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Acta Metallurgica Sinica(English Letters) 2016年第4期29卷 373-381页

作者： Nian-Wei Dai Jun-Xi Zhang Qi-Meng Chen Xin Zhang Fa-He Cao Jian-Qing Zhang Shanghai Key Laboratory of Materials Protection and Advanced Materials in electric Power Shanghai University of Electric Power Department of Chemistry Zhejiang University

X-ray diffraction, Raman spectroscopy and scanning electron microscopy were employed to investigate the effects of the DC electric field on the composition, formation and structure of corrosion products formed on the surface of the steel immersed in NaCl solution. The results show that goethite （α-FeOOH）, akaganeite （β-FeOOH）, lepidocrocite （γ- FeOOH） and magnetite （Fe3O4） are the major constituents among the corrosion products. The arrangement of different levels of the DC electric field intensity gives rise to the following results. The little higher DC electric field intensity （around 100-200 kV/m） promotes the crystallinity and growth of y-FeOOH; obviously, much higher DC electric field intensity （greater than 400 kV/m） prevents the growth of α-FeOOH and facilitates the generation of Fe3O4. Both the promotional growth of γ-FeOOH and suppression of α-FeOOH growth indicated the weakness of the protectiveness of the rust layer. Consequently, the suppression of the transformation of α-FeOOH from y-FeOOH favors the yield of the Fe3O4, which works as a large cathode area and would be about to quicken the subsequent steel corrosion.

关键词： Steel Atmospheric corrosion Rust electric field Raman spectroscopy

Operation-area-constrained Adaptive Primary Frequency Support Strategy for electric Vehicle Clusters

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Journal of Modern Power Systems and Clean Energy 2023年第6期11卷 1982-1994页

作者： Tianqi Liu Pengyu Wang Qiao Peng Min Zhang Tengxin Wang Jinhao Meng College of electrical Engineering Sichuan UniversityChengdu 610065China electric Power Research Institute State Grid Shanxi Electric Power CompanyTaiyuan 030001China

Due to their fast response and strong short-term power throughput capacity, electric vehicles(EVs) are promising for providing primary frequency support to power grids. However, due to the complicated charging demands of drivers, it is challenging to efficiently utilize the regulation capacity of EV clusters for providing stable primary frequency support to the power grid. Accordingly, this paper proposes an adaptive primary frequency support strategy for EV clusters constrained by the charging-behavior-defined operation area. First, the forced charging boundary of the EV is determined according to the driver's charging behavior, and based on this, the operation area is defined. This ensures full utilization of the available frequency support capacity of the EV. An adaptive primary frequency support strategy of EV clusters is then proposed. The output power of EV is adaptively regulated according to the real-time distance from the EV operating point to the forced charging boundary. With the proposed strategy, when the EV approaches the forced charging boundary, its output power is gradually reduced to zero. Then, the rapid state-of-charge declines of EVs and sudden output power reductions in EV clusters caused by forced charging to meet the driver's charging demands can be effectively avoided. EV clusters can then provide sustainable frequency support to the power grid without violating the driver's charging demands. Simulation results validate the proposed operation-area-constrained adaptive primary frequency support strategy, which outperforms the average strategy in terms of stable output maintenance and the optimal utilization of regulation capacities of EV clusters.

关键词： Primary frequency control frequency support electric vehicle vehicle-to-grid(V2G) operation area charging behavior

Accommodation of Curtailed Wind Power by electric Boilers Equipped in Different Locations of Heat-supply Network for Power System with CHPs

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Journal of Modern Power Systems and Clean Energy 2021年第4期9卷 930-939页

作者： Yunfeng Ma Yang Yu Zengqiang Mi School of electrical and Electronic Engineering North China Electric Power UniversityBeijingChina Department of electrical Engineering North China Electric Power UniversityBaodingChina

electric boilers (EBs) provide an alternative method to deal with the accommodation of curtailed wind power. To pursue the minimum coal consumption in the system, a dispatching model integrating combined-heat-and-power (CHP) plants and EBs in different locations is developed, and the penalty of wind power curtailment and cost of EB employment are also incorporated in the model. The transmission loss and transportation lag of heat-supply network as well as the elasticity of heat load are considered in this paper. A kind of constrained programming with stochastic and fuzzy parameters is applied to deal with the uncertainties. A case in East Inner Mongolia in China demonstrates that the EBs are able to absorb curtailed wind power and supply the heat. The results indicate that the utility of EBs in the primary or secondary heat-supply network to accommodate curtailed wind power is mainly related to the efficiency of heat transmission and the elasticity of heat load.

