Analytical Approach to the Calculation of Parasitic Capacitance between Winding Turns

At high frequencies, winding components behave differently than at low frequencies. Therefore, suitable models are required which can predict coil performances over the whole possible range of frequencies they can be operated. Inductors used in power electronic conversion, magnetic sensors, EMC equipments, and also motor windings can experience frequency levels above several hundreds of kHz where parasitic resistance and capacitance can affect significantly their intended operation. One of the main problems is modeling turn-to-turn capacitance of coils both for single- and multiple-layer windings. The lumped parameter models used in literature for HF inductor simulation are based on simplified approaches to the turn-to-turn and turn-to-core capacitance calculation. In this paper, an analytical approach based on conformal mapping to calculate the exact solution for the turn-to turn and turn-to-core capacitances for coils with different geometrical structures is introduced.