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. Furthermore, 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.