Hybrid equivalent of asymmetrical network for electromagnetic transient studies

Developing an accurate network equivalent to reduce the computational time of an electromagnetic transient study has been the major task of many researches in the past two decades. However, still no accurate wide band equivalent for an asymmetrical network is addressed in the literature. This paper presents a Hybrid equivalent for the external system, assuming that it contains an asymmetrical transmission system at the terminal of this external system. The proposed method is based on the introduction of an asymmetrical transmission system in the model through application of a real constant transformation matrix in the subsystem and dealing with its asymmetrical effects in the external system. To simplify the development of the equivalent for a network involving asymmetry, its effect is shared between the subsystem and the external system, as it will be shown. This is the main underlying idea in the proposed Hybrid equivalent model. This method is employed to develop the equivalent of a sample asymmetrical network.