Power transformer is one of the most important devices in power system. In order to carry out real-time on-line monitoring of transformer winding condition and find the winding deformation fault in time

we put forward a new method for on-line monitoring of winding deformation. In the method

the current and voltage on both sides of the transformer are employed to build characteristic figure that can reflect winding deformation. First

an electric model was built by a simulation software to simulate normal and faulty windings. Then

an experiment platform for the deformation fault of the transformer winding was set up

and a set of experrments were carred out to verify the repeatability and sensitivity by setting different winding faults. In the cases of both simulation and practical tests

the parameters of the characteristic figure have changed obviously and the repeatability is good. The results show that the proposed method can reflect the winding fault sensitively

deserving to be promoted in practice.