Abstract: 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.

Abstract: 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.

Abstract: 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.