A High Voltage DC Optical Harmonic Measurement Device

Abstract

A high-voltage DC optical harmonic measuring device is disposed on a DC current carrying conductor through a double-optical-path fiber sensitive ring. The two pieces of harmonic current output data ofthe double-optical-path fiber sensitive ring are connected to the input end of a first optical component and the input end of a second optical component through two polarization maintaining optical cables respectively. The output end of the first optical component is connected to the input end of a first signal processing circuit. The output end of the second optical component is connected to theinput end of a second signal processing circuit. The output data of the first signal processing circuit and the second signal processing circuit are connected to the input end of a merging unit. A first control monitoring circuit and a second control monitoring circuit are also connected to the first signal processing circuit and the second signal processing circuit respectively. The high-voltageDC optical harmonic measuring device solves the bottleneck problem of the transfer characteristic of conventional high harmonic collection, meets the 4kHz sampling rate requirement of low-order harmonic protection metering devices and the 50kHz sampling rate requirements of high-order harmonic protection and power quality metering devices.

Description

Technical field[0001]The invention belongs to the technical field of electrical measurement, and relates to a harmonic measurement device, in particular an optical dual-channel harmonic current measurement device used in the field of high-voltage direct current transmission and transformation.Background technique[0002]With the development and progress of society, a large number of power electronic devices and non-linear loads are connected to the power grid system, and the resulting power harmonics cause the deterioration of power quality. Power harmonics have a serious impact on the safe and stable operation of the power grid. Since the DC grid contains a large number of power electronic devices and nonlinear loads, this will cause a large amount of harmonic currents to be injected into the grid and cause the grid voltage to be distorted. These devices are the harmonic sources of the power system. The harmonic sources in DC power systems mainly include: various rectifier equipment,...

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Problems solved by technology

Accurate measurement of harmonic information is the basis and premise of harmonic monitoring and governance. The Chinese national standard GB / T20840.8-2007 Transformer Part 8: Electronic current transformer requires that the quality measurement ratio difference of the 50th harmonic is less than 5%, the angular difference is less than 5°, and the traditional current transformer is technically difficult to meet the above harmonic measurement requirements due to the limitation of the principle

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