Fast and Very Fast Electromagnetic Transients of Three-phase Three Limb Transformers: Theoretical Approach and Experiments

This paper proposes a new model of asymmetric three-phase three legged transformers for the simulation of transient operation. In the current literature, several models yield incomplete and inaccurate results, both in the steady-state and transient operations. Among all these models, the idea of using a PI model [5] seemed the most promising. We have improved the model by taking into account the fast and very fast electromagnetic transients. An analysis is performed on over-current and overvoltage in the unbalanced three-phase asymmetrical transient behavior. The simulation results are compared with experimental ones to validate the suggested model.