Research on Integration of Transformer Protection and On-line Detecting Winding Deformation Based on Equivalent Circuit Equation

This paper bring forward new algorithms that integrate on-line detecting winding deformation into transformer, which is based on Equivalent Circuit Equation (ECE) of transformer. Firstly, the protection algorithm based on ECE is presented, and the criterion functions are derived for single-phase and three-phase transformer. The leakage inductance is the key parameter in ECE, which is not available and changes follow winding deformation, the least square is adopted to service as parameter identification. The mathematical models for identification are derived. The dynamic simulation experiment data indicates that on-line identification of transformer winding leakage inductance parameter is not only precise but can effectively detect winding deformation. The protection algorithm is theoretically clear and it can correctly and rapidly recognize the various transformer internal short circuits with distinct features.