CN112816057A

CN112816057A - Device and method for improving directional sensitivity of EFPI (EFPI) membrane

Info

Publication number: CN112816057A
Application number: CN202110214273.6A
Authority: CN
Inventors: 司文荣; 傅晨钊; 虞益挺; 姚维强; 关宏; 苏卫华; 倪鹤立; 刘家妤
Original assignee: State Grid Shanghai Electric Power Co Ltd
Current assignee: State Grid Shanghai Electric Power Co Ltd
Priority date: 2021-02-26
Filing date: 2021-02-26
Publication date: 2021-05-18

Abstract

The invention relates to an EFPI membrane directional sensitivity improving device and a method, wherein the device is arranged on a membrane of an EFPI optical fiber sensor probe, the improving device comprises a mass block, and the mass block is arranged on the membrane of the EFPI optical fiber sensor probe, so that a novel membrane structure with different natural frequencies and response sensitivity is formed. Compared with the prior art, the invention has the advantages of more consistent sensitivity response characteristic in the range of 0-180 degrees of ultrasonic incidence angle, capability of adjusting the natural frequency of the diaphragm and the like.

Description

Device and method for improving directional sensitivity of EFPI (EFPI) membrane

Technical Field

The invention relates to an EFPI optical fiber sensor probe, in particular to an EFPI membrane directional sensitivity improving device and method.

Background

The optical fiber sensor based on the optical fiber coupling technology has a good application prospect in detection of Partial Discharge (PD) ultrasonic waves, optical signals and pulse current of electrical equipment. Through the development and exploration of related technologies for many years, an extrinsic Fabry-Perot interferometer (EFPI) optical fiber sensor method, namely an EFPI optical fiber sensor, is widely researched and applied to ultrasonic signal detection of partial discharge of electrical equipment such as transformers and gas insulated switchgear. The principle of the EFPI optical fiber sensor and a common diaphragm structure are shown in figures 1-4, and the EFPI optical fiber sensor is a high-performance acoustic ultrasonic wave detection system which converts ultrasonic waves into mechanical vibration by using a sensitive diaphragm structure, converts the mechanical vibration into optical parameter change by using a Fabry-Perot interference technology, and finally converts, collects and demodulates the optical parameter change by related instruments such as a photoelectric detector and the like. However, research and practical engineering show that the conventional planar diaphragm structure has certain defects in directional sensitivity, and the consistency difference in the sensitivity response of the ultrasonic incident angle of 0-180 degrees is large.

Disclosure of Invention

The present invention is directed to overcoming the above-mentioned drawbacks of the prior art and providing a device and a method for improving the directional sensitivity of an EFPI diaphragm, in which a mass structure is introduced into the center of the diaphragm, so that the EFPI diaphragm has a relatively uniform sensitivity response characteristic in an ultrasonic incident angle range of 0 to 180 °, and the natural frequency of the diaphragm can be adjusted.

The purpose of the invention can be realized by the following technical scheme:

according to one aspect of the invention, an EFPI membrane directional sensitivity improving device is provided and is installed on a membrane of an EFPI optical fiber sensor probe, and the improving device comprises a mass block which is installed on the membrane of the EFPI optical fiber sensor probe, so that a novel membrane structure with different natural frequencies and response sensitivity is formed.

Preferably, the mass is mounted at the center of the diaphragm.

As a preferred technical scheme, the mass block is of a square-table structure.

Preferably, the mass block comprises a mass block front surface and four mass block side walls, and the mass block front surface and the four mass block side walls form an ultrasonic three-dimensional receiving surface.

As a preferred technical scheme, the mass block is of a pyramid structure.

As a preferred technical solution, the mass block is a prism-shaped structure.

As the preferred technical scheme, the novel diaphragm structure of the probe increases the thickness T and the side length of the mass block by the design parameter thickness h and the equivalent working radius a of the plane diaphragm.

As an optimal technical scheme, when ultrasonic waves in different directions act on the side wall of the mass block, the mass block is subjected to sound pressure to cause the diaphragm to deform, so that the cavity length of the EFPI optical fiber sensor probe changes to generate corresponding light intensity change, and a wider incidence angle range is detected.

As a preferable technical scheme, the novel diaphragm structure of the probe detects a wider incidence angle range and can meet the requirement of 0-180 DEG ultrasonic signals.

According to another aspect of the present invention, a method for the directional sensitivity improvement device of the EFPI diaphragm is provided, which combines and designs a novel diaphragm structure with different natural frequencies and response sensitivities by introducing a mass block structure in the center of the EFPI fiber sensor probe diaphragm.

