Polymer Composites for Electrical Engineering Polymer Composites for Electrical Engineering Edited by Xingyi Huang Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, Shanghai Jiao Tong University, Shanghai, China Toshikatsu Tanaka Waseda University, Tokyo, Japan This edition first published 2022 © 2022 John Wiley & Sons Ltd All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by law. Advice on how to obtain permission to reuse material from this title is available at http://www.wiley.com/go/permissions. The right of Xingyi Huang and Toshikatsu Tanaka to be identified as the authors of the editorial material in this work has been asserted in accordance with law. 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Library of Congress Cataloging- in- Publication Data Applied for: [HB ISBN: 9781119719601] Cover Design: Wiley Cover Image: © Nikifor Todorov Set in 9.5/12.5pt STIXTwoText by Straive, Pondicherry, India 10 9 8 7 6 5 4 3 2 1 v Contents List of Contributors xv Preface xix 1 Polymer Composites for Electrical Energy Storage 1 Yao Zhou 1.1 Introduction 1 1.2 General Considerations 1 1.3 Effect of Nanofiller Dimension 3 1.4 Orientation of Nanofillers 7 1.5 Surface Modification of Nanofillers 11 1.6 Polymer Composites with Multiple Nanofillers 13 1.7 Multilayer-structured Polymer Composites 16 1.8 Conclusion 19 References 21 2 Polymer Composites for Thermal Energy Storage 29 Jie Yang, Chang-Ping Feng, Lu Bai, Rui-Ying Bao, Ming-Bo Yang, and Wei Yang 2.1 Introduction 29 2.2 Shape-stabilized Polymeric Phase Change Composites 32 2.2.1 Micro/Nanoencapsulated Method 33 2.2.2 Physical Blending 35 2.2.3 Porous Supporting Scaffolds 36 2.2.4 Solid–Solid Composite PCMs 37 2.3 Thermally Conductive Polymeric Phase Change Composites 39 2.3.1 Metals 40 2.3.2 Carbon Materials 41 2.3.3 Ceramics 41 2.4 Energy Conversion and Storage Based on Polymeric Phase Change Composites 42 2.4.1 Electro-to-Heat Conversion 42 2.4.2 Light-to-Heat Conversion 45 2.4.3 Magnetism-to-Heat Conversion 47 vi Contents 2.4.4 Heat-to-Electricity Conversion 48 2.5 Emerging Applications of Polymeric Phase Change Composites 48 2.5.1 Thermal Management of Electronics 49 2.5.2 Smart Textiles 50 2.5.3 Shape Memory Devices 51 2.6 Conclusions and Outlook 51 Acknowledgments 52 References 52 3 Polymer Composites for High-Temperature Applications 63 Sen Niu, Lixue Zhu, Qiannan Cai, and Yunhe Zhang 3.1 Application of Polymer Composite Materials in High-Temperature Electrical Insulation 63 3.1.1 High-Temperature-Resistant Electrical Insulating Resin Matrix 63 3.1.1.1 Silicone Resins 64 3.1.1.2 Polyimide 64 3.1.1.3 Polyether Ether Ketone 65 3.1.1.4 Polybenzimidazole 65 3.1.1.5 Polyphenylquinoxaline 65 3.1.1.6 Benzoxazine 66 3.1.2 Modification of Resin Matrix with Reinforcements 66 3.1.2.1 Mica 66 3.1.2.2 Glass Fiber 66 3.1.2.3 Inorganic Nanoparticles 67 3.1.3 Modifications in the Thermal Conductivity of Resin Matrix 67 3.1.3.1 Mechanism of Thermal Conductivity 68 3.1.3.2 Intrinsic High Thermal Conductivity Insulating Material 68 3.1.3.3 Filled High Thermal Conductivity Insulating Material 69 3.2 High-Temperature Applications for Electrical Energy Storage 70 3.2.1 General Considerations for High-Temperature Dielectrics 70 3.2.2 High-Temperature-Resistant Polymer Matrix 71 3.2.3 Polymer Composites for High-Temperature Energy Storage Applications 71 3.2.4 Surface Modification of Nanocomposite for High-Temperature Applications 