Method and means for monitoring faults in an electric power system and the like
AssigneeElectric Power Research Institute, Inc.
InventorsJames J. Burke, Dale A. Douglass, Robert A. Lacy, Richard J. Murphy, Delano D. Wilson, Jonathan B. Wright
Life of this patent
Estimating the term…
Abstract
A selected point in an electric power system is monitored for subsequent fault analysis. The voltage and current at the point is continuously sampled with samples for a predetermined period of time being temporarily stored in memory. In response to a Fault Event, voltage and current samples at differing sample rates and for differing periods of time are recorded. Voltage and current samples after a Cold Load Pickup are recorded, also the recorded samples allow later analysis of the fault and identification of the cause of the fault.
Claims10
The method of monitoring an electric power system and recording faults for subsequent analysis comprising the steps of
- (a) monitoring voltage and current at a selected point in said system,
- (b) identifying voltage and current above preselected values,
- (c) recording voltage and current values at a plurality of sampling rates for a predetermined period of time subsequent to voltage and current exceeding said preselected values,
- (d) recording voltage and current values at a plurality of sampling rates for a predetermined period of time subsequent to the re-establishment of voltage and current after a fault interruption thereof, and
- (d) recording voltage and current values at a plurality of sampling rates and for predetermined periods of times subsequent to current exceeding a zero level following a preselected period of zero level current.
Apparatus for monitoring and recording voltage and current in an electric power system for subsequent fault analysis comprising
- (a) current monitoring means for measuring current at a selected point in said electric power system,
- (b) voltage monitoring means for measuring voltage at said selected point in said electric power system,
- (c) means for identifying measured voltage and current above preselected values,
- (d) means for recording voltage at a plurality of sampling rates for predetermined periods of time subsequent to voltage and current exceeding said preselected values, recording voltage and current values at a plurality of sampling rates for predetermined periods of time subsequent to the re-establishment of voltage and current after a fault interrupt thereof, and recording the voltage and current values at a plurality of sampling rates for predetermined periods of time subsequent to current exceeding a zero level following a predetermined period of zero level current.
Dependencies are inferred from the claim text.