CN108732416B - MEMS micro-mirror high-voltage electrostatic sensor with digital front end - Google Patents

Abstract

The invention discloses a front-end digital MEMS micro-mirror high-voltage electrostatic sensor, wherein one end of a metal cantilever is fixed in a fixed frame, the other end of the metal cantilever is suspended, a sealing cover, the fixed frame, a base and a PCB (printed circuit board) are sequentially fixed from top to bottom, a conductive column is arranged on the base, a high-voltage conductor to be detected is electrically connected with the conductive column through the PCB, a reflective array is arranged on the upper surface of the metal cantilever and is positioned right above the conductive column, an optical fiber probe is arranged on the sealing cover and is positioned right above the reflective array, and the optical fiber probe is connected with a light emitting/receiving device through an optical fiber; the reflection array is composed of a plurality of first reflection strips and a plurality of second reflection strips, wherein the emissivity of the first reflection strips is larger than the reflectivity of the second light-emitting strips, the first reflection strips and the second reflection strips are distributed in a staggered mode in sequence, the sensor can directly detect the electrostatic voltage on the high-voltage conductor, and the output signal is a digital signal.

Description

A front-end digital MEMS micromirror high voltage electrostatic sensor

technical field

The invention relates to a high-voltage electrostatic sensor, in particular to a front-end digitalized MEMS micromirror high-voltage electrostatic sensor.

Background technique

High-voltage power capacitors are widely used in power systems and test stations. Because the electric charge stored in the capacitor is in a static state, it is difficult to be sensed by general measurement methods, including principles and methods such as electromagnetic induction and magnetic field measurement. At present, it is used for high-voltage electrostatic induction Due to its large size, high power consumption and high cost, it is technically and economically difficult to apply to high-voltage capacitors equipped in a large number of power departments. Therefore, Human casualties caused by the invisibility of the stored charge in capacitors are frequently reported every year, causing irreparable damage to families, businesses and society. In addition, high-voltage electrostatic discharge will generate a large transient pulse current, accompanied by strong electromagnetic radiation, which directly affects the normal operation of electronic electrostatic sensitive equipment such as control systems and measuring instruments in the laboratory, and even has the potential to cause fire and explosion. Therefore, the monitoring of high-voltage static electricity has become a research hotspot in the field of electrical equipment in recent years.

Direct contact measurement of high-voltage electrostatic field is the most accurate and convenient method. However, the static high voltage of the busbar connected to the energy storage device can reach several tens of kV to hundreds of kV, which makes the equipment for direct measurement of high-voltage electrostatic field need to be more precise. Large insulation margin, its volume cannot be miniaturized. In addition, the high-voltage busbar usually has a complex layout and long wiring. To monitor its high-voltage static electricity in real time, a large number of direct measuring instruments can be completed, which requires high space and cost. In recent years, a large number of studies have begun to focus on the non-contact indirect measurement of high-voltage electric fields, and a variety of mechanical or optical-based electric field sensors have been designed. However, in the electrostatic field, the electric field cannot provide continuous energy to the sensor, and the charge on the high-voltage conductor cannot maintain the macroscopic motion continuously, which becomes the difficulty of electrostatic field measurement, making the current electric field sensor less sensitive to low frequency or electrostatic field. . At the same time, the current sensors that can be used to measure high-voltage electrostatic fields have disadvantages such as complex structure, large volume, and high cost, and cannot be mass-produced. During the operation of the power system or electrical laboratory, a large number of non-contact indirect measuring instruments are required to monitor the accident-prone points of the high-voltage busbar online to ensure the safety of operators and electronic equipment. Therefore, the existing electric field The sensor cannot meet this requirement, and the output of the existing sensor is an analog signal, which requires subsequent processing.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art, and to provide a front-end digitized MEMS micromirror high-voltage electrostatic sensor, which can directly detect the electrostatic voltage on the high-voltage conductor, and the output signal is a digital signal. Small size, low cost and simple structure.

