Research on transformer syspathetic inrush current in initail period of power system

In the initial period of power system restoration, charging the transformer without load will result in sympathetic inrush current appearing in its adjacent transformer. The sympathetic inrush current will appear as a result of the saturation.. In view of fundamental representations of flux linkage, with the help of the integral model of sympathetic inrush of two shunt-wound transforms, the paper derives a formula that the sympathetic inrush current value is decided by the integral value of public bus voltage in a period. From the formula, this paper get the generation reason of sympathetic inrush current that public bus voltage in two shunt-wound transforms depresses suddenly so that linkage of neighboring running transformer changes. Then analyzes the influence of system resistance on sympathetic inrush current. This analysis provides a sound theoretical basis for a complete understanding of the phenomenon.