Study on Characteristics of Sympathetic Current and the Infection to Differential Protection of Transformers with Inner Bridge Connection

Firstly,the principle of sympathetic interaction in the parallel connection and the series connection are analyzed.Then characteristics of sympathetic current 、harmonic components of sympathetic current 、the dead angle and proportion of second harmonic current are studied by using MATLAB simulation result.At last,combine with the characteristics of sympathetic interaction,we make a systematic study on the infection to the differential protection of transformer with inner bridge connection.the corresponding measures are put forward.