72 3.2.5 Sandwich Structure of Nanoparticles for High-Temperature Applications 75 3.3 Application of High-Temperature Polymer in Electronic Packaging 77 3.3.1 Synthesis of Low Dielectric Constant Polymer Materials Through Molecular Structure Design 80 3.3.1.1 Fluorine-Containing Low Dielectric Constant Polymer 80 3.3.1.2 Low Dielectric Constant Polymer Material Containing Nonpolar Rigid Bulk Group 81 3.3.2 High-Temperature-Resistant Low Dielectric Constant Polymer Composite Material 82 3.3.2.1 Low Dielectric Constant Polyoxometalates/Polymer Composite 83 3.3.2.2 Low Dielectric Constant POSS/Polymer Composite 85 Contents vii 3.4 Application of Polymer Composite Materials in the Field of High-Temperature Wave-Transmitting and Wave-Absorbing Electrical Fields 86 3.4.1 Wave-Transmitting Materials 88 3.4.1.1 The High-Temperature Resin Matrix 88 3.4.1.2 Reinforced Materials 89 3.4.2 Absorbing Material 89 3.4.2.1 The High-Temperature Resin Matrix 90 3.4.2.2 Inorganic Filler 90 3.5 Summary 91 References 92 4 Fire-Retardant Polymer Composites for Electrical Engineering 99 Zhi Li, En Tang, and Xue-Meng Cao 4.1 Introduction 99 4.2 Fire-Retardant Cables and Wires 100 4.2.1 Fundamental Overview 100 4.2.2 Understanding of Fire-Retardant Cables and Wires 101 4.2.2.1 Polyethylene Composites 101 4.2.2.2 Ethylene-Vinyl Acetate (EVA) Copolymer 103 4.2.2.3 Polyvinyl Chloride Composites 105 4.2.2.4 Other Polymers 108 4.3 Fire-Retardant Polymer Composites for Electrical Equipment 109 4.3.1 Fundamental Overview 109 4.3.2 Understanding of Fire-Retardant Polymer Composites for Electrical Equipment 110 4.3.2.1 HIPS and ABS Composites 110 4.3.2.2 PC/ABS Composites 112 4.3.2.3 PC Composites 115 4.3.2.4 PBT Composites 116 4.4 Fire-Retardant Fiber Reinforced Polymer Composites 117 4.4.1 Fundamental Overview 117 4.4.2 Understanding of Fire-Retardant Fiber Reinforced Polymer Composites 118 4.4.2.1 Reinforced PBT and PET Composites 118 4.5 Conclusion and Outlook 118 References 119 5 Polymer Composites for Power Cable Insulation 123 Yoitsu Sekiguchi 5.1 Introduction 123 5.2 Trend in Nanocomposite Materials for Cable Insulation 125 5.2.1 Overview 125 5.2.2 Polymer Materials as Matrix Resin 125 5.2.3 Fillers 128 5.2.4 Nanocomposites 130 5.2.4.1 XLPE Nanocomposites 131 viii Contents 5.2.4.2 PP Nanocomposites 131 5.2.4.3 Nanocomposite with Cluster/Cage Molecule 131 5.2.4.4 Copolymer and Polymer Blend 131 5.3 Factors Influencing Properties 138 5.4 Issues in Nanocomposite Insulation Materials Research 139 5.5 Understanding Dielectric and Insulation Phenomena 140 5.5.1 Electromagnetic Understanding 140 5.5.2 Understanding Space Charge Behavior by Q(t) Method 141 References 146 6 Semi-conductive Polymer Composites for Power Cables 153 Zhonglei Li, Boxue Du, Yutong Zhao, and Tao Han 6.1 Introduction 153 6.1.1 Function of Semi-conductive Composites 153 6.1.2 Development of Semi-conductive Composites 154 6.2 Conductive Mechanism of Semi-conductive Polymer Composites 155 6.2.1 Percolation Theory 157 6.2.2 Tunneling Conduction Theory 157 6.2.3 Mechanism of Positive Temperature Coefficient 158 6.3 Effect of Polymer Matrix on Semi-conductivity 159 6.3.1 Thermoset Polymer Matrix 159 6.3.2 Thermoplastic Polymer Matrix 162 6.3.3 Blended Polymer Matrix 163 6.4 Effect of Conductive Fillers on Semi-conductivity 165 6.4.1 Carbon Black 165 6.4.2 Carbonaceous Fillers with One- and Two-Dimensions 166 6.4.3 Secondary Filler for Carbon