A method for the analysis and control of mica tape impregnation processes

The impregnation of mica tape insulations usually is monitored with dielectric capacitance measurements. In this work, a method is developed that translates measured capacitance and loss into an average drag coefficient that characterizes flow resistance, which is the critical parameter of the process. In a first step, the impregnation depth is determined based on an appropriate model of the dielectric measurement. The impregnation depth curve and its derivative are then used to compute the average drag coefficient, which is defined in the framework of a standard porous media flow model. The method has been developed and tested for cylindrical insulators. Appropriate extensions to rectangular insulators are indicated.