Landis+gyr Innovations, Inc.

Landis+gyr, Inc.

Frank J Boudreau, Jr

Matthew Eric Kraus

Matt E Kraus

David Allan Stenberg

Dave Stenberg

Detlef Griessman

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

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

Certain aspects and features include a system and method for energy measurement in electric meter systems. In an example, an electric meter receives an Alternating Current (A/C) signal. The electric meter includes a current measurement device that is configured to obtain a current measurement of a current of the A/C signal. The current measurement includes a fundamental frequency component and a noise component. The electric meter receives a current measurement signal from the current measurement device and filters the noise component from the current measurement, thereby creating a filtered current measurement signal. When the filtered current measurement signal is greater than a starting current threshold, the electric meter calculates an energy consumption measurement.

Gating energy consumption accumulation by detecting a fundamental component of a current

A progressively contacting switch includes a set of contacts connected to an input. The set includes a first sacrificial contact formed of a first metal and a first conducting contact formed of a second metal. The switch further includes a movable set of contacts connected to an output. The movable set includes a second sacrificial contact formed of the first metal and a second conducting contact formed of the second metal. The switch includes an element configurable to connect the movable set of contacts such that the first sacrificial contact connects to the second sacrificial contact at a first time, thereby causing a current to flow from the input to the output, and while the first sacrificial contact remains connected to the second sacrificial contact, the first conducting contact connects with the second conducting contact at a later time.

Progressively contacting switch

Certain aspects and features include a system and method for validating fundamental-only power measurements. A meter testing application calculates an expected registration for a meter under test by comparing a fundamental demand indicating an amount of power expected to be delivered by the fundamental component to a known load with a wideband demand indicating an amount of power expected to be delivered by the wideband voltage to the known load. The application further measures, from the meter under test, a measured registration by applying the wideband voltage component and the known load to the meter under test, which is configured to measure power consumption from the fundamental component only. The application calculates based on the expected registration and the measured registration, an error for the meter. When the error is outside a tolerance, the application identifies the meter under test as non-compliant.

Validating fundamental-only energy measurement

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

A sensor includes a non-magnetic core having a first winding wrapped thereon. The first winding has a center tap dividing the first winding into a first winding portion and a second winding portion. The center tap is coupled to a reference voltage. The first winding portion and the second winding portion are configured to sense first AC signals, and have a balanced susceptibility to second AC signals. The differential integrating circuit is configured to provide common mode rejection of the second AC signals. The differential integrator circuit is operably coupled to the first winding portion and the second winding portion.

Method for improving common mode rejection in a rogowski coil-based circuit

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 sensor includes a core, first and second windings, an integrating amplifier circuit and a DC balancing circuit. The first and second windings are wrapped around the core. The integrating amplifier circuit has a first input coupled to the first winding, and an output operably coupled to the second winding. The DC balancing circuit is operably coupled between the output of the integrating amplifier circuit and the first input of the integrating amplifier circuit.

Self-shielded DI/DT transformer for a meter

A current measurement circuit includes an integrator, first and second transformers, and a current measurement unit. The first transformer includes a first winding about a magnetic core. The magnetic core has an opening through which a current to be measured passes. The first winding is configured to generate a first current based on a first flux in the magnetic core. The second transformer includes second and third windings. The second winding is coupled to receive the first current from the first winding. The second winding has a terminal coupled to the third winding. The third winding is coupled to a first input of the integrator circuit. The output of the integrator circuit is operably coupled to provide an error current to the second transformer. The current measurement unit measures the current through the second winding of the second transformer.

Growing community of inventors

Otterbein, IN, United States of America

Frank J Boudreau, Jr