What can a second stator ground fault cause in a power system?

A second stator ground fault in a power system can lead to a variety of issues, all of which are significant for the safe and efficient operation of electrical machinery. When such a fault occurs, it can short out parts of the field winding, leading to a failure in the magnetic field balance required for normal operation. This shorting can disrupt the operation of the generator or motor.

Additionally, a second stator ground fault can cause high unit vibrations. This results from the unbalanced forces created by uneven currents in the system. When one winding is shorted, it can lead to inconsistencies in the electromagnetic forces that can manifest as mechanical vibrations in the unit.

Moreover, rotor heating can occur due to unbalanced currents caused by the fault. The unbalanced currents result in a distribution of electrical forces that can overheat specific components of the rotor, leading to thermal stress and potentially damaging the rotor over time.

Therefore, all these factors combined highlight that a second stator ground fault can indeed lead to shorting of field windings, increased vibrations, and rotor heating, which makes the option encompassing all these consequences the most accurate.