Fault sensor device with radio transceiver
First Claim
1. A method of distinguishing between a plurality of different types of faults using a fault sensor that monitors current of an AC power transmission or distribution line, comprising the steps of:
- a) detecting when the current exceeds a first predetermined threshold level;
b) at a first predetermined time after the current has been detected as exceeding the predetermined threshold level, checking to see if said current is zero;
c) if the current at said first predetermined time is not zero, checking to see if the current is less than a second predetermined threshold level; and
d) if the current at said first predetermined time is zero, at a second predetermined time after the current has been detected as exceeding the predetermined threshold level, checking to see if the current is zero.
2 Assignments
0 Petitions
Accused Products
Abstract
A fault sensor device which can detect and distinguish abnormal current and voltage events on an alternating current overhead and underground power transmission or distribution line. The abnormal current events are momentary outage, sustained outage, normal overload, and inrush on transmission or distribution lines. The sensor can further distinguish whether the momentary or sustained fault is a line to ground fault, line to line fault or a three phase fault. It can also identify the faulted phase(s). In the overload scenario, the sensor can identify if the overload has occurred on all three phases or only on one or two phases of the power line in an unbalanced situation. The voltage events are open line(s) on one, or two of the phases with a possibility of a fallen live wire and voltage sag. The sensor can identify which of the three phases or if all three phases of the power line are open or on the ground. The sensing device can be attached to an overhead or underground transmission or distribution line and automatically transmits an alarm signal or general information to a control, switching center or any designated ground station when the device detects a fault condition. The device can also be remotely programmed and reprogrammed to alter its trigger or threshold level or time delay to reset the device when a fault has occurred.
96 Citations
7 Claims
-
1. A method of distinguishing between a plurality of different types of faults using a fault sensor that monitors current of an AC power transmission or distribution line, comprising the steps of:
-
a) detecting when the current exceeds a first predetermined threshold level; b) at a first predetermined time after the current has been detected as exceeding the predetermined threshold level, checking to see if said current is zero; c) if the current at said first predetermined time is not zero, checking to see if the current is less than a second predetermined threshold level; and d) if the current at said first predetermined time is zero, at a second predetermined time after the current has been detected as exceeding the predetermined threshold level, checking to see if the current is zero. - View Dependent Claims (2, 3)
-
-
4. A method of distinguishing between a plurality of different types of faults using a fault sensor that monitors current and voltage of an AC power transmission or distribution line, comprising the steps of:
-
a) detecting when the current exceeds a first predetermined threshold level; b) at a first predetermined time after the current has been detected as exceeding the predetermined threshold level, checking to see if said current is zero; c) if the current at said first predetermined time is not zero, checking to see if the current is less than a second predetermined threshold level; d) if the current at said first predetermined time is zero, at a second predetermined time after the current has been detected as exceeding the predetermined threshold level, checking to see if the current is zero; e) if in step a) the current does not exceed the first predetermined threshold level, checking to see if the voltage has experienced a drop of at least a predetermined relative magnitude; f) if in step e) the voltage has experienced a drop of predetermined relative magnitude, at a predetermined time thereafter, checking to see if the drop of at least predetermined relative magnitude persists; and g) if in step f) the drop of at least predetermined relative magnitude persists, checking to see if the voltage is zero. - View Dependent Claims (5, 6, 7)
-
Specification