Article
Materials Science, Paper & Wood
Enze Zhang, Hanbo Zheng, Chuansheng Zhang, Jiaqi Wang, Kuikui Shi, Jing Guo, Harald Schwarz, Chaohai Zhang
Summary: The study introduced a non-destructive method based on multivariate chemical indicators to improve the reliability and accuracy of transformer cellulose paper insulation assessment, which was validated by experiments.
Review
Green & Sustainable Science & Technology
Anu Kumar Das, Aniket Shivaji Chavan, Dayal Ch. Shill, Saibal Chatterjee
Summary: Currently, most electric utility transformers use insulation materials consisting of cellulose impregnated with mineral oil. Traditional mineral oil is considered harmful to the environment, prompting researchers to explore renewable insulating oils with high environmental and fire safety features. However, vegetable insulating oils are still 2-3 times more expensive, leading some researchers to experiment with new vegetable oils like Jatropha Curcas oil.
SUSTAINABLE ENERGY TECHNOLOGIES AND ASSESSMENTS
(2021)
Article
Chemistry, Physical
Christine Browne, Michael J. Hertaeg, David Joram Mendoza, Mahdi Naseri, Maoqi Lin, Gil Garnier, Warren Batchelor
Summary: Researchers have developed a new type of micropatterned cellulose nanocrystal (CNC) free-standing films that can control the surface hydrophobicity by manipulating the dimensions of the channels. Sharp channels with dimensions of 5 mu m x 6 mu m were achieved using a 2.2 wt% suspension with a CNC:CMC ratio of 10:1, which is the smallest patterned channel size reported so far. By varying the channel dimensions, the water droplet contact angle can be adjusted to resist or promote wetting, without altering the surface chemistry.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2023)
Article
Engineering, Electrical & Electronic
Hanbo Zheng, Enchen Yang, Xufan Li, Chenyao Liu, Zijian Wang, Tao Yang, Wei Yao
Summary: This study focuses on the thermal aging process of cellulosic insulating paper and identifies the main reaction pathways for formic acid generation. Experimental results support the feasibility of formic acid as an aging indicator for cellulosic insulating paper.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2021)
Article
Materials Science, Paper & Wood
Shanshan Liu, Xiujing Liu, Qiang Wang, Yingchao Wang, Xingxiang Ji, Guihua Yang, Jiachuan Chen, Yonghao Ni
Summary: Superhydrophobic and strong cellulosic paper was fabricated through a two-step process of heavy refining and dip coating. The resulting paper showed high water contact angle and low uptake of hydrophobic solution, making it suitable for high value-added utilization of fiber.
Review
Energy & Fuels
Enze Zhang, Jiang Liu, Chaohai Zhang, Peijun Zheng, Yosuke Nakanishi, Thomas Wu
Summary: Chemical compounds dissolved in insulating oil can excellently monitor the aging condition of paper, which has attracted increasing interest in the field of transformer condition monitoring and fault diagnosis. This study provides a comprehensive insight into the indicators of insulating paper aging, including aging characteristics, physico-chemical characteristics, shortcomings of different compounds, generation pathways and mechanisms, and monitoring technologies. It is expected that these chemical indicators can provide better guidance for evaluating paper insulation performance and transformer aging. The study also outlines the latest research progress, current challenges, and future prospects.
Article
Engineering, Electrical & Electronic
Hanbo Zheng, Enchen Yang, Shuyue Wu, Weijie Lv, Hang Yang, Xufan Li, Xiaoqing Luo, Wei Hu
Summary: This article simulated the thermal aging process of cellulosic insulating paper to identify the main reaction pathways for the formation of CO2 and CO molecules, revealing that the amount of CO2 and CO generated is closely related to temperature. The study provides theoretical support for the accurate application of carbon oxides aging evaluation index at different temperatures.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2022)
Article
Materials Science, Composites
Tiantian Xia, Mengyun Wu, Junbao Yan, Feihua Yang, Xuyi Wang, Yingbin Jia, Hua Wang, Siwei Xiong, Luoxin Wang
Summary: The chemical structure change during thermal oxidative aging of ACFs/PPS composite paper was studied, along with the correlation between the evolution of chromophore/auxochrome groups and color appearance development. A correlation model among the degrees of thermal aging, color appearance evolution, and mechanical properties changes was established using color space theory. The change in color factor could be used to rapidly estimate the degree of aging and mechanical strength of ACFs/PPS composite paper under different conditions.
