On circuit theory approach to evaluate the stray capacitances of two coupled inductors

The authors provide a method for evaluating three lumped equivalent capacitances which take into account the physical effects of stray capacitances in two coupled inductors. Capacitance evaluation is performed in two steps. Initially, the resistance and leakage inductance of every winding and the core exciting equivalent impedance are evaluated by means of discrete parameter estimation. Then the three equivalent capacitances are evaluated by means of three simple mathematical expressions once the natural oscillation frequencies of the two coupled inductors in the experimental test are determined. The definitions and the mathematical theory underlying the method are outlined. The actual reponse of the two coupled inductors is compared with the response of the identified model and the test results show a good correlation between them