关键词： Wind power combined-heat-and-power(CHP)unit electric boiler(EB) heat-supply network

Design scheme for fast charging station for electric vehicles with distributed photovoltaic power generation

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Global Energy Interconnection 2019年第2期2卷 150-159页

作者： Jing Zhang Chang Liu Ruiming Yuan Taoyong Li Kang Li Bin Li Jianxiang Li Zhenyu Jiang China electric Power Research Institute Beijing Electric Vehicle Charging and Replacing Engineering Technology Research Center electric Power Research Institute State Grid Jibei Electric Power Company Limited electric Power Research Institute State Grid Shandong Electric Power Company

The demand for fast charging is increasing owing to the rapid expansion of the market for electric vehicles. In addition, the power generation technology for distributed photovoltaic has matured. This paper presents a design scheme for a fast charging station for electric vehicles equipped with distributed photovoltaic power generation system taking the area with certain conditions in Beijing as an example construction site. The technical indexes and equipment lectotype covering the general framework and subsystems of the charging station are determined by analyzing the charging service demand of fast charging stations. In this study, the layout of the station is developed and the operation benefits of the station is analyzed. The design scheme realizes the design objective of "rationalization, modularization and intelligentization" of the fast charging station and can be used as reference for the construction of a fast charging network in urban area.

关键词： electric vehicle Fast charging station Charging demand Design scheme Distributed photovoltaic

LSTM-based Energy Management for electric Vehicle Charging in Commercial-building Prosumers

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Journal of Modern Power Systems and Clean Energy 2021年第5期9卷 1205-1216页

作者： Huayanran Zhou Yihong Zhou Junjie Hu Guangya Yang Dongliang Xie Yusheng Xue Lars Nordström State Key Laboratory of Alternate electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China Center for electric Power and Energy Technical University of DenmarkLyngbyDenmark State Grid electric Power Research Institute NanjingChina Division of electric Power and Energy Systems School of Electrical Engineering and Computer ScienceKTH Royal Institute of TechnologyStockholmSweden

As typical prosumers,commercial buildings equipped with electric vehicle(EV)charging piles and solar photovoltaic panels require an effective energy management ***,the conventional optimization-model-based building energy management system faces significant challenges regarding prediction and calculation in online *** address this issue,a long short-term memory(LSTM)recurrent neural network(RNN)based machine learning algorithm is proposed in this paper to schedule the charging and discharging of numerous EVs in commercial-building *** the proposed system control structure,the LSTM algorithm can be separated into offline and online *** the offline stage,the LSTM is used to map states(inputs)to decisions(outputs)based on the network *** the online stage,once the current state is input,the LSTM can quickly generate a solution without any additional prediction.A preliminary data processing rule and an additional output filtering procedure are designed to improve the decision performance of LSTM *** simulation results demonstrate that the LSTM algorithm can generate near-optimal solutions in milliseconds and significantly reduce the prediction and calculation pressures compared with the conventional optimization algorithm.

关键词： Building energy management system(BEMS) electric vehicle(EV) long short-term memory(LSTM) recurrent neural network machine learning prosumer

Energy harvesting technology for AC overhead insulated transmission line based on electric field induction

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High Voltage 2024年第4期9卷 816-825页

作者： Le Zhou Hongwei Liu Kun Zuo Kuo Shang School of electrical and Electronic Engineering North China Electric Power UniversityBeijingChina electric Power Company of Sichuan Province Tianfu Power Supply Company ChengduSichuanChina Changde Power Supply Branch State Grid Hunan Electric Power Company LimitedChangdeHunanChina

To solve the problem of the energy harvesting(EEH)effect of the condition monitoring devices power supply on the transmission line is not *** authors designed three kinds of EEH schemes based on AC electric field induction,which can effectively improve the output power of load power *** EEH principle of each scheme was analysed in detail,and the influence factors such as the shape of outer energy harvester,capacitance compensation and impedance matching characteristics were ***,the experiment showed that 140.9 mW of power was obtained in direct-mode field EEH when the line voltage level was 10 *** high-potential field EEH mode obtained 4.1 mW of *** harvesting effect of the inner energy harvester with the same potential as the aluminium wire was obviously better,and 30.7 mW of power was ***,based on the third mode,when the load resistance was 2200Ω,the rectifier received 23.7 mW DC *** experimental results are in agreement with the theoretical analysis,which verifies the effectiveness of the electric field induction power supply technology.

