摘要:
An electronic energy meter is described. The meter includes, in one form, voltage and current sensors having their outputs coupled to an analog to digital converter. The digital signals output by the converter are supplied to a digital signal processor (DSP) which outputs digitized metering quantities to a microcomputer. Using the metering quantities supplied by the DSP, the microcomputer performs additional metering calculations and functions. In one aspect, the present invention is directed to a method for determining whether an option board is being used and, if so, controlling meter operations in accordance with the coupled option board. In another aspect, the present invention is directed to a high function option board which, when enabled, operates as a master and the meter microcomputer automatically switches from its normal master mode to slave mode. In yet another aspect, the present invention is directed to converting the functionality of the electronic electricity meter from a first mode of operation to a second mode of operation. In still another aspect, the present invention is directed to a structure for avoiding, or minimizing, the loss of billing data when converting, or upgrading (or downgrading), meter operations.
摘要:
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.
摘要:
A demand electronic electricity meter having load profile recording capabilities is presented. Load profile recording requires memory for storing the recorded information, whereby either on-board memory or external memory is required. Load profile parameters include the number of channels (e.g., 1, 2 or more channels), interval size (e.g., 1, 5, 10, 15, 30 or 60 minutes), quantities to be recorded (e.g., kWh and kvarh, kVAh, or Qh) and channel scalar/divisor (e.g., for each channel, a 2 byte divisor and a 2 byte scalar). With two channels, only two quantities are available for recording, kWh and the one other quantity that the meter has been configured to record, (e.g., kvarh, KVAh, or kQh). For each quantity selected, snapshots of the corresponding total accumulator; (i.e. total kWh and total kvarh, kVAh or kQh) are automatically maintained.
摘要:
The present invention, in one embodiment, is a method for metering energy consumption with an electric meter. The method includes steps of: generating metering quantities for a plurality of phase voltages from a multiphase voltage source, including generating revenue-related data; monitoring voltage changes on at least one of the phase voltages; and performing a predetermined task in response to a voltage change on at least one of the phase voltages while continuing to generate revenue-related data.
摘要:
An energy meter capable of converting from one mode of operation to another mode of operation is described. In the one embodiment, the present apparatus measures energy consumption, and converts operation from a first mode to a second mode.
摘要:
The present invention, in one embodiment, is a method for operating an electronic electric meter having current and voltage sensors configured to generate measurements of current and voltage, respectively; a microcomputer coupled to the current and voltage sensors and having on-chip masked read only memory (ROM); and a nonvolatile, alterable memory coupled to the microcomputer. The method includes steps of: storing vectors pointing to program portions of the ROM in the non-volatile memory; and using the stored vectors to operate the microcomputer to execute the program portions stored in the ROM to control operation of the meter.
摘要:
A method of operating a relay device, the method comprising the steps of: computing positive-sequence first and second current-phasor for the first and second main circuit-breakers and computing currents from phasors, and the bus-tie-breaker; computing positive-sequence voltage for the bus-tie-breaker; triggering a method when at least one fault current at the bus-tie-breaker exceeds a threshold, without the presence of a fault on one of the feeders; determining whether the fault is internal or external, wherein the fault is internal if the positive-sequence current of the first and second main circuit breakers is in phase; and wherein if the positive-sequence current through the first main circuit breaker is not in-phase with the positive-sequence current through the second main circuit breaker, the fault is external to the bus; determining whether the fault is on a first or second side of the tie circuit; and locating the fault.
摘要:
A method of performing energy calculations in a power distribution system is provided. The method includes sampling a first voltage at a first module in the power distribution system; communicating the first voltage from the first module to a central controller; performing an energy calculation in the central controller based at least in part on the first voltage; and applying the energy calculation to a second module in the power distribution system. In some embodiments, the energy calculation is also based upon a second current from the second module.
摘要:
The present invention, in one embodiment, is a method for defining meter data calculations in an electronic electric meter. The method includes steps of: storing a set of predefined data calculation instructions in a non-volatile memory of the meter; storing a first set of vectors in a memory of the meter, the vectors pointing to data calculations of the set of predefined data calculation instructions; metering a plurality of electrical quantities of a power source; and controlling calculations performed on the metered electrical quantities in accordance with the data calculation instructions pointed to by the first stored set of vectors.
摘要:
A method of operating a relay device, the method comprising the steps of: providing main circuit-breakers and a bus-tie-breaker connecting the main-circuit-breakers; defining a partial-differential-zone comprising a main circuit breaker and the bus-tie breaker; assigning a first value to the direction of the fault current flowing into the partial differential zone; -assigning a second value to the direction of the fault currents flowing out of the partial-differential-zone, wherein the first value is not equal to the second value; -comparing the values assigned to the fault currents; determining if the fault currents are flowing into the partial differential zone; and determining if at least two of the fault-currents is flowing in a different direction with respect to the partial-differential-zone wherein one of the fault currents is flowing into the partial-differential-zone and one of the fault currents is flowing out of the partial differential zone.