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Zhidong Jia
Tsinghua University Department of Electrical Engineering and Engineering Laboratory of Power Equipment Reliability in Complicated Coastal Environments, Tsinghua Shenzhen International Graduate School Tsinghua University Beijing China

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Article
Published: 01 November 2020 in Journal of Polymer Science
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Silicone grease, consisting of polydimethylsiloxane (PDMS) chains and silica, has been widely used in electrical power systems; this causes thermal aging of silicone grease at high temperatures. In this study, the thermal degradation process of silicone grease was analyzed at different temperatures using reactive force field (ReaxFF). The effects of different factors, such as silica surface chemistry and oxygen content, on the final products have been studied. The results showed that the final products can be divided into two main categories: small gaseous molecules and large‐molecule products. The number of gaseous hydrocarbon products and their unsaturation increased with increasing temperature. The large‐molecule products were consisted of silica and surrounding PDMS chains, which were broken and reorganized during the thermal degradation process. The time interval required for the formation of the large‐molecule products is larger when silica with a modified surface is used. The addition of oxygen during thermal degradation provided a new decomposition route. The O/Si ratio in the residue of silica grease increased while the C/Si ratio decreased with the increasing oxygen content. A new method for the generation of SiO2 residues in a sufficient oxygen environment was proposed based on the reactions between oxygen and Si–CH3.

ACS Style

Xinyu Wei; Chi Xu; Zhidong Jia; Xilin Wang. Molecular dynamics simulation of thermal degradation of silicone grease using reactive force field. Journal of Polymer Science 2020, 138, 1 .

AMA Style

Xinyu Wei, Chi Xu, Zhidong Jia, Xilin Wang. Molecular dynamics simulation of thermal degradation of silicone grease using reactive force field. Journal of Polymer Science. 2020; 138 (15):1.

Chicago/Turabian Style

Xinyu Wei; Chi Xu; Zhidong Jia; Xilin Wang. 2020. "Molecular dynamics simulation of thermal degradation of silicone grease using reactive force field." Journal of Polymer Science 138, no. 15: 1.

Journal article
Published: 06 May 2020 in Applied Materials Today
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The applications of dielectric functionally graded materials in high-voltage systems have emerged as a potential strategy to obtain superior insulation performance in recent years. However, the existing preparation methods mainly rely on simple lamination or centrifugal force intervention, and cannot adapt to the complex electric field spatial distribution. In this work, we developed low partial discharge (PD), high flashover voltage barium titanate/epoxy resin (BT/ER) insulation composites with graded permittivity, which were assembled by the in situ electric field. Our approach involves (a) the migration and deposition of BT in high electric field strength regions, driven by in situ electrophoretic forces in the BT/ER suspension (dispensable), (b) the alignment of BT in high electric field strength regions, driven by in situ dielectrophoretic forces in the BT/ER suspension, and (c) the “freezing” of the composite structure by curing. The insulation performance of the samples after this electric field structuring was assessed by PD measurements and flashover tests. The PD of the samples with 2.0 vol% BT and electric field treatment was significantly reduced, and the flashover voltage was increased by 31.8% compared with the pure ER sample. Optical microscope images, scanning electron microscope (SEM) images and finite element simulations also verify that this type of electric field structuring can effectively reduce the electric field non-uniform coefficient. We believe that the strategy of electric field assembly to prepare graded permittivity materials (GPMs) is promising candidate for high performance insulation applications.

ACS Style

Zikui Shen; Xilin Wang; Tianfeng Zhang; Zhidong Jia. In situ electric field driven assembly to construct adaptive graded permittivity BaTiO3/epoxy resin composites for improved insulation performance. Applied Materials Today 2020, 20, 100647 .

AMA Style

Zikui Shen, Xilin Wang, Tianfeng Zhang, Zhidong Jia. In situ electric field driven assembly to construct adaptive graded permittivity BaTiO3/epoxy resin composites for improved insulation performance. Applied Materials Today. 2020; 20 ():100647.

Chicago/Turabian Style

Zikui Shen; Xilin Wang; Tianfeng Zhang; Zhidong Jia. 2020. "In situ electric field driven assembly to construct adaptive graded permittivity BaTiO3/epoxy resin composites for improved insulation performance." Applied Materials Today 20, no. : 100647.

Case report
Published: 10 April 2020 in Applied Sciences
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The composition of contamination deposited on transmission line insulators can affect their surface flashover voltage. Currently, there is no rapid on-line method to detect this contamination composition in power grids. In this paper, we applied laser-induced breakdown spectroscopy (LIBS) to analyze contamination on insulator surfaces. Usually, Na and Ca salts are found in contamination along with various sulfate, carbonate, and chloride compounds. As an element’s detection method, LIBS can only measure a certain element content, for example, Ca. The mixture of various compounds with the same cations can influence the LIBS signal. The influence of mixing ratios on the calibration curves and relative spectral intensity was studied via LIBS. Na2CO3, NaHCO3, CaSO4, and CaCO3 samples containing different proportions of Na and Ca were prepared. The linear correlation coefficients (R2) for the Na and Ca calibration curves generated using various mixing ratios were analyzed. The results showed that the mixture ratio did not dramatically affect the linear calibration curves for mixtures containing the same cations. This finding may significantly reduce the difficulty of applying LIBS analysis for complex contamination on insulators. The laser energy density had effects on the spectral characteristics of the measured elements. The partial least-square regression (PLSR) model can improve the accuracy of Na and Ca prediction.

