Harmonics Correction of J–A Hysteresis Model

The J–A hysteresis theory is widely used in the modeling of magnetic characteristics of electromagnetic current transformers (CTs), but there is a large error in the model when considering the harmonics excitation, and unfortunately, the harmonic pollution in modern power grids is becoming more and more serious. Considering that the nonlinearity error of the CT for measurement is less than 0.2S, that is, the ratio error at 100% rated current is < 0.2%, and the phase error is
$ < 10^{\prime} $
, the correction of the magnetic characteristics of each harmonic is approximately applicable to the principle of linear superposition. Therefore, this article uses the dung beetle algorithm (DBA) to identify the parameters, corrects the J–A model parameters for each harmonic, and then linearly superimposes the magnetic characteristics of each harmonic to realize the magnetic characteristics modeling. Taking the 0.2S permalloy core CT as an example, the simulation analysis and experimental results show that the proposed method can accurately reflect the transmission characteristics of the CT at harmonic excitation. The approximate linear superposition of the multiple harmonics magnetic characteristics introduces a ratio error of 0.01% and a phase error of
$0.5^{\prime} $
, and its influence can be ignored, thus confirming that the correction method is reasonable and effective.