CN105842549A - Optical fiber Fabry-Perot electric field sensor for electrostatic field measurement - Google Patents

Abstract

An optical fiber Fabry-Perot electric field sensor for electrostatic field measurement is disclosed and belongs to the field of sensors. The optical fiber Fabry-Perot electric field sensor is aimed at solving a problem that test results are affected because a metal probe of a conventional electric field sensor can easily cause electric field distortion. The optical fiber Fabry-Perot electric field sensor comprises a hollow hemisphere, a quartz column, two quartz rods, an insulation outer wall, a quartz thin sheet, a trimmer and an optical fiber collimator, wherein the two quartz rods are parallel to each other and arranged horizontally, the two quartz rods are connected to a middle part of the quartz column in a welded manner, the hollow hemisphere is fixed on an upper end of the quartz column in a glued manner, the upper end of the quartz column is positioned in an empty chamber of the hollow hemisphere, the quartz thin sheet is fixed on a lower end of the quartz column in a glued manner, the quartz thin sheet is arranged horizontally, an upper end face of the optical fiber collimator is parallel to an end face of the quartz thin sheet, and the optical fiber collimator is fixed in the trimmer in a glued manner; an insulation outer wall is arranged outside the two quartz rods, the quartz thin sheet and an upper half part of the trimmer; thin films of 50% reflectivity are plated on the upper end face of the optical fiber collimator and the end face of the quartz thin sheet, and an FP chamber is formed between the two reflective films. The optical fiber Fabry-Perot electric field sensor is used for electrostatic field measurement.

Description

The optical fibre Fabry-perot electric-field sensor measured for electrostatic field

Technical field

The invention belongs to sensor field.

Background technology

Electric field measurement technology is not only widely used in the electric-field intensity measured near ultra-high-tension power transmission line and around transformer station, is also Researcher understands and measures near Faulty insulator, Transformer Winding, hv cable termination, high-voltage switch equal-height pressure equipment Electric Field Distribution provide technological means.Measured near transmission line of electricity, around transformer station and within power equipment by reality The size of electric field, for research transmission line of electricity monitoring running state, Electric Power Equipment Insulation state estimation, power plant design manufacture The field such as process optimization and Power System Electromagnetic Compatibility provides strong data support, healthy and stable to whole power industry Operation has great importance.

Conventional electrical measures electric field methods potentiometer balanced methods for magnesium and charge method.The measuring principle of potentiometer balanced methods for magnesium is by measuring electricity Electric field is measured in position distribution, but complex process measures trouble, and accuracy is poor.Charge method is by measuring metal probe at electricity In Chang, the electric charge of capture measures electric field, but metal probe is put in electric field, and electric field can be made to produce distortion, therefore its accuracy The highest.In order to improve the structure of electric-field sensor, improving the precision of sensor, it is innovated by many scholars, as Within 1992, foreign scholar M.Kanda ohmic load dipole realizes the measurement to electric field；In 20 end of the centurys, domestic application is relatively For universal three-dimensional ball-type electric field measurement system, field mill formula electric field measurement system etc..Although with traditional electric field measurement system phase Really increase than its measurement scope and precision, but its error is the biggest.At the beginning of 20 end of the centurys-21 century, along with light The research and development of fiber communication technology are with practical, and optical fiber sensing technology obtains tremendous development, and Chinese scholars is one after another by sight Invest and measure in electric-field intensity according to optical principle, propose Pockels effect such as 2004-2006 years Tsing-Hua University and Kerr effect is applied in electric field measurement, but owing to temperature is relatively big on its impact, therefore its degree of accuracy is the highest.North in 2008 Capital university of communications application electroluminescent effect achieves the measurement of complex electrical field, but owing to controlling light path more difficulty and being vulnerable to The impact of temperature, its unstable properties.

Summary of the invention

The invention aims to solve existing electric-field sensor metal probe and easily cause electric field distortion, thus affect test result Problem, it is provided that a kind of for electrostatic field measure optical fibre Fabry-perot electric-field sensor.