Black Filled Composites 167 6.5 Effect of Semi-conductive Composites on Space Charge Injection 169 6.6 Conclusions 172 References 173 7 Polymer Composites for Electric Stress Control 179 Muneaki Kurimoto 7.1 Introduction 179 7.2 Functionally Graded Solid Insulators and Their Effect on Reducing Electric Field Stress 179 7.3 Practical Application of ε-FGMs to GIS Spacer 181 7.4 Application to Power Apparatus 182 References 188 8 Composite Materials Used in Outdoor Insulation 191 Wang Xilin, Jia Zhidong, and Wang Liming 8.1 Introduction 191 8.2 Overview of SIR Materials 192 8.2.1 RTV Coatings 193 Contents ix 8.2.2 Composite Insulators 195 8.2.3 Liquid Silicone Rubber (LSR) 196 8.2.4 Aging Mechanism and Condition Assessment of SIR Materials 197 8.3 New External Insulation Materials 198 8.3.1 Anti-icing Semiconductor Materials 199 8.3.2 Hydrophobic CEP 201 8.4 Summary 202 References 203 9 Polymer Composites for Embedded Capacitors 207 Shuhui Yu, Suibin Luo, Riming Wang, and Rong Sun 9.1 Introduction 207 9.1.1 Development of Embedded Technology 207 9.1.2 Dielectric Materials for Commercial Embedded Capacitors 210 9.2 Researches on the Polymer-Based Dielectric Nanocomposites 213 9.2.1 Filler Particles 213 9.2.2 Epoxy Matrix 216 9.2.2.1 Modification to Improve Dielectric Properties 219 9.2.2.2 Modification to Improve Mechanical Properties 221 9.3 Fabrication Process of Embedded Capacitors 224 9.4 Reliability Tested of Embedded Capacitor Materials 229 9.5 Conclusions and Perspectives 230 References 230 10 Polymer Composites for Generators and Motors 235 Hirotaka Muto, Takahiro Umemoto, and Takahiro Mabuchi 10.1 Introduction 235 10.2 Polymer Composite in High-Voltage Rotating Machines 236 10.3 Ground Wall Insulation 237 10.3.1 Mica/Epoxy Insulation 237 10.3.2 Electrical Defect in the Insulation of Rotating Machines and Degradation Mechanism 238 10.3.3 Insulation Design and V-t Curve 239 10.4 Polymer Nanocomposite for Rotating Machine 240 10.4.1 Partial Discharge Resistance and a Treeing Lifetime of Nanocomposite as Material Property 241 10.4.1.1 PD Resistance 241 10.4.1.2 Electrical Treeing Lifetime 242 10.4.2 Breakdown Lifetime Properties of Realistic Insulation Defect in Rotating Machine 244 10.4.2.1 Voltage Endurance Test of Void Defect 245 10.4.2.2 Voltage Endurance Test in Mica/Epoxy Nanocomposite-Layered Structure 247 10.4.2.3 V-t Curves in Coil Bar Model with Mica/Epoxy Nanocomposite Insulation 248 10.5 Stress-Grading System of Rotating Machines 252 10.5.1 Silicon Carbide Particle-Loaded Nonlinear-Resistive Materials 252 x Contents 10.5.2 End-turn Stress-Grading System of High-Voltage Rotating Machines 253 References 255 11 Polymer Composite Conductors and Lightning Damage 259 Xueling Yao 11.1 Lightning Environment and Lightning Damage Threat to Composite-Based Aircraft 259 11.1.1 The Lightning Environment 259 11.1.1.1 Formation of Lightning 259 11.1.2 Lightning Test Environment of Aircrafts 261 11.1.2.1 Zone 1 262 11.1.2.2 Zone 2 263 11.1.2.3 Zone 3 263 11.1.2.4 Current Component A – First Return Strike 264 11.1.2.5 Current Component Ah – Transition Zone First Return Strike 264 11.1.2.6 Current Component B – Intermediate Current 264 11.1.2.7 Current Component C – Continuing Current 264 11.1.2.8 Component C* – Modified Component C 264 11.1.2.9 Current Component D – Subsequent Strike Current 266 11.1.3 Waveform Combination in Different Lightning Zones for Lightning Direct Effect