The control of the asymmetric ground fault current of the line

During the asymmetric ground fault, the relationship of the current through the line with the inserting voltage and the inserting inductance is analyzed and a novel control method for the asymmetric ground fault current is presented. When the ground fault occurs, the fault current can be controlled to zero and the current through the fault line can be controlled to that in the normal operation by adjusting the insertion inductance and the amplitude of the insertion source voltage appropriately, in addition, adjusting the insertion source voltage to lead (lag) the corresponding phase bus voltage by 120 degree at the sending (receiving) terminal, from (into) which the active power flow goes during the normal operation. And a novel fault current controller (FCC) is also presented, which consists of the series-connection transformer, the shunt-connection transformer, adjustable inductors and on-load taps. FCC is equivalent to the adjustable inductor and the voltage source in series. The source voltage can be control to lead or lag the corresponding phase bus voltage by 120 degree. And the amplitude of the source voltage and the equivalent inductance of FCC can also be adjusted independently. Furthermore, the control strategy of the asymmetrical ground fault current suitable for FCC is also presented, by which the current through the fault line can be controlled to that in the normal operation and the fault current can also be controlled to zero. The proposed control strategy is verified with the simulation and the experiment.