潮流计算是电网规划与运行分析的基础,目前一些系统分析工作需要收敛的潮流工况。针对电力系统研究所潮流及暂态稳定程序(power system department,Bonneville Power Administration,PSD-BPA)中运行方式安排时出现的无功潮流无解问题,...潮流计算是电网规划与运行分析的基础,目前一些系统分析工作需要收敛的潮流工况。针对电力系统研究所潮流及暂态稳定程序(power system department,Bonneville Power Administration,PSD-BPA)中运行方式安排时出现的无功潮流无解问题,提出一种无功潮流收敛性的二阶段自动调整方法。对于不收敛的潮流,首先通过节点类型转换将500 kV输电网上含无功补偿的节点转为PV节点,获取量化无功不收敛的指标。其次,按电网分区将转换类型的节点逐步还原,以还原节点的电压幅值及各分区的电压水平为参考制定第一阶段调整策略;通过Floyd算法确定输电网无功调整路径且由节点补偿量进行修正,获得第二阶段调整策略并使潮流恢复收敛。最后,以某省实际电网验证算法在无功潮流收敛性调整方面的有效性。展开更多
Manganese ferrite(MnFe_(2)O_(4))has the advantages of simple preparation,high resistivity,and high crystal symmetry.Herein,we have developed an electrochemical sensor utilizing graphene and MnFe_(2)O_(4) nanocomposite...Manganese ferrite(MnFe_(2)O_(4))has the advantages of simple preparation,high resistivity,and high crystal symmetry.Herein,we have developed an electrochemical sensor utilizing graphene and MnFe_(2)O_(4) nanocomposites modified glassy carbon electrode(GCE),which is very efficient and sensitive to detect bisphenol A(BPA).MnFe_(2)O_(4)/graphene(GR)was synthesized by immobilizing the MnFe_(2)O_(4) microspheres on the graphene nanosheets via a simple one-pot solvothermal method.The morphology and structure of the MnFe_(2)O_(4)/GR nanocomposite have been characterized through scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).In addition,electrochemical properties of the modified materials are comparably explored by means of cyclic voltammetry(CV),electrochemical impedance spectroscopy(EIS)and differential pulse voltammetry(DPV).Under the optimal conditions,the proposed electrochemical sensor for the detection of BPA has a linear range of 0.8-400μmol/L and a detection limit of 0.0235μmol/L(S/N=3)with high sensitivity,good selectivity and high stability.In addition,the proposed sensor was used to measure the content of BPA in real water samples with a recovery rate of 97.94%-104.56%.At present,the synthesis of MnFe_(2)O_(4)/GR provides more opportunities for the electrochemical detection of BPA in practical applications.展开更多
文摘潮流计算是电网规划与运行分析的基础,目前一些系统分析工作需要收敛的潮流工况。针对电力系统研究所潮流及暂态稳定程序(power system department,Bonneville Power Administration,PSD-BPA)中运行方式安排时出现的无功潮流无解问题,提出一种无功潮流收敛性的二阶段自动调整方法。对于不收敛的潮流,首先通过节点类型转换将500 kV输电网上含无功补偿的节点转为PV节点,获取量化无功不收敛的指标。其次,按电网分区将转换类型的节点逐步还原,以还原节点的电压幅值及各分区的电压水平为参考制定第一阶段调整策略;通过Floyd算法确定输电网无功调整路径且由节点补偿量进行修正,获得第二阶段调整策略并使潮流恢复收敛。最后,以某省实际电网验证算法在无功潮流收敛性调整方面的有效性。
基金Project(2108085ME184)supported by the Natural Science Foundation of Anhui Province,ChinaProject(2022AH010019)supported by the Innovation Team Project of Anhui Provincial Department of Education,China+1 种基金Project(GXXT-2021-057)supported by the Collaborative Innovation Project of Anhui Provincial Department of Education,ChinaProject(2020QDZ36)supported by the Doctoral Scientific Research Startup Foundation of Anhui Jianzhu University,China。
文摘Manganese ferrite(MnFe_(2)O_(4))has the advantages of simple preparation,high resistivity,and high crystal symmetry.Herein,we have developed an electrochemical sensor utilizing graphene and MnFe_(2)O_(4) nanocomposites modified glassy carbon electrode(GCE),which is very efficient and sensitive to detect bisphenol A(BPA).MnFe_(2)O_(4)/graphene(GR)was synthesized by immobilizing the MnFe_(2)O_(4) microspheres on the graphene nanosheets via a simple one-pot solvothermal method.The morphology and structure of the MnFe_(2)O_(4)/GR nanocomposite have been characterized through scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).In addition,electrochemical properties of the modified materials are comparably explored by means of cyclic voltammetry(CV),electrochemical impedance spectroscopy(EIS)and differential pulse voltammetry(DPV).Under the optimal conditions,the proposed electrochemical sensor for the detection of BPA has a linear range of 0.8-400μmol/L and a detection limit of 0.0235μmol/L(S/N=3)with high sensitivity,good selectivity and high stability.In addition,the proposed sensor was used to measure the content of BPA in real water samples with a recovery rate of 97.94%-104.56%.At present,the synthesis of MnFe_(2)O_(4)/GR provides more opportunities for the electrochemical detection of BPA in practical applications.