Testing 269 11.1.4 Application of CFRP Composites in Aircraft 269 11.2 The Dynamic Conductive Characteristics of CFRP 271 11.2.1 A Review of the Research on the Conductivity of CFRP 271 11.2.2 The Testing Methods 272 11.2.2.1 Specimens 272 11.2.2.2 The Test Fixture 273 11.2.2.3 Lightning Impulse Generator and Lightning Waveforms 274 11.2.3 The Experimental Results of the Dynamic Impedance of CFRP 275 11.2.3.1 The Nondestructive Lightning Current Test 275 11.2.3.2 The Applied Lightning Current Impulse and the Response Voltage Impulse 278 11.2.3.3 Equivalent Conductivity of CFRP Laminates Under Different Lightning Impulses 280 11.2.3.4 Equivalent Conductivity of CFRP Laminates with Different Laminated Structures 282 11.2.4 The Discussion of the Dynamic Conductive Characteristics of CFRP 282 11.2.4.1 The Conduction Path of the CFRP Laminate Under a Lightning Current Impulse 282 11.2.4.2 Dynamic Conductance of CFRP Laminate 284 11.2.4.3 The Inductive Properties of CFRP Laminates 286 11.2.4.4 Equivalent Conductivity of CFRP Laminates Subjected to Lightning Current Impulses with Higher Intensity 288 11.3 The Lightning Strike-Induced Damage of CFRP Strike 289 11.3.1 Introduction of the Lightning Damage of CFRP 289 11.3.2 Single Lightning Strike-Induced Damage 290 Contents xi 11.3.2.1 Experimental Setup for Single Lightning Strike Test 290 11.3.2.2 Experimental Results of Single Lightning Strike-Induced Damage 292 11.3.2.3 Evaluation for Single Lightning Strike-Induced Damage 297 11.3.3 Multiple Lightning Strikes-Induced Damage 300 11.3.3.1 Experimental Method for Multiple Consecutive Lightning Strike Tests 300 11.3.3.2 Experimental Results of Multiple Lightning Damage 303 11.3.3.3 Multiple Lightning Damage Areas and Depths of CFRP Laminates 308 11.3.3.4 Analysis for Multiple Lightning Damage of CFRP Laminates 309 11.3.3.5 Evaluation for Multiple Lightning Damage of CFRP Laminates 313 11.4 The Simulation of Lightning Strike-Induced Damage of CFRP 319 11.4.1 Overview of Lightning Damage Simulation Researches 319 11.4.2 Establishment of the Coupled Thermal-Electrical Model 321 11.4.2.1 Finite Element Model 321 11.4.2.2 Simulated Lightning Component A 322 11.4.2.3 Pyrolysis Degree Calculation 322 11.4.2.4 Dynamic Conductive Properties 322 11.4.2.5 Pyrolysis-Dependent Material Parameters 323 11.4.3 Simulation Physical Fields of Lightning Current on CFRP Laminates 323 11.4.3.1 Temperature and Pyrolysis Fields 323 11.4.3.2 Mechanical Analysis 325 11.4.4 Simulated Lightning Damage Results 325 11.4.4.1 Numerical Criterion for Lightning Damage 325 11.4.4.2 In-Plane Lightning Damage Evaluation 327 11.4.4.3 In-Depth Lightning Damage Evaluation 331 References 331 12 Polymer Composites for Switchgears 339 Takahiro Imai 12.1 Introduction 339 12.2 History of Switchgear 340 12.3 Typical Insulators in Switchgears 342 12.3.1 Epoxy-based Composite Insulators 342 12.3.2 Insulator-Manufacturing Process 343 12.3.2.1 Vacuum Casting Method 344 12.3.2.2 Automatic Pressure Gelation Method 344 12.3.2.3 Vacuum Pressure Impregnation Method 345 12.4 Materials for Epoxy-based Composites 345 12.4.1 Epoxy Resins 345 12.4.2 Hardeners 346 12.4.3 Inorganic Fillers and Fibers 347 12.4.4 Silane Coupling Agents 348 12.4.5 Fabrication of Epoxy-based Composites 349 12.5 Properties of Epoxy-based Composites 351 12.5.1 Necessary Properties of Epoxy-based Composites for Switchgears 351 12.5.2 Resistance to Thermal Stresses 352