Ground fault location identification for multiple drive high resistance grounding systems

One of the more difficult problems to solve in industrial plants is to locate and eliminate a ground fault in High Resistance Grounding (HRG) system. This is because ground fault conditions in these systems do not draw enough current to reliably trip the ground fault current detector in the drive. This paper studied the ground fault identification (GFI) using voltage measuring method for multiple-drive HRG systems. The character of the voltage signals at different stages of the drive operating condition is studied. It is demonstrated that the location of the ground fault can be identified much easier if the appropriate operating conditions can be combined in the system level.