Novel on-site power meter calibration instrument

Abstract

The invention discloses a novel on-site power meter calibration instrument. The novel on-site power meter calibration instrument comprises a tong-type ammeter and a direct-current compensation circuit, wherein an alternating-current / direct-current detection circuit is arranged in the tong-type ammeter and used for detecting alternating current and direct current of the ammeter; the direct-current compensation circuit is used for neutralizing magnetic fluxes generated by direct-current components of the tong-type ammeter. In the calibration instrument, alternating current and direct current passing through the tong-type ammeter are detected by the alternating-current / direct-current detection circuit composed of hall elements; the calibration instrument is driven by the direct-current compensation circuit, and a reverse magnetic flux is injected into the iron core of the tong-type ammeter through compensation coils, so that the magnetic core in the tong-type ammeter cannot be saturated, real errors of a power meter can be accurately measured when the direct-current components are included in loads, the measurement accuracy of the tong-type ammeter is improved, and the actual problem of the measurement difference between an on-site customer power meter and a total measuring meter is solved.

Description

technical field [0001] The invention relates to an electric energy meter calibrator. Background technique [0002] The following phenomena are often found during on-site verification and line inspection: [0003] 1. The electric energy meter that has been calibrated in the laboratory is found to have a large error in the calibration data at the work site [0004] 2. There is a large error in the electric energy metering data between the customer's electric energy meter installed on the site and the total metering meter, and no line modification has been found on the site. [0005] After a lot of data testing and analysis, it is found that the reasons are as follows: [0006] The existence of DC component in the load will cause the iron core of the clamp transformer to enter the saturation region. In theory, the current in the primary winding of the transformer will be used for excitation, and the secondary current of the transformer is 0, which cannot truly reflect the pri...

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Problems solved by technology

[0003] 1. The energy meter that passed the calibration in the laboratory was found to have a large error in the calibration data at the work site

[0004] 2. There is a large error in the electric energy measurement data between the customer's electric energy meter and the meter installed on the site, and no line modification has been found on site

[0006] The presence of DC components in the load will cause the iron core of the clamp transformer to enter the saturation region. In theory, the current in the primary winding of the transformer will be used for excitation, and the secondary current of the transformer is 0, which cannot truly reflect the primary current. size, thereby affecting the measurement accuracy of the clamp ammeter, making the on-site calibration work invalid, and even damaging the equipment in severe cases

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