Detection and location of a ground-fault in the excitation circuit of a 106 MVA synchronous generator by a new on-line method

After the location of the ground fault, thanks to numerous intentional ground faults tests along the field winding with different fault resistance values, the influence of the capacitance of the rotor is analysed. It can be concluded that the location method has an acceptable accuracy and the rotor capacitance has not a significant influence. However the detection method could produce unwanted trips due to the capacitive current in non-faulty conditions.