Landis+gyr, Inc.

Siemens Power Transmission & Distribution, Inc.

Siemens Transmission & Distribution. LLC

Paul M Griffin, Jr

Guy H Berthiaume

William I Jenrette

A method of monitoring variations is carried out within an electrical energy meter containing means therein for metering a quantity of electrical energy generated by a supplier and transferred via a power supply line to a load. The method includes a first step of sensing a line voltage transferred via the power supply line to the load during the energy measurement time interval. The method also includes the step of detecting a variation in a magnitude of the sensed line voltage relative to an acceptable voltage level, wherein the variation exceeds a first variation threshold. The method then includes the step of capturing a first waveform of the sensed line voltage corresponding to the time when the variation is detected. Finally, the method includes the steps of detecting a subsequent reduction in the variation of the magnitude of the sensed line voltage such that the variation is equal to or less than the first variation threshold and capturing a second waveform of the sensed line voltage corresponding to the time when the subsequent reduction in the variation is detected.

Power quality utility metering system having waveform capture

An electrical utility meter having harmonic data templates advantageously enables a user to determine whether equipment at a particular site is susceptible to electrical damage or interference. According to an exemplary embodiment, the meter generates measured harmonic data for a plurality of phases in the polyphase electrical system. A user may select at least one of a plurality of predetermined templates including one or more harmonic data thresholds. Each of the predetermined templates corresponds to a condition where a specific device is susceptible to electrical damage or interference. The measured harmonic data is compared with the one or more harmonic data thresholds included in the at least one selected predetermined template. An alarm is generated when the measured harmonic data exceeds the one or more harmonic data thresholds included in the at least one selected predetermined template. According to a preferred embodiment, the alarm is generated in dependence upon the specific template whose one or more harmonic data thresholds are exceeded.

Electrical utility meter having harmonic data templates for power quality alarm thresholds

An electrical energy meter includes a voltage digitizing circuit, a current digitizing circuit, a metering circuit, a clock circuit, and a source of externally-generated time standard information. The voltage digitizing circuit is operable to obtain analog line voltage information and generated digital line voltage information therefrom. Similarly, the current digitizing circuit is operable to obtain analog line current information and generate digital line current information therefrom. The metering circuit is operable to receive the digital line voltage information and the digital line current information and generate metering information therefrom. The clock circuit is operable to generate calendar/clock information, said clock circuit having a calibration input for receiving precision time calibration information. The source of externally-generated time standard information is operably coupled to provide precision time calibration information to the calibration input of the clock circuit.

Growing community of inventors

Charlotte, NC, United States of America

Paul M Griffin, Jr