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US 10,468,208 B2Granted
Method and arrangement for electrical service disconnect
AssigneeLandis+Gyr, Inc.
InventorAnibal Diego Ramirez
Life of this patent
Estimating the term…
Abstract
An electrical utility meter includes metering circuitry configured for connection to at least one utility power line and a service disconnect member. The metering circuitry is configured to receive an electrical signal corresponding to a line voltage on the at least one utility power line. The service disconnect member is configured for connection to the at least one utility power line. A control circuit is configured to deliver a control signal to the service disconnect member synchronously with a zero crossing of the electrical signal corresponding to the line voltage on the at least one utility power line.
Claims19
An arrangement for use in an electrical utility meter comprising:
- metering circuitry configured for connection to at least one utility power line connected to a load, the metering circuitry operable to generate metering information representative of an electrical quantity regarding electrical energy delivered to the load;
- a service disconnect member configured for connection to the at least one utility power line, the service disconnect member having a connected state and a disconnected state, the service disconnect member configured to couple the at least one utility power line to the load in the connected state and configured to decouple the utility power line from the load in the disconnected state,
- wherein the service disconnect member includes three relays configured for connection to three-phase utility power lines, each relay having a connected state and a disconnected state, and each relay configured to couple one phase of the three-phase utility power lines to the load in the connected state and configured to decouple the one phase of the three-phase utility power lines from the load in the disconnected state;
- a zero crossing detector configured to detect one or more zero crossings of an electrical signal corresponding to a line voltage on the at least one utility power line;
- and
- a control circuit configured to deliver a control signal to the service disconnect member at a delivery time, wherein the delivery time is calculated to time delivery of the control signal to the service disconnect member such that the service disconnect member either couples or decouples the at least one utility power line to the load synchronously with the one or more zero crossings of the electrical signal,
- wherein the service disconnect member balances coupling or decoupling of each phase of the three-phase utility power lines synchronously with an associated zero crossing of such phase over time, and wherein balancing the coupling or decoupling of each phase comprises:
- identifying a first zero crossing of a first phase of the three-phase utility power lines;
- timing a first simultaneous disconnect of three phases of the three-phase utility power lines to the first zero crossing of the first phase of the three-phase utility power lines;
- identifying a second zero crossing of a second phase of the three-phase utility power lines;
- timing a second simultaneous disconnect of the three phases of the three-phase utility power lines, subsequent to the first simultaneous disconnect, to the second zero crossing of the second phase of the three-phase utility power lines;
- and
- balancing a quantity of disconnects of the three phases timed to zero crossings of the first phase with a quantity of disconnects of the three phases timed to zero crossings of the second phase.
10 more elements
A method of controlling an electrical utility meter connected to three-phase utility power lines connected to a load, the method comprising:
- obtaining response time data for a service disconnect member associated with the electrical utility meter;
- receiving a connect signal or a disconnect signal for the service disconnect member;
- determining a first zero crossing of a first phase of the three-phase utility power lines connected to the load;
- calculating a first delivery time at which to issue a first control signal configured to close or open the service disconnect member synchronously with the first zero crossing of the electrical signal, based on the response time data and first zero crossing time;
- determining a second zero crossing of a second phase of the three-phase utility power lines connected to the load;
- calculating a second delivery time at which to issue a second control signal configured to close or open the service disconnect member synchronously with the second zero crossing of the electrical signal, based on the response time data and the second zero crossing time;
- balancing coupling or decoupling of each phase of the three-phase utility power lines synchronously with an associated zero crossing of such phase over time, wherein balancing the coupling or decoupling of each phase comprises:
- delaying delivery of the first control signal until the first delivery time such that the service disconnect member simultaneously either couples or decouples three phases of the three-phase utility power lines to the load synchronously with the first zero crossing of the first phase of the three-phase utility power lines;
- delaying delivery of the second control signal until the second delivery time such that the service disconnect member simultaneously either couples or decouples the three phases of the three-phase utility power lines to the load synchronously with the second zero crossing of the second phase of the three-phase utility power lines;
- and
- balancing a quantity of disconnects of the three phases timed to zero crossings of the first phase with a quantity of disconnects of the three phases timed to zero crossings of the second phase.
8 more elements
An electrical utility meter comprising:
- metering circuitry configured for connection to three-phase utility power lines, the metering circuitry configured to receive an electrical signal corresponding to a line voltage on the three-phase utility power lines;
- a service disconnect member configured for connection to the three-phase utility power lines;
- and
- digital processing circuitry configured to:
- receive temperature data from a temperature sensor;
- and
- calculate a first delivery time of a first control signal based on the temperature data and a time of a first zero crossing;
- a control circuit configured to deliver the control signal to the service disconnect member, at the delivery time, synchronously with the first zero crossing of the electrical signal corresponding to the line voltage on the three-phase utility power lines;
- wherein the service disconnect member is further configured to balance coupling or decoupling of each phase of the three-phase utility power lines synchronously with an associated zero crossing of such phase over time, and wherein balancing the coupling or decoupling of each phase comprises:
- timing a first simultaneous disconnect of three phases of the three-phase utility power lines to the first zero crossing of a first phase of the three-phase utility power lines;
- identifying a second zero crossing of a second phase of the three-phase utility power lines;
- timing a second simultaneous disconnect of the three phases of the three-phase utility power lines, subsequent to the first simultaneous disconnect, to the second zero crossing of the second phase of the three-phase utility power lines;
- and
- balancing a quantity of disconnects of the three phases timed to zero crossings of the first phase with a quantity of disconnects of the three phases timed to zero crossings of the second phase.
11 more elements
Dependencies are inferred from the claim text.