Research On Detection System For Optical Current Transformer Based On DSP

Current transformer is one of the important equipment in the power system,but with the economic development, the shortcomings of the traditional currenttransformer are gradually exposed, and optical current transformer has manycharacteristics that the traditional current transformer can not be compared, sopeople begin to research the practical application of all-optical currenttransformer to replace the traditional current transformer. In practical applicationstudy, the detection accuracy of the terminal detection system in all-opticalcurrent transformer is one of the important indicators. To solve the problem, thisarticle carries out research of the terminal detection system and design a set ofdigital and efficient detection system based on DSP and virtual instrumentLabVIEW.This paper deeply analyzes the detection mechanism of all-optical currenttransformer and the detection principle of photoelectric detection technology,selected the optical structure of reflective optical fiber current transformer as abasis to carry on designing the detection system. Taking advantage of Jonesmatrix and Bessel functions to analyze the optical output signal, proposing a kindof detection schemes which is based on correlation detection method, and usingmatlab simulation software to verify the detection scheme. On the basis of thesimulation feasible, this text achieves the detection system from both hardwareand software. In hardware, for the output signal characteristics that designs signalconditioning circuits and data acquisition circuit. Among them, the signalconditioning circuit includes a photoelectric conversion, preamplification, filtercircuit and the DC bias of four parts, and the data acquisition circuit designs withDSP chip as the core, using its internal AD module and serial communication SCImodule two parts to achieve. And in the software, the DSP chip can be programmed to control the acquisition and serial signal transmission circuit, atthe same time the need to program virtual instrument LabVIEW software for dataprocessing and detection system operation interface in PC, making the detectionsystem in the form of interface to show the measured parameter. Finally, inlaboratory conditions, advantage of the designed detection system experimentbuilds the experimental platform, carrying on experimental verification, throughthe analysis of the experimental results to prove the feasibility of this designedend detection system for all-optical current transformer.