Modeling and experimental validation of a dynamic regional saturation J-A model for protective current transformer

The analysis and accuracy of modeling the protective current transformer are yet not suitable for a wide range of current levels, especially under weak transient saturation. It is necessary to develop a mathematical tool allowing to create field models of current transformers allow modeling not only steady modes, but also transients ones. With the support of the large current transient test conducted on the real protective current transformers, multiple test levels from 6 to 48 kA transients were obtained. This paper devoted to the study of modeling protective current transformers more accurately proposes an improved dynamic regional saturation J-A model. It emphasizes the excess loss of the core under transient conditions, and designs a numerical solution for the proposed dynamic regional saturation J-A current transformer model without iteration, so that it can simulate the secondary output of the current transformer online. By numerous data which are actually saturated in the transient flow test, the proposed dynamic partitioned saturation J-A model, the static J-A model and the dynamic J-A model are compared and verified, respectively. Extensive results prove the effectiveness of the proposed method, which is capable to modeling protective current transformer transient of the actual situation. And the average error under a wide range test is relatively stable.