关键词： field harvesting mode

Temperature‐dependent adaptive conductivity coating for surface charge release and electric field control under electro‐thermal coupling field

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High Voltage 2023年第5期8卷 1082-1092页

作者： Jianyi Xue Zhu Zhang Binbin Li Yushun Zhao Lijian Ding School of electrical Engineering and Automation Hefei University of TechnologyHefeiChina electric Power Research Institute of State Grid Anhui electric Power Co. Ltd.HefeiChina

Surface charge accumulation is the potential criminal for surface insulation failure on spacers under direct current(DC)*** existence of thermal gradient posing the difficulty of surface charge *** study proposes a temperature‐dependent adaptive conductivity coating technique for surppressing surface charge accumulation under electro‐thermal coupling field.A two‐dimensional axis‐symmetrical simulation model regrading surface charge computation is *** effects of thermal gradients and coating conductivity on surface charge and electric field distribution are *** results show that the thermal gradient increases the bulk conductive current,therefore aggravating surface charge *** effects of the coating condcutivity on surface charge and electric field contains three *** lower coating conductivity leads to aggravated homo‐polarity charge *** increasing the coating conductivity,the surface charge and electric field are significantly suppressed at the obtained optimal conductivity,where the bulk and surface conductive current reach a balance *** increasing the coating conductivity results in aggravated hetero‐polarity ***,the increase of thermal gradient to an appropriate extent contributes to the further suppression of surface charge on coated *** is hoped that this study could provide some references for designing highly reliable DC GIL under electro‐thermal coupling field.

关键词： coating charge conductivity

Online model identification of lithium-ion battery for electric vehicles

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Journal of Central South University 2011年第5期18卷 1525-1531页

作者：胡晓松孙逢春邹渊 National Engineering Laboratory for electric Vehicles Beijing Institute of Technology

In order to characterize the voltage behavior of a lithium-ion battery for on-board electric vehicle battery management and control applications,a battery model with a moderate complexity was *** battery open circuit voltage (OCV) as a function of state of charge (SOC) was depicted by the Nernst *** equivalent circuit network was adopted to describe the polarization effect of the lithium-ion battery.A linear identifiable formulation of the battery model was derived by discretizing the frequent-domain description of the battery *** recursive least square algorithm with forgetting was applied to implement the on-line parameter *** validation results show that the on-line calibrated model can accurately predict the dynamic voltage behavior of the lithium-ion *** maximum and mean relative errors are 1.666% and 0.01%,respectively,in a hybrid pulse test,while 1.933% and 0.062%,respectively,in a transient power *** on-line parameter calibration method thereby can ensure that the model possesses an acceptable robustness to varied battery loading profiles.

关键词： battery model on-line parameter identification lithium-ion battery electric vehicle

Synthesis, structure, optical, and electric properties of Ce-doped CuInTe_2 compound

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Chinese Physics B 2014年第12期23卷 469-475页

作者：付丽郭永权 School of Energy Power and Mechanical Engineering North China Electric Power University

Ce-doped Cu In Te2（CICT） semiconducting compounds are successfully synthesized. The phase structures, optical,and electric properties are investigated using powder X-ray diffraction（XRD）, field emission scanning electron microscopy（FESEM）, X-ray photoelectron spectrometer（XPS）, Raman spectrometer, ultraviolet and visible spectrophotometer（UVVis）, and a standard four-probe method. Cu In1-xCex Te2 crystallizes into a tetragonal structure with predominant orientation along the [112] direction. The lattice parameters are a = 6.190（6） A–6.193（0） A and c = 12.406（5） A–12.409（5） A. Ce prefers to occupy the 4b crystal position. According to the analysis of XPS spectra, Ce shows the mixture of valences 4＋and 3＋. Raman spectra reveal that the photon vibrating model in the CICT follows A1 mode in a wavenumber range of123 cm^-1–128 cm^-1. UV-Vis spectra show that the band gap Eg values before and after 0.1 mole Ce doped into Cu In Te2 are 1.28 e V and 1.16 e V, respectively. It might be due to the mixture of valences for Ce. Ce doped into Cu In Te2 still shows the semiconductor characteristics.

关键词： CuIn1-xCexTe2 chalcopyrite Raman spectrum band gap semiconductor

Modeling porous structure of oil-pressboard interface and its effect on electric field distribution

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Journal of Central South University 2015年第1期22卷 338-343页

作者：司马文霞姜赤龙毛文奇唐信 State Key Laboratory of Power Equipment & System Security and New Technology(Chongqing University) State Grid Hunan electric Power Corporation Maintenance Company State Grid Hunan electric Power Corporation

The oil-pressboard insulation is a typical composite insulation system widely used in the design and manufactory of large power apparatus. The implement of oil-pressboard insulation may lead to surface electrification and discharge at the interface under certain condition. It is of significant importance to take an insight into the phenomenon occurring at the interface. Through experiment, the pressboard is found as a porous material. The interface changes abruptly from bulk pressboard to the bulk oil as a result of the porous structure. A new model is proposed which divides the interface into bulk oil region, transition region, and bulk pressboard region. The width of the transition region is decided according to the microtome figure. The effective permittivity of the transition region is calculated using a new model based on fractal theory. The model is validated and compared with previous calculation model. The effect of the existence of transition region on the electric field distribution is discussed.

关键词： oil-pressboard interface transition region effective permittivity fractal electric field distribution