Analysis of fabrication error and optimization technique of λ/4 wave plate for fiber optical current transformer

2021 ◽  
Author(s):  
Yongguang Wang ◽  
Guochen Wang ◽  
Boya Zhang ◽  
Wei Gao ◽  
Zhuo Wang
2014 ◽  
Vol 511-512 ◽  
pp. 178-184
Author(s):  
Duan Lei Yuan ◽  
Zhou He ◽  
Hai Yan Wang ◽  
Guang Chao Yan

The optical structure and working principle of reflection structure fiber optical current sensor was presented, the Jones matrix of Polarizer, wave plate, fiber optical sensor head, theoretical mathematical model of the reflection structure fiber optical current sensor were established. based on the theoretical mathematical model, the polarization error was simulation analyzed, the simulation result shown that to be improve the accuracy of fiber optical current transformer, it should be reduced the polarizer axis angle error, ensure the consistency of the phase modulation for the two beams light, the shaft angle of the wave plate should be controlled within 0°±2°,and phase delay should be controlled within 90°±3°, the influence of linear birefringence effects can be effectively restrained by using a large number of circular birefringence. The simulation results provide a theoretical basis for the realization of reflection structure fiber optical current sensor.


2019 ◽  
Vol 14 (11) ◽  
pp. 1606-1615
Author(s):  
Jicheng Yu ◽  
Changxi Yue ◽  
Jun Li ◽  
Dengyun Li ◽  
He Li

Current transformer is one of the main equipment in ±10 kV DC distribution network. Traditional electromagnetic current transformer has poor anti-jamming capacity and poor insulation, so it cannot realize transient protection. The emergence of all-optical fiber current transformer brings solutions to these problems, which has attracted more and more attention. In this study, aiming at the problem of error and compensation of λ/4 waveform of all-fiber current transformer, the fabrication method of λ/4 waveform is studied, the mathematical model of the waveform is established, the influence of the waveform error on the scale factor is analyzed, and a calculating device of angle difference and ratio difference to compare the error is designed. The device adopts the principle of traceability of quantities to collect the state data of the wave plate. At the same time, in order to collect data for errors, database technology and network technology are used to realize remote transmission of monitoring data. The error of the λ/4 wave plate is compensated, the bidirectional principle generated by the birefringence in the fiber ring is analyzed, and the data logic description of the transformer sensitive ring is performed. The phase delay and the angle of the shaft are selected as the main factors causing the error. Compensation is performed by means of peak segmentation and variable cancellation. In the experimental process, compared with the error sampling of the traditional transformer, the error calculated by the current amplitude and phase angle parameters obtained by the all-fiber current transformer is more accurate, and the compensation scheme can suppress the size of the birefringence and improve sensing accuracy of fiber optic current transformers. This study provides a powerful reference for the error analysis of all-fiber current transformer λ/4 wave plates, which is beneficial to promote the better application of such current transformers.


2019 ◽  
Vol 1311 ◽  
pp. 012012
Author(s):  
Dengyun Li ◽  
Min Lei ◽  
Dandan Zhang ◽  
Shi Mo ◽  
Yongfeng Chai

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Fubin Pang ◽  
Qiang Huang ◽  
Yu Liu ◽  
Peng Li ◽  
Xiangping Kong ◽  
...  

The fiber optical current transformer (FOCT) with sine wave modulation has been widely used in the DC transmission project, while its fault rate is much higher than that of an electromagnetic current transformer, which seriously threatens the safe operation of power grid. In order to investigate the fault mechanism of FOCT, the output signal model of the FOCT photodetector is established, and its basic methods of modulation and demodulation are analyzed to explore the influencing factors of the signal processing method used in the calculation of measured current. It is found that the reduction of the second harmonic component in the photodetector output is the root cause of FOCT fault, and the optical path, modulation signal amplitude, and measured current are important factors affecting the second harmonic component. The influencing law of three factors on the second harmonic component is calculated by simulation and the characteristic differences between them are given. Finally, the fault simulation test of FOCT light intensity and a modulation circuit were carried out in the laboratory, and the results verify the correctness of theoretical analysis. The research in this paper provides reference for fault analysis and reliability improvement of FOCT.


2019 ◽  
Vol 2 (6) ◽  
pp. 531-540
Author(s):  
Songlin Gu ◽  
Liu Han ◽  
Dongwei Liu ◽  
Wenbin Yu ◽  
Zhihong Xiao ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document