Patent ID: 11879927
Assignee: S&C ELECTRIC COMPANY
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A method for determining if a fault condition exists in an electrical network, the method comprising:
interrupting by opening a fault protection device a flow of current through the fault protection device responsive to the fault condition within the electrical network to isolate a first grid portion from remaining grid portions of a plurality of grid portions of the electrical network;
monitoring a voltage angle of a voltage waveform across a vacuum gap switching arrangement disposed in parallel to the fault protection device if the fault protection device has opened to interrupt the current flow, the vacuum gap switching arrangement including at least one vacuum gap switching element;
triggering at a predetermined voltage angle a breakdown of a vacuum gap in the at least one vacuum gap switching element to induce a temporary current flow through the vacuum gap switching arrangement;
measuring the induced temporary current flow through the vacuum gap switching arrangement to provide a measured current flow; and
determining whether the fault condition exists based at least in part on the measured current flow and a measured impedance value based on a relationship between the voltage and the temporary current flow;
verifying the absence of the fault condition when the measured impedance value is greater than a fault detection threshold; and
reconnecting by closing the fault protection device the first grid portion to the remaining grid portions of the plurality of grid portions of the electrical network if the fault no longer exists.