A Calibration Method for Eliminating Truncation Error of Digital Energy Meter

Abstract

The invention relates to a verification device for eliminating the truncation error of a digital electric energy meter. , the other output is to the conventional standard electric energy meter, the conventional standard electric energy meter and the digital electric energy meter to be checked are respectively connected with the input of the electric energy pulse error comparator; the present invention also relates to the method of the above-mentioned device, including the steps of: (1) generating a three-phase energy AC current / voltage; (2) Convert the sampled analog quantity into a data stream that conforms to the communication protocol; (3) On the one hand, the data stream is connected to the digital energy meter under inspection, and on the other hand, it enters the routine after D / A conversion. (4) Calculate the difference between the pulses output by the above two meters. The invention effectively eliminates the truncation error due to the limitation of the communication protocol, and makes the error data more accurate.

Description

technical field [0001] The invention belongs to the technical field of digital electric energy metering, in particular to a verification device and method for eliminating the truncation error of a digital electric energy meter. Background technique [0002] With the rapid development of smart grid, the digital substation based on IEC61850 standard has become the trend of substation construction, and the digital electric energy metering system will gradually become the main body of electric energy metering. In the digital electric energy metering system, the interface mode and working principle of the digital electric energy meter are all Fundamental changes have taken place. The signals received by the digital energy meter are digitized current and voltage signals transmitted by optical fiber Ethernet. There are no current transformers, voltage transformers, and A / D conversion units. There is no error in theory, but In the actual operation process, since the length of each p...

AI Technical Summary

Problems solved by technology

[0002] With the rapid development of smart grid, the digital substation based on IEC61850 standard has become the trend of substation construction, and the digital electric energy metering system will gradually become the main body of electric energy metering. In the digital electric energy metering system, the interface mode and working principle of the digital electric energy meter are all Fundamental changes have taken place. The signals received by the digital energy meter are digitized current and voltage signals transmitted by optical fiber Ethernet. There are no current transformers, voltage transformers, and A / D conversion units. There is no error in theory, but In the actual operation process, since the length of each phase current / voltage information is limited to 2 bytes in the IEC61850-9-1 protocol, this results in a truncation error of the sampled data. In the system, this error inevitably exists, but in the actual digital substation, the truncation error caused by the limitation of the IEC61850-9-1 protocol should be regarded as the error of the electronic transformer. In the metering system, the A / D conversion is completed in the electronic transformer. When the value of the digital energy meter is directly transmitted from the electronic transformer through the optical fiber, there is already a truncation error, and in the actual electronic transformer inspection process , it does contain this part of the error

Images