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

Claim 11:
12. An arrangement for determining existence of a fault condition in an electrical network, the fault arrangement comprising:
a fault protection device, the fault protection device including a switch operable in an open state to interrupt a flow of current to a first grid portion from remaining grid portion of a plurality of grid portions in the electrical network;
a vacuum gap switching arrangement coupled in parallel to the fault protection device, the vacuum gap switching arrangement including a vacuum gap switch;
a voltage sensor coupled to the electrical network, the voltage sensor being configured to measure a voltage angle on the network;
a current sensor coupled to the network, the current sensor being configured to measure current flow on the network; and
a control module coupled to the voltage sensor, the current sensor and the vacuum gap switching arrangement,
the control module configured to instruct the vacuum gap switching arrangement to trigger a breakdown across the vacuum gap switch when the voltage angle corresponds to a predetermined switching voltage angle so as to cause a temporary current flow through the vacuum gap switching arrangement,
said control module determining whether the fault condition exists based at least in part on a characteristic of the temporary current flow as measured by the current sensor a measured impedance value based on a relationship between the voltage and the temporary current flow, and an absence of the fault condition when the measured impedance value is greater than a fault detection threshold; and
switch of the fault protection device reconnect to a closed state to reestablish current flow to the fist grid portion to the remaining grid portion of the plurality of the grid portion of the electric network if the fault condition no longer exists.