A Novel Bidirectional Interaction Model and Electric Energy Measuring Scheme of EVs for V2G with Distorted Power Loads

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.

Traceability Technology of DC Electric Energy Metering for On-Site Inspection of Chargers

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%.

Measurement of Secondary Electron Energy Spectra of Polymethyl Methacrylate

We report on a novel and convenient method of measuring secondary electron spectra for insulators in a secondary electron yield measurement system with a planar grid analyzer configuration and a metal mesh probe. In this measurement, the planar grid is negatively biased to force some emitted secondary electrons to return to the sample surface and to neutralize charges accumulated on the sample during the previous beam irradiation. The surface potential of the sample is then measured by use of a metal mesh probe. The grid bias for neutralization corresponding to the zero surface potential is determined based on the linear relationship between the surface potential and the grid bias. Once the surface potential equals zero, the secondary electron spectra of polymethyl methacrylate（PMMA） are studied experimentally by measuring the -curve and then fitting it to Everhart＇s formula. The measurement results show that the peak energy and the full width at half maximum of the spectra are 4.26 eV and 14.06 eV, respectively.

Energy flow problem solution based on state estimation approaches and smart meter data

Accurate electric energy(EE)measurements and billing estimations in a power system necessitate the development of an energy flow distribution model.This paper summarizes the results of investigations on a new problem related to the determination of EE flow in a power system over time intervals ranging from minutes to years.The problem is referred to as the energy flow problem(EFP).Generally,the grid state and topology may fluctuate over time.An attempt to use instantaneous(not integral)power values obtained from telemetry to solve classical electrical engineering equations leads to significant modeling errors,particularly with topology changes.A promoted EFP model may be suitable in the presence of such topological and state changes.Herein,EE flows are determined using state estimation approaches based on direct EE measurement data in Watt-hours(Volt-ampere reactive-hours)provided by electricity meters.The EFP solution is essential for a broad set of applications,including meter data validation,zero unbalance EE billing,and nontechnical EE loss check.

Energy Measures on a Homogeneous Hierarchical Gasket

On a homogeneous hierarchical gasket we give a linear extension method to compute the energy measures of harmonic functions with respect to the standard energy.

Improvement of Beam Energy Measurement System for BES-III

The beam energy measurement system is significant and profit for both BES-III detector and BEPC-II accelerator. The detection of the high energy scattering photons is realized by virtue of the Compton backscattering principle. Many advanced techniques and precise instruments are employed to acquire the highly accurate measurement of positron/electron beam energy. During five years’ running period, in order to satisfy the requirement of data taking and enhance the capacity of measurement itself, the upgradation of system is continued, which involves the components reformation of laser and optics subsystem, replacement of view-port of the laser to vacuum insertion subsystem, the usage of electric cooling system for high purity germanium detector, and the refinement of data acquisition and processing subsystem. The upgrading of system guarantees the smooth and effective measuring of beam energy at BEPC-II and accommodates the accurate offline energy values for further physics analysis at BES-III.

Research on Green Transformation of Campus Sponge and Energy Saving Facilities on Sloping Land

Based on the renovation of sponge and energy-saving facilities in a middle school in Nanning,this paper systematically studies the overall elevation of the campus,the composition of the drainage system and the layout of space functions,and formulates a characteristic scheme for the renovation of sponge and energy-saving facilities according to the characteristics of the sloping campus.In order to control the total amount of rainwater runoff,the sponge transformation mainly adopts the transformation methods of partition catchment,upper storage and lower use,multi-stage detection and classification treatment.For the purpose of solar energy and wind energy utilization,solar photovoltaic panels and small-scale wind power generation system are adopted.The application effects of sponge and energy-saving facilities are estimated and evaluated.

Dark Energy from Kaluza-Klein Spacetime and Noether’s Theorem via Lagrangian Multiplier Method

The supposedly missing dark energy of the cosmos is found quantitatively in a direct analysis without involving ordinary energy. The analysis relies on five dimensional Kaluza-Klein spacetime and a Lagrangian constrained by an auxiliary condition. Employing the Lagrangian multiplier method, it is found that this multiplier is equal to the dark energy of the cosmos and is given by where E is energy, m is mass, c is the speed of light, and λ is the Lagrangian multiplier. The result is in full agreement with cosmic measurements which were awarded the 2011 Nobel Prize in Physics as well as with the interpretation that dark energy is the energy of the quantum wave while ordinary energy is the energy of the quantum particle. Consequently dark energy could not be found directly using our current measurement methods because measurement leads to wave collapse leaving only the quantum particle and its ordinary energy intact.

