Method for correcting direct current component in alternating current system

Abstract

The invention discloses a method for correcting a DC component in an AC system, and the method comprises the following steps: S1, enabling a signal collection device to measure a group of DC offset correction values under the no-load condition of a platform body after the calibration of an electric meter is completed; S2, in the normal metering stage of the electricity meter, enabling the signal acquisition device to measure a set of DC offset correction values again, and S3, according to the formula T, calculating the external input direct current value. In the step S1, after meter calibration is completed, a table body does not output current, and it is ensured that a metering chip is in an EMM mode at present; the method comprises the following steps: step S11, closing the high pass of the NVM1; S12, configuring a waveform cache to be in a 128-point synchronous sampling mode; step S13, starting a direct current offset automatic correction function; and S14, after t1 seconds, reading the value of the DCOSIx register, storing the value of the DCOSIx register in an EEPROM, and recording the value of the DCOSIx and testing direct current through a DCoffset function, so that high-precision metering of alternating current errors is realized through a compensation coefficient.

Description

technical field [0001] The invention relates to the technical field of electric power detection, in particular to a method for correcting a DC component in an AC system. Background technique [0002] With the rapid development of smart grid technology, the power load structure in the power grid has undergone great changes, and non-linear loads are increasing, such as various frequency conversion devices, half-bridge or full-bridge rectifier equipment, electric arc furnaces, rolling mills, and electrified railways. In a large number of applications, these nonlinear loads generate a large number of non-sinusoidal waves injected into the power grid, causing distortion of the voltage and current waveforms of the power system, and causing varying degrees of damage to many electrical equipment such as generators, relay protection devices, communication equipment, and automatic control devices. Then affect the accuracy of measurement. [0003] DC bias or DC interference in AC po...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to solve the problem of difficult DC component detection and correction in the AC system, and proposes a method for correcting the DC component in the AC system. Through the DCoffset function, the DC current is tested, so as to achieve high AC error through the compensation coefficient. Precision measurement