Numerical field analysis for an air cored spiral strip type pulse transformer

The structure of an air cored high voltage pulse transformer is relatively simple, but considerable attention is needed to prevent breakdown between transformer windings. Since the thickness of the windings in spiral strip type is on the order of sub-millimeter, field enhancement at the edge of the windings is very high. It is, therefore, important to find proper electrical insulation parameter to make the system compact. Several shapes of the winding are considered and are analyzed by numerical field simulations to find an optimum transformer design parameter. Two design parameters are considered in the numerical simulation. Those are radius of the tip and radius of the edge in the transformer. The several dielectric insulation materials also are analyzed numerically to find out the field grading in the windings.