General Electric Company

Donald F Bullock

Warren R Germer

Maurice J Ouellette

David Dean Elmore

Ansell W Palmer

Gregory Paul Lavoie

Curtis Whitmore Crittenden

Leslie J Rosenau

Austin F Wilson

Daniel Arthur Staver

Robert E Lee, Jr

Mark J Plis

Larry A Schmidt

Samuel G Hardy

Richard G Farnsworth

David H Masury

Kenneth W Atherton

Harold L Stucker

Mark E Hoffman

Roland J Provost

Thomas Maehl

Robert C Mayo

Ellen D Edge

Raymond E Fearnley

Thomas H Stevens

Jeffrey W Mammen

Francois Y Simon

Gerard Chevalier

Jokin Galletero

Arthur C Burt

Sivarama Seshu Putcha

Marshall A Lemay

David B Miles

Methods and systems for an electrical meter are provided. The meter includes a current sensor configured to be communicatively coupled to a conductor, and a processor communicatively coupled to the current sensor wherein the processor is configured to receive signals indicative of current flow through the conductor and wherein the processor is further configured to process the signals to determine an imbalance between the positive half cycle of the current flowing through the conductor and the negative half cycle of the current flowing through the conductor to detect a DC influence on the current sensor.

Methods and systems for detecting DC influence in a current sensor

An electricity meter which, in one embodiment, includes a digital signal processor configurable for generating energy measurements for a plurality of meter form types and connections is described. In the one embodiment, the meter includes voltage and current sensor for generating signals representative of current and voltage at a load, and the digital signal processor (DSP) is coupled to the voltage and current sensors. The DSP includes a memory, and a plurality of selectable instruction sets corresponding to respective meter form types are stored in the DSP memory. The form types includes meter ANSI form and meter ANSI form type forms, and the instruction sets include processing steps to be executed to determine line voltages and line currents for respective meter form types. The meter also includes a microcomputer coupled to the DSP for receiving data generated by the DSP. The microcomputer is operable transmit a selection command to the DSP to control selection of one of the instruction sets stored in the DSP memory. An optical port may be electrically coupled to the microcomputer, and the microcomputer is configured to receive a control command from the optical port. The microcomputer uses the control command to generate the selection command.

Electronic electricity meter configurable to operate in a plurality of meter forms and ratings

Line voltage and line current signals are sensed on a power line having at least one conducting path. The sensed line voltages and line currents are converted into a digital signal. A phase-to-neutral voltage signal and phase current signal are computed from the digital signal to thereby define a phase of the power line. An interval of orthogonality is determined from the sensed voltage and current signals, coinciding with passage of an integral number of cycles of a fundamental frequency reference signal which is computed from the computed phase-to-neutral voltage signal. A vector metering quantity is computed for the determined interval of orthogonality from the computed phase-to-neutral voltage signal and the computed phase current signal. The vector metering quantities to be computed may be identified and computed based upon an associated detent. The vector metering quantity is also computed based on an identified circuit topology.

Vector electricity meters and associated vector electricity metering

An apparatus and method for measuring electrical energy and quadergy and for performing line frequency compensation includes a compensation integrated circuit for adjusting the determined reactive load quadergy, based on variations between the actual line frequency and the rated line frequency of the meter. Reactive load quadergy is determined by phase-shifting the line voltage by a fixed time interval, based on the rated line frequency of the meter. The determined reactive load quadergy is adjusted to compensate for variations in line frequency. Because the determined reactive load quadergy is output by an electric meter as a continuous pulse train, adjustment to the determined reactive load quadergy is performed by adding or subtracting state changes from the pulse train and then registering the adjusted reactive load quadergy.

Apparatus and method for measuring electrical energy and quadergy and

Electronic energy meter

A method of operating a meter to perform the steps of generating a measure of real energy consumed, generating a measure of reactive energy consumed, and generating, from the real energy and reactive energy measures, a measure of apparent energy consumed. In one embodiment, the real energy and reactive energy measures are provided as integer quantity inputs. Particularly, assume S=kVAh, P=kWh, Q=kVARh, and R=Residue. Respective registers store values of P, [2P+1], Q, [2Q+1], and the sum [P.sup.2 +Q.sup.2 ]. Initially, the P, Q, and [P.sup.2 +Q.sup.2 ] registers are set to zero, while the [2P+1] and [2Q+1] registers are initialized to 1. At the arrival of a P pulse, the value in the [2P +1] register is added to the [P.sup.2 +Q.sup.2 ] register, then the P register is incremented by 1 and the [2P+1] register is incremented by 2. Exactly the same steps are carried out subsequent to receipt of a Q pulse. A set of registers also is used to store the S and [2S+1] data, and generation of the S pulses is determined as follows. After arrival of either a P or Q pulse, a trial subtraction of [2S+1] is made from the [P.sup.2 +Q.sup.2 ] register. If the subtraction does not cause an underflow, an S pulse is generated, the S register is incremented by 1, and the [2S+1] register is incremented by 2. If the subtraction causes an underflow, the [P.sup.2 +Q.sup.2 ] register is reset to its previous value, the other registers are not incremented, and no S pulse is generated.

