveness of EIA. Therefore, the present paper is focused on the quality review of a number of EIS submitted to the Brazilian Federal Environmental Agency (Ibama) to instruct the assessment of electric power transmission systems. Based on the application of the EIS quality review package as proposed by Lee and Colley (1992), the outcomes reveal opportunities for improving the scope of EIA, analysis of alternatives, prediction of magnitude and the assessment of impact significance. Finally, the development and/or adaptation of a similar tool for the systematic review of the quality of EIA reports is recommended.展开更多
This paper introduces several alternative statistical approaches to modeling and prediction of electric energy generated by photovoltaic farms. The statistical models use outputs of a numerical weather prediction mode...This paper introduces several alternative statistical approaches to modeling and prediction of electric energy generated by photovoltaic farms. The statistical models use outputs of a numerical weather prediction model as their inputs. Presented statistical models allow for easy-to-compute predictions, both in temporal sense and for out-of-sample individual farms. Model performance is illustrated on a sample of real photovoltaic farms located in the Czech Republic.展开更多
The work presents a demand side response(DSR) model,which assists electricity consumers to proactively mitigate peak demand on electrical networks in Eastern and Southern Australia. A low-cost technical arrangement,...The work presents a demand side response(DSR) model,which assists electricity consumers to proactively mitigate peak demand on electrical networks in Eastern and Southern Australia. A low-cost technical arrangement,which is made of Internet relay,a router,solid state switches,and the suitable software,is used to control electricity demand at user's premises. The model allows shifting loads from peak to off-peak periods in order to reduce peaks,which helps to moderate the national electrical demand. The model can be concurrently used to accommodate the utilization of renewable energy sources and the introduction of electric vehicles. The results present possible savings on the electrical energy consumption in the designated regions.展开更多
Over all fuel condition and the money we spend on the said fuel leads us to think about savings. What can we do? As individuals, we can educate our students and their family members. The easiest way to do that is to ...Over all fuel condition and the money we spend on the said fuel leads us to think about savings. What can we do? As individuals, we can educate our students and their family members. The easiest way to do that is to monitor their weekly spending for them. Together with their family members, the students have to monitor the consumption of electrical energy through three weeks. In the first week, they should spend electricity as they do everyday. During the second week they have the increase of spending of electrical energy. The third week is the saving energy week. They have to make a plan with their family members on how to save energy, for example, turning offthe lights in the empty rooms, turning offthe TV when there is no one watching it, etc.. Every week they have to note the data in kilowatts. When they acquire all the information and transform it into money they can see if it's worth saving electrical energy or not. They will see they don't have to give up the comforts of the modern life. The value of the project is in the fact that many households continue with the electrical energy saving. In fact, the number of the households is increasing.展开更多
In the new competitive environment of the electricity market, risk analysis is a powerful tool to guide investors under both contract uncertainties and energy prices of the spot market. Moreover, simulation of spot pr...In the new competitive environment of the electricity market, risk analysis is a powerful tool to guide investors under both contract uncertainties and energy prices of the spot market. Moreover, simulation of spot price scenarios and evaluation of energy contracts performance, are also necessary to the decision maker, and in particular to the trader to foresee opportunities and possible threats in the trading activity. In this context, computational systems that allow what-if analysis, involving simulation of spot price, contract portfolio optimization and risk evaluation are rather important. This paper proposes a decision support system not only for solving the problem of contracts portfolio optimization, by using linear programming, but also to execute risks analysis of the contracts portfolio performance, with VaR and CVaR metrics. Realistic tests have demonstrated the efficiency of this system.展开更多
With the increasing demand for petroleum resources and environmental issues,new energy electric vehicles are increasingly being used.However,the large number of electric vehicles connected to the grid has brought new ...With the increasing demand for petroleum resources and environmental issues,new energy electric vehicles are increasingly being used.However,the large number of electric vehicles connected to the grid has brought new challenges to the operation of the grid.Firstly,A novel bidirectional interaction model is established based on modulation theory with nonlinear loads.Then,the electric energy measuring scheme of EVs for V2G is derived under the conditions of distorted power loads.The scheme is composed of fundamental electric energy,fundamental-distorted electric energy,distorted-fundamental electric energy and distorted electric energy.And the characteristics of each electric energy are analyzed.Finally,the correctness of the model and energy measurement method is verified by three simulation cases:the impact signals,the fluctuating signals,and the harmonic signals.展开更多
