Current Transformer Electromagnetic Modelling based on Measurement Data

Inhalt:
An electromagnetic current transformer modelling approach, based on the current transformer’s topological model, meas-urement data, and basic design information is presented in this paper. The model of the electromagnetic current trans-former is confirmed to be accurate by employing the primary current injection technique across a broad range of current amplitudes, extending up to saturation. A model parameter sensitivity analysis outlines the effect on the transient current accuracy. The Jiles-Atherton hysteresis model is used together with the saturation characteristic of the current transformer for magnetic core representation. Particularly during operations with overcurrent, the hysteresis model provides a more precise transient current response. The practice of testing current transformers using a model-based approach yields high-quality data that can be used to evaluate the transformer’s accuracy. This data, when used for the electromagnetic model-ling of the current transformer, can generate additional value. As the power systems undergoes a change in topology and generation mixture, the testing of the assets and the interaction between the different assets becomes more important in future. In the realms of asset management, predictive maintenance, and forecasting, the data can be utilized as a compo-nent of a digital twin for the current transformer. Digital twin should be capable to replicate the electromagnetic behaviour of the transformer under a wide range of operating conditions.