Ultrahigh voltage(UHV)and extra-high voltage(EHV)have been widely used in power system,so the requirement for technology of operation management,as well as the accident analysis and disposal are more pressing.Based on...Ultrahigh voltage(UHV)and extra-high voltage(EHV)have been widely used in power system,so the requirement for technology of operation management,as well as the accident analysis and disposal are more pressing.Based on the theory of Newton-Laphson power flow method,this simulation system imitates the primary device and secondary circuit,together with the normal,the abnormal and accidents in operation.Through simulation in various situations,it validates that this design is capable of simulating the complicated faults in UHV and EHV accurately and in real time.In addition,it can analyse and dispose them efficiently.展开更多
Recent researches in the development of in-plane micro-supercapacitor(MSC)have been dedicated to advancing its energy density in a finite storage area.However,the low ion-accessible surface area of plane electrode mat...Recent researches in the development of in-plane micro-supercapacitor(MSC)have been dedicated to advancing its energy density in a finite storage area.However,the low ion-accessible surface area of plane electrode material has been the bottleneck limiting the energy output of MSC.Herein,we design a stable ionic liquid(IL)-MXene microemulsion system in virtue of tween-20(TW20),gathering IL-TW20 microdroplets around MXene nanosheets.The microemulsion can adhere on the current collector and form the dense MXene-TW20-IL film.The IL as spacer and electrolyte is retained in the interlamination of MXene with the elimination of the TW20 during heat treatment,which enlarges the ion-accessible surface area of the MXene electrode.Thus,the MSC based on the flexible MXene-IL film exhibits a high areal capacitance(44.6 mF·cm^(−2)),a high areal and volumetric energy density(50.7μW·h·cm^(−2)and 39 mW·h·cm^(−3)),surpassing most of the reported MXene-based MSCs.And the MSC unit can be arbitrarily integrated in terms of various energy and voltage requirements.For instance,the integrated array with thirty MSC units in series realizes a high voltage output of 90 V,widening the range of application in next-generation microelectronic devices.展开更多
The corona onset voltage gradient(COG)of conductors is a key parameter in the design of overhead transmission lines.The commonly used semi-empirical calculation formula proposed by Peek(1910s)at present can roughly es...The corona onset voltage gradient(COG)of conductors is a key parameter in the design of overhead transmission lines.The commonly used semi-empirical calculation formula proposed by Peek(1910s)at present can roughly estimate the COG of single conductors and is not applicable to large cross-section bundle conductors.In this paper,experiments are conducted to investigate the corona characteristics of a whole series of bundle conductors at different altitudes,and a prediction formula is proposed for the COG of large cross-section bundle conductors on AC transmission lines considering the altitude correction.The calculated values using the proposed prediction formula are compared with the experimental values of the COG in two cases:UHV eight-bundle conductors at an altitude of 19 m;500 kV UHV four-bundle conductors in Wuhan,Xining,Geermu,and Nachitai at four different altitudes.The results show that the use of the formula can predict the COG of bundle conductors with the radius of 1.34 cm to 1.995 cm and the number of subconductors of 4 to 12 at altitudes of 19 m to 4000 m above the mean sea level.The research findings can provide a reference for the design of EHV and UHV overhead transmission lines and even those in higher voltage levels.展开更多
超高压(Extra High Voltage,EHV)输电线路多为同塔双回,引雷面积大,更易遭受到雷击,特别是对于山谷间大跨度的杆塔常发生绕击跳闸事故。据运检单位统计表明,绕击是引起线路跳闸的主要原因。因此,对输电线路雷电绕击进行分析,探讨影响同...超高压(Extra High Voltage,EHV)输电线路多为同塔双回,引雷面积大,更易遭受到雷击,特别是对于山谷间大跨度的杆塔常发生绕击跳闸事故。据运检单位统计表明,绕击是引起线路跳闸的主要原因。因此,对输电线路雷电绕击进行分析,探讨影响同塔双回输电线路防雷性能的敏感因素是十分必要的。建立500 kV输电线路的绕击模型,该模型采用电气几何模型(Electrical Geometric Model,EGM)法,通过呼高、地面坡度、保护角、导线相序排列变化所导致的雷电绕击跳闸次数变化来反映出各因素对于绕击耐雷性能的影响。展开更多
基金China Postdoctoral Science Foundation(No.20080441149)Shandong Province Postdoctoral Innovation Program Foundation(No.200803036)SDUST Research Fund(No.2010KYTD101)
文摘Ultrahigh voltage(UHV)and extra-high voltage(EHV)have been widely used in power system,so the requirement for technology of operation management,as well as the accident analysis and disposal are more pressing.Based on the theory of Newton-Laphson power flow method,this simulation system imitates the primary device and secondary circuit,together with the normal,the abnormal and accidents in operation.Through simulation in various situations,it validates that this design is capable of simulating the complicated faults in UHV and EHV accurately and in real time.In addition,it can analyse and dispose them efficiently.
