TRANSFORMER DIFFERENTIAL PROTECTION BASED ON THE CHARACTERISTIC ANALYSIS OF THE FIRST AND SECOND HALF CYCLE OF THE MAGNETIZING IN-RUSH CURRENT
Sun Zhijie; Chen Yunlun(Nanjing Electric Power Automation Equipment Factory, 210003, Nanjing, China)
By finding the derivatives of the phase differential currents of the magnetizing in-rush currents and then comparing the first half cycle with the second half. fault or in-rush current can be discriminated. Model device based on this principle shows that its operation is reliable and noise immunity is strong.