Polarisation spectrum analysis for diagnosis of insulation systems

The new method of test described in this paper is based on analysis of the polarisation spectrum traced from the results of Recovery Voltage Measurements. This method makes possible the assessment of oil/paper insulation systems such as in transformers. This new method is of significant importance as it is nondestructive and nonintrusive and gives full information on the state of oil/paper insulation systems. The condition of the paper is the decisive factor in the reliability of the overall system; high moisture content due to ageing or some external factor can cause failure as a result of increased dielectric losses at high temperature or release of moisture into the oil