ACS Style

Shan Lu; Xinwei Wang; Tianzheng Wang; Xinran Qin; Xilin Wang; Zhidong Jia. Analysis of Salt Mixture Contamination on Insulators via Laser-Induced Breakdown Spectroscopy. Applied Sciences 2020, 10, 2617 .

AMA Style

Shan Lu, Xinwei Wang, Tianzheng Wang, Xinran Qin, Xilin Wang, Zhidong Jia. Analysis of Salt Mixture Contamination on Insulators via Laser-Induced Breakdown Spectroscopy. Applied Sciences. 2020; 10 (7):2617.

Chicago/Turabian Style

Shan Lu; Xinwei Wang; Tianzheng Wang; Xinran Qin; Xilin Wang; Zhidong Jia. 2020. "Analysis of Salt Mixture Contamination on Insulators via Laser-Induced Breakdown Spectroscopy." Applied Sciences 10, no. 7: 2617.

Journal article
Published: 13 February 2020 in Molecules
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Surface pollution deposition in a high voltage surface can reduce the surface flashover voltage, which is considered to be a serious accident in the transmission of electric power for the high conductivity of pollution in wet weather, such as rain or fog. Accordingly, a rapid and accurate online pollution detection method is of great importance for monitoring the safe status of transmission lines. Usually, to detect the equivalent salt deposit density (ESDD) and non-soluble deposit density (NSDD), the pollution should be collected when power cut off and bring back to lab, time-consuming, low accuracy and unable to meet the online detection. Laser-induced breakdown spectroscopy (LIBS) shows the highest potential for achieving online pollution detection, but its application in high voltage electrical engineering has only just begun to be examined. In this study, a LIBS method for quantitatively detecting the compositions of pollutions on the insulators was investigated, and the spectral characteristics of a natural pollution sample were examined. The energy spectra and LIBS analysis results were compared. LIBS was shown to detect pollution elements that were not detected by conventional energy spectroscopy and had an improved capacity to determine pollution composition. Furthermore, the effects of parameters, such as laser energy intensity and delay time, were investigated for artificial pollutions. Increasing the laser energy intensity and selecting a suitable delay time could enhance the precision and relative spectral intensities of the elements. Additionally, reducing the particle size and increasing the density achieved the same results.

ACS Style

Xinwei Wang; Shan Lu; Tianzheng Wang; Xinran Qin; Xilin Wang; Zhidong Jia. Analysis of Pollution in High Voltage Insulators via Laser-Induced Breakdown Spectroscopy. Molecules 2020, 25, 822 .

AMA Style

Xinwei Wang, Shan Lu, Tianzheng Wang, Xinran Qin, Xilin Wang, Zhidong Jia. Analysis of Pollution in High Voltage Insulators via Laser-Induced Breakdown Spectroscopy. Molecules. 2020; 25 (4):822.

Chicago/Turabian Style

Xinwei Wang; Shan Lu; Tianzheng Wang; Xinran Qin; Xilin Wang; Zhidong Jia. 2020. "Analysis of Pollution in High Voltage Insulators via Laser-Induced Breakdown Spectroscopy." Molecules 25, no. 4: 822.

Conference paper
Published: 31 October 2019 in Lecture Notes in Electrical Engineering
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Polymer insulators offered several benefits over original ceramic insulators on exceptional hydrophobicity and anti-pollution flashover, which has been widely used in power transmission lines to improve contamination performance all over the world. As an organic polymer, the biological corrosion resistance of silicone rubber is one disadvantage. It is important to investigate the discharge mechanism of algae-fouled silicone rubber. This paper aims to explore the discharge mechanism of algae-fouled silicone rubber based on special hydrophilic property of biological contaminants. Artificial pollution flashover test and computer simulation are conducted to explore the discharge process and characteristics of the algae-fouled silicon rubber, and the biological pollution discharge model of silicon rubber is to be established. Results show that the arc channel communicated algae population rather than clean silicone rubber surface, and the severity of discharge is positively correlated with the density of algae. On the other hand, biological pollution reduces flashover voltage by about 45%. Algae reduces the flashover voltage of silicone rubber surface, which affects the surface discharge of silicone rubber. This part of the hydrophilic surface of the silicone rubber discharge is completely different from the ordinary hydrophobic silicone rubber surface.

ACS Style

Shifang Yang; Zhidong Jia; Xiaogang Ouyang. Research on the Discharge Mechanism of the Algae-Contaminated Insulators. Lecture Notes in Electrical Engineering 2019, 3 -11.

