EVALUATION OF INSULATION LIFETIME OF CABLES FOR POWER AND CONTROL SYSTEMS IN MINING ELECTRICAL EQUIPMENT

Abstract

The relevance of the research is provided by flexible cables design perfection for power and control systems of mining electrical equipment. The application of modern insulation materials is the main way for improving flexible cables properties. Currently, mining cables are produced with the rubber insulation. Advanced solution for improving the design of flexible mining cable is application of ethylene-propylene rubber, which has a higher heat resistance as compered to chloroprene and butyl rubber. The transmitted power is increased and a high values of thermal stability current at a short current with the requiring cycle flexibility is provided. The practical application of brand-new cables in the mining electrical equipment is impossible without lifetime characteristics testing. The lack of recommendations in the technical literature on the methodology of such tests requires studies to predict the service life, taking into account changes in the physical and mechanical properties of the ethylene-propylene rubber. The main aim of the research is to develop the method and to determine the service life of flexible cables with ethylene-propylene rubber insulation for power and control systems of mining electrical equipment. Objects: flexible mining cable, insulation, ethylene-propylene rubber, physical and mechanical properties, activation energy, service life. Methods: experimental methods for evaluating the physical and mechanical properties, and heat resistance of polymeric materials; mathematical methods for solving nonlinear systems of equations and test results statistical analysis. Results. The method for determining the service life of cables with ethylene-propylene rubber insulation was developed. This method is based on the physical and mechanical properties prediction considering the activation energy Ea of thermal destruction processes. The service life of flexible mine cables is determined taking into account temperature.

Keywords

• mining electrical equipment
• flexible mining cables
• insulation
• ethylene-propylene rubber
• thermal aging
• elongation at break
• activation energy
• service life