The optical fibre Fabry-perot electric-field sensor measured for electrostatic field of the present invention, electric-field sensor includes hollow half Ball, quartz column, two quartz rods, insulation outer wall, quartz thin slice, micro actuator and optical fiber collimator；

Two quartz rod horizontal positioned, and parallel to each other, the middle part vertical of quartz column has two quartz rods, quartz column The intrinsic hollow hemisphere of upper end glue, and the upper end of quartz column is positioned at the cavity of hollow hemisphere, the intrinsic quartz of lower end glue of quartz column Thin slice, quartz wafer level placement, the upper surface of optical fiber collimator is parallel with the end face of quartz thin slice, and optical fiber collimator glue is solid In micro actuator, the outside of two quartz rods, quartz thin slice and micro actuator top half is provided with insulation outer wall；

The upper surface of optical fiber collimator is parallel with the end face of quartz thin slice, and both ends of the surface are all coated with the film of 50% reflectivity, and two Reflect intermembranous formation FP chamber.

Advantages of the present invention: the optical fibre Fabry-perot electric-field sensor for electrostatic field measurement that the present invention provides does not makes On the premise of electric field is distorted, improve dynamic range and the degree of accuracy measuring electric-field intensity, it is proposed that a kind of at electrostatic field Electric field measurement new method under environment, proposes based on Fabry-Perot (FP) principle of interference and have developed for electric field measurement Optical fiber FP electric-field sensor.The technical indicator of the FP electric-field sensor developed is as follows: the range of dynamic measurement of electric field Being 0-59KV/m, the degree of accuracy can reach 98%.

Accompanying drawing explanation

Fig. 1 is the structural representation of the optical fibre Fabry-perot electric-field sensor measured for electrostatic field of the present invention；

Fig. 2 is the left view of Fig. 1；

Fig. 3 is electric-field sensor FP chamber length and Output optical power relation, and wherein, abscissa represents the chamber in sensor FP chamber Long, unit is μm, and ordinate represents the power of light, and unit is mW；

Fig. 4 is intensity demodulation principle schematic；

Fig. 5 is the structural representation of the electric field measurement system of the optical fibre Fabry-perot electric-field sensor for electrostatic field measurement Figure.

Detailed description of the invention

Detailed description of the invention one: present embodiment is described below in conjunction with Fig. 1 and Fig. 2, for electrostatic field described in present embodiment The optical fibre Fabry-perot electric-field sensor measured, electric-field sensor includes hollow hemisphere 1,2, two quartz rods of quartz column 3, insulation outer wall 4, quartz thin slice 5, micro actuator 6 and optical fiber collimator 7；

Two quartz rod 3 horizontal positioned, and parallel to each other, the middle part vertical of quartz column 2 has two quartz rods 3, stone The intrinsic hollow hemisphere of upper end glue 1 of English post 2, and the upper end of quartz column 2 is positioned at the cavity of hollow hemisphere 1, quartz column 2 Lower end glue intrinsic quartz thin slice 5, quartz thin slice 5 horizontal positioned, the upper surface of optical fiber collimator 7 and quartz thin slice 5 End face is parallel, and optical fiber collimator 7 glue is solid in micro actuator 6, two quartz rods 3, quartz thin slice 5 and micro actuator 6 upper half The outside of part is provided with insulation outer wall 4；

The upper surface of optical fiber collimator 7 is parallel with the end face of quartz thin slice 5, and both ends of the surface are all coated with the film of 50% reflectivity, Two reflect intermembranous formation FP chamber.

In present embodiment, when sensor is placed in electric field, the outer wall of hollow hemisphere 1 is acted on by electric field force, to field intensity Upper zone moves, and pulls quartz column 2, quartz column 2 to drive two quartz rods 3 that miniature deformation occurs so that FP chamber Chamber length changes；Owing to FP chamber length changes, light path also there occurs change, interferes light also can change therewith, Signal handling equipment obtains electric-field intensity according to the change of interference fringe.

Detailed description of the invention two: embodiment one is described further by present embodiment, hollow hemisphere 1 uses polypropylene material Material, its outer radius is 12.7mm, and inside radius is 11.5mm.

Detailed description of the invention three: embodiment one is described further by present embodiment, the radius in quartz column 2 cross section is 1.05mm, a length of 30mm.

Detailed description of the invention four: embodiment one is described further by present embodiment, the radius in quartz rod 3 cross section is 1.05mm, a length of 30mm.

Detailed description of the invention five: embodiment one is described further by present embodiment, quartz thin slice 5 a diameter of 10mm, thickness is 60 μm, and surface is coated with the reflectance coating that reflectivity is 50%.

Detailed description of the invention six: embodiment one is described further by present embodiment, the diameter of optical fiber collimator 7 end face For 4.13mm, end face is coated with the reflectance coating that reflectivity is 50%, and Insertion Loss is 0.3dB.

