Abstract: A group metering method (and system) for monitoring electrical energy consumption by a plurality of proximate users replaces multiple individual user-meters by a single electronic meter. A single computational engine computes consumed energy values by the users and deploys a single subsection set (display, real time clock, and non-volatile memory) which can be located on a PCB. The system, usable for single or three phase, may be located out of reach from the users to make it tamper proof. Individual ADCs obtain electrical current values (through current transformers,) of power consumed by individual users and cooperate with a single DSP to compute energy consumption by individual users, readable on a common display in round robin fashion. Differences between the sum of energy values consumed by the users and a consolidated energy reading beyond a known threshold are reported as possible user-tampering. Asynchronous communication ports communicate with display units and AMR modules.

Abstract: An electronic meter includes a sensing circuit for sensing voltage and current values of a waveform, an analog-to-digital converter for converting the sensed voltage and current values to digital voltage and current values, a digital filter for delaying one or both of the digital voltage and current values to compensate for a phase shift error in the sensing circuit, and a computation circuit for computing one or more parameters of the waveform in response to the phase compensated voltage and current values. The electronic meter may be calibrated by applying to the meter a test waveform having a known phase shift, measuring the phase shift using the electronic meter, determining a phase shift error based on the difference between the known phase shift and the measured phase shift and determining digital filter coefficients to produce a digital filter delay that corresponds to the phase shift error.

Abstract: An electronic meter includes a sensing circuit for sensing voltage and current values of a waveform, an analog-to-digital converter for converting the sensed voltage and current values to digital voltage and current values, a digital filter for delaying one or both of the digital voltage and current values to compensate for a phase shift error in the sensing circuit, and a computation circuit for computing one or more parameters of the waveform in response to the phase compensated voltage and current values. The electronic meter may be calibrated by applying to the meter a test waveform having a known phase shift, measuring the phase shift using the electronic meter, determining a phase shift error based on the difference between the known phase shift and the measured phase shift and determining digital filter coefficients to produce a digital filter delay that corresponds to the phase shift error.

Abstract: An electronic meter includes a sensing circuit for sensing voltage and current values of a waveform, an analog-to-digital converter for converting the sensed voltage and current values to digital voltage and current values, a digital filter for delaying one or both of the digital voltage and current values to compensate for a phase shift error in the sensing circuit, and a computation circuit for computing one or more parameters of the waveform in response to the phase compensated voltage and current values. The electronic meter may be calibrated by applying to the meter a test waveform having a known phase shift, measuring the phase shift using the electronic meter, determining a phase shift error based on the difference between the known phase shift and the measured phase shift and determining digital filter coefficients to produce a digital filter delay that corresponds to the phase shift error.

Abstract: An electronic meter, such as an electronic energy meter, includes a sensing circuit for sensing one or more values of a waveform, a memory having a memory bus, a digital signal processor coupled to the memory for calculating at least one parameter value of the waveform in response to the sensed values, and a microcontroller coupled to the memory for performing control functions of the electronic meter. The digital signal processor generates a bus request when access to the memory is required. The microcontroller grants access to the memory in response to the bus request. The sensing circuit may sense and digitize current and voltage values of a polyphase power line.

Abstract: An electronic meter includes a sensing circuit for sensing voltage and current values of a waveform, an analog-to-digital converter for converting the sensed voltage and current values to digital voltage and current values, a digital filter for delaying one or both of the digital voltage and current values to compensate for a phase shift error in the sensing circuit, and a computation circuit for computing one or more parameters of the waveform in response to the phase compensated voltage and current values. The electronic meter may be calibrated by applying to the meter a test waveform having a known phase shift, measuring the phase shift using the electronic meter, determining a phase shift error based on the difference between the known phase shift and the measured phase shift and determining digital filter coefficients to produce a digital filter delay that corresponds to the phase shift error.

Abstract: An electronic meter, such as an electronic energy meter, includes a sensing circuit for sensing one or more values of a waveform, a memory having a memory bus, a digital signal processor coupled to the memory for calculating at least one parameter value of the waveform in response to the sensed values, and a microcontroller coupled to the memory for performing control functions of the electronic meter. The digital signal processor generates a bus request when access to the memory is required. The microcontroller grants access to the memory in response to the bus request. The sensing circuit may sense and digitize current and voltage values of a polyphase power line.

Abstract: An electronic power meter for metering the consumption of electrical energy on power lines includes phase compensation on current transformers, whereby the acquisition of one of the two samples for the current signals is delayed and time shifted averaged, such that the average of the two signals provides a compensated signal. The amount of delay is determined from the phase lag the current transformers exhibit during the process of calibration for phase compensation. The amount of compensation that is applied varies with current, thus compensation for the non-linearity in the phase shift for the current transformers. The degree of non-linearity is computed which results in only two variables that define the phase lag at higher current and the degree of non-linearity. The technique helps in using inexpensive current transformers in the meter.