Compared with a planar diaphragm, the invention adopts the mass block structure with smaller size and thicker thickness to improve the directional sensitivity of the diaphragm, namely when ultrasonic waves in different directions act on the side wall of the mass block, the mass block is subjected to the action of sound pressure to cause the deformation of the diaphragm, so that the cavity length change of the EFPI optical fiber sensor probe generates corresponding light intensity change, thereby detecting the ultrasonic signal with wider incidence angle range, namely meeting the requirement of 0-180 degrees.

Drawings

FIG. 1 is a schematic diagram of an EFPI fiber optic sensor;

FIG. 2 is an enlarged view of portion A of FIG. 1;

FIG. 3 is a schematic structural diagram of a conventional diaphragm I;

FIG. 4 is a schematic structural diagram of a second common diaphragm;

FIG. 5 is a schematic structural view of embodiment 1;

FIG. 6 is a schematic structural view of embodiment 2;

FIG. 7 is a schematic structural view of embodiment 3.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of protection of the present invention.

Example 1

As shown in fig. 5, the directional sensitivity improving device for the EFPI membrane is installed on the membrane 1 of the EFPI fiber sensor probe, and the improving device comprises a mass block 2, and the mass block 2 is installed on the membrane 1 of the EFPI fiber sensor probe, so that a novel membrane structure with different natural frequencies and response sensitivities is formed.

The mass block is arranged at the central position of the diaphragm. The mass block is of a square-table structure. The mass block comprises a mass block front surface 3 and four mass block side walls 4, and the mass block front surface 3 and the four mass block side walls 4 form an ultrasonic three-dimensional receiving surface.

When the EFPI optical fiber sensor probe works, the diaphragm 1 converts ultrasonic waves into mechanical vibration. Due to the introduction of the mass block 2, the plane of the central mass block of the planar membrane in fig. 5 is converted into an ultrasonic three-dimensional receiving plane consisting of the front surface 3 of the mass block and four side walls 4 of the mass block, so that an ultrasonic signal with a wider incidence angle range, namely, meeting 0-180 degrees, is detected. At the moment, the thickness T and the side length l of the mass block are increased by the design parameter thickness h and the equivalent working radius a of the planar diaphragm of the diaphragm structure of the probe, so that the requirement for detecting the PD ultrasonic signals of electrical equipment is further met.

The invention can combine and design a novel diaphragm structure with different natural frequencies and response sensitivities by introducing the mass block structure in the center of the EFPI optical fiber sensor probe diaphragm. Compared with a planar diaphragm, the mass block structure with smaller size and thicker thickness can improve the directional sensitivity of the diaphragm, namely when sound waves in different directions act on the side wall of the mass block, the mass block is subjected to sound pressure action to cause the diaphragm to deform, so that the length of the probe cavity of the EFPI optical fiber sensor changes to generate corresponding light intensity change, and accordingly ultrasonic signals with wider incidence angle range meeting the requirement of 0-180 degrees are detected.

Example 2

As shown in fig. 6, the mass block has a pyramid structure, and the mass block includes four mass block sidewalls having a triangular structure, which is the same as that in embodiment 1.

Example 3

As shown in fig. 7, the mass block has a prism structure, the mass block includes a front surface and four side walls, and the side walls of the mass block have a rectangular structure, which is the same as that of embodiment 1.

While the invention has been described with reference to specific embodiments, the invention is not limited thereto, and various equivalent modifications and substitutions can be easily made by those skilled in the art within the technical scope of the invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. The device is characterized in that the lifting device comprises a mass block, and the mass block is arranged on the membrane of the EFPI optical fiber sensor probe, so that a novel membrane structure with different natural frequencies and response sensitivity is formed.

2. The device of claim 1, wherein the mass is mounted in a center of the membrane.

3. The device of claim 1, wherein the mass is a square-table structure.

4. The device of claim 3, wherein the proof mass comprises a front face and four side walls, the front face and the four side walls forming an ultrasonic receiving surface.

5. The device of claim 1, wherein the mass has a pyramid-shaped structure.

6. The device of claim 1, wherein the mass has a prism-shaped structure.

7. The device of claim 4, wherein the thickness T and the side length of the mass block are increased by the design parameter thickness h and the equivalent working radius a of the planar diaphragm of the novel diaphragm structure of the probe.

8. The device of claim 4, wherein when ultrasonic waves in different directions act on the sidewall of the mass block, the mass block is subjected to sound pressure to cause deformation of the diaphragm, so that the cavity length of the probe of the EFPI fiber sensor changes to generate corresponding light intensity changes, thereby detecting a wider range of incidence angles.

9. The device of claim 8, wherein the novel diaphragm structure of the probe detects a wider range of incident angles, which can satisfy 0-180 ° ultrasound signals.

10. The method for improving the directional sensitivity of the EFPI diaphragm of claim 1 is characterized in that the method combines and designs a novel diaphragm structure with different natural frequencies and response sensitivities by introducing a mass block structure in the center of the EFPI optical fiber sensor probe diaphragm.