Detailed description of the invention seven: embodiment one is described further by present embodiment, insulation outer wall 4 and micro actuator 6 All use polytetrafluoroethylmaterial material.

Detailed description of the invention eight: present embodiment is described below in conjunction with Fig. 5, measures for electrostatic field described in present embodiment The electric field measurement system of optical fibre Fabry-perot electric-field sensor, this system include electric-field sensor, ASE wideband light source 1-1, Isolator 1-2, coupler 1-3, spectroanalysis instrument 1-4, signal handling equipment 1-5, accessory structure 1-6, globular hinge cut with scissors Chain 1-7 and base 1-8；

The insulation outer wall 4 of electric-field sensor is fixed on the side end face of accessory structure 1-6, and the lower end of accessory structure 1-6 is passed through Globular hinge hinge 1-7 is fixed on base 1-8；

Being placed in DC electric field by electric-field sensor, the outer wall of hollow hemisphere 1 is acted on by electric field force, to the higher district of field intensity Territory is moved, and pulls quartz column 2, quartz column 2 to drive two quartz rods 3 that miniature deformation occurs so that the chamber long hair in FP chamber Raw change；The light that ASE wideband light source 1-1 sends is by after isolator 1-2, and a part accesses spectroanalysis instrument 1-4 and letter Number processing equipment 1-5, another part enters coupler 1-3, is then passed through Optical Fiber Transmission and enters in optical fiber collimator 7, light Through the upper surface of optical fiber collimator 7, entrance is formed by optical fiber collimator 7 plated film end face and quartz thin slice 5 plated film end face In FP chamber, and roundtrip forms interference in FP chamber, interferes light to reflex to, in optical fiber collimator 7, transmit through optical fiber 8, By coupler 1-3, enter spectroanalysis instrument 1-4 and signal handling equipment 1-5, signal handling equipment 1-5 according to interfering bar The change of line obtains electric-field intensity.

In present embodiment, the centre wavelength of the light that ASE wideband light source 1-1 sends is 1550nm.Optical fiber collimator 7 The relative photo that interference is constant phase difference, frequency is identical that upper surface is formed with the end face roundtrip of quartz thin slice 5.

The mode obtaining electric-field intensity is:

$\mathrm{\Δ}l=l_Q+\frac{I-I_Q}{k}---\left(2\right)$

$\mathrm{\Δ}l=\frac{9{\mathrm{\π\ϵ}}_0{(\mathrm{\ϵ}-{\mathrm{\ϵ}}_0)}^2{l}^3}{192000E_0{I}_0{(\mathrm{\ϵ}+2{\mathrm{\ϵ}}_0)}^2}{R}^2{E}^2---\left(5\right).$

Wherein, Δ l is the long variable quantity of sensor cavity, l_QFor the FP cavity length that Q point is corresponding, I is Output optical power, I_Q For the Output optical power that Q point is corresponding, k is the slope of AB line segment, ε₀For permittivity of vacuum, ε is hollow hemisphere phase To dielectric constant, l is quartz rod length, E₀For the elastic modelling quantity of quartz material, I₀For the cross section of quartz rod used away from, R is The radius of hollow hemisphere, E is for executing outward electric-field intensity.

In the present invention, by be used for electrostatic field measure optical fibre Fabry-perot electric-field sensor through ANSYS software emulation, Can obtain preferable effect, when surveyed electric-field intensity reaches 60KV/m, measure error starts to increase, and therefore selects 0-59KV/m can reach 98% as the measurement scope of FP electric-field sensor, its accuracy rate.This sensor disclosure satisfy that The requirements such as electric field measurement range is big, accuracy is high, antijamming capability is strong.Meanwhile, this sensor bulk is little, simple in construction, just In installation.This electric-field sensor has preferable application prospect in power system.

When quartz rod internal diameter 0.4mm external diameter 2.1mm length 30mm, medium ball radius 12.7mm thickness 1.2mm, stone During English column internal diameter 0.4mm external diameter 2.1mm length 30mm, shown in Ansys simulation software simulation result table 1.

Table 1 is Ansys software emulation data

As it is shown on figure 3, from Fig. 3 selected linear interval, as shown in Figure 4, working curve is carried out linear fit, then should Fitting a straight line is as the working curve of sensor, such as the AB line segment in Fig. 4.

