Integration unit for electric energy quality monitoring and synchronous sampling method of integration unit

Abstract

An integration unit for electric energy quality monitoring comprises a clock pulse synchronizing module M1, a sampling pulse output module M2, a data receiving and decoding module M3, an interpolation moment calculating module M4, an interpolation data processing module M5 and an assembly line control module M6 which are implemented through field programmable gate array (FPGA). The invention further provides a synchronous sampling method of the integration unit. By combining the synchronous pulse method with the interpolation method, the problem about low synchronizing accuracy caused by the use of single synchronizing method is effectively solved. Secondly, the problem about instable sampling accuracy during long-term operating is solved by adopting the self-adaption adjustment interpolation moment algorithm, and the problem about low accuracy of ultraharmonics is solved by adopting the third-order newton interpolation algorithm. In addition, the integral system adopts assembly line control mode and is guaranteed to stably operate at high sampling speed. The integration unit creates conditions for an electric energy quality monitoring device to access a digital substation.

Description

Technical field [0001] The invention relates to a merging unit used for power quality monitoring to complete the interface function of an electronic transformer. The invention also relates to a method for synchronous sampling by the combining unit. Background technique [0002] With the development of smart grid technology and the popularization of the IEC 61850 standard, the application of electronic transformers and their interface devices, the merging unit, has become an irreversible trend. The merging unit is one of the key equipment in the smart grid. Its main function is to complete the interface function of the electronic transformer, merge and collect the sampling signals of the multiple primary electronic transformers and send the combined data to the secondary protection via Ethernet , Measurement and control, metering, power quality monitoring devices. But at present, the application of electronic transformers and merging units are mainly concentrated in the fields o...

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Problems solved by technology

At present, the sampling rate of the merging unit for protection measurement and control is low (80 points / cycle), and the harmonic accuracy is low (generally guaranteed to be 5 times), and the synchronous sampling method used by it cannot be directly applied to the field of power quality because of the following defects:

[0004] (1) The synchronous pulse or interpolation method used alone, its synchronization accuracy cannot meet the requirements of power quality monitoring, and the synchronous pulse method alone is greatly disturbed by the hardware environment, and the interpolation algorithm alone is likely to cause signal spectrum distortion;

[0005] (2) After running for a long time, due to changes in the environment and hardware parameters, the synchronous sampling time drifts, which further leads to a decrease in measurement accuracy;

[0006] (3) The interpolation algorithm cannot meet the requirements of high-order harmonics. Generally, the interpolation algorithms mainly used by the merging unit are linear interpolation or second-order Lagrangian interpolation. These algorithms cannot meet the high-order harmonic accuracy requirements of power quality

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