ON A CIRCUIT-THEORY APPROACH TO EVALUATE THE STRAY CAPACITANCES OF 2 COUPLED INDUCTORS

This paper provides a method for evaluating three lumped equivalent ca pacitances which take into account the physical effects of stray capac itances in two coupled inductors. Capacitance evaluation is performed in two steps: (i) initially, the resistance and leakage inductance of each winding, together with the magnetic core equivalent impedance, ar e evaluated by means of discrete parameter estimation; (ii) successive ly, the three equivalent capacitances are evaluated by resolving a lin ear set of three algebraical equations after the natural oscillation f requencies of the two coupled inductors in experimental tests are dete rmined. The paper provides both the definitions and the mathematical t heory on which the method is based. The actual response of two coupled inductors was compared with the response of the identified model; tes ts showed a good correlation between them.