Method for determining electrical energy consumption

A current sensor employs a main resistor of a low temperature-coefficient material for producing a voltage drop proportional to a load current therein. A second resistor, also of a low temperature-coefficient material, and preferably having a resistance substantially exceeding that of the main resistor, is connected in parallel with the main resistor. The current divides between the main and the second resistors according to the ratio of their resistances. An output signal, reduced at least in accordance with a ratio of resistances of the first and second resistors, is obtained from the second resistor. Resistive heating of the main resistor is reduced by using a short path length in the direction of current flow and as large an area transverse to the direction of current as possible. A current transformer may employ the second resistor as a primary to step down further the current in the output signal.

Low temperature coefficient shunt for current measurement

A sensor for measuring large magnitudes of A.C. current utilizes a current divider having parallel conductors and a current comparator coupled to one of the conductors so arranged as to perform first and second stages of scaling of the A.C. current to obtain an output signal from the sensor proportional to the A.C. current. The overall sensor ratio is the product of the ratios of the first and second stages, thereby permitting very large ratios to be obtained. Components of the sensor are arranged so as to cause cancellation of magnetic fields by the sensor and to make the sensor immune from incident magnetic fields.

Coaxial current sensors

A modular versatile electronic energy meter is provided with current voltage and register modules which may be selected and readily interconnected along with a selected output circuit board and including a plurality of features which may be customized late in the manufacturing cycle or after manufacture, including jumpers adapted to be selectively cut and attachable switch restrictors. Reduction and standarization of components and uncomplex interconnections are provided, along with apparatus to assure proper assembly and testing of the modular meter.

Modular construction for electronic energy meter

A kilowatthour meter includes a voltge stator having a phase lag and light-load adjust assembly which permits smooth adjustment of its phase lag adjust and its light-load adjust from either end of the voltage stator. Each adjustment provides the same effect on the speed of the rotatable disk of the kilowatthour meter. The end of the voltage stator from which adjustment may be performed is established by selectably engaging adjustment screws in the accessible ends of the phase lag adjust and light-load adjust. Thus, voltage stators installed in either left or right positions on the kilowatthour meter are identical except for the ends into which the adjustment screws are installed being the only difference.

Phase lag and light-load adjust for voltage stator

A terminal for a watthour meter employs an offset portion internal to the watthour meter for disposing contacting surfaces for connection to current-coil conductors at four different transverse locations. Formation of the offset produces an under surface used as one element for capturing and applying compression force to a washer over a terminal gasket. A projection from the opposite surface of the terminal forms a bearing surface as the other element for applying compression force to the washer over the terminal gasket. Two holes, optionally tapped, are provided for connection of a voltage coil lead. One of the two holes remains free for connection even though the other may be covered by the current-coil conductor.

Terminal for watthour meters

A current sensor employs a folded conductor bar having aligned holes therein to generate magnetic fluxes in the holes proportional to a current flowing in the bar. Each of the two holes has two windings therein wound in opposition to each other but connected for adding their voltages. Corresponding windings in the two holes are wound in opposition to each other and are connected for adding their voltages. The windings in each hole are offset from a center line, whereby magnetic fluxes generated by current flowing in the bar induce voltages in the coils but magnetic fluxes from external sources produce voltages which substantially cancel. A feedback arrangement is disclosed for creating an opposing magnetic flux such that essentially zero magnetic flux is present in the magnetic cores of the windings. A multi-range current measurement device employs a tapped feedback winding selectively connectable to an output amplifier for producing an output voltage having a range set by the number of turns selected on the tapped feedback winding.

Folded bar current sensor

A polyphase, socket-style meter employs identical left and right current stators. The angles about the meter disk, at which the left and right current stators are located, are adjusted to place the centers of their cores in alignment with their connector tabs. Identical current stator coils encircle the cores. The axes of the cores are slightly skewed with respect to the axes of the coils. The diameters of the coil helices are made large enough to accommodate the skew.

Identical left-right current stators for polyphase watthour meter

A solid state electronic pulse scaler uses the ratio of two integers to control a ratio of its input and output frequencies. In one embodiment, the pulse scaler is used as a calibration device to adjust for manufacturing tolerances in an electric metering device. In another embodiment, the pulse scaler is used to provide a pulse-initiator output to external circuits. A further embodiment includes both of the above functions in a single device. A switch-selectable control is provided to determine the consequences of input pulses generated during reverse rotation of a meter disk. The reverse pulses may be used to generate output pulses on the same, or a separate, channel as that employed for forward pulses, ignored, or temporarily stored and subtracted from ensuing forward pulses.

Solid state electronic pulse scaler using ratio of two integers

A watthour meter frame for an electric watthour meter includes pairs of orthogonal machined plane surfaces against which bearings are urged for accurately positioning the ends of a disk shaft of an electric watthour meter. Clearances are provided in the watthour meter frame for machining all pairs of machined surfaces without either changing the cutting tool or rotating the watthour meter frame. Worm gear bearings are similarly positioned in the watthour meter frame against three machined plane surfaces which may be machined in the same operation, and with the same cutting tool, as used in forming the pairs of machined surfaces for the disk shaft bearings. The worm gear bearings include a cylindrical barrel which is resiliently urged into contact with a pair of plane machined surfaces in a bearing well and a positioning flange having a bearing surface which is resiliently urged into a face surface surrounding the bearing well. Since the disk shaft and the worm gear are both located with respect to accurately machined plane surfaces in the watthour meter frame, sufficient relative and absolute accuracy is obtained to eliminate mesh adjustment of the worm gear.

Growing community of inventors

Somersworth, NH, United States of America

Donald F Bullock