Checking device and method for eliminating truncation errors of digital electric energy meter

Abstract

The invention relates to a checking device for eliminating truncation errors of a digital electric energy meter. The checking device comprises a three-phase alternating current power supply and an A / D / A (analog to digital to analog) conversion checking device, wherein one path of the A / D / A conversion checking device is output to a to-be-detected digital electric energy meter, the other path of the A / D / A conversion checking device is output to a conventional standard electric energy meter, and the conventional standard electric energy meter and the to-be-detected digital electric energy meter are respectively in input connection with an electric energy pulse error comparator. The invention also relates to a method for the device. The method comprises the following steps that (1) three-phase alternating-current current / voltage is generated; (2) the sampling analog quantity is converted into data flows conforming to communication protocols; (3) on one hand, the data flows are accessed to the to-be-detected digital electric energy meter, and on the other hand, the data flows are subjected to D / A (digital to analog) conversion and then enter the conventional standard electric energy meter; (4) difference values of pulses output by the two meters are worked out. The device and the method have the advantages that the truncation errors generated due to communication protocol limitation are effectively eliminated, so error data is 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