| The current is an important parameter of power equipment measurement, monitoring and protection, to ensure the power system operate safely, stably, reliably and economically, we need to measure it precisely. There are several problems with traditional high-voltage current transformer, such as heavy weight, large volume, narrow frequency band, saturation, high cost, difficulties in transportation and installation. In practical application, electronic current transformer has more advantages than the traditional electromagnetic transformer, however, there are many problems such as design and manufacturing process, stability, consistency of passive electronic current transformer, so it is difficult to widely extend the application of it; the sensing module of active electronic current transformer is placed in the high-voltage terminal, power supply and repair is the biggest problem of it, and it is also vulnerable to electromagnetic interference.The sensing signal of fiber Bragg grating sensor is modulated by wavelength, in addition to many advantages of the ordinary optical fiber sensor, it is more superior that it has strong anti-interference property, don’t need reference point, has small volume, distributed high resolution and large measurement range.This paper involes design, development and test of two types of piezoelectric fiber Bragg grating current sensor,. Some of the tests are carried out according to the national technical specification JJG313-2010"The regulations of measuring current transformer verification ". The main research contents are as follows:1. We designed a piezoelectric drive type optical fiber Bragg grating current sensor based on Rogowski coil and iron core coil based on low power current transformer (LPCT) measuring element. Add temperature compensation fiber Bragg grating. Analyzed each part of the apparatus in theory and built a current sensor measurement model of it.2. We developed and select different spare parts which are necessary for two types of current sensor, the sensor is assembled by laboratory equipment, suitable adhesive and processing technology. Derived the theoretical sensitivity and resolution by calculating:the sensitivity of current transducer based on Rogowski coil is0.0756pm/A, the resolution is13.23A; the sensitivity of current sensor based on LPCT is0.0567pm/A, the resolution is17.64A.3. According to the different test condition of two types of sensor and its components, we set up the test requirements of system which meet the function requirement and carried out the experiment, because of the restricted conditions, we made simulation test on current sensor LPCT. In the experimental, we gave full considerations to the sensor drift, error of experimental data and the personal safety in experiment, finally, by the analysis of the fusion experimental data, we verified the corresponding relationship between wavelength change and current, relised that the influence of temperature on current sensor is relatively large, calculated the static indexes of two types of sensors.4. We tested the measuring element which is composed of Rogowski coil and integrator, the results showed that:there is a linear relationship between the Rogowski coil input-output, the linearity is1; the sensitivity is0.0079V/A, accuracy grade is0.2, which met the requirements of measuring current transformer; Tested on the sensing element which is composed of Bragg grating used for measure, temperature compensated Bragg grating and stack reactor type piezoelectric ceramic, results showed that:The relationship between the center wavelength Bragg grating and the driving voltage is linear, linear>0.96; sensitivity is about8.67pm/V.5. We tested the current transducer based on Rogowski coil, Take fusion analysis on wavelength data of grating used for measure and temperature compensation grating, results showed that:the nonlinear error is3.47%FS, repeatability is4.16%FS, sensitivity is0.0702pm/A. Tested the simulation LPCT of current sensor, Take fusion analysis on wavelength data grating used for measure and temperature compensation grating, results showed that:the nonlinear error is7.27%FS, sensitivity is12.123pm/V, repeatability is7.69%FS. |
PDF Full Text Request