The Calculation of Polarization Spectrum and Activation Energy of Insulation during Accelerated Thermal Stress

One of the cardinal properties of the insulation system of the electrical equipment is its electrical strength. Usually it is expressed as value of breakdown voltage. There is not electrical destruction of material under this one. The determination of breakdown voltage exactly is possible only by doing electrical strength test. It is a destructive test on insulation system made by solid material. This test is not suitable for service condition. There isn't only one test method that can complex diagnose the state of insulation system. The utilization of set of diagnostic methods is necessary. The biggest meaning in monitoring of high voltage insulation system ageing consists in methods based on regular non-destructive diagnostics. The analysis of results from several diagnostic methods is the principle. The issue of such diagnostics is detailed information about ageing process of insulation system of high voltage equipment. The high voltage motor is a very important element in the production process. A breakdown of its insulating system may cause a loss to the production. Therefore the importance of measuring and testing of its electrical properties is increasing more and more in conjunction with advances of power engineering equipment. This paper describes the use of polarization spectrum determination for diagnostic purposes, especially for insulating systems of high voltage machines. The study of absorption current during accelerated thermal degradation is presented in this paper. Absorptive currents are analyzed. The thermal behavior of a simple model of multi-layer insulation material based on ReMica is described together with recommendation for practical utilization. The activation energy during accelerated thermal stress is calculated and analyzed.