A novel parallel hybrid electrical urban bus (PHEUB) configuration consisting of an extra one-way clutch and an automatic mechanical transmission (AMT) is taken as the study subject. An energy management strategy ...A novel parallel hybrid electrical urban bus (PHEUB) configuration consisting of an extra one-way clutch and an automatic mechanical transmission (AMT) is taken as the study subject. An energy management strategy combining a logic threshold approach and an instantaneous optimization algorithm is proposed for the investigated PHEUB. The objective of the energy management strategy is to achieve acceptable vehicle performance and drivability requirements while simultaneously maximizing the engine fuel consumption and maintaining the battery state of charge in its operation range at all times. Under the environment of Matlab/Simulink, a computer simulation model for the PHEUB is constructed by using the model building method combining theoretical analysis and bench test data. Simulation and experiment results for China Typical Bus Driving Schedule at Urban District (CTBDS_UD) are obtained, and the results indicate that the proposed control strategy not only controls the hybrid system efficiently but also improves the fuel economy significantly.展开更多
The geometric structures of an Nit radical in different external electric fields are optimized by using the density functional B3P86/cc-PVSZ method, and the bond lengths, dipole moments, vibration frequencies and IR s...The geometric structures of an Nit radical in different external electric fields are optimized by using the density functional B3P86/cc-PVSZ method, and the bond lengths, dipole moments, vibration frequencies and IR spectrum are obtained. The potential energy curves are gained by the CCSD (T) method with the same basis set. These results indicate that the physical property parameters and potential energy curves may change with the external electric field, especially in the reverse direction electric field. The potential energy function of zero field is fitted by the Morse potential, and the fitting parameters are in good accordance with the experimental data. The potential energy functions of different external electric fields are fitted adopting the constructed potential model. The fitted critical dissociation electric parameters are shown to be consistent with the numerical calculation, and the relative errors are only 0.27% and 6.61%, hence the constructed model is reliable and accurate. The present results provide an important reference for further study of the molecular spectrum, dynamics and molecular cooling with Stark effect.展开更多
文摘This article aims at giving a contribution to the issue of accounting electrical energy sale and purchase agreements in accordance with the faithful representation principle. To this end, it must be ascertained whether electrical energy is bought/sold for an industrial use exclusively, so that the relevant transaction will be accounted as a normal purchase/sale, or through the lease of the relevant production plant, which would require the supply contract to be accounted in compliance with International Accounting Standards (IAS) 17 "Leasing". Alternatively, it must also be ascertained whether the relevant party is implementing financial trading strategies, as in such hypothesis, the supply contract is to be accounted as a financial instrument according to International Financial Reporting Standards (IFRS) 9/IAS 39 "Financial Instruments". Finally, the modalities used by a number of companies listed on European regulated markets to account such kind of contracts will be analyzed.
文摘<span style="font-family:Verdana;">Today, energy is a vital component in the functioning of a hospital. Hospital technical facilities have several types of technologies, these include appliances for use;examination apparatus. So, for Quality Health Care in a hospital, there is</span><span style="font-family:Verdana;"> a</span><span style="font-family:Verdana;"> need to ensure the proper functioning of hospital equipment. In addition to the required maintenance as specified by the device manufacturer, </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">quality of the electrical energy across the device must be ensured. This article is an analysis of the quality of electric energy at the substation of National Hospital of Niamey. Thereby, the data collection, followed by the data processing and analysis revealed the parameters characterizing the quality of electrical energy across the substation. Our studies have shown that the substation is underutilized as the maximum inrush current is less than half the available current. </span><span style="font-family:Verdana;">The </span><span style="font-family:Verdana;">current </span><span style="font-family:Verdana;">was </span><span style="font-family:Verdana;">consumed by the three phases ha</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> resulted </span><span style="font-family:Verdana;">in</span><span style="font-family:Verdana;"> a strong current unbalance (230</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">A). However, the current unbalance and the voltage amplitude</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> are admissible according</span><span style="font-family:Verdana;">ly</span><span style="font-family:Verdana;"> base on EN50160 standard. Furthermore, the harmonics voltages present in this medium </span><span style="font-family:Verdana;">are</span><span style="font-family:Verdana;"> in the accepted range (1.8%) according to IEEE 519 standard. However, the fundamental frequency does not meet the standard, but the difference obtained has no adverse effect.</span>
文摘The urgent need for sustainable energy choices, local sustainable value creation, and reduction of import dependencies and non-sustainable resource use in Namibia cannot be over emphasised. This study was conducted with the ultimate goal to provide the basis for accurate energy fuel mix and climate change monitoring, and reporting and planning for addressing a global problem at local/domestic level. The energy consumption and production data for the country were used with International Panel on Climate Change (IPCC) and International Energy Agency (IEA) conversions, and carbon footprint calculation tools to determine the GHG emissions and air pollutants per type of energy fuel;and the carbon footprint associated with each energy fuel option for the country. The study showed that: 1) there is no single energy fuel which is not associated with GHG emissions and/or other environmental implications;2) increase in population and energy consumption and production yields increase in GHGs and other major pollutants (SO<sub>x</sub>, NO<sub>x</sub>, Particulate Matter);and 3) the choice of fuel mix determines the success of GHG emissions reduction. A future energy mix dominated by renewable energy technologies;and a balanced view of the actual benefits of the Namibian energy supply choices was also recommended.