AMA Style

Shifang Yang, Zhidong Jia, Xiaogang Ouyang. Research on the Discharge Mechanism of the Algae-Contaminated Insulators. Lecture Notes in Electrical Engineering. 2019; ():3-11.

Chicago/Turabian Style

Shifang Yang; Zhidong Jia; Xiaogang Ouyang. 2019. "Research on the Discharge Mechanism of the Algae-Contaminated Insulators." Lecture Notes in Electrical Engineering , no. : 3-11.

Journal article
Published: 01 August 2019 in Polymers
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Metal cabinets such as switch cabinets and ring network cabinets have the advantages of small footprints and good protection for equipment and offer neat and orderly protection. They are widely used in power systems. In a hot and humid environment, condensation can easily cause equipment to age and even cause insulation failure. Therefore, research on reliable anticondensation methods is of great significance for the safe operation of power equipment. In this study, phase change capsules with phase transition temperatures of 22 and 32 °C were used as fillers and liquid silicone rubber was used as a matrix to prepare liquid silicone rubber composites filled with phase change capsules for a temperature-control coating. Studies have shown that liquid silicone rubber coatings containing phase change capsules can significantly enhance the anticondensation performance of metal cabinets. By using a temperature-control coating on the surface where the cabinet experiences condensation, the temperature difference between the surface and the dew point is reduced, thereby slowing down the condensation rate and even preventing condensation.

ACS Style

Juyi Guo; Xilin Wang; Jun Wang; Chuan Chen; Yu Liu; Weinan Fan; Zhidong Jia. Study on the Anticondensation Characteristics of Liquid Silicone Rubber Temperature-Control Coatings. Polymers 2019, 11, 1282 .

AMA Style

Juyi Guo, Xilin Wang, Jun Wang, Chuan Chen, Yu Liu, Weinan Fan, Zhidong Jia. Study on the Anticondensation Characteristics of Liquid Silicone Rubber Temperature-Control Coatings. Polymers. 2019; 11 (8):1282.

Chicago/Turabian Style

Juyi Guo; Xilin Wang; Jun Wang; Chuan Chen; Yu Liu; Weinan Fan; Zhidong Jia. 2019. "Study on the Anticondensation Characteristics of Liquid Silicone Rubber Temperature-Control Coatings." Polymers 11, no. 8: 1282.

Journal article
Published: 06 April 2019 in Electric Power Systems Research
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Polymer insulators are reported to be contaminated by algae in tropical and subtropical climates around the world. Here, the biological contaminates were sectorial distributed on the insulator surface, stretching from the edge of the shed to the interior section near the core. The radial growth ratio and axial length of the algal column was varying under different environmental conditions. To explore the flashover characteristics under these conditions, the triangle plate model was established, in which algal colonization varied in radial growth ratio and algal column length quantitatively, and the inorganic pollutants were divided into three pollution degrees. The results showed that the increasing algal distribution gradually decreased the flashover voltage, whereas when the algal column was too slender, the flashover voltage increased. Meanwhile, the arc tended to elongate within the bio-contaminated area, and the flashover voltage significantly decreased when the algal column nearly covered the full specimen. Furthermore, surface conductivity and pollutant resistance were theoretically deduced from the Obenaus model, the results of which coincided with the calculated value from the flashover measurements. The change in discharge characteristics was attributed to the loss of hydrophobicity. This research could provide valuable information for the maintenance of bio-contaminated insulators in transmission lines of power systems.

ACS Style

Shifang Yang; Zhidong Jia; Xiaogang Ouyang. Effects of asymmetrical algal distribution on the AC flashover characteristics of bio-contaminated silicone rubber insulators. Electric Power Systems Research 2019, 172, 296 -302.

AMA Style

Shifang Yang, Zhidong Jia, Xiaogang Ouyang. Effects of asymmetrical algal distribution on the AC flashover characteristics of bio-contaminated silicone rubber insulators. Electric Power Systems Research. 2019; 172 ():296-302.

Chicago/Turabian Style

Shifang Yang; Zhidong Jia; Xiaogang Ouyang. 2019. "Effects of asymmetrical algal distribution on the AC flashover characteristics of bio-contaminated silicone rubber insulators." Electric Power Systems Research 172, no. : 296-302.

Journal article
Published: 05 March 2019 in Applied Sciences
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In order to study the wet snow flashover characteristics of 500-kV AC insulator strings under different arrangements, wet snow flashover tests were carried out in the large climate chamber of China Electric Power Research Institute (CEPRI). The wet snow flashover voltages were obtained by the even-rising method and the flashovers were filmed by a camera. The test results showed that the installation of an anti-icing shed of large diameter could increase the wet snow flashover voltage. The distance between the two insulators was a key parameter that influenced the discharge process and the flashover voltage. Under Λ-string arrangement, for common insulators, the flashover performance of iced insulators increased with the connection angle; for anti-icing insulators, the flashover performance increased at first and then decreased with the connection angle. In wet snow conditions, when the connection angle was at the commonly adopted angle of 60°, the flashover performance of the common insulators under the V-string and Λ-string arrangements was almost the same. For anti-icing insulators, however, the V-string arrangement was recommended according to the tests. The results obtained in this study can provide a reference for external insulation design in wet snow conditions.