POLYMER COMPOSITES
(2023)
Article
Engineering, Electrical & Electronic
Ruimin Song, Weigen Chen, Dingkun Yang, Haiyang Shi, Ruyue Zhang, Zewei Wang
Summary: Detecting insulation performance through testing Raman spectroscopy of transformer oil is noninvasive and shows great promise in on-site diagnosis. The method proposed in this article has the potential to provide accurate determination for diagnosing oil-immersed transformers' aging conditions.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2021)
Article
Materials Science, Paper & Wood
Abderrazak Hamam, Mounira Maiza, Mohamed M. Chehimi, Dehbia Oukil
Summary: In this study, a cellulosic paper substrate coated with polypyrrole through in situ polymerization was developed, followed by the coating of silver nanoparticles. Characterization and electrochemical tests confirmed the unique high performance electrocatalytic properties of this low-cost, flexible cellulosic paper electrode material in aqueous solutions.
Article
Materials Science, Paper & Wood
Hui Ren, Wenxuan Mo, Bo Li
Summary: As a chemical additive, surfactants are widely used in papermaking processes, but their effects on fiber properties, especially during paper recycling, have been rarely studied. This research investigated the effects of three types of surfactants on cellulosic fibers and paper properties during five-time recycling. The results showed that cationic surfactant CTAB had a negative effect on paper properties, while anionic surfactant SDBS had both positive and negative effects. Nonionic surfactant TX-100 was generally more beneficial for fiber and paper. This study improved the understanding of surfactant application in papermaking.
Article
Energy & Fuels
Anthony Igiligi, Armin Vielhauer, Mathias Ehrenwirth, Christian Hurm, Thorsten Summ, Christoph Trinkl, Daniel Navarro Gevers
Summary: The application of voltage reduction in medium and low voltage grids has been implemented since the 1980s to reduce peak power demand or energy consumption. Conservation Voltage Reduction (CVR) is one such approach that uses a voltage control device to adjust the voltage setpoint, thereby affecting the active and reactive power supply in the network. This research aims to determine and validate the CVR factor (CVRf) for peak demand reduction by comparing measurement data obtained during regular tap changes with randomly distributed periods outside tap change operations.
Article
Computer Science, Information Systems
Song Cheng, Wei Sun, Qingguo Chen, Guokai Huang
Summary: This study investigates the influence of oil replacement on the assessment of aging states in transformer insulation paper, and proposes a modified model to improve the accuracy of the assessment.
Review
Chemistry, Applied
Tongtong Yun, Yehan Tao, Qiang Li, Yi Cheng, Jie Lu, Yanna Lv, Jian Du, Haisong Wang
Summary: This review focuses on the superhydrophobic modification and high value-added applications of cellulosic paper-based materials, providing valuable insights for the rational construction of sustainable functional devices. It also presents the comprehensive discussion of functionalized applications, including paper straw and paper mulch film, with great industrialization potential and value.
CARBOHYDRATE POLYMERS
(2023)
Article
Multidisciplinary Sciences
Ahmed S. Belal, Jehan El Nady, Azza Shokry, Shaker Ebrahim, Moataz Soliman, Marwa Khalil
Summary: Constructing copper hydroxide nanorods layer onto cellulosic filter paper surface can produce superhydrophobic and superoleophilic properties. The modified surface is rougher and has good hydrophobicity and separation efficiency. The absorption capacity for diesel oil is high, and the flux is influenced by the viscosity of the oil.
SCIENTIFIC REPORTS
(2021)
Article
Engineering, Electrical & Electronic
Jiefeng Liu, Kuo Jiang, Qingyin Wang, Heng Zhang, Enze Zhang, Xianhao Fan, Yiyi Zhang
Summary: An improved second-order kinetic model is proposed in this study to describe the degradation process of transformer paper insulation, taking into account the influence of non-uniform thermal field. The relationship between the parameters in the improved model and the temperature and moisture content at different winding heights is obtained. The results show that the proposed model provides a more scientific description of the degradation of paper insulation.