文摘At present,the increasing consumption of electrical energy is accompanied by the increasing pressure on natural environment,excessive discharge of waste gas,and accelerated rate of global warming.Photovoltaic new energy plays an important role in reducing costs and improving resource utilization.The leading power industries should come up with new designs of equipment that is in line with the green concept,improve the utilization of photovoltaic energy,and realize sustainable economic development.In view of this,this paper mainly analyzes the application of photovoltaic new energy in electrical energy conservation.
基金supported by the national Natural Science Foundation of China(NSFC)under Grant 61233008 and 51377001by the International Science and Technology Cooperation Program of China under Grant 2015DFA70580by the State Grid Science and Technology Project of China under Grant 5216A213509X.
文摘Cyber-physical electrical energy systems(CPEES)combine computation,communication and control technologies with physical power system,and realize the efficient fusion of power,information and control.This paper summarizes and analyzes related critical scientific problems and technologies,which are needed to be addressed with the development of CPEES.Firstly,since the co-simulation is an effective method to investigate infrastructure interdependencies,the co-simulation platform establishment of CPEES and its evaluation is overviewed.Then,a critical problem of CPEES is the interaction between energy and information flow,especially the influence of failures happening in information communication technology(ICT)on power system.In order to figure it out,the interaction is analyzed and the current analysis methods are summarized.For the solution of power system control and protection in information network environment,this paper outlines different control principles and illustrates the concept of distributed coordination control.Moreover,mass data processing and cluster analysis,architecture of communication network,information transmission technology and security of CPEES are summarized and analyzed.By solving the above problems and technologies,the development of CPEES will be significantly promoted.
基金supported by the National Natural Science Foundation of China(52003153,51877132 and 52002300)Program of Shanghai Academic Research Leader(21XD1401600)+1 种基金State Key Laboratory of Electrical Insulation and Power Equipment(EIPE20203,EIPE21206)the Major Research Plan of National Natural Science Foundation of China(92066103)。
文摘Relaxor ferroelectric polymers display great potential in capacitor dielectric applications because of their excellent flexibility,light weight,and high dielectric constant.However,their electrical energy storage capacity is limited by their high conduction losses and low dielectric strength,which primarily originates from the impact-ionization-induced electron multiplication,low mechanical modulus,and low thermal conductivity of the dielectric polymers.Here a matrix free strategy is developed to effectively suppress electron multiplication effects and to enhance mechanical modulus and thermal conductivity of a dielectric polymer,which involves the chemical adsorption of an electron barrier layer on boron nitride nanosheet surfaces by chemically adsorbing an amino-containing polymer.A dramatic decrease of leakage current(from 2.4×10^(-6)to 1.1×10^(-7)A cm^(-2)at 100 MV m^(-1))and a substantial increase of breakdown strength(from 340 to 742 MV m^(-1))were achieved in the nanocompostes,which result in a remarkable increase of discharge energy density(from 5.2 to 31.8 J cm^(-3)).Moreover,the dielectric strength of the nanocomposites suffering an electrical breakdown could be restored to 88%of the original value.This study demonstrates a rational design for fabricating dielectric polymer nanocomposites with greatly enhanced electric energy storage capacity.
