End of line protection with trip signal engaging
AssigneeViking Sentinel Technology, LLC
InventorsVahid Madani, Robert B. Stuart, Ronald E. Smith, Kenneth Hyung Choi, Justin Dongjin Choi
Life of this patent
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Abstract
The present disclosure pertains to detection of abnormal, risky, or aberrant conditions in a power distribution network and to corresponding trip signals being used to trip open devices such as reclosers upstream of where the abnormal condition is detected. Detection of open phase on a distribution circuit prevents severed conductors from causing a ground fault, therefore avoiding the possibility of fire and dangerous conditions. The voltage unbalance may be measured using an end of line relay that includes an electrical sensor or relay, a tripping mechanism, and a signal transmitter.
Claims20
A method for engaging a trip signal at an interrupting device of a set of three phase electric distribution lines, the method comprising:
- measuring, via one or more sensors, a potential from a three phase transformer at one end of the set of three phase distribution lines;
- detecting an abnormal condition with respect to the set of distribution lines based on the measured potential, wherein the abnormal condition is selected from the group consisting of:
- (a) a voltage unbalance;
- (b) a negative sequence voltage unbalance;
- or (c) both a voltage unbalance and a negative sequence unbalance;
- responsive to detecting an abnormal condition, transmitting the trip signal from another device to the interrupting device without use of a positive sequence power source, thereby blocking the interrupting device at least temporarily from closing;
- wherein the detection is performed via a tripping apparatus that includes four conductors, three of the four conductors tapping the three phase transformer, and one of the four conductors being a ground or neutral.
A system connected to a set of three phase electric distribution lines, comprising:
- one or more sensors configured to measure a potential substantially at a far end of a power distribution network, the far end of the power distribution network being opposite from a source of the power, said sensors configured for detecting an abnormal condition selected from the group consisting of:
- (a) a voltage unbalance;
- (b) a negative sequence voltage unbalance;
- or (c) both a voltage unbalance and a negative sequence unbalance;
- a three phase transformer at the far end;
- a tripping apparatus located away from the three phase transformer, wherein the tripping apparatus includes four conductors, three of the four conductors tapping the three phase transformer, and one of the four conductors being a ground or neutral;
- a transmitter configured to transit a trip signal on the one or more measurements to said tripping device without use of a positive sequence power source;
- and,
- an interrupting device configured to be blocked from closing a circuit by reception of the trip signal.
Dependencies are inferred from the claim text.