Modeling Distortion Signals of Power Grid Based on Wiener-G Functionals

The uniform mathematical model of distortion signals in power grid has been setup with the theory of Wiener-G Functional. Firstly,the Matlab simulation models were established. Secondly,the Wiener kernel of power load was found based on the Gaussian white noise as input. And then the uniform mathematical model of the power grid signal was established according to the homogeneous of the same order of Wiener functional series. Finally,taking three typical distortion sources which are semiconductor rectifier,electric locomotive and electric arc furnace in power grid as examples,we have validated the model through the Matlab simulation and analyzed the simulation errors. The results show that the uniform mathematical model of distortion signals in power grid can approximation the actual model by growing the items of the series under the condition of the enough storage space and computing speed.

Measuring the inequality using energy consumption data in China

With the support by the National Natural Science Foundation of China,the research team led by Prof.Wei Chu(魏楚)and Prof.Zheng Xinye(郑新业)at the Department of Energy Economics,School of Economics,Renmin University of China,measures the inequality using the household energy

An Efficient EH-WSN Energy Management Mechanism

An Energy-Harvesting Wireless Sensor Network （EH-WSN） depends on harvesting energy from the environment to prolong network lifetime. Subjected to limited energy in complex environments, an EH-WSN encounters difficulty when applied to real environments as the network efficiency is reduced. Existing EH-WSN studies are usually conducted in assumed conditions in which nodes are synchronized and the energy profile is knowable or calculable. In real environments, nodes may lose their synchronization due to lack of energy. Furthermore, energy harvesting is significantly affected by multiple factors, whereas the ideal hypothesis is difficult to achieve in reality. In this paper, we introduce a general Intermittent Energy-Aware （lEA） EH-WSN platform. For the first time, we adopted a double-stage capacitor structure to ensure node synchronization in situations without energy harvesting, and we used an integrator to achieve ultra-low power measurement. With regard to hardware and software, we provided an optimized energy management mechanism for intermittent functioning. This paper describes the overall design of the lEA platform, and elaborates the energy management mechanism from the aspects of energy management, energy measurement, and energy prediction. In addition, we achieved node synchronization in different time and energy environments, measured the energy in reality, and proposed the light weight energy calculation method based on measured solar energy. In real environments, experiments are performed to verify the high performance of lEA in terms of validity and reliability. The lEA platform is shown to have ultra-low power consumption and high accuracy for energy measurement and prediction.

Survey and analysis of energy consumption in office buildings in Tianjin

An energy audit of 24 office buildings was conducted in Tianjin, including basic information of buildings, building energy system and energy bills. The investigation results showed that the average intensity of energy consumption in office buildings in Tianjin accounts for 161.51 kW-h/（mZ.a）. By breaking the energy consumption down into detailed items, it was found that the heating system consumed the highest amount of energy （46.6%）, followed by equipment （35.9%）, cooling system （11%） and lighting system （6.69%）. The main factors for office building energy consumption were found and some feasible measures to save energy were proposed.

Evaluating the energy impact potential of energy efficiency measures for retrofit applications:A case study with U.S.medium office buildings

Quantifying the energy savings of various energy efficiency measures(EEMs)for an energy retrofit project often necessitates an energy audit and detailed whole building energy modeling to evaluate the EEMs;however,this is often cost-prohibitive for small and medium buildings.In order to provide a defined guideline for projects with assumed common baseline characteristics,this paper applies a sensitivity analysis method to evaluate the impact of individual EEMs and groups these into packages to produce deep energy savings for a sample prototype medium office building across 15 climate zones in the United States.We start with one baseline model for each climate zone and nine candidate EEMs with a range of efficiency levels for each EEM.Three energy performance indicators(EPIs)are defined,which are annual electricity use intensity,annual natural gas use intensity,and annual energy cost.Then,a Standard Regression Coefficient(SRC)sensitivity analysis method is applied to determine the sensitivity of each EEM with respect to the three EPIs,and the relative sensitivity of all EEMs are calculated to evaluate their energy impacts.For the selected range of efficiency levels,the results indicate that the EEMs with higher energy impacts(i.e.,higher sensitivity)in most climate zones are high-performance windows,reduced interior lighting power,and reduced interior plug and process loads.However,the sensitivity of the EEMs also vary by climate zone and EPI;for example,improved opaque envelope insulation and efficiency of cooling and heating systems are found to have a high energy impact in cold and hot climates.