基金the financial support of Innovation Fund Denmark through Project 3045-00012B
文摘Hydrogen as an energy carrier represents one of the most promising carbon-free energy solutions.The ongoing development of power-to-gas(Pt G)technologies that supports large-scale utilization of hydrogen is therefore expected to support hydrogen economy with a final breakthrough.In this paper,the economic performance of a MW-sized hydrogen system,i.e.a composition of water electrolysis,hydrogen storage,and fuel cell combined heat and power plant(FCCHP),is assessed as an example of hydrogen-based bidirectional electrical energy storage(EES).The analysis is conducted in view of the Danish electricity spot market that has high price volatility due to its high share of wind power.An economic dispatch model is developed as a mixed-integer programming(MIP)problem to support the estimation of variable cost of such a system taking into account a good granularity of the technical details.Based on a projected technology improvement by 2020,sensitivity analysis is conducted to illustrate how much the hydrogen-based EES is sensitive to variations of the hydrogen price and the capacity of hydrogen storage.
基金funded by King Abdulaziz University,Jedda Saudi Arabia and King Abdulah City for Atomic and Renewable Energy,Riyadh,Saudi Arabia Grant No.(KCR-KFL-13-20)thereforethe authors gratefully acknowledge their technical and financial support.
文摘The economics,infrastructure,transportation,and level of living of a country are all influenced by energy.The gap between energy usage and availabil-ity is a global issue.Currently,all countries rely on fossil fuels for energy genera-tion,and these fossil fuels are not sustainable.The hydrogen proton exchange membrane fuel cell(PEMFC)power system is both clean and efficient.The fuel delivery system and the PEMFC make up the majority of the PEMFC power sys-tem.The lack of an efficient,safe,and cost-effective hydrogen storage system is still a major barrier to its widespread use.Solid hydrogen storage has the large capacity,safety and good reversibility.As a hydrogen source system,the hydro-gen supply characteristics affect the characteristics of the PEMFC at the output.In this paper,a mathematical model of a hydrogen source reactor and PEMFC based on chemical absorption/desorption of solid hydrogen storage is established,and a simulation model of a PEMFC power system coupled with solid hydrogen storage is established using MATLAB/SIMULINK software,and the hydrogen supply of the reactor is analyzed in detail.The influence of prominent factors is evaluated.The research results show that the proposed method improved the system perfor-mance.At the same time,increasing the PEMFC temperature,increasing the area of the proton exchange membrane and the oxygen supply pressure can increase the output power of the power system.
基金Supported by the National Basic Research Program of China under Grant Nos 2013CB921900 and 2014CB920900the National Natural Science Foundation of China under Grant No 11374021)(S.Yan,Z.Xie,J.-H,Chen)+1 种基金support from the Elemental Strategy Initiative conducted by the MEXT,Japana Grant-in-Aid for Scientific Research on Innovative Areas"Science of Atomic Layers"from JSPS
文摘The energy bandgap is an intrinsic character of semiconductors, which largely determines their properties. The ability to continuously and reversibly tune the bandgap of a single device during real time operation is of great importance not only to device physics but also to technological applications. Here we demonstrate a widely tunable bandgap of few-layer black phosphorus (BP) by the application of vertical electric field in dual-gated BP field-effect transistors. A total bandgap reduction of 124 meV is observed when the electrical displacement field is increased from 0.10 V/nm to 0.83 V/nm. Our results suggest appealing potential for few-layer BP as a tunable bandgap material in infrared optoelectronies, thermoelectric power generation and thermal imaging.
文摘The on-site inspection of high-power DC chargers results in new DC high-current measurement and DC energy traceability system requirements.This paper studies the traceability technology of electric energy value for automotive high-power DC chargers,including:(1)the traceability method of the built-in DC energy meter and shunt of the charger;(2)precision DC high current and small precision DC voltage output and measurement technology.This paper designs a 0.1 mA∼600 A DC high current measurement system and proposes a 0.005 level DC powermeasurement traceability system.The uncertainty evaluation experiment of theDC powermeasurement calibration system and the high-power DC charger’s on-site calibration experiment results verify the method’s effectiveness and feasibility in this paper.The experimental results show that the combined standard uncertainty of the DC power metering verification system can be 0.0451%.
