Theory and Application of Dynamic Wetting of High Voltage Insulator

Bin Cao, PhD, is an Assistant Professor at the Institute of Advanced Technologies in Energy and Electrical Engineering at Tsinghua University, China. He has published 80 peer-reviewed journal papers and received the 2024 Geneva Invention Exhibition Gold Award. Dr. Cao is an active member of CIGRE NGN, the Chinese Insulator Standardization Technical Committee, and the IEEE PES High Voltage Surface Discharge Technical Committee. Liming Wang, PhD, is the Director of the Institute of Advanced Technologies in Energy and Electrical Engineering and a full professor at Tsinghua University, China. He has authored over 760 peer-reviewed papers, including 104 in IEEE Transactions journals, and holds 128 patents. Professor Wang serves as Chair of the IEEE DEIS Technical Committee on Discharges in Gas at UHV, Vice Chair of the China Electric Power Insulator Standardization Committee and was the recipient of the 2024 IEEE DEIS Caixin Sun and Stan Gryzbowski Lifetime Achievement Award.

• PrefaceAcknowledgmentsAbout the AuthorsAcronymsList of FiguresList of Tables1 Challenges in Insulation of Transmission Equipment with Climate Change1.1 Classical Theories of Pollution Discharge on Insulators1.2 Insulator contaminating1.3 Insulator wetting1.4 Characterization Parameters for External Insulation1.5 Pollution monitoring technology1.6 Main Content of the Book2 Wetting Behavior of Insulator Contamination at Saturated Humidity2.1 introduction2.2 Example Arrangement2.3 Results2.4 Impact of Non-Soluble Deposit Density (NSDD) and Surface Angle2.5 Summary3 Soluble Salt Dissolution in Contaminated Layers3.1 introduction3.2 Experimental Arrangement3.3 Results3.4 Relationship Between Equivalent Salt Density (ESDD) and Conductivity3.5 Summary4 Wetting Behavior of Insulator Contamination at Unsaturated Humidity4.1 Introduction4.2 Experimental Arrangement4.3 Results4.4 Relationship Between Humidity, Contamination, and Leakage Current4.5 Summary5 Temperature Differences and Their Effect on Wetting Behavior5.1 Introduction5.2 Experimental Arrangement5.3 Results5.4 Summary6 Characterization of Salt Fog Environments and its effect on the outdoor insulation6.1 Introduction6.2 Equivalent soluble salt concentration6.3 Results6.4 Comprehensive Model for Predicting flashover voltage in the Salt Fog Environments6.5 Summary7 Effect of Hydrophobicity on the Contamination Wetting7.1 Introduction7.2 Experimental Arrangement7.3 Results7.4 Dissolving Characteristics of Soluble Salts at Water Drop and Dry Band7.5 Summary8 Wetting characteristics of the hydrophobic material surface through condensation8.1 Introduction8.2 Experimental Arrangement8.3 Results8.4 Discussion8.5 Summary9 Flashover Characteristics of Hydrophobic Surfaces with different wetting degree9.1 Introduction9.2 Flashover characteristics with lower wetting degree9.3 Flashover characteristics with higher wetting degree9.4 Discussion of Surface Flashover with Water Involved9.5 Summary10 Factors Influencing the Hydrophobic Surface Flashover and Their Application10.1 Introduction10.2 Wetting Prerequisite of Flashover on Hydrophobic Surface10.3 Effect of Contamination on Flashover Voltage under Different Wetting Conditions10.4 Dynamic Behavior of Water Droplets under Electric Field10.5 Replacement and Maintenance Strategies for Degraded Hydrophobic Insulators10.6 Summary11 Insulator Contamination Monitoring based on its hygroscopicity under unsaturated humidity11.1 Introduction11.2 Development of Online Monitoring Devices11.3 System Application11.4 Algorithms for Real-Time Contamination Assessment11.5 Assessment method of pollution degree for Hydrophobic surface11.6 Summary12 Insulator Contamination Monitoring at saturated moisture12.1 Introduction12.2 Test Specimens, facilities & Procedure12.3 Experimental results12.4 analyses and discussion12.5 Influence of Partial Electric Arc on the Contamination Monitoring in View of Leakage Current12.6 Summary13 Spatial and Temporal Analysis of Contamination on Insulator Surfaces13.1 introduction13.2 Artificial contamination test13.3 Contamination components of actual operating insulators13.4 Summary14 Correction Methods for Soluble Salt Components in Contamination Assessment14.1 introduction14.2 Analysis of Surface Conductivity for Soluble Salt Detection14.3 Correction Method for Soluble Salt Components and Equipment14.4 Experimental Validation of Correction Methods14.5 Engineering Implications14.6 SummaryReferences