基金the financial support from the National Natural Science Foundation of China(Nos.22005168 and 21878063)the Taishan Scholars Program of Shandong Province(No.tsqn201909119)+2 种基金the Natural Science Foundation of Shandong Province(No.ZR2020QB118)the Key Program of Natural Science Foundation of Shandong Province(No.ZR2020KB011)the Talent Foundation funded by Province and Ministry Coconstruction Collaborative Innovation Center of Eco-chemical Engineering(No.STHGYX2219).
文摘Recent researches in the development of in-plane micro-supercapacitor(MSC)have been dedicated to advancing its energy density in a finite storage area.However,the low ion-accessible surface area of plane electrode material has been the bottleneck limiting the energy output of MSC.Herein,we design a stable ionic liquid(IL)-MXene microemulsion system in virtue of tween-20(TW20),gathering IL-TW20 microdroplets around MXene nanosheets.The microemulsion can adhere on the current collector and form the dense MXene-TW20-IL film.The IL as spacer and electrolyte is retained in the interlamination of MXene with the elimination of the TW20 during heat treatment,which enlarges the ion-accessible surface area of the MXene electrode.Thus,the MSC based on the flexible MXene-IL film exhibits a high areal capacitance(44.6 mF·cm^(−2)),a high areal and volumetric energy density(50.7μW·h·cm^(−2)and 39 mW·h·cm^(−3)),surpassing most of the reported MXene-based MSCs.And the MSC unit can be arbitrarily integrated in terms of various energy and voltage requirements.For instance,the integrated array with thirty MSC units in series realizes a high voltage output of 90 V,widening the range of application in next-generation microelectronic devices.
基金This work was supported by the National Natural Science Foundation of China(51577069,51277073)National Basic Research Programme of China(2011CB209401)+2 种基金the Science and Technology Project of State Grid Corporation of China(SGTYHT/15-JS-191)the Science and Technology Program of EPPEI(K201909-D)the Fundamental Research Funds for the Central Universities(2020MS092).
文摘The corona onset voltage gradient(COG)of conductors is a key parameter in the design of overhead transmission lines.The commonly used semi-empirical calculation formula proposed by Peek(1910s)at present can roughly estimate the COG of single conductors and is not applicable to large cross-section bundle conductors.In this paper,experiments are conducted to investigate the corona characteristics of a whole series of bundle conductors at different altitudes,and a prediction formula is proposed for the COG of large cross-section bundle conductors on AC transmission lines considering the altitude correction.The calculated values using the proposed prediction formula are compared with the experimental values of the COG in two cases:UHV eight-bundle conductors at an altitude of 19 m;500 kV UHV four-bundle conductors in Wuhan,Xining,Geermu,and Nachitai at four different altitudes.The results show that the use of the formula can predict the COG of bundle conductors with the radius of 1.34 cm to 1.995 cm and the number of subconductors of 4 to 12 at altitudes of 19 m to 4000 m above the mean sea level.The research findings can provide a reference for the design of EHV and UHV overhead transmission lines and even those in higher voltage levels.
文摘为保障低压配电线路检修作业安全,有必要研究低压配线在停运检修状态下的感应电压和电流。采用EMTP建模仿真,分别计算了上海地区4个超/特高压交、直流输电工程线路下方平行架设的380 V低压配线上的感应电压、电流,对影响感应的因素进行了分析,并设计研发了低压配电线路感应电压消除装置。仿真结果表明,超/特高压交、直流线路在其下方停运的380 V配线上产生较大的感应电压和电流,感应电压最高可达30~70 k V。试验结果表明,低压配线感应电压消除装置在线路停运时将其两端接地,能有效消除配电线路上的感应电压。
