A new approach to breakdown voltage and nondestructive parameters of micaceous insulation systems

A novel mathematical approach is proposed to calculate the breakdown voltage and nondestructive parameters in connection with the internal state of aged micaceous insulation systems. After a short review of the conventional cumulative aging theory, it is pointed out that residual breakdown data do not always obey the theory, and that the internal change observed with SEM (scanning electron microscopy) seems to reflect on the measured values. To explain the phenomena comprehensively, the concept of `defect distribution X´ is introduced. Breakdown voltage and nondestructive parameters are shown to be derived from the distribution X. An example of a simulation is presented