Article
Engineering, Electrical & Electronic
Yiyi Zhang, Chuqi Xu, Wenchang Wei, Yuke Deng, Shuangxi Nie, Junwei Zha
Summary: This study demonstrates that doping nano-SiC particles can enhance the thermal stability and mechanical properties of cellulose, providing practical application significance.
Article
Engineering, Electrical & Electronic
Jiefeng Liu, Qingyin Wang, Xianhao Fan, Tengyue Sun, Yiyi Zhang
Summary: This study proposes an improved geometric model for constructing the frequency-domain spectroscopy (FDS) of oil-paper insulation under axial nonuniform aging. By comparing the FDS calculated by the proposed model with the collected data, the accuracy of the model has been verified, with a mean relative error (MRE) of less than 14.40%. This work is expected to provide an effective tool for constructing the FDS database of nonuniform aged oil-paper insulation.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2023)
Article
Engineering, Multidisciplinary
Xiaolian Zhang, Baocong Lin, Minghui Yin, Sipeng Hao, Chaohai Zhang, Tengjun Zuo
Summary: This article studies the frequency control method of a net-zero smart building energy system with a wind power system, analyzing the influence of wind turbulence characteristics on system frequency. The novelty lies in formulating the relationship between frequency deviation and turbulence characteristics, and designing an innovative frequency controller that incorporates an additional reference power output to improve frequency regulation performance based on turbulence characteristics. Simulations and experiments on a frequency control experimental platform demonstrate the effectiveness and superiority of the improved control method.
IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS
(2023)
Article
Engineering, Electrical & Electronic
Xingtuo Zhang, Yiyi Zhang, Alu Xu, Chunli Meng, Zhonghuan Su
Summary: This article proposes an automated insulator surface condition analysis method based on vision measurement and convolutional neural network (CNN). The method extracts features using CNN and utilizes a softmax classifier to obtain analysis results. It also introduces a novel attention module, called JFCMSPA, to efficiently learn feature importance. Experimental results demonstrate the effectiveness of the method and its value in power equipment inspection.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Article
Engineering, Electrical & Electronic
Jiefeng Liu, Boshu Song, Enze Zhang, Heng Zhang, Yiyi Zhang, Hui Hwang Goh
Summary: This work proposes a two-stage residual lifespan prediction model for insulating paper based on methanol and furfural indicators. The changes in the contents of methanol and furfural in the oil are examined to determine two demarcation points for dividing the insulation's life into different aging stages. By coupling with the second-order aging kinetic equation, the two-stage residual lifespan model is obtained. The proposed model is proven to be valid with a mean absolute percentage error of 5.6% for insulating paper's residual lifespan when compared to the conventional method of using a single indicator.
IEEE TRANSACTIONS ON POWER DELIVERY
(2023)
Article
Engineering, Electrical & Electronic
Min-gang Tan, Chaohai Zhang, Rui Zhang, Bin Chen
Summary: It is of great significance to extract voltage sag disturbances with high signal-to-noise ratio (SNR) in order to locate the voltage sag source in distribution networks. This study summarizes two classical disturbance extraction methods (DEM) and proposes three new DEMs with higher SNR based on sine wave reconstruction. The new DEMs show better SNR performance and adaptability to voltage sag localization algorithms compared to classical DEMs.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2023)
Article
Materials Science, Paper & Wood
Yiyi Zhang, Yuke Deng, Wenchang Wei, Chuqi Xu, Junwei Zha
Summary: The mechanical and thermal properties of cellulose insulating paper with different NFC doping mass fractions were analyzed through molecular dynamics simulations and experiments, and the optimal doping ratio of NFC was determined. The results showed that the NFC-modified insulating paper exhibited improved mechanical properties, thermal conductivity, thermogravimetric properties, and glass transition temperature compared to ordinary insulating paper.
