Patent ID: 7102355

Claim:
A method for detecting an incipient ground fault that may occur in an electrical propulsion system of a traction vehicle, said electrical propulsion system comprising a plurality of electrical devices, said method comprising: a) turning off a first set of the plurality of electrical devices of the electrical propulsion system; b) contemporaneously connecting each electrical device in the set to a respective ground fault augmenting signal, wherein the ground fault augmenting signal connected to any individual one of the electrical devices in the set has associated therewith a signal with a unique electrical characteristic; c) monitoring a ground signal when each electrical device in the set is connected to its respective ground fault augmenting signal; d) determining whether the monitored ground signal indicates a presence of an incipient ground fault, and whether the incipient ground fault, if any, has the unique electrical characteristic associated with one of the respective ground fault augmenting signals connected to one of the electrical devices in the set; and e) when the incipient ground fault exhibits the unique electrical characteristics associated with one of the respective ground fault augmenting signals connected to one of the electrical devices in the set, assigning the incipient ground fault to said one electrical device.