ACS Style

Jingwei Xu; Fanghui Yin; Longji Li; Qingfeng Wen; Hao Wang; Shunnan Liu; Zhidong Jia; Masoud Farzaneh. Wet Snow Flashover Characteristics of 500-kV AC Insulator Strings with Different Arrangements. Applied Sciences 2019, 9, 930 .

AMA Style

Jingwei Xu, Fanghui Yin, Longji Li, Qingfeng Wen, Hao Wang, Shunnan Liu, Zhidong Jia, Masoud Farzaneh. Wet Snow Flashover Characteristics of 500-kV AC Insulator Strings with Different Arrangements. Applied Sciences. 2019; 9 (5):930.

Chicago/Turabian Style

Jingwei Xu; Fanghui Yin; Longji Li; Qingfeng Wen; Hao Wang; Shunnan Liu; Zhidong Jia; Masoud Farzaneh. 2019. "Wet Snow Flashover Characteristics of 500-kV AC Insulator Strings with Different Arrangements." Applied Sciences 9, no. 5: 930.

Journal article
Published: 03 March 2019 in Sensors
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Silicone rubber material is widely used in high-voltage external insulation systems due to its excellent hydrophobicity and hydrophobicity transfer performance. However, silicone rubber is a polymeric material with a poor ability to resist electrical tracking and erosion; therefore, some fillers must be added to the material for performance enhancement. The inclined plane test is a standard method used for evaluating the tracking and erosion resistance by subjecting the materials to a combination of voltage stress and contaminate droplets to produce failure. This test is time-consuming and difficult to apply in field inspection. In this paper, a new and faster way to evaluate the tracking and erosion resistance performance is proposed using laser-induced breakdown spectroscopy (LIBS). The influence of filler content on the tracking and erosion resistance performance was studied, and the filler content was characterized by thermogravimetric analysis and the LIBS technique. In this paper, the tracking and erosion resistance of silicone rubber samples was correctly classified using principal component analysis (PCA) and neural network algorithms based on LIBS spectra. The conclusions of this work are of great significance to the performance characterization of silicone rubber composite materials.

ACS Style

Ping Chen; Xilin Wang; Xun Li; Qishen Lyu; Naixiao Wang; Zhidong Jia. A Quick Classifying Method for Tracking and Erosion Resistance of HTV Silicone Rubber Material via Laser-Induced Breakdown Spectroscopy. Sensors 2019, 19, 1087 .

AMA Style

Ping Chen, Xilin Wang, Xun Li, Qishen Lyu, Naixiao Wang, Zhidong Jia. A Quick Classifying Method for Tracking and Erosion Resistance of HTV Silicone Rubber Material via Laser-Induced Breakdown Spectroscopy. Sensors. 2019; 19 (5):1087.

Chicago/Turabian Style

Ping Chen; Xilin Wang; Xun Li; Qishen Lyu; Naixiao Wang; Zhidong Jia. 2019. "A Quick Classifying Method for Tracking and Erosion Resistance of HTV Silicone Rubber Material via Laser-Induced Breakdown Spectroscopy." Sensors 19, no. 5: 1087.

Journal article
Published: 30 November 2018 in Molecules
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Recently, composite materials with nonlinear dielectric or resistive properties performed well in electric field homogenization and space charge suppression in a high voltage transmission and distribution system. For the purpose of obtaining insulation materials with desirable dielectric and electrical resistance properties, we investigated several fillers with nonlinear electrical properties doped in silicon rubber composites, and their dependency on the temperature and field. The samples of silicone rubber composites with different components were prepared using barium strontium titanate (BST) and zinc oxide (ZnO) as the filler, and high temperature vulcanized silicone rubber (SiR) as the matrix. The investigations revealed that the BST-doped samples showed different dielectric properties compared to ZnO-doped composites, with an increase in the electric field, which was nonlinear. The resistivity of both doped samples was similar. Results demonstrated that it was possible to achieve higher values of permittivity, and lower values of tanδ and resistivity, with respect to unfilled silicone rubber composites over a wide electrical field and temperature range. Discussion of the results attributes these important functional behaviours to the spontaneous polarization of nonlinear nanoparticles and the interaction between the SiR chains and the nonlinear nanoparticles at the interfacial area.

ACS Style

Juyi Guo; Xilin Wang; Zhidong Jia; Jun Wang; Chuan Chen. Nonlinear Electrical Properties and Field Dependency of BST and Nano-ZnO-Doped Silicone Rubber Composites. Molecules 2018, 23, 3153 .

AMA Style

Juyi Guo, Xilin Wang, Zhidong Jia, Jun Wang, Chuan Chen. Nonlinear Electrical Properties and Field Dependency of BST and Nano-ZnO-Doped Silicone Rubber Composites. Molecules. 2018; 23 (12):3153.

