Detection of internal winding faults in power transformers based on graphical characteristics of voltage and current

Power transformers are voltage conversion facilities in substation, which directly affect the safe operation of the grid. Since winding deformation is one of the most common transformer faults, it´s of important engineering significance to protect transformer from faults, especially induced by short-circuit current failures, and ensure its safe operation through online monitoring of winding deformations. This paper tries to propose a newly developed winding deformation online monitoring method based on Lissajous graphical analysis of voltage and current. The basic principle of the proposed method was introduced in this paper, and winding experiments were carried out to verify the feasibility of the proposed method. Finally, it has been concluded that this method has reached the potential to online detection of transformer winding deformations.