Measurement uncertainty of the instantaneous characteristics of non-linear coil obtained by Dommel's method

The characteristics of coil are obtained through the following measurement: the root mean square (RMS) coil current, as a function of RMS coil voltage, and the coil loss, as a function of RMS coil voltage. These values were then transformed, using Dommel's method, into instantaneous characteristics of non-linear coil, in a form of a non-linear inductance, representing saturation effect; in parallel with the non-linear resistance representing coil loss. The instantaneous characteristics are composed of peak values of resistance current and voltage, and inductance current and flux. The uncertainties of the characteristics are defined through the uncertainty of the peak values. The uncertainty of instantaneous characteristics is calculated on an example of a coil realised as unloaded iron-cored toroid transformer with a strip-wounded core made of oriented transformer sheets (M5-type) using the adaptive Monte-Carlo method (MCM) and uncertainty framework of Guide to the expression of uncertainty in measurement' (GUM). Results reveal the peculiarities of both methods and the impact of the uncertainty of measured values on the uncertainty of instantaneous characteristics.