Chicago/Turabian Style

Juyi Guo; Xilin Wang; Zhidong Jia; Jun Wang; Chuan Chen. 2018. "Nonlinear Electrical Properties and Field Dependency of BST and Nano-ZnO-Doped Silicone Rubber Composites." Molecules 23, no. 12: 3153.

Journal article
Published: 06 November 2018 in Electric Power Systems Research
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Recently, to improve the anti-fouling flashover performance of porcelain and glass insulators, room temperature vulcanized (RTV) silicone rubber coatings have been widely applied to their surface. However, it was found that, in warm and humid areas in China, the presence of RTV silicone coating could facilitate the growth of biological contamination such as algae. This study firstly analyzed the biofouling regularity of algae growth on the surface of outdoor RTV-coated insulators, considering growth direction, distribution on sheds, substation equipment, insulating material and effect of corona discharge. The effects of algae on the surface micro morphology, functional groups and flashover voltage of field insulator were then studied. The effects of environmental factors on algae growth were studied in detail. Finally, the influence of algae on the hydrophobicity and flashover characteristics of the RTV coating was examined. Through research, the growth regularity of algae on insulator surface is presented and put forward some measures to prevent and control algae growth. The results also showed that the presence of algae could decrease flashover performance of the RTV-coated insulators. However, the effect of algae on the aging of materials was insignificant.

ACS Style

Xiaogang Ouyang; Fanghui Yin; Zhidong Jia; Shifang Yang; Ye Wang; Huan Bai; Xinghai Zhang; Yawei Li; Hongbo Chen. Research of biological contamination and its effect on the properties of RTV-coated insulators. Electric Power Systems Research 2018, 167, 138 -149.

AMA Style

Xiaogang Ouyang, Fanghui Yin, Zhidong Jia, Shifang Yang, Ye Wang, Huan Bai, Xinghai Zhang, Yawei Li, Hongbo Chen. Research of biological contamination and its effect on the properties of RTV-coated insulators. Electric Power Systems Research. 2018; 167 ():138-149.

Chicago/Turabian Style

Xiaogang Ouyang; Fanghui Yin; Zhidong Jia; Shifang Yang; Ye Wang; Huan Bai; Xinghai Zhang; Yawei Li; Hongbo Chen. 2018. "Research of biological contamination and its effect on the properties of RTV-coated insulators." Electric Power Systems Research 167, no. : 138-149.

Journal article
Published: 01 October 2018 in Electric Power Systems Research
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Algae contamination was observed on the surface of composite insulators in a subtropical environment especially China; this contamination affects the external insulation performance of high voltage direct current transmission and distribution equipment. This paper explores the effects of algae on the hydrophobicity of silicone rubber under various circumstances and its mechanism, through hydrophobicity experiments and the measurements of surface conductivity and flashover voltage. Particularly, as a biological contaminate, algae population was changing during the test period, so the results were corrected to illuminate the effect of algae growth. Among the climate parameters, humidity was noted as the major environmental factor affecting the extent of the decrease of hydrophobicity rather than temperature and illumination. Other factors, such as algae density and surface roughness, played a minor role in the influence of hydrophobicity of algae-fouled insulators. The surface conductivity increased with algae cells density in different humidity exponentially. The algae contamination decreased the flashover voltage significantly with the change of algae density. Besides, extracellular polymeric substances, including polysaccharides and proteins, were deduced to be primarily responsible for the change of hydrophobicity because of their strong viscosity and water adhesion effect. The results about hydrophobicity of algae-fouled silicone rubber could provide useful information for the maintenance of algae-fouled insulators. © 2017 Elsevier B.V.

ACS Style

Shifang Yang; Zhidong Jia; Xiaogang Ouyang; Huan Bai; Ruitong Liu. Hydrophobicity characteristics of algae-fouled HVDC insulators in subtropical climates. Electric Power Systems Research 2018, 163, 626 -637.

AMA Style

Shifang Yang, Zhidong Jia, Xiaogang Ouyang, Huan Bai, Ruitong Liu. Hydrophobicity characteristics of algae-fouled HVDC insulators in subtropical climates. Electric Power Systems Research. 2018; 163 ():626-637.

Chicago/Turabian Style

Shifang Yang; Zhidong Jia; Xiaogang Ouyang; Huan Bai; Ruitong Liu. 2018. "Hydrophobicity characteristics of algae-fouled HVDC insulators in subtropical climates." Electric Power Systems Research 163, no. : 626-637.

Proceedings article
Published: 01 September 2018 in 2018 28th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV)
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Algae are found grow on the surface of room temperature vulcanized (RTV) silicone rubber coated insulators installed in warm and humid region such as Sichuan, which brings potential operating risk to power transmission and transformation equipment. In this research, two different types of 110kV RTV coated post insulators with algae growth were obtained from Sichuan. Firstly, the algae coverage rate of upper and lower surfaces of top, middle and bottom shed of insulators were calculated through the image processing method respectively. Then, the wet impulse puncture voltage and fog flashover voltage were tested on the algae-grow insulators as well as clean ones. Lastly, the equivalent salt deposit density (ESDD) and no soluble deposit density (NSDD) of insulators were measured. The results show that the algae on the lower surface of insulators are significantly less than the upper surface. Algae have no effect on impulse puncture voltage of insulators. However, the algae decrease the flashover voltage of insulators under the condition of steam fog by 25.2%~44.0% compared to the clean ones.

