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An Online Calibration System for Digital Input Electricity Meters Based on Improved Nuttall Window

This paper proposes an improved online calibration technique for digital input electricity meters. The technique employs a double-spectral-line interpolation fast Fourier transform algorithm with four-item, three-order Nuttall window to reduce the measurement error caused by spectrum leakage, frequency fluctuation, noise pollution, and harmonic interference. A calibration system of friendly human–computer interaction is designed using LabVIEW. Simulation and practical results show that the proposed calibration system with improved Nuttall window algorithm is of high accuracy and reliability when compared with the traditional calibration algorithm currently used by industry practice.