In Fig. 4, choose the midpoint Q operating point as sensor of interval AB, the FP chamber that A, B, Q 3 is corresponding Length is respectively l₁、l₂、l_Q, corresponding Output optical power is I₁、I₂、I_Q, k is the slope of AB line segment, has:

$l_Q=\frac{l_1+l_2}{2},I_Q=\frac{I_1+I_2}{2},k=\frac{I_2-I_1}{l_2-l_1}---\left(1\right)$

When recording Output optical power and being I, according to linear relationship, the change of cavity length amount Δ l of sensor can be obtained, it may be assumed that

$\mathrm{\Δ}l=l_Q+\frac{I-I_Q}{k}---\left(2\right)$

Can be obtained by electrodynamics theory deduction:

$F=\frac{9{\mathrm{\π\ϵ}}_0{(\mathrm{\ϵ}-{\mathrm{\ϵ}}_0)}^2}{4{(\mathrm{\ϵ}+2{\mathrm{\ϵ}}_0)}^2}{R}^2{E}^2---\left(3\right)$

From the deflection formula of simply supported beam:

$\mathrm{\Δ}l=\frac{{\mathrm{Fl}}^3}{48000\mathrm{\ϵ}I}---\left(4\right)$

Long variation delta l of sensor cavity can be obtained by formula (3) and (4) and execute outward the relation of electric-field intensity E:

$\mathrm{\Δ}l=\frac{9{\mathrm{\π\ϵ}}_0{(\mathrm{\ϵ}-{\mathrm{\ϵ}}_0)}^2{l}^3}{192000E_0{I}_0{(\mathrm{\ϵ}+2{\mathrm{\ϵ}}_0)}^2}{R}^2{E}^2;$

Wherein, ε₀For permittivity of vacuum, ε is hollow hemisphere relative dielectric constant, and l is quartz rod length, E₀For stone The elastic modelling quantity of English material, I₀For the cross section of quartz rod used away from, R is the radius of hollow hemisphere.

From emulation data and theory deduction, this structure disclosure satisfy that the measurement area requirement of sensor, it is possible to surveys accurately Go out electric field, and ensure that 98%.

Claims (7)

1. the optical fibre Fabry-perot electric-field sensor measured for electrostatic field, it is characterised in that electric-field sensor includes sky Heart hemisphere (1), quartz column (2), two quartz rods (3), insulation outer wall (4), quartz thin slice (5), micro actuators (6) With optical fiber collimator (7)；

Two quartz rod (3) horizontal positioned, and parallel to each other, the middle part vertical of quartz column (2) has two quartz rods (3), the intrinsic hollow hemisphere of the upper end glue (1) of quartz column (2), and the upper end of quartz column (2) is positioned at hollow hemisphere (1) Cavity in, the lower end glue of quartz column (2) intrinsic quartz thin slice (5), quartz thin slice (5) horizontal positioned, fiber optic collimator The upper surface of device (7) is parallel with the end face of quartz thin slice (5), and optical fiber collimator (7) glue is solid in micro actuator (6), The outside of two quartz rods (3), quartz thin slice (5) and micro actuator (6) top half is provided with the outer wall (4) that insulate；

The upper surface of optical fiber collimator (7) is parallel with the end face of quartz thin slice (5), and both ends of the surface are all coated with 50% reflectivity Film, two reflect intermembranous formation FP chamber.

The optical fibre Fabry-perot electric-field sensor measured for electrostatic field the most according to claim 1, its feature exists In, hollow hemisphere (1) uses polypropylene material, and its outer radius is 12.7mm, and inside radius is 11.5mm.

The optical fibre Fabry-perot electric-field sensor measured for electrostatic field the most according to claim 1, its feature exists In, the radius in quartz column (2) cross section is 1.05mm, a length of 30mm.

The optical fibre Fabry-perot electric-field sensor measured for electrostatic field the most according to claim 1, its feature exists In, the radius in quartz rod (3) cross section is 1.05mm, a length of 30mm.

The optical fibre Fabry-perot electric-field sensor measured for electrostatic field the most according to claim 1, its feature exists In, a diameter of 10mm of quartz thin slice (5), thickness is 60 μm, and surface is coated with the reflectance coating that reflectivity is 50%.

The optical fibre Fabry-perot electric-field sensor measured for electrostatic field the most according to claim 1, its feature exists In, a diameter of 4.13mm of optical fiber collimator (7) end face, end face is coated with the reflectance coating that reflectivity is 50%, and Insertion Loss is 0.3dB.

The optical fibre Fabry-perot electric-field sensor measured for electrostatic field the most according to claim 1, its feature exists In, insulation outer wall (4) and micro actuator (6) all use polytetrafluoroethylmaterial material.