Calculation of the Parameters of a Two-Winding Transformer without a Magnetic Circuit

Abstract

A technique for calculating the parameters of a transformer without a magnetic circuit with two cylindrical coaxial multilayer windings of the same length has been developed. Such parameters as inductance, resistance, capacitance, and temperature of windings are determined, which are used to calculate periodic voltages and currents in the steady-state power supply mode of the active load, when the primary winding of the transformer is connected to the voltage inverter. The formulas for calculating the transformer parameters, voltages, and currents, which are obtained based on the equations of electromagnetic fields and electric circuits, are programmed using the Mathcad software. The method’s reliability is confirmed by a satisfactory agreement between the calculated and the experimental values of the transformer parameters, as well as by similar calculated and experimental values of periodic voltage on the resistive load. The results obtained testify to the possibility of the efficient use of transformers without magnetic circuit with high coupling coefficient at sufficiently high frequencies, when the quality factors of the windings are high, the surface effect in the conductors of the windings is negligible and the undesirable shunting effect of parasitic capacitances in the windings is still insignificant.