Shumilov M. The Improvement of Electrical and Mechanical Strength of High-voltage Polymeric Insulators under the Influence of Combined Operational Factors

Object of study - electrophysical processes causing puncture and damage of polymeric and composite materials in a strong electric field; the aim - improvement of high-voltage polymeric insulator design by means of improvement of their electric and mechanical strength under concurrent influence of a strong electric field, mechanical loads and climatic factors, as well as by means of improvement of polymeric insulators' manufacturing technique; the methods of research and apparatus - computer and physical simulation; experimental investigations on polymeric insulators test models and dummies manufactured on DESMA injection-molding machines and FINN POWER press equipment; statistical methods of research and experimental data processing; experiments on polymeric insulators test models and dummies; experimental investigations are carried out with impulse-voltage and current generators, vapor and cooling chambers, high-voltage and high-current measuring systems; theoretical and practical results - theoretically and experimentally proved effectiveness of application of nonshrinking silicon rubbers of additive vulcanization for obtaining of weathershed housing and sealing of high-voltage polymeric insulator power blocks; the nature of moisture motion in a high electric field in cellular fiberglass plastics and the process of formation of the areas of initiation of partial discharges influencing the location of fiberglass plastic's "brittle fractures" are specified; it is shown that the application of boron-free glass-fibre-reinforced plastics increases polymeric insulators' resistance to "brittle fracture"; the mechanisms of split phase's and bypass loop's influence on electric field distribution close to polymeric insulator sets are specified; a new design of puncture indicator for polymeric insulators is developed and patented; novelty - is that the effectiveness of application of new electrical insulating materials: silicon rubbers of additive vulcanization and boron-free glass-fibre-reinforced plastic rods is scientifically justified; the degree of implementation - the science-based technical decisions and technologies given in the thesis are used in designing and production development of 35 to 750 kV ЛКЦ insulators having one-piece weathershed housing at "ES Polymer" scientific manufacturing enterprise, Artemovsk; scope of use - is the development and manufacture of high-voltage polymeric insulators and external polymeric insulation of high-voltage electrical equipment.