Intelligent electronic device having circuitry for highly accurate voltage sensing
First Claim
1. An intelligent electronic device, comprising:
- a first voltage input for receiving a sensed voltage from a first phase of an electrical distribution system, the first voltage input being coupled to a first voltage divider;
a second voltage input for receiving a sensed voltage from a neutral phase of the electrical distribution system, the second voltage input being coupled to a second voltage divider; and
an inverting operational amplifier (op amp) coupled to the first and second voltage inputs for providing an output proportional to the voltage of the first phase referenced to the neutral phase, an inverting input of the op amp is coupled to an output of the first voltage divider and a non-inverting input of the op amp is coupled to an output of the second voltage divider,wherein the first voltage divider is adjustable to match a ratio of the first voltage divider to a ratio of the second voltage divider.
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Accused Products
Abstract
An intelligent electronic device (IED), e.g., an electrical power meter having circuitry for an input voltage structure with an adjusting voltage divider, resulting in a highly accurate power measurement, is provided. The IED includes a first voltage input for receiving a sensed voltage from a first phase of an electrical distribution system, the first voltage input being coupled to a first voltage divider; a second voltage input for receiving a sensed voltage from a neutral phase of the electrical distribution system, the second voltage input being coupled to a second voltage divider; and an inverting operational amplifier (op amp) coupled to the first and second voltage inputs for providing an output proportional to the voltage of the first phase referenced to the neutral phase, wherein the first voltage divider is adjustable to match a ratio of the first voltage divider to a ratio of the second voltage divider.
155 Citations
54 Claims
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1. An intelligent electronic device, comprising:
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a first voltage input for receiving a sensed voltage from a first phase of an electrical distribution system, the first voltage input being coupled to a first voltage divider; a second voltage input for receiving a sensed voltage from a neutral phase of the electrical distribution system, the second voltage input being coupled to a second voltage divider; and an inverting operational amplifier (op amp) coupled to the first and second voltage inputs for providing an output proportional to the voltage of the first phase referenced to the neutral phase, an inverting input of the op amp is coupled to an output of the first voltage divider and a non-inverting input of the op amp is coupled to an output of the second voltage divider, wherein the first voltage divider is adjustable to match a ratio of the first voltage divider to a ratio of the second voltage divider. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A sensor comprising:
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a potential transformer having an input coupled to a first phase of an electrical distribution system and an output coupled to a first voltage divider; a voltage input for receiving a sensed voltage from a neutral phase of the electrical distribution system, the voltage input being coupled to a second voltage divider; and an inverting operational amplifier (op amp) coupled to the first and second voltage inputs for providing an output proportional to the voltage of the first phase referenced to the neutral phase, an inverting input of the op amp is coupled to an output of the first voltage divider and a non-inverting input of the op amp is coupled to an output of the second voltage divider, wherein the first voltage divider is adjustable to match a ratio of the first voltage divider to a ratio of the second voltage divider. - View Dependent Claims (19, 20, 21, 22)
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23. An intelligent electronic device, comprising:
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a neutral voltage input for receiving a sensed voltage from a neutral phase of an electrical distribution system, the neutral voltage input being coupled to a neutral voltage divider having a first and second fixed resistor; at least one phase voltage input for receiving a sensed voltage from at least one phase of the electrical distribution system, the at least one phase voltage input being coupled to a phase voltage divider, wherein the phase voltage divider is adjustable to match a ratio of the phase voltage divider to a ratio of the neutral voltage divider; at least one inverting operational amplifier (op amp) coupled to the neutral voltage input and the at least one phase voltage input for providing an output proportional to the voltage of the at least one phase referenced to the neutral phase, an inverting input of the at least one op amp is coupled to an output of the phase voltage divider and a non-inverting input of the at least one op amp is coupled to an output of the neutral voltage divider; and a controller for adjusting the phase voltage divider to match the ratio of the phase voltage divider to the ratio of the neutral voltage divider. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
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35. An intelligent electronic device, comprising:
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a neutral voltage input configured to receive a sensed voltage from a neutral phase of an electrical distribution system, the neutral voltage input being coupled to a neutral voltage divider; at least one phase voltage input configured to receive a sensed voltage from at least one phase of the electrical distribution system, the at least one phase voltage input being coupled to a phase voltage divider; and at least one inverting operational amplifier (op amp) coupled to the neutral voltage input and the at least one phase voltage input and configured to provide an output proportional to the voltage of the at least one phase referenced to the neutral phase, an inverting input of the at least one op amp is coupled to an output of the phase voltage divider and a non-inverting input of the at least one op amp is coupled to an output of the neutral voltage divider, wherein a ratio of the phase voltage divider matches a ratio of the neutral voltage divider. - View Dependent Claims (36, 37, 38, 39, 40, 41, 42)
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43. An intelligent electronic device, comprising:
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at least one first voltage input for receiving a sensed voltage from at least one first phase of an electrical distribution system, the at least one first voltage input being coupled to a first voltage divider; at least one second voltage input for receiving a sensed voltage from at least one second phase of the electrical distribution system, the at least one second voltage input being coupled to a second voltage divider; and at least one operational amplifier (op amp) coupled to the at least one first voltage input and the at least one second voltage input for providing an output proportional to the voltage of the at least one first phase referenced to the at least one second phase, a first input of the at least one op amp is coupled to an output of the first voltage divider and a second input of the at least one op amp is coupled to an output of the second voltage divider; wherein the first or second voltage divider is adjustable to match a ratio of the first voltage divider to a ratio of the second voltage divider. - View Dependent Claims (44, 45, 46, 47, 48)
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49. An intelligent electronic device, comprising:
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a neutral voltage input configured to receive a sensed voltage from a neutral phase of an electrical distribution system, the neutral voltage input being coupled to a neutral voltage divider; at least one phase voltage input configured to receive a sensed voltage from at least one phase of the electrical distribution system, the at least one phase voltage input being coupled to a phase voltage divider; and at least one operational amplifier (op amp) coupled to the neutral voltage input and the at least one phase voltage input and configured to provide an output proportional to the voltage of the at least one phase referenced to the neutral phase, a first input of the at least one op amp is coupled to an output of the phase voltage divider and a second input of the at least one op amp is coupled to an output of the neutral voltage divider. - View Dependent Claims (50, 51, 52, 53, 54)
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Specification