A Method for Calculating the Impedance of Three-phase Transformer in Photovoltaic Power Station Based on Power Loss

In the new energy power generation system, the transformer impedance as part of the grid impedance will affect the stability of the system. In order to calculate the transformer impedance, considering that the existing methods rely on the transformer nameplate parameters and require offline detection, this paper proposes an on-line calculation method of transformer impedance based on power loss. This method considers the influence of transformer impedance on system power and establishes a transformer power loss model, based on which a fitting calculation method for transformer impedance is proposed. Finally, the effectiveness of the method is verified by a specific transformer simulation model in photovoltaic power station.