Working principles of the energy measurement system at BEPCⅡ

The proposed beam energy measurement system at BEPC II is composed of three parts： the laser source and optics system, the laser-electron interaction system and the HPGe detector system. The working principles of each system are expounded together with the calculation for preliminary design. The normaliza- tions of laser and electron beams are put forth and used for the evaluation of intensity of the backscattering photon. The simulation of HPGe detector is also performed for understanding the working properties.

Beam energy measurement system at BEPCⅡ

The beam energy measurement system at BEPCII is composed of there parts： laser source and optics system, laser-electron interaction system and High Purity Germanium （HPGe） detector system. The special components and construction of each part are introduced, especially about radiation background measurement in the storage ring, which is of great importance for the safe commissioning of HPGe detector.

Upgrade of beam energy measurement system at BEPC-Ⅱ

The beam energy measurement system is of great importance for both BEPC-II accelerator and BES-III detector. The system is based on measuring the energies of Compton back-scattered photons. In order to meet the requirements of data taking and improve the measurement accuracy, the system has continued to be upgraded, which involves the updating of laser and optics subsystems, replacement of a view-port of the laser to the vacuum insertion subsystem, the use of an electric cooling system for a high purity germanium detector, and improvement of the data acquisition and processing subsystem. The upgrade system guarantees the smooth and efficient measurement of beam energy at BEPC-II and enables accurate offline energy values for further physics analysis at BES-III.

Effect of the PTO damping force on the wave pressures on a 2-D wave energy converter

The information of the wave loads on a wave energy device in operational waves is required for designing an efficient wave energy system with high survivability. It is also required as a reference for numerical modeling. In this paper, a novel system, which integrates an oscillating wave energy converter with a pile-restrained floating breakwater, is experimentally investigated in a 2-D wave flume. The measurements of the wave pressure on the wet-surface of the device are made as the function of the power take-off（PTO） damping force. It is shown that the wave pressure is significantly affected by the PTO system, in particular, at the edges, and the wave pressure varies under different wave conditions. From the results, conclusions can be drawn on how the PTO damping force and wave conditions affect the loads on the device, which is of engineering concern for constructing safe and reliable devices.

Online Energy Measure and Analysis System for Large-Scale Public Buildings

Large-scale public buildings have high energy density, which on average consume 5 to 15 times more electricity than residential buildings. In Beijing, those public buildings account for about ten percent of the total building area, but their energy consumption （except heating） amounts to more than thirty percent of the total. Few electric meters are installed in those public buildings, however, making it more difficult to monitor how the energy is used.

A cost effective approach to design of energy efficient residential buildings

The objective of this study is to identify cost-optimal efficiency packages at several levels of building energy savings.A two-story residential building located in Jordan is selected as a case study.DesignBuilder software is used to predict the annual energy usage of a twostory residence in Irbid,Jordan.Real-time experimental data from a single isolated controlled room was used to verify the proposed model.In addition to energy analysis,the economic,environmental,and social benefits of the proposed design have been investigated.The sequential search optimization approach is used to estimate the minimum cost of the building while considering various design scenarios.In addition,the impact of various energy conservation techniques on residential buildings is assessed,and the payback period for each program is calculated.Ultimately,the optimal combination of design to achieve energy efficiency measures has been identified in several climate regions.The simulations results predict that the annual electricity consumption can be reduced up to 50%if the proper combinations of energy conservation measures are selected at the lowest cost.The payback period is 9.3 years.Finally,energy efficiency measures can lead to a total of 9470 jobs/year job opportunities.The study provide practical framework to link between energy performance criteria and economic goals of building.Linking the energy performance requirements to economic targets provides guidelines for homeowners,contractors,and policymakers for making a suitable decision regarding the retrofitting of existing residential buildings.The study focuses on developing new methodologies that support minimizing costs during a building’s lifecycle while maximizing environmental benefits which can not be identified by a series of parametric analyses using individual energy-efficient measures.

Measurement of the ripple of magnet power supply and its effect to the beam energy

Objective:This study is aimed at measuring the ripple of magnetic power supply of BEPCII and checking its effect to beam energy.Materials and methods:A sensor made of printed circuit board coils is designed and manufactured.The sensor was inserted into a good area region of the magnetic field with the surface perpendicular to the field force lines.The change of the magnetic field would be detected according to Faraday’s law.Results:The experiment result indicates that the timedependent ripple of the magnetic field is in the magnitude of ppm.Conclusion:Such a small effect of the time-dependent ripplecan be negligibleto beam energy.