A signifcant challenge in the progress and development of Building-Integrated-Photovoltaic(B-I-PV)systems is concerned with the extraction of maximum power from PV modules.The PV system archtecture is an essential fea...A signifcant challenge in the progress and development of Building-Integrated-Photovoltaic(B-I-PV)systems is concerned with the extraction of maximum power from PV modules.The PV system archtecture is an essential feature to extract the maximum power.The conventional PV-centralinverter architecture consists of various connections among the PV modules,which are sensitive to shading effects and pro-duces mismatching power loss under partial shading conditions(PSCs),Hence,photovoltaic-distributed-maximum power point tracking(PV-D-MPPT)architecture has been proposed to extract the maximum power.In.PV-1 D-MPPT architecture,the output terminals of DC-DC converters are connected either in series or parallel configuration.The main limitation of the series configuration in open-loop MPPT control is the crosscoupling effect.Because of cross-coupling effects,the maximum-power-point(M-P-P)operation of shaded PV modules is lost under PSCs.The lost in M-P-P operation of shaded PV module also affects the unshaded modules M-P-P operation.Under crosscoupling ffeets,the DC-DC converters are consuming the power instead of delivering to the load.Despite the research activity,there are hardly any papers presenting a clear,comprehensive and mathematical analysis on the existence of cross-couplings in PV string-integrated-converters(S-1-Cs).This article presents a mathematical analysis and also explains the conditions for the existent of cross-coupling ffeets.The experimental results also validate with the mathematically analysed results.This article also discusses the modeling of the two-diode model of PV module,design of boost type S-1C,and the Perturb and Observe(P&O)MPPT algorithm implementation.展开更多
作为当今世界上最先进的测流仪器,水平式声学多普勒流速剖面仪(Horizontal Acoustic Doppler Current Profiler,H-ADCP)因其精度高、速度快等突出优势在河流中的应用越来越广泛,但在航运业发达地区,由于受船行波的影响,很难得到稳定可...作为当今世界上最先进的测流仪器,水平式声学多普勒流速剖面仪(Horizontal Acoustic Doppler Current Profiler,H-ADCP)因其精度高、速度快等突出优势在河流中的应用越来越广泛,但在航运业发达地区,由于受船行波的影响,很难得到稳定可靠的流速数据,阻碍了HADCP在平原河网地区的应用和推广。目前技术上很难做到完全消除船行波的影响,本文将HADCP应用在平原河网地区对流速进行测量,并分析了船行波对测量精度的影响。从H-ADCP设备选型、测量和安装方式、测量预处理、数据后处理等多方面入手,可以有效消减船行波对H-ADCP的影响,从而提高测流精度。同时,通过实验测量断面一天内平均流速变化情况,得到受船行波影响后的流速波形,然后采用数据处理手段,验证了所提方法的可行性。展开更多
文摘A signifcant challenge in the progress and development of Building-Integrated-Photovoltaic(B-I-PV)systems is concerned with the extraction of maximum power from PV modules.The PV system archtecture is an essential feature to extract the maximum power.The conventional PV-centralinverter architecture consists of various connections among the PV modules,which are sensitive to shading effects and pro-duces mismatching power loss under partial shading conditions(PSCs),Hence,photovoltaic-distributed-maximum power point tracking(PV-D-MPPT)architecture has been proposed to extract the maximum power.In.PV-1 D-MPPT architecture,the output terminals of DC-DC converters are connected either in series or parallel configuration.The main limitation of the series configuration in open-loop MPPT control is the crosscoupling effect.Because of cross-coupling effects,the maximum-power-point(M-P-P)operation of shaded PV modules is lost under PSCs.The lost in M-P-P operation of shaded PV module also affects the unshaded modules M-P-P operation.Under crosscoupling ffeets,the DC-DC converters are consuming the power instead of delivering to the load.Despite the research activity,there are hardly any papers presenting a clear,comprehensive and mathematical analysis on the existence of cross-couplings in PV string-integrated-converters(S-1-Cs).This article presents a mathematical analysis and also explains the conditions for the existent of cross-coupling ffeets.The experimental results also validate with the mathematically analysed results.This article also discusses the modeling of the two-diode model of PV module,design of boost type S-1C,and the Perturb and Observe(P&O)MPPT algorithm implementation.
文摘作为当今世界上最先进的测流仪器,水平式声学多普勒流速剖面仪(Horizontal Acoustic Doppler Current Profiler,H-ADCP)因其精度高、速度快等突出优势在河流中的应用越来越广泛,但在航运业发达地区,由于受船行波的影响,很难得到稳定可靠的流速数据,阻碍了HADCP在平原河网地区的应用和推广。目前技术上很难做到完全消除船行波的影响,本文将HADCP应用在平原河网地区对流速进行测量,并分析了船行波对测量精度的影响。从H-ADCP设备选型、测量和安装方式、测量预处理、数据后处理等多方面入手,可以有效消减船行波对H-ADCP的影响,从而提高测流精度。同时,通过实验测量断面一天内平均流速变化情况,得到受船行波影响后的流速波形,然后采用数据处理手段,验证了所提方法的可行性。
