Implementation of the State-Space Power Transformer Model in ATP for High Frequency Transient Studies

State-space representation is a practical, efficient and reliable way to evaluate the high-frequency interaction of a transformer with the power network under different types of disturbances. Currently, this representation is available in commercial electromagnetic transient programs; however, this important tool is not yet implemented in the alternative transient program ATP. This paper describes the implementation methodology of the state-space model of the power transformer in ATP using the Norton type-94 component and foreign models. The proposed implementation incorporates several aspects relevant to its application in realistic situations, including initialization from steady state, customization of information exchange between the manufacturer and the purchaser, and accurate consideration of damping. The implemented model in ATP is validated on a real 50 MVA power transformer by means of three relevant example cases, obtaining an excellent agreement between the reference data and those calculated with ATP.