Design And Theory Research On Dual-Mode Interferometric Optical Voltage Transformer

The study achievements of the types and fundamental principles of optic voltagestransformers during the last few years are particularly surveyed in this paper. Thedual-mode interferometer optic voltage transformer is deeply researched and thecomplete system theory model has been established. The relevant theories are employedto analyze the operational principle and characteristics of the components required, themethod of selecting appropriate parameters of the components are offered. We alsointroduce the principle of white-light interferometer and active homodyne phase tracking,analyze the influencing factors of the systematic error in detail, and provide methods ofreducing the systematic error. The voltage and electric field are analyzed using finiteelement method. The transducer probe is filled with air, and is made up of three crystals.The project to specific design of a transducer probe is proposed. Using Matlab simulatesthe parameters of transducer probe.This paper introduces an all-fiber optical voltage transducer, which is used tomeasure the high voltage of power system. The transducer is based on the conversepiezoelectric effect of quartz. The piezoelectric deformation of the cylinder-shapedtransducer crystal induced by an applied ac voltage is sensed by an elliptical-coredual-mode fiber wound onto the circumferential surface. White-light interferometry andactive homodyne phase tracking detect the resulting modulation of the differential phasebetween LP01 mode and LP11 mode in fiber.Based on the measure of signal phase, a new active homodyne phase trackingtechnology is proposed. Using this technology measures out the phase shift and gainedthe measured voltage. The new active homodyne phase tracking technology adds a phasemodulation part in interferometer and produces phase change .In tracking condition, theorthoconjugate is kept and the measure of signal phase change is transformed to themeasure of phase modulation part's compensation.The systematic error is analyzed and the methods of reducing systematic error areprovided. In intervening light-strong signal of system, when the vestigial visibility isignored, we use the active homodyne phase tracking technology to linearly track thechanges of fiber-optic phase shift. When the vestigial visibility is not ignored, thevestigial visibility is monished as the fiber-optic phase shift is increased. When thedifference in the group indices is bigger, the vestige visibility can be eliminated. Theenvironment temperature is mostly factor of influence optic voltages transformersprecision. The error of piezoelectricity constant is compensated by a measure. We canlimit fiber length to minis temperature influence of visibility function.The voltage and electric field are analyzed by using finite element method,providing credibility theory gist for transducer's dielectric designs. Using air breakdowntheory, the electric field intensity of two poles and air dielectric intensity are calculated.The transducer probe is dielectric designed.Finally, the math model of transducer probe and the structure model of transducerprobe are presented. The parameters of transducer probe are comprehensively analyzedand simulated based on Matlab.The sensing and transmission of signals are all completed by fiber. Therefore,optical elements, such as couplers, electro-optical crystal, and polarizes are no used. Inaddition, the transducer probe is filled with air. So, the transducer is a system of simple,nicety, safety credibility, price low and no pollution.