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Direct current even harmonic error calibration method and electric energy meter

A technology of DC even-order and error calibration, applied in the direction of measuring electrical variables, instruments, measuring devices, etc., can solve the problem that the transformer cannot resist the DC component, and achieve the effect of improving accuracy and reducing costs

Active Publication Date: 2021-06-22
江阴长仪集团有限公司
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Problems solved by technology

[0007] Aiming at the problem that the transformer of the electric energy meter cannot resist the DC component, the present invention provides a method for calibrating the DC even-order harmonic error and the electric energy meter. On the premise of not increasing the hardware cost, the accuracy of the electric energy meter is greatly improved by means of compensation, which can Resist DC even harmonics and meet the error requirements

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  • Direct current even harmonic error calibration method and electric energy meter
  • Direct current even harmonic error calibration method and electric energy meter
  • Direct current even harmonic error calibration method and electric energy meter

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Embodiment Construction

[0049] In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in combination with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are exemplary only, and are not intended to limit the scope of the present invention. Also, in the following description, descriptions of well-known structures and techniques are omitted to avoid unnecessarily obscuring the concept of the present invention.

[0050] Taking an electric energy meter with a current specification of 0.2-0.5(60)A as an example, the specific test data is shown in Table 1 below.

[0051] Table 1:

[0052]

[0053]

[0054] It can be seen from Table 1 that the greater the current, the greater the error change due to the influence of DC even-order harmonics. In the case of a power factor of 1.0, the current is below 30A, and the error change meets...

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Abstract

The invention relates to a direct-current even-order harmonic error calibration method and an electric energy meter, and the method comprises the steps that the fitting of direct-current even-order harmonic errors corresponding to different power factors and different current value ranges of the electric energy meter is carried out, and fitting formulas are obtained; primary current waveform data of the electric energy meter are collected for FFT conversion and judgment, and when direct-current even-order harmonics exist, the fitting formula corresponding to a current current effective value and a power factor is adopted to calculate a metering error, and the metering value of the electric energy meter is compensated. On the premise that hardware cost is not increased, the precision of the electric energy meter is greatly improved in a compensation mode, direct-current even-order harmonics can be resisted, and the error requirement is met. The cost of electric energy meter transformation is greatly reduced, and most electric energy meters can meet standard requirements only by software upgrading. Different power factors and different current ranges are reasonably divided, error curves are fitted respectively, compensation curves are changed according to actual conditions, and compensation precision is improved.

Description

technical field [0001] The invention belongs to the technical field of electric energy measurement, and in particular relates to a method for calibrating DC even-order harmonic errors and an electric energy meter. Background technique [0002] In grid loads, the common harmonics are odd harmonics, and traditional harmonic control is aimed at odd harmonics, and DC even harmonics are rare in general electrical equipment. But now the industry is more and more developed, there are more and more electrical equipment, and there are more and more DC even-order harmonics, which are common in arc equipment, electromagnetic saturation equipment, electronic switching equipment, etc., such as various steelmaking equipment, Arc welding machines, reactors, various AC / DC converters (rectifiers, inverters) and thyristor controllable switchgear. In addition, the hair dryers commonly used in our homes and the chargers of two-wheeled electric vehicles also contain DC even-order harmonics. ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01R35/04G01R22/00
CPCG01R35/04G01R22/00Y02E40/40
Inventor 张晓东陈文藻缪炜姜震蒋冬强何志超
Owner 江阴长仪集团有限公司
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