文摘The high consumption of electricity and issues related to fossil energy have triggered an increase in energy prices and the scarcity of fossil resources.Consequently,many researchers are seeking alternative energy sources.One potential technology,the Microbial Fuel Cell(MFC)based on rice,vegetable,and fruit wastes,can convert chemical energy into electrical energy.This study aims to determine the potency of rice,vegetable,and fruit waste assisted by Cu/Mg electrodes as a generator of electricity.The method used was a laboratory experiment,including the following steps:electrode preparation,waste sample preparation,incubation of the waste samples,construction of a reactor using rice,vegetable,and fruit waste as a source of electricity,and testing.The tests included measuring electrical conductivity,electric current,voltage,current density,and power density.Based on the test results,the maximum current and voltage values for the fruit waste samples were 5.53 V and 11.5 mA,respectively,with a current density of 2.300 mA/cm^(2) and a power density of 12.719 mW/cm^(2).The results indicate the potential for a future development.The next step in development involves determining the optimum conditions for utilizing of rice,vegetable,and fruit waste.The results of the electrical conductivity test on rice,vegetable,and fruit waste samples were 1.51,2.88,and 3.98 mS,respectively,with the highest electrical conductivity value found in the fruit waste sample.
文摘The presented circular current loop model reveals that charged fundamental particles such as the electron consist essentially of electric and magnetic energy. The magnetic properties have the same order of magnitude as the electric ones. The electromagnetic field energy is the origin of the inertial mass. The Higgs boson, existing or not, is not needed to “explain” particle mass. The magnetic moment of fundamental particles is not anomalous! The “anomaly” indicates the existence of a small additional amount of kinetic energy. Thus, fundamental particles are not purely field-like such as photons and not (essentially) mass-like such as atoms, they represent a special kind of matter in between. Their kinetic energy is obviously not due to any relativistic effect but is related to an independent physical law that provides, together with the magnetic energy, the angular momentum exactly to be ħ/2. Fundamental particles are (at least) two-dimensional. In the simplest case their core consists of two concentric, nearly identical current loops. Their relative design details, the “anomaly” factor, and the rotational velocity of the uniformly distributed elementary charge follow from the stability condition, i.e. electric and magnetic force balance, and do not depend on the particle’s rest mass! Fundamental particles are objects of classical physics. Their magnetic forces are the true origin of the weak and strong nuclear interactions. For their explanation bosons and gluons are not needed.
文摘A good quality Environmental Impact Statement (EIS) is key for the effectiveness of Environmental Impact Assessment (EIA) processes and consequently to the acceptability of projects subject to EIA. The international literature has contributed to the understanding of the essential aspects to be verified regarding the quality of EIS, offering a wide spectrum of good practice examples related to the content of the studies. Even so, there is a need for empirical studies that allow the identification of specific aspects related to the context of application of the EIS, which could lead to the identification of opportunities to improve both the quality of the reports and also the effectiveness of EIA. Therefore, the present paper is focused on the quality review of a number of EIS submitted to the Brazilian Federal Environmental Agency (Ibama) to instruct the assessment of electric power transmission systems. Based on the application of the EIS quality review package as proposed by Lee and Colley (1992), the outcomes reveal opportunities for improving the scope of EIA, analysis of alternatives, prediction of magnitude and the assessment of impact significance. Finally, the development and/or adaptation of a similar tool for the systematic review of the quality of EIA reports is recommended.
文摘This paper introduces several alternative statistical approaches to modeling and prediction of electric energy generated by photovoltaic farms. The statistical models use outputs of a numerical weather prediction model as their inputs. Presented statistical models allow for easy-to-compute predictions, both in temporal sense and for out-of-sample individual farms. Model performance is illustrated on a sample of real photovoltaic farms located in the Czech Republic.
基金supported by Directorate General of Higher Education Department of National Education, the Indonesian Government and the State Polytechnic of Ujung Pandang, Makassar, Indonesia, and the Australia Power Institute (API)
文摘The work presents a demand side response(DSR) model,which assists electricity consumers to proactively mitigate peak demand on electrical networks in Eastern and Southern Australia. A low-cost technical arrangement,which is made of Internet relay,a router,solid state switches,and the suitable software,is used to control electricity demand at user's premises. The model allows shifting loads from peak to off-peak periods in order to reduce peaks,which helps to moderate the national electrical demand. The model can be concurrently used to accommodate the utilization of renewable energy sources and the introduction of electric vehicles. The results present possible savings on the electrical energy consumption in the designated regions.