Article
Engineering, Electrical & Electronic
Chuying Liu, Heng Zhang, Yiyi Zhang, Ji Liu, Jiefeng Liu
Summary: Alcohol indicators in oil are used to assess the aging condition of transformer paper insulation. Fluctuations in alcohol concentration in insulating oil impact the accuracy of aging assessment. Low molecular acid (LMA) plays a significant role in influencing alcohol concentration in insulating oil. However, the mechanism of LMA on alcohol diffusion in oil-paper insulation has not been thoroughly studied. This research investigates the microscopic mechanism of alcohol diffusion under the influence of LMA using molecular dynamics simulation and experimental verification.
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
(2023)
Article
Multidisciplinary Sciences
Hetong Wang, Kuishuang Feng, Peng Wang, Yuyao Yang, Laixiang Sun, Fan Yang, Wei-Qiang Chen, Yiyi Zhang, Jiashuo Li
Summary: Under a high-cost scenario for battery critical materials, the adoption of electric vehicles in China may be greatly reduced, leading to increased carbon emissions. It is crucial to have affordable EVs for meeting climate commitments, but the expected surge in prices of critical materials could hinder EV uptake.
NATURE COMMUNICATIONS
(2023)
Article
Polymer Science
Ping Huang, Wenyao Yu, Chunhao Lu, Xinghua He, Yiyi Zhang, Yansong Liu, Jiaheng Zhou, Yuwang Liang
Summary: An accelerated thermal ageing experimental platform is established to evaluate the insulation status of cross-linked polyethylene (XLPE) after thermal ageing. Measurements of polarization and depolarization current (PDC) and elongation at break are conducted under different ageing durations. The results show that the ER% of XLPE insulation decreases with ageing degree, and the polarization and depolarization current increase significantly. The proposed stable relaxation charge quantity and dissipation factor at 0.1 Hz have a good fitting relationship with the ER% of XLPE insulation, effectively evaluating the thermal ageing state of XLPE insulation.
Article
Polymer Science
Zhiyi Pang, Yi Li, Yiyi Zhang
Summary: Using density functional theory, the microscopic reactions and space charge characteristics of ethylene propylene diene monomer (EPDM) under electric fields were studied. The results showed that as the electric field intensity increased, the total energy decreased while the dipole moment and polarizability increased, leading to a decrease in EPDM's stability. The elongation of the molecular chain under the electric field resulted in a decline in its mechanical and electrical properties. The findings also revealed that EPDM became more susceptible to trapping free electrons or injecting charge with increased electric field intensity.
Article
Green & Sustainable Science & Technology
Yiyi Zhang, Huanzhi Fu, Xinghua He, Zhen Shi, Tao Hai, Peng Liu, Shan Xi, Kai Zhang
Summary: In this study, the properties and key nodes of the regional sectoral electricity-related water network in China were analyzed using a multi-regional input-output model and complex network analysis. The results showed that electricity transmission can affect regional water consumption index and key nodes were identified based on degree, intensity, betweenness centrality, and closeness centrality indicators. This study can provide references for the common sustainable development of power systems and water resources.
Article
Chemistry, Multidisciplinary
Xueling Wei, Jie Nong, Yiyi Zhang, Hansi Ma, Rixing Huang, Zhenkun Yuan, Zhenfu Zhang, Zhenrong Zhang, Junbo Yang
Summary: This study introduces Sb2S3 phase change material into nanoantenna design, utilizing genetic algorithms and finite-difference time-domain (FDTD) solutions to achieve tunable structural color and Mie resonance in reflection mode. Sb2S3 phase change material with wide band gap and low propagation loss enables reversible color change and can be used in angle-sensitive detectors.
Article
Engineering, Electrical & Electronic
Min-gang Tan, Chaohai Zhang, Bin Chen
Summary: An optimal configuration method of the power quality monitor (PQM) considering voltage sag location is proposed. The method includes several steps: utilizing integer linear programming to obtain optimal schemes while ensuring observability, employing a decision tree to filter out the scheme with better voltage sag location accuracy, defining three indicators of PQM monitoring, and testing the optimal deployment scheme on the IEEE 39-node network.
ELECTRIC POWER SYSTEMS RESEARCH
(2023)
