Research On The Key Technology Of Optical Fiber Interference Voltage Sensors Based On Converse Piezoelectric Effect

The optical fiber voltage sensor is a new type of power measurement device that primarily utilizes the special properties of optical fiber to measure voltage.Its basic principle involves modifying the parameters within the optical fibers in response to voltage changes,thereby altering the light propagation path and the optical path difference,resulting in a change in light intensity.By measuring the variations in light intensity,the magnitude of the voltage can be obtained.Optical fiber voltage sensors offer advantages such as high accuracy,sensitivity,and strong immunity to interference.The development of optical fiber voltage sensor systems is continually expanding,and the signal processing system,as a crucial component,plays a vital role in improving measurement accuracy,observing voltage waveforms,and enabling functions like remote communication.It is also evolving towards digitization,network integration,and intelligent capabilities.This paper focuses on studying the voltage measurement and demodulation of optical fiber voltage sensors,specifically the fiber interferometric voltage sensors,in conjunction with laser interference-related technologies.The main research objectives of this paper are as follows:Firstly,based on the fundamental principle of the interference-type optical fiber voltage sensor,this paper conducts research on the converse piezoelectric effect of piezoelectric ceramics and laser interference theory.Subsequently,a detailed derivation of the self-mixing interference theory model is presented,and the correspondence between the interference signal and phase is analyzed,laying a theoretical foundation for subsequent experiments.Furthermore,to address the issues in traditional optical voltage sensors,such as the need for additional reference optical paths for interference or the complexity resulting from fiber microfabrication,a voltage measurement method based on self-mixing interference is proposed.In this method,light passes through the sensing fiber to capture the external voltage information and is reflected at the end of the fiber.The reflected light undergoes self-mixing interference within the laser cavity,and the interference signal is detected by a photodetector in the laser.The detected signal is then processed using a reverse point identification algorithm to extract the phase information of the interference signal.Through voltage fitting,the voltage measurement is achieved.The feasibility of this approach is validated through experiments.Compared to other optical voltage sensors,the proposed method eliminates the need for couplers and photodetectors,requiring only a single sensing fiber for voltage measurement.This solution effectively solves the complexity associated with traditional optical voltage sensor structures.Lastly,to address the issue of offline signal processing and the long processing time required for phase information extraction in interference-based optical voltage sensors using algorithmic construction of orthogonal signals,a real-time signal demodulation method is proposed,which utilizes the characteristics of fiber couplers for orthogonal detection of interference signals.Subsequently,algorithms are employed to deconvolve the obtained phase information.The effectiveness of this approach is validated through experiments.By leveraging the properties of passive device fiber couplers,this method enables real-time display of results in software,effectively solving the problem of long processing times associated with algorithmic processing of interference signals.