Three-phase high-precision harmonic electric energy meter

Abstract

The invention provides a three-phase high-precision harmonic electric energy meter which comprises a frequency measurement module, a sampling control module, an amplitude and phase calculating module,a harmonic phase compensation module and a harmonic electric energy accumulation module connected successively. The electric energy meter has the advantages that 1) hardware frequency measurement iscombined with software frequency measurement, software and hardware filtering measures are used to eliminate interference of higher harmonic waves in frequency measurement, and full-period sampling isensured in the source; 2) the M2 sampling control module uses a PWM+DMA automatic control manner, the sampling process needs no intervention of a CPU, and the data processing efficiency and reliability in the high sampling rate are ensured; 3) the M3 amplitude and phase calculating module uses a prime factor and subgroup algorithm to reduce influence caused by frequency fluctuation and harmonic amplitude fluctuation, and improve the consistence; and 4) the M4 harmonic phase compensation module compensates the phase angle of each harmonic power accurately to realize high-precision harmonic power measurement. Thus, the high-precision harmonic electric energy is accumulated.

Description

technical field [0001] The invention relates to the field of grid electric energy metering, in particular to a three-phase high-precision harmonic electric energy meter. Background technique [0002] The construction of energy Internet and smart grid solves energy problems, reduces carbon emissions, and improves the reliability and automation level of the power grid. At the same time, due to the extensive use of power electronics technology and nonlinear loads, the harmonic pollution of the power grid is becoming more and more serious. . Harmonic pollution not only causes harm to power grid equipment, but also affects the accuracy of electric energy metering and demand measurement, affects the fairness of metering, and brings economic interest disputes. The main reason is that the current billing energy meters basically use the full-wave algorithm. For non-linear load users, they not only output harmonics to the grid, but also pay less electricity bills. When linear users a...

AI Technical Summary

Problems solved by technology

An important premise for DFT calculation is to ensure that the sampling value is sampled at the current frequency at a full cycle and at equal intervals. If the frequency tracking is inaccurate, resulting in non-full cycle sampling, it will cause spectrum leakage and seriously affect the accuracy of harmonic measurement; especially in harmonic In the case of severe distortion, the ordinary zero-crossing detection method can no longer meet the requirements, and the method needs to be further improved;

[0005] 2) Due to the characteristics of the sensor con

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