文摘Over all fuel condition and the money we spend on the said fuel leads us to think about savings. What can we do? As individuals, we can educate our students and their family members. The easiest way to do that is to monitor their weekly spending for them. Together with their family members, the students have to monitor the consumption of electrical energy through three weeks. In the first week, they should spend electricity as they do everyday. During the second week they have the increase of spending of electrical energy. The third week is the saving energy week. They have to make a plan with their family members on how to save energy, for example, turning offthe lights in the empty rooms, turning offthe TV when there is no one watching it, etc.. Every week they have to note the data in kilowatts. When they acquire all the information and transform it into money they can see if it's worth saving electrical energy or not. They will see they don't have to give up the comforts of the modern life. The value of the project is in the fact that many households continue with the electrical energy saving. In fact, the number of the households is increasing.
文摘In the new competitive environment of the electricity market, risk analysis is a powerful tool to guide investors under both contract uncertainties and energy prices of the spot market. Moreover, simulation of spot price scenarios and evaluation of energy contracts performance, are also necessary to the decision maker, and in particular to the trader to foresee opportunities and possible threats in the trading activity. In this context, computational systems that allow what-if analysis, involving simulation of spot price, contract portfolio optimization and risk evaluation are rather important. This paper proposes a decision support system not only for solving the problem of contracts portfolio optimization, by using linear programming, but also to execute risks analysis of the contracts portfolio performance, with VaR and CVaR metrics. Realistic tests have demonstrated the efficiency of this system.
基金This work is supported by China Postdoctoral Science Foundation(2021M690798)Guizhou Province Science and Technology Plan Project(No.[2021]General 085)+1 种基金National Natural Science Foundation of China(No.61603034)the Fundamental Research Funds for the Central Universities(Nos.FRF-BD-19-002A,FRF-DF-20-14).
文摘With the increasing demand for petroleum resources and environmental issues,new energy electric vehicles are increasingly being used.However,the large number of electric vehicles connected to the grid has brought new challenges to the operation of the grid.Firstly,A novel bidirectional interaction model is established based on modulation theory with nonlinear loads.Then,the electric energy measuring scheme of EVs for V2G is derived under the conditions of distorted power loads.The scheme is composed of fundamental electric energy,fundamental-distorted electric energy,distorted-fundamental electric energy and distorted electric energy.And the characteristics of each electric energy are analyzed.Finally,the correctness of the model and energy measurement method is verified by three simulation cases:the impact signals,the fluctuating signals,and the harmonic signals.
基金Shanghai Municipal Science and Technology Commission, China (No. 033012017).
文摘A novel parallel hybrid electrical urban bus (PHEUB) configuration consisting of an extra one-way clutch and an automatic mechanical transmission (AMT) is taken as the study subject. An energy management strategy combining a logic threshold approach and an instantaneous optimization algorithm is proposed for the investigated PHEUB. The objective of the energy management strategy is to achieve acceptable vehicle performance and drivability requirements while simultaneously maximizing the engine fuel consumption and maintaining the battery state of charge in its operation range at all times. Under the environment of Matlab/Simulink, a computer simulation model for the PHEUB is constructed by using the model building method combining theoretical analysis and bench test data. Simulation and experiment results for China Typical Bus Driving Schedule at Urban District (CTBDS_UD) are obtained, and the results indicate that the proposed control strategy not only controls the hybrid system efficiently but also improves the fuel economy significantly.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11147158 and 11264020the Jiangxi Province Natural Science Foundation under Grant No 2010GQW0031the Jiangxi Province Scientific Research Program of the Education Bureau under Grant No GJJ12483
文摘The geometric structures of an Nit radical in different external electric fields are optimized by using the density functional B3P86/cc-PVSZ method, and the bond lengths, dipole moments, vibration frequencies and IR spectrum are obtained. The potential energy curves are gained by the CCSD (T) method with the same basis set. These results indicate that the physical property parameters and potential energy curves may change with the external electric field, especially in the reverse direction electric field. The potential energy function of zero field is fitted by the Morse potential, and the fitting parameters are in good accordance with the experimental data. The potential energy functions of different external electric fields are fitted adopting the constructed potential model. The fitted critical dissociation electric parameters are shown to be consistent with the numerical calculation, and the relative errors are only 0.27% and 6.61%, hence the constructed model is reliable and accurate. The present results provide an important reference for further study of the molecular spectrum, dynamics and molecular cooling with Stark effect.