ACS Style

Xiaogang Ouyang; Zhidong Jia; Ruiyang Guan; Shifang Yang; Yanglin Li. Influence of Algae Growth on the Electrical Performance of RTV Coated Post Insulators. 2018 28th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) 2018, 1, 147 -150.

AMA Style

Xiaogang Ouyang, Zhidong Jia, Ruiyang Guan, Shifang Yang, Yanglin Li. Influence of Algae Growth on the Electrical Performance of RTV Coated Post Insulators. 2018 28th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV). 2018; 1 ():147-150.

Chicago/Turabian Style

Xiaogang Ouyang; Zhidong Jia; Ruiyang Guan; Shifang Yang; Yanglin Li. 2018. "Influence of Algae Growth on the Electrical Performance of RTV Coated Post Insulators." 2018 28th International Symposium on Discharges and Electrical Insulation in Vacuum (ISDEIV) 1, no. : 147-150.

Journal article
Published: 10 August 2018 in Sensors
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The fast detection of classical contaminants and their distribution on high-voltage transmission line insulators is essential for ensuring the safe operation of the power grid. The analysis of existing insulator contamination has traditionally relied on taking samples during a power cut, taking the samples back to the lab and then testing them with elemental analysis equipment, especially for sugars, bird droppings, and heavy metal particulates, which cannot be analysed by the equivalent salt deposit density (ESDD) or non-soluble deposit density (NSDD) methods. In this study, a novel method called laser-induced breakdown spectroscopy (LIBS) offering the advantages of no sample preparation, being nearly nondestructive and having a fast speed was applied for the analysis of metal contamination. Several LIBS parameters (laser energy and delay time) were optimized to obtain better resolution of the spectral data. The limit of detection (LOD) of the observed elements was obtained using a calibration curve. Compared to calibration curves, multivariate analysis methods including principal component analysis (PCA), k-means and partial least squares regression (PLSR) showed their superiority in analyzing metal contamination in insulators. Then, the elemental distribution of natural pollution was predicted using LIBS to fully capture information about the bulk elements (Na, Ni, Cu, Mn, Ca, etc.) of entire areas with PLSR. The results showed that LIBS could be a promising method for accurate direct online quantification of metal contamination in insulators.

ACS Style

Naixiao Wang; Xilin Wang; Ping Chen; Zhidong Jia; Liming Wang; Ronghui Huang; Qishen Lv. Metal Contamination Distribution Detection in High-Voltage Transmission Line Insulators by Laser-induced Breakdown Spectroscopy (LIBS). Sensors 2018, 18, 2623 .

AMA Style

Naixiao Wang, Xilin Wang, Ping Chen, Zhidong Jia, Liming Wang, Ronghui Huang, Qishen Lv. Metal Contamination Distribution Detection in High-Voltage Transmission Line Insulators by Laser-induced Breakdown Spectroscopy (LIBS). Sensors. 2018; 18 (8):2623.

Chicago/Turabian Style

Naixiao Wang; Xilin Wang; Ping Chen; Zhidong Jia; Liming Wang; Ronghui Huang; Qishen Lv. 2018. "Metal Contamination Distribution Detection in High-Voltage Transmission Line Insulators by Laser-induced Breakdown Spectroscopy (LIBS)." Sensors 18, no. 8: 2623.

Journal article
Published: 14 March 2018 in IEEE Transactions on Dielectrics and Electrical Insulation
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In recent years, microorganisms such as algae have been found on composite and RTV coated insulators in humid environment in southwest and southern China. Algae growth poses a potential threat to the outer insulation of electrical power system because of the special features of biological foul. Insulator samples with algae growth were obtained from transmission towers of 500 kV Tianguang DC transmission line and the influence of algae growth on the external insulation performance was studied in this paper. A measurement circuit was used to measure the partial surface conductivity of algae and non-algae dots on insulator surfaces. Water spray classification method was used to test the hydrophobicity of algae and non-algae parts of the insulators. An image processing method was proposed to discern algae on the insulator surfaces and calculate the algae coverage rate. The withstand capability of insulator were tested at working voltage and 1.2 times working voltage. The research results showed that the presence of algae increased the local salt distribution and reduced the hydrophobicity of insulator surfaces. The results also indicated that impacts of algae contanmination to withstand capability of insulators were limited when the algae coverage rate was less than 20%.

ACS Style

Xiaogang Ouyang; Zhidong Jia; Shifang Yang; Xiaoguang Shang; Xilin Wang; Hao Chen; Daobang Zhou; Ruitong Liu. Influence of algae growth on the external insulation performance of HVDC insulators. IEEE Transactions on Dielectrics and Electrical Insulation 2018, 25, 263 -271.

