Derivation of Universal Three-Phase Detailed Model of Transformer and Method for solving singularity of its three-phase node admittance matrix

Three-phase detailed model of transformer plays a critical role in calculation and analysis for multi-voltage level distribution networks, its accuracy is directly related to the reasonableness of results. This paper presents a universal three-phase detailed model of transformer,which is derived with symmetric phasor method according to winding wiring and phase-shifting angle,and has general versatility. For a given transformer, its three-phase detailed model is acquired by substituting parameters of winding wiring and phase shifting angle into the proposed model in this paper, it does't need to derivation again,which brings great convenience to engineering applications. Further more,solutions to singularity of three-phase nodal admittance matrix of transformer are proposed by adding additional conditions. The correctness of the proposed universal model is verified by comparing with existing literature.