A system and method for detecting a flicker of electrical energy provided via a service type to an energy meter. The system comprises a memory for storing a respective voltage threshold for each different service type; a digital signal processor for measuring a respective phase voltage for each meter element of the energy meter; and a microcontroller for retrieving the voltage threshold for the service type from the memory and comparing the measured phase voltage to the voltage threshold to determine an occurrence of flicker.
RELATED APPLICATION DATA
The present application claims priority from and is a C-I-P of PCT application No. PCT/US97/18457, having an international filing date of Oct. 16, 1997, which claims priority from provisional application Ser. No. 60/028,986, filed on Oct. 22, 1996.
A system and method for synchronizing power system data gathered in response to unscheduled power system events such as faults. A plurality of protective devices communicate over a peer-to-peer communication network, and when a first device detects the occurrence of a power system event, the device records cycles of power system data before, after, or surrounding the power system event. The first device informs remote devices via the network of the event and a time tag associated with the event, and the remote devices record synchronized power system data.
A system and method of indicating power quality in an electric power system that generates an indication of power quality reflective of the worst observed power quality event over both a short and a long interval of time in which each component of the indicator is weighted by a user programmable factor to control its relative influence.
A composite power quality indication generated from user weighted statistical contributions of selected system parameters provides an overall indication of power quality in an electric power distribution system. The user defined weightings are maintained over time by continually updating sensitivities that normalize the component contributions to the composite power quality indication. The current composite power quality indication is displayed in relation to its long-term mean and to dynamic thresholds determined as multiples of the standard deviation of the long-term mean.
Dynamic thresholds statistically derived are used to define normal conditions at a specific site in an electric power distribution system. High and low and/or caution and alarm thresholds for various parameters are generated as multiples of the standard deviation of the long-term average of measured values calculated from samples gathered over repetitive intervals, such as ten minutes. Weekly averages are used until sufficient data has been gathered to maintain a running one year average.
A power meter is provided having an auto-calibration feature and a data acquisition node for measuring the power usage and power quality of electrical power in an electrical power distribution network. The auto-calibration feature calibrates the power meter at predetermined time increments and as a function of temperature changes.
