The development and utilization of large-scale distributed power generation and the increase of impact loads represented by electric locomotives and new energy electric vehicles have brought great challenges to the st...The development and utilization of large-scale distributed power generation and the increase of impact loads represented by electric locomotives and new energy electric vehicles have brought great challenges to the stable operation of the regional power grid.To improve the prediction accuracy of power systems with source-load twoterminal uncertainties,an adaptive cubature Kalman filter algorithm based on improved initial noise covariance matrix Q0 is proposed in this paper.In the algorithm,the Q0 is used to offset the modeling error,and solves the problem of large voltage amplitude and phase fluctuation of the source-load two-terminal uncertain systems.Verification of the proposed method is implemented on the IEEE 30 node system through simulation.The results show that,compared with the traditional methods,the improved adaptive cubature Kalman filter has higher prediction accuracy,which verifies the effectiveness and accuracy of the proposed method in state estimation of the new energy power system with source-load two-terminal uncertainties.展开更多
This work investigated the effect of granular activated carbon adsorption （GACA） on fluorescence characteristics of dissolved organic matter （DOM） in secondary effluent, by means of excitation-emission matrix （EE...This work investigated the effect of granular activated carbon adsorption （GACA） on fluorescence characteristics of dissolved organic matter （DOM） in secondary effluent, by means of excitation-emission matrix （EEM） spectra, the fluorescence regional integra- tion （FRI） method, synchronous spectra, the fluorescence index defined as the ratio of fluorescence emission intensity at wavelength 450nm to that at 500nm at excitation （λex）= 370 am, and the wavelength that corre- sponds to the position of the normalized emission band at its half intensity （λ0.5）. DOM in the secondary effluent from the North Wastewater Treatment Plant （Shenyang, China） was fractionated using XAD resins into 5 fractions： hydrophobic acid （HPO-A）, hydrophobic neutral （HPO- N）, transphilic acid （TPI-A）, transphi｜ic neutral （TPI-N） and hydrophilic fraction （HPI）. Results showed that fluorescent materials in HPO-N and TPI-N were less readily removed than those in the other fractions by GACA. The relative content of fluorescent materials in HPO-A, TPI-A and HPI decreased whereas that in HPO- N and TPI-N increased as a consequence of GACA. Polycyclic aromatics in all DOM fractions were preferen- tially absorbed by GACA, in comparison with bulk DOM expressed as DOC. On the other hand, the adsorption of aromatic amino acids and humic acid-like fluorophores exhibiting fluorescence peaks in synchronous spectra by GACA seemed to be dependent on the acid/neutralproperties of DOM fractions. All five fractions had decreased fluorescence indices as a result of GACA. GACA led to a decreased λ0.5 value for HPO-A, increased ,λ0.5 values for HPO-N, TPI-A and HPI, and a consistent λ0.5 value for TPI-N.展开更多
基金supported by the Tianyou Youth Talent Lift Program of Lanzhou Jiaotong University,the Nature Science Foundation of Gansu(No.21JR1RA255)the Gansu University Innovation Fund Project(Nos.2020A-036 and 2021B-111).
文摘The development and utilization of large-scale distributed power generation and the increase of impact loads represented by electric locomotives and new energy electric vehicles have brought great challenges to the stable operation of the regional power grid.To improve the prediction accuracy of power systems with source-load twoterminal uncertainties,an adaptive cubature Kalman filter algorithm based on improved initial noise covariance matrix Q0 is proposed in this paper.In the algorithm,the Q0 is used to offset the modeling error,and solves the problem of large voltage amplitude and phase fluctuation of the source-load two-terminal uncertain systems.Verification of the proposed method is implemented on the IEEE 30 node system through simulation.The results show that,compared with the traditional methods,the improved adaptive cubature Kalman filter has higher prediction accuracy,which verifies the effectiveness and accuracy of the proposed method in state estimation of the new energy power system with source-load two-terminal uncertainties.
文摘This work investigated the effect of granular activated carbon adsorption （GACA） on fluorescence characteristics of dissolved organic matter （DOM） in secondary effluent, by means of excitation-emission matrix （EEM） spectra, the fluorescence regional integra- tion （FRI） method, synchronous spectra, the fluorescence index defined as the ratio of fluorescence emission intensity at wavelength 450nm to that at 500nm at excitation （λex）= 370 am, and the wavelength that corre- sponds to the position of the normalized emission band at its half intensity （λ0.5）. DOM in the secondary effluent from the North Wastewater Treatment Plant （Shenyang, China） was fractionated using XAD resins into 5 fractions： hydrophobic acid （HPO-A）, hydrophobic neutral （HPO- N）, transphilic acid （TPI-A）, transphi｜ic neutral （TPI-N） and hydrophilic fraction （HPI）. Results showed that fluorescent materials in HPO-N and TPI-N were less readily removed than those in the other fractions by GACA. The relative content of fluorescent materials in HPO-A, TPI-A and HPI decreased whereas that in HPO- N and TPI-N increased as a consequence of GACA. Polycyclic aromatics in all DOM fractions were preferen- tially absorbed by GACA, in comparison with bulk DOM expressed as DOC. On the other hand, the adsorption of aromatic amino acids and humic acid-like fluorophores exhibiting fluorescence peaks in synchronous spectra by GACA seemed to be dependent on the acid/neutralproperties of DOM fractions. All five fractions had decreased fluorescence indices as a result of GACA. GACA led to a decreased λ0.5 value for HPO-A, increased ,λ0.5 values for HPO-N, TPI-A and HPI, and a consistent λ0.5 value for TPI-N.