AMA Style

Xiaogang Ouyang, Zhidong Jia, Shifang Yang, Xiaoguang Shang, Xilin Wang, Hao Chen, Daobang Zhou, Ruitong Liu. Influence of algae growth on the external insulation performance of HVDC insulators. IEEE Transactions on Dielectrics and Electrical Insulation. 2018; 25 (1):263-271.

Chicago/Turabian Style

Xiaogang Ouyang; Zhidong Jia; Shifang Yang; Xiaoguang Shang; Xilin Wang; Hao Chen; Daobang Zhou; Ruitong Liu. 2018. "Influence of algae growth on the external insulation performance of HVDC insulators." IEEE Transactions on Dielectrics and Electrical Insulation 25, no. 1: 263-271.

Journal article
Published: 19 June 2017 in RSC Advances
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Core-satellite CaCu 3 Ti 4 O 12 @ZnO-doped silicone rubber composites exhibited both excellent nonlinear conductive and dielectric properties with nanofillers for the first time. The application of polymer composites with electric field dependent nonlinear conductive and dielectric characteristics for high voltage equipment is an effective method to control electric field stress and disperse space charges. In this study, core-satellite CaCu 3 Ti 4 O 12 @ZnO fillers were synthesized and doped into silicone rubber composites, and compared to a mixture of CaCu 3 Ti 4 O 12 and ZnO with the same filler concentration. The composites exhibited both nonlinear conductive and nonlinear dielectric properties with nanoparticle fillers for the first time. Both the nonlinear conductive coefficient and dielectric coefficient increased with filler concentration. The classical current-path model was utilized to explain the nonlinear conductive properties, while the interface-barrier-layer-capacitor model and double-depletion-layer model were introduced to explain the nonlinear dielectric properties, which would broaden the thinking for the fabrication of nonlinear composites.

ACS Style

Jun Wang; Xilin Wang; Youwei Yao; Juyi Guo; Xiaogang Ouyang; Zhidong Jia. Nonlinear electrical characteristics of core-satellite CaCu 3 Ti 4 O 12 @ZnO doped silicone rubber composites. RSC Advances 2017, 7, 31654 -31662.

AMA Style

Jun Wang, Xilin Wang, Youwei Yao, Juyi Guo, Xiaogang Ouyang, Zhidong Jia. Nonlinear electrical characteristics of core-satellite CaCu 3 Ti 4 O 12 @ZnO doped silicone rubber composites. RSC Advances. 2017; 7 (50):31654-31662.

Chicago/Turabian Style

Jun Wang; Xilin Wang; Youwei Yao; Juyi Guo; Xiaogang Ouyang; Zhidong Jia. 2017. "Nonlinear electrical characteristics of core-satellite CaCu 3 Ti 4 O 12 @ZnO doped silicone rubber composites." RSC Advances 7, no. 50: 31654-31662.

Conference paper
Published: 01 June 2017 in 2017 IEEE Electrical Insulation Conference (EIC)
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Algae have recently been colonized on insulator surfaces, especially on surfaces of composite and RTV-coated insulators installed in warm and humid regions. The adverse effect produced by algae on hydrophobicity, flashover characteristics, and the material performance of insulators has been previously demonstrated in the laboratory. However, previous studies have not explored the research method for measuring the degree of growth to determine the severity of the effect of algae on insulators. A new kind of image processing method based on color segmentation is presented to discriminate the distribution of algae on the insulator surface. Two main procedures are included in this method. First, the unambiguous insulator images are obtained using a digital camera presupposed with a white balance. Second, the green algae pixels are recognized and extracted from the insulator images through a specific MATLAB program, which is determined to be capable of discriminating the algae distribution and calculating the algae coverage rate and characteristic green value. The insulators acquired from the 500-kV DC transmission lines have been considered for this study. Results show that the growth degree of algae was more serious on RTV-coated insulators than on composite insulators.

ACS Style

Xiaogang Ouyang; Zhidong Jia; Shifang Yang; Hao Chen; Cong Wei. Research of image processing method on alage conolized on the insulator surface. 2017 IEEE Electrical Insulation Conference (EIC) 2017, 26 -29.

AMA Style

Xiaogang Ouyang, Zhidong Jia, Shifang Yang, Hao Chen, Cong Wei. Research of image processing method on alage conolized on the insulator surface. 2017 IEEE Electrical Insulation Conference (EIC). 2017; ():26-29.

Chicago/Turabian Style

Xiaogang Ouyang; Zhidong Jia; Shifang Yang; Hao Chen; Cong Wei. 2017. "Research of image processing method on alage conolized on the insulator surface." 2017 IEEE Electrical Insulation Conference (EIC) , no. : 26-29.

Conference paper
Published: 01 June 2017 in 2017 IEEE Electrical Insulation Conference (EIC)
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Algae contamination was widely observed on the surface of RTV (Room Temperature Vulcanized Silicone Rubber) surface, which was a threat to the external insulation performance of composite insulating materials. Algae growth on RTV coating was simulated under artificial laboratory conditions in this paper. The electrical performance of algae coated RTV materials was measured by flashover tests and leakage current. Results showed that algae changed the microstructure of the material surface and algal cells reduced the flashover voltage and increased the risk of flashover of silicone rubber material. The research on the influence of the external insulation performance was important for the operation and maintenance of composite insulators.

