Error test system and test method of digital metering device

Abstract

The invention provides an error test system and method for a digitized metering device. The error test system and method can meet requirements for whole error test and dissemination of the value of quantity of the digitized metering device in a semi-breaker wiring mode, and can simultaneously test and compare the whole error and the sum of a single error of an electronic transformer and a single error of a digitized electric energy meter by changing characteristic error influence quantity of the digitized metering device. The test system comprises the digitized metering device, a traditional standard current transformer, a three-phase electronic transformer calibrator, a three-phase standard digitized electric energy meter, a traditional three-phase standard electric energy meter and a three-phase test power supply used for outputting an electric load; the test method based on the test system compares and analyzes the whole error and the sum of single errors of dissemination of the value of the quantity in the digitized metering device by independently testing the whole error, the error of the electronic transformer and the error of the tested three-phase digitized electric energy meter, specific sources of the errors are determined, and operation and regulation are conducted according to actual working conditions.

Description

technical field [0001] The invention relates to the field of error testing of digital metering devices, in particular to an error testing system and testing method of digital metering devices. Background technique [0002] The digital metering device or digital metering system in a smart substation or a digital substation is a combined unit of an electronic transformer including an electronic voltage transformer and an electronic current transformer and a digital input (or a traditional voltage transformer and a traditional current transformer) Combination unit of transformer and analog input), switch, digital energy meter, clock synchronization system and optical fiber. Electronic transformers generally digitize the current and voltage signals on the high-voltage side, and then transmit the digitized current and voltage information to the merging unit through optical fiber. The merging unit complies with IEC60044, IEC61850-9-1, IEC61850-9-2 / LE, etc. The standard combines t...

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Problems solved by technology

However, its disadvantage is that it does not solve the problem of traceability of the individual error test of the electronic transformer and digital energy meter to a higher level of standard value.

[0008] In summary, the disadvantages of the existing digital metering device error testing method and its testing system are: 1) the existing method cannot change the unique error influence quantity of the digital metering device to test the error of the digital metering device; for the digital metering device, due to The measurement of voltage and current is realized through multi-channel dispersed independent sampling and optical fiber digital message transmission. Compared with traditional metering devices, new error sources are added, such as electronic transformer data sampling delay and merging unit data processing transmission delay. , message packet loss, message code error, message jitter, voltage and current harmonics, clock asynchrony, clock inaccuracy, etc., resulting in problems such as error out-of-tolerance and poor error stability of the digital metering device during field operation. The evolution mechanism of the error of the digital metering device under working conditions is not yet clear, but due to the lack of effective testing and analysis methods for the amount of error influence, the problems in the field operation cannot be solved

[0009] 2) The existing method cannot test the error of a digital metering device in the connection mode of a half circuit breaker; the existing method is only applicable to the error in the digital metering device of a substation with a main connection mode such as double busbar and single busbar, etc., this digital metering device It consists of a set of voltage transformers (including ABC three-phase), a set of current transformers (including ABC three-phase), a three-phase digital energy meter and related equipment in one interval

The existing error test method only provides a set of current outputs, and cannot and cannot provide the sum current output representing the two-way branch current, nor does it provide a digital signal representing the two-way branch current, so the existing method is not suitable for one and a half Error Test of Digital Electric Energy Metering Device in Circuit Breaker Wiring Mode

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