Landis+gyr Innovations, Inc.

Landis+gyr, Inc.

Radian Research, Inc.

Bobick, David Andrew

Kraus, Matthew Eric

Matthew Eric Kraus

Frank J Boudreau, Jr

Detlef Griessman

Glenn A Mayfield

David A Bobick

Doug Busekrus

David Andrew Bobick

A method for determining degradation of a capacitor in an electric meter includes, charging the capacitor to a predetermined voltage value during a charging period using charging circuitry of the electric meter, discharging the capacitor, during a discharge period, from the predetermined voltage value using discharging circuitry of the electric meter, measuring, during the discharge period, a first capacitor voltage value at a first time and a second capacitor voltage value at a second time later than the first time using capacitor measurement circuitry of the electric meter, determining, by a processor of the electric meter, a capacitance value of the capacitor based on the first voltage value, the second voltage value, the first time, and the second time, comparing the determined capacitance value to a capacitance threshold value, and determining that the capacitor is in a degraded condition when the calculated capacitance value is below the capacitance threshold value.

In-situ testing of electric double layer capacitors in electric meters

An electric meter in a utility box is capable of detecting arcing conditions between meter blades and a meter socket in the utility box at a premises. The electric meter includes a current-transformer structure forming an enclosed space. An arc detection antenna can be placed in the enclosed space along with the current transformer. The current-transformer structure is placed on a baseplate of the electric meter near the blades connected to the meter socket. Leads of the arc detection antenna are electrically connected to an arc detection circuit configured to detect arcing conditions based on the signal received from the arc detection antenna. If it is determined that the arcing condition is present, the electric meter may be activated to interrupt the connection between the power source and the premises.

Arc detection antenna in electric meter systems

Techniques described herein detect a meter orientation based on a temperature gradient measured for a utility meter. A method for detecting a meter orientation includes determining a set of temperature measurements including a respective temperature measurement at two or more temperature sensors of a utility meter. The method further includes comparing the set of temperature measurements to a thermal fingerprint of the utility meter. The thermal fingerprint represents a baseline set of one or more temperature gradients based on the two or more temperature sensors over time. The method further includes detecting a meter orientation based on comparing the set of temperature measurements to the thermal fingerprint of the utility meter.

Detecting utility meter orientation based on a temperature gradient of the utility meter

Techniques for hot socket detection are disclosed. In an example, a meter includes a current transformer with a secondary bifilar winding. The meter is in proximity to a current coil. The secondary bifilar winding includes a first bifilar winding and a second bifilar winding. A start lead of the first bifilar winding is connected to a start lead of the second bifilar winding. The meter further includes a voltage source configured to generate a direct current (DC) voltage signal. The DC voltage signal is provided to a finish lead of the first bifilar winding. A first sense resistor is connected between a finish lead of the second bifilar winding and ground. A processing circuit receives a signal indicating a voltage across the first sense resistor and determines a temperature associated with the current coil. The processing circuit is further configured to detect a hot socket condition based on the temperature.

Hot socket detection at an electric meter

A method for electrical arc detection in an electrical connection between an electric meter and a socket is provided. The method may include receiving a vibration signal from a vibration sensor and an arc detection signal from an arc detector. The vibration signal may be correlated in time with the arc detection signal. An electrical arc may be detected based on the correlating the vibration signal with the arc detection signal.

Electrical arc detection for electric meter socket connections

A fault detection system of a utility meter for measuring electrical energy consumed by a load includes at least one current transformer, a temperature sensor, and a processor. The at least one current transformer is configured to generate a current measurement signal based on a current provided to the load. The temperature sensor is configured to generate a temperature signal based on a detected temperature of the utility meter. The processor is operably connected to the at least one current transformer and to the temperature sensor. The processor is configured to generate a phase angle value corresponding to a phase angle of the current measurement signal. The processor is further configured to generate a fault signal responsive to the temperature signal indicating that the detected temperature is greater than a predetermined temperature value and the phase angle value indicating detection of a leading current.

Method and system for hot socket detection and tampering detection in a utility meter

A method detects an error in a meter having a current transformer, a burden resistor unit and a resistive path switchably connectable across the burden resistor unit. The method includes obtaining in the processing circuit a first value representative of the voltage magnitude across the burden resistor unit while the resistive path is operably decoupled across the burden resistor unit. The method also includes closing a switching element to operably couple the resistive path across the burden resistor unit, and obtaining in a processing circuit a second value representative of a voltage magnitude across the burden resistor unit. The method further includes determining in the processing circuit whether an error exists based on the first value, the second value, and at least one predetermined stored value.

Detecting current measurement tampering by current transformer parallel impedance

An electricity meter includes a disconnect switch connected to a service transformer, a line-side sense circuit, a load-side sense circuit, and a measurement and control circuit. The disconnect switch is configured to receive a phase voltage and an anti-phase voltage from the service transformer. The line-side sense circuit includes a first sense circuit configured to detect the phase voltage delivered to the electricity meter and a second sense circuit configured to detect the anti-phase voltage delivered to the electricity meter, the first sense circuit and the second sense circuit are each connected to a floating reference node. The load-side sense circuit is configured to detect the existence of a phase load and an anti-phase load at a service entrance. The measurement and control circuit is configured to receive a phase output voltage and an anti-phase output voltage from the line-side sense circuit and further configured to receive a phase load output voltage and anti-phase load output voltage from the load-side sense circuitry.

Load-side sense with floating ground reference

An arrangement for use in a utility meter includes a transformer, a voltage source, a sensor, and a processor. The transformer includes a primary winding, a first secondary winding, and a second secondary winding. The voltage source is operably connected to generate a voltage signal and to provide the voltage signal to the first secondary winding. The generated voltage signal has a corresponding current formed at least in part by an impedance defined in part by a permeability of the transformer. The sensor is operably connected to generate a permeability signal indicative of the corresponding current. The processor is operably connected to the sensor and is configured to generate a hot socket detection signal responsive to the permeability signal indicating that the permeability of the transformer has fallen below a threshold value.

Method and system for hot socket detection in a utility meter

A sensor includes a core, first and second windings, an integrating amplifier circuit and a DC stabilization circuit. The first and second windings are wrapped around the core. The integrating amplifier circuit has a first input coupled to receive a sensed current from the first winding, and an output operably coupled to provide a current the second winding. The integrating amplifier circuit is configured to generate a phase shift from an input current received at the first input and the current provided to the second winding. The DC stabilization circuit includes a first resistive path coupled between the output of the integrating amplifier circuit and the first input of the integrating amplifier circuit, and a second resistive path coupled between the first winding and the first input of the integrating amplifier circuit.

Self-shielded Di/Dt transformer for a meter

A method and apparatus for testing a transformer. A controller generates a switching signal and supplies the switching signal to a solid state switch in circuit with a test load of known magnitude, switching the solid state switch to place the test load in circuit with the transformer. A signal through or across the transformer is then measured. Methods and apparatus for testing a transformer comprise the controller and solid state switch placing a series of test loads of different known magnitudes in circuit with the transformer from the lowest magnitude to the highest, from the highest to the lowest, or both. Additionally, a test load array comprises a plurality of power resistors, a heat sink for accommodating the plurality of power resistors, and a material providing electrical insulation of the power resistors from the heat sink and thermal conductivity between the power resistors and the heat sink.

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Jamestown, IN, United States of America

Matthew Eric Kraus