Digital Watthour Meter Auto-Calibrate Using Microprocessor (original) (raw)
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2016 Conference on Precision Electromagnetic Measurements (CPEM 2016), 2016
A novel high-precision wattmeter is developed based on a standard watt converter design using time-division multiplication. A commercial 22-b delta-sigma A/D converter is used for the measurement of the watt converter output dc voltage. The measurement results are presented on a local display. In addition to power, the instrument measures ac voltage and ac current and displays their measured values on separate displays. Two prototypes were tested and compared with an existing standard watt converter connected to a high-precision digital voltmeter. The measurement results are presented and analyzed. Achieved measurement uncertainties (k = 2) of the power measurement are better than 50 µW/VA.
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A new calibration method related to a twin-type microcalorimeter is proposed for high-frequency power sensors. This method is based on intrinsic compensation of feeding line losses, operation that results in a unitary-gain microcalorimeter, whose mathematical model becomes similar to that of the lossless ideal system. Moreover, the time-consuming procedure required for a proper and autonomous microcalorimeter calibration, based on short or open-circuit load, is not necessary, and the microcalorimeter mount-dismount operation between raw measurements and microcalorimeter calibration steps disappears. The overall measurement time becomes about two times shorter when this system is used for the effective efficiency calibration of power sensors.
—In our research work we presented a structure of a smart electrical energy meter that integrates a calibration board to automate this process. To calibrate the electrical meter on site we need a power source that provides a known and stable AC voltage, instead of using the line voltage that we can't predict its value at the time of calibration. For this reason, we have designed an AC-AC converter that respects some specifications as output voltage RMS value, output current RMS value and stability... The chosen structure is an indirect AC-AC converter (AC-DC-AC converter). The DC-AC converter is a voltage source inverter (VSI).To control the switches, we have used a digital control based on feedforward technique to eliminate the input variations. In this paper we detail the structure of the converter, the calculation method of the error and of the correction. Finally we present the results of simulation on MATLAB, in temporal and spectral forms. These results valid our design by the stabilization of the AC output voltage and the very low THD.
Development of a Self-Calibrated Embedded System for Energy Management in Low Voltage
Energies
Due to the growing concern and search for energy sustainability, there has been an increase in recent years in solutions in the area of energy management and efficiency related to the Internet of Things (IoT), the home energy management system (HEMS), and the building energy management system (BEMS). The availability of the energy consumption pattern in real time is part of the necessity presented by this research. It is essential for perceiving and understanding the savings opportunities. In this context, this manuscript presents the development of a self-calibrated embedded system to measure, monitor, control, and forecast the consumption of electrical loads, enabling the improvement of energy efficiency through the management of loads performed by the demand side. The validation of the produced device was performed by comparing the readings of the device with the readings obtained through the evaluation system of the integrated circuit manufacturer ADE9153A®, Analog Devices® purc...
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IEEE Transactions on Instrumentation and Measurement, 1991
An algorithm for adaptive internal calibration of a precision voltage calibrator is discussed. Due to the built-in self-calibration procedure and real-time data processing of measurement results, improved reliability, and traceability are obtained. By evaluating internal calibration results, a learning control algorithm is feasible, which extends the normal recalibration cycle.
Software Development and Its Validation for Semi-Automatic Measurement of Multifunction Calibrator
International Journal on Electrical Engineering and Informatics
This paper describes an early development of built-up software for semi-automatic measurement of the multifunction calibrator using the direct method with the high-resolution digital multimeter (DMM) and its validation. The software was developed by SNSU-BSN to control the calibrator and DMM using the GPIB interface. The key advantages of this development were that the software could be used easily, safely, and fast with high accuracy and precision. The developed software has been validated by comparing it to manual measurement. The type A uncertainties achieved by semi-automatic measurement were less than 0.1 µV/V for dc voltage, 0.2 µA/A for dc current, 2 µV/V for ac voltage at 1 kHz, 100 µA/A for ac current at 1 kHz, and 0.1 µΩ/Ω for resistance with each absolute normalized error of the comparison was less than 1. It showed that both the manual and semi-automatic measurements had a good agreement in each measurement, and also the evaluated type A uncertainty in the semi-automatic measurement was smaller than the manual measurement.
An automatic calibrator for wattmeters with harmonic analysis capability
Measurement, 1999
This paper deals with a three-phase phantom-power generator, which is designed for calibrating digital wattmeters with harmonic analysis capability. The calibration of such instruments is a critical task due to the lack of suitable calibrators. Fortunately, the calibration procedure can be limited to the first harmonic components when digital wattmeters are employed to characterise electrical machines, so that also simple calibrator design can be adopted. This paper describes a three-phase calibrator arrangement which is able to generate an arbitrary spectrum up to 5 kHz and a phantom power variable up to 3 kVA per phase. The uncertainty on the power associated to the first harmonic components is of about 0.1% in nonsinusoidal conditions. The calibrator employs a Direct Digital Synthesis technique, so that a frequency change of the output signal can be obtained without modifying the sampling frequency. Such a technique also permits to generate the frequency modulated signals that are often encountered at the output of static power converters that feed electrical machines.