ACS Style

Shifang Yang; Zhidong Jia; Xiaogang Ouyang; Huan Bai; Xinghai Zhang. Influence of algae growth on the electrical performance of RTV coating. 2017 IEEE Electrical Insulation Conference (EIC) 2017, 321 -324.

AMA Style

Shifang Yang, Zhidong Jia, Xiaogang Ouyang, Huan Bai, Xinghai Zhang. Influence of algae growth on the electrical performance of RTV coating. 2017 IEEE Electrical Insulation Conference (EIC). 2017; ():321-324.

Chicago/Turabian Style

Shifang Yang; Zhidong Jia; Xiaogang Ouyang; Huan Bai; Xinghai Zhang. 2017. "Influence of algae growth on the electrical performance of RTV coating." 2017 IEEE Electrical Insulation Conference (EIC) , no. : 321-324.

Conference paper
Published: 01 September 2016 in 2016 IEEE International Conference on High Voltage Engineering and Application (ICHVE)
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Condensation problems in outdoor RMU exist widely at the area which has a hot and humid climate such as the south of China, resulting in the corrosion of the equipment in the RMU. Once the switch operation mechanism corrodes, it would cause the switch to act abnormally. What is worse, the insulation performance of the equipment will be reduced. Improving the ability of natural ventilation is a safe, widely adaptable and energy-saving method to prevent the condensation in RMU. In this paper, considering the physical structure of RMU, the operating conditions of the equipment and the influence factors of ventilation and heat dissipation, a 3D flow field model is established. Then the flow fields about the model are analyzed with the software ANSYS. The results shows that, the original inlet shape is not conducive to the effect of ventilation of the RMU; the original size of RMU is too small to affect the capacity of ventilation. And the capacity of ventilation can be improved by optimizing the shape of the inlet; in addition, proper widening and heightening the size of the RMU can also enhance the effect of ventilation.

ACS Style

Wei Zhang; Zhengguo Zhu; Zikui Shen; Ye Wang; Zhidong Jia; Zhi-Qiang Yan. Research on method of anti-condensation in RMU based on finite element analysis. 2016 IEEE International Conference on High Voltage Engineering and Application (ICHVE) 2016, 1 -4.

AMA Style

Wei Zhang, Zhengguo Zhu, Zikui Shen, Ye Wang, Zhidong Jia, Zhi-Qiang Yan. Research on method of anti-condensation in RMU based on finite element analysis. 2016 IEEE International Conference on High Voltage Engineering and Application (ICHVE). 2016; ():1-4.

Chicago/Turabian Style

Wei Zhang; Zhengguo Zhu; Zikui Shen; Ye Wang; Zhidong Jia; Zhi-Qiang Yan. 2016. "Research on method of anti-condensation in RMU based on finite element analysis." 2016 IEEE International Conference on High Voltage Engineering and Application (ICHVE) , no. : 1-4.

Conference paper
Published: 25 August 2016 in 2016 IEEE Electrical Insulation Conference (EIC)
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Room temperature vulcanized silicone rubber (RTV) coatings have been widely used in the world to prevent the pollution flashover in transmission lines. Thickness of the RTV coatings which was hard to measure with regular methods, was one of the most important properties and required by State Grid Company. As a fast and online analysis method, laser-induced breakdown spectroscopy (LIBS) has been applied in different fields. With LIBS, this paper studied the depth of the laser-ablated craters and the emission spectra of RTV coatings. Using a laser, focusing on the coating surface, together with a spectrometer and the scanning electron microscope (SEM) for observation, the linear relationship between the crater depth and the number of laser pulses was observed and the emission spectra were observed. The result showed that the depth of laser-ablated craters on RTV had a linear relationship with the number of laser pulses, which could be further applied to the measurement of the RTV thickness of coatings.

ACS Style

Xilin Wang; Han Wang; Zhidong Jia; Liming Wang; Xinghai Zhang; Degang Gan; Yawei Li. A new method to measure RTV coatings thickness with laser-induced breakdown spectroscopy (LIBS) technique. 2016 IEEE Electrical Insulation Conference (EIC) 2016, 81 -84.

AMA Style

Xilin Wang, Han Wang, Zhidong Jia, Liming Wang, Xinghai Zhang, Degang Gan, Yawei Li. A new method to measure RTV coatings thickness with laser-induced breakdown spectroscopy (LIBS) technique. 2016 IEEE Electrical Insulation Conference (EIC). 2016; ():81-84.

Chicago/Turabian Style

Xilin Wang; Han Wang; Zhidong Jia; Liming Wang; Xinghai Zhang; Degang Gan; Yawei Li. 2016. "A new method to measure RTV coatings thickness with laser-induced breakdown spectroscopy (LIBS) technique." 2016 IEEE Electrical Insulation Conference (EIC) , no. : 81-84.