Power quality utility metering system having waveform capture
First Claim
1. In 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 during an energy measurement time interval, a method of monitoring variations in the electrical energy, comprising the steps of:
- a) sensing a line voltage transferred via the power supply line to the load during the energy measurement time interval;
b) 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;
c) capturing a first waveform of the sensed line voltage corresponding to the time when said variation is detected;
d) 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
e) capturing a second waveform of the sensed line voltage corresponding to the time when the subsequent reduction in the variation is detected.
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Accused Products
Abstract
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.
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Citations
44 Claims
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1. In 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 during an energy measurement time interval, a method of monitoring variations in the electrical energy, comprising the steps of:
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a) sensing a line voltage transferred via the power supply line to the load during the energy measurement time interval;
b) 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;
c) capturing a first waveform of the sensed line voltage corresponding to the time when said variation is detected;
d) 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
e) capturing a second waveform of the sensed line voltage corresponding to the time when the subsequent reduction in the variation is detected. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
detecting a subsequent variation in a magnitude of the sensed line voltage relative to an acceptable voltage level, wherein said variation exceeds the first variation threshold and a second variation threshold; and
capturing a third waveform of the sensed line voltage corresponding to the time when said variation exceeding the first variation threshold and the second variation threshold is detected.
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9. The method of claim 8 further comprising the steps of:
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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 second variation threshold and greater than the first variation threshold;
capturing a fourth waveform of the sensed line voltage corresponding to the time when the subsequent reduction in the variation is detected.
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10. The method of claim 1 further comprising the step of obtaining user input identifying the first variation threshold.
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11. The method of claim 1 wherein step c) further comprises capturing the first waveform such that said captured first waveform includes information representative of a the sensed line voltage prior to and contemporaneous with the detection of said variation.
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12. The method of claim 1 wherein step c) further comprises capturing the first waveform such that said captured first waveform includes information representative of the sensed line voltage contemporaneous with and subsequent to the detection of said variation.
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13. The method of claim 1 wherein step c) further comprises capturing the first waveform such that said captured first waveform includes information representative of the sensed line voltage prior to, contemporaneous with, and subsequent to the detection of said variation.
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14. An electrical energy meter for detecting line voltage variations in real-time, comprising:
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a voltage digitizing circuit operable to obtain analog line voltage information and generate digital line voltage information therefrom;
a current digitizing circuit operable to obtain analog line current information and generate digital line current information therefrom;
a metering circuit operable to receive the digital line voltage information and the digital line current information and generate metering information therefrom;
a power quality circuit operable to receive the digital line voltage information and obtain magnitude information therefrom, the magnitude information representative of the magnitude of the line voltage, detect a variation in the magnitude of the line voltage relative to an acceptable voltage level, wherein said variation exceeds a first variation threshold, capture a first waveform in the form of a first set of digital line voltage information corresponding to the time when said variation is detected, detect a subsequent reduction in the variation of the magnitude of the line voltage such that the variation is equal to or less than the first variation threshold, capture a second waveform in the form of a second set of digital line voltage information corresponding to the time when the subsequent reduction in the variation is detected. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22)
detect a variation in a magnitude of the line voltage relative to an acceptable voltage level, wherein said variation exceeds the first variation threshold and a second variation threshold; and
capture a third waveform in the form of a first set of digital line voltage information corresponding to the time when said variation that exceeds the first variation threshold and the second variation threshold is detected.
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22. The electrical energy meter of claim 21 wherein the power quality circuit is further operable to:
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detect a subsequent reduction in the variation of the magnitude of the line voltage such that the variation is equal to or less than the second variation threshold and greater than the first variation threshold; and
capture a fourth waveform in the form of a first set of digital line voltage information corresponding to the time when the subsequent reduction in the variation is detected.
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23. An apparatus for providing control parameters to an electrical energy meter, the electrical energy meter having a power quality circuit, the power quality circuit operable to capture a first waveform of a sensed line voltage corresponding to a time when a variation of the sensed line voltage relative to an acceptable voltage level exceeds a first variation threshold, and further operable to capture a second waveform of a sensed line voltage when the variation of the sensed line voltage relative to an acceptable voltage level exceeds a second variation threshold, the apparatus comprising:
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a) a user interface operable to receive information identifying a first variation threshold and the second variation threshold;
b) a programming device configured to provide information to the electrical meter, the programming device operable to communicate control parameters to the electrical energy meter, the control parameters including the information identifying the first variation threshold and the second variation threshold. - View Dependent Claims (24)
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25. In 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 of a customer during an energy measurement time interval, a method of monitoring variations in the metered quantity of electrical energy, comprising the steps of:
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a) sensing a line voltage transferred via the power supply line to the load during the energy measurement time interval;
b) detecting a variation in a magnitude of the sensed line voltage relative to an acceptable voltage level, wherein said variation exceeds a first variation threshold;
c) capturing a first waveform of the sensed line voltage corresponding to the time when said variation is detected;
d) detecting a subsequent variation in the magnitude of the sensed line voltage relative to the acceptable voltage level, wherein said subsequent variation exceeds a second variation threshold; and
e) capturing a second waveform of the sensed line voltage corresponding to the time when the subsequent variation is detected wherein the subsequent variation exceeds the acceptable voltage level when the variation exceeds the acceptable voltage level, and the subsequent variation is less than the acceptable voltage level when the variation is less than the acceptable voltage level. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34, 35)
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36. An electrical energy meter for detecting line voltage variation in real-time, comprising:
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a voltage digitizing circuit operable to obtain analog line voltage information and generated digital line voltage information therefrom;
a current digitizing circuit operable to obtain analog line current information and generate digital line current information therefrom;
a metering circuit operable to receive the digital line voltage information and the digital line current information and generate metering information therefrom;
a power quality circuit operable to receive the digital line voltage information and obtain magnitude information therefrom, the magnitude information representative of the magnitude of the line voltage, detect a variation in the magnitude of the line voltage relative to an acceptable voltage level, wherein said variation exceeds a first variation threshold, capture a first waveform in the form of a first set of digital line voltage information corresponding to the time when said variation is detected, detect a subsequent variation of the magnitude of the line voltage, wherein said subsequent variation exceeds a second variation threshold, and capture a second waveform in the form of a second set of digital line voltage information corresponding to the time when the subsequent variation is detected wherein the subsequent variation exceeds the acceptable voltage level when the variation exceeds the acceptable voltage level, and the subsequent variation is less than the acceptable voltage level when the variation is less than the acceptable voltage level. - View Dependent Claims (37, 38, 39, 40, 41, 42)
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43. In 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 during an energy measurement time interval, a method of monitoring variations in the electrical energy, comprising the steps of:
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a) sensing a line energy signal transferred via the power supply line to the load during the energy measurement time interval;
b) detecting a variation in a magnitude of the sensed line energy signal relative to an acceptable line energy level, wherein the variation exceeds a first variation threshold;
c) capturing a first waveform of the sensed line energy signal corresponding to the time when said variation is detected;
d) detecting a subsequent reduction in the variation of the magnitude of the sensed line energy signal such that the variation is equal to or less than the first variation threshold; and
e) capturing a second waveform of the sensed line energy signal corresponding to the time when the subsequent reduction in the variation is detected. - View Dependent Claims (44)
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Specification