In order to achieve the above purpose, the front-end digitalized MEMS micromirror high-voltage electrostatic sensor of the present invention includes a PCB circuit board, a MEMS micromirror, an optical fiber and a light transmitter/receiver; wherein, the MEMS micromirror includes a base, a micromirror and a cover , wherein the micromirror includes a fixed frame and a metal cantilever, one end of the metal cantilever is fixed in the fixed frame, the other end of the metal cantilever is suspended, the cover, the fixed frame, the base and the PCB circuit board are fixed in order from top to bottom, the base The seat is provided with a conductive column, the high-voltage conductor to be tested is electrically connected to the conductive column through the PCB circuit board, the upper surface of the metal cantilever is provided with a reflective array, the reflective array is located directly above the conductive column, and the cover is provided with an optical fiber probe. Located just above the reflective array, the fiber probe is connected to the light transmitter/receiver through an optical fiber;

The reflective array is composed of several first reflective strips and several second reflective strips, wherein the first reflective strips have a higher emissivity than the second light-emitting strips, and the first reflective strips and the second reflective strips are alternately distributed in sequence.

The PCB circuit board includes a board base, a metal lead, a voltage connector and an optical fiber adapter, wherein the metal lead, the voltage connector and the optical fiber adapter are all located on the board base, and one end of the metal lead is connected to the voltage connector. The other end is connected with the conductive column, the high-voltage conductor to be tested is electrically connected with the voltage connector, and the optical fiber is connected with the optical fiber adapter.

A TSV hole is opened on the base, wherein the TSV hole is filled with a solid conductive material to form a conductive column.

The cover is provided with an installation hole for installing the optical fiber probe, wherein the optical fiber probe is fixed in the installation hole by an adhesive.

The optical fibers are single-mode fibers, multi-mode fibers, or fiber bundles.

The metal cantilever is a constant-section cantilever beam, a variable-section cantilever beam or a bending spring.

The present invention has the following beneficial effects:

During the specific operation of the front-end digitized MEMS micromirror high-voltage electrostatic sensor of the present invention, the high-voltage conductor to be measured is connected to the conductive column through the PCB circuit board, so that the high-voltage conductor to be measured and the conductive column have the same voltage, and the high-voltage conductor to be measured is connected to the conductive column through the conductive column. An electrostatic attraction is generated on the metal cantilever, which makes the metal cantilever bend. Since the upper surface of the metal cantilever is provided with a reflective array, the reflective array consists of a number of first reflective strips and a number of second reflective strips, and the first reflective strip and the second reflective stripe The reflectivity of the metal cantilever is different. During the bending process of the metal cantilever, the reflective array moves in the measuring laser beam, and the digital signal with 0-1 interval can be obtained according to the change of the reflected light intensity, so as to realize the direct contact measurement of the high-voltage conductor to be measured. At the same time, the subsequent circuit and the high-voltage terminal are isolated to avoid adverse effects on the subsequent circuit. The structure is simple, the volume is small, and the manufacturing cost is high, which is convenient for distributed real-time monitoring in industrial sites.

Description of drawings

Fig. 1 is the structural representation of the present invention;

2 is a schematic structural diagram of the PCB circuit board 1 in the present invention;

3 is a schematic structural diagram of the MEMS micromirror 2 in the present invention;

FIG. 4 is a schematic structural diagram of the micromirror 22 in the present invention.

Among them, 1 is a PCB circuit board, 2 is a MEMS micromirror, 3 is an optical fiber, 4 is an optical transmitter/receiver, 11 is a board base, 12 is a metal lead, 13 is a voltage connector, 14 is an optical fiber adapter, and 21 is the base The seat, 22 is a micromirror, 23 is a cover, 211 is a conductive column, 231 is a fiber probe, and 223 is a reflective array.

Detailed ways

Below in conjunction with accompanying drawing, the present invention is described in further detail:

1 to 4, the front-end digital MEMS micromirror high-voltage electrostatic sensor according to the present invention includes a PCB circuit board 1, a MEMS micromirror 2, an optical fiber 3 and a light transmitter/receiver 4; wherein, the MEMS micromirror 2 includes a base The seat 21, the micromirror 22 and the cover 23, wherein the micromirror 22 includes a fixed frame and a metal cantilever, one end of the metal cantilever is fixed in the fixed frame, the other end of the metal cantilever is suspended, the cover 23, the fixed frame, the base 21 and the PCB circuit board 1 are sequentially fixed from top to bottom, the base 21 is provided with a conductive column 211, the high-voltage conductor to be tested is electrically connected to the conductive column 211 through the PCB circuit board 1, and the upper surface of the metal cantilever is provided with a reflective array 223, The reflective array 223 is located just above the conductive column 211, the cover 23 is provided with an optical fiber probe 231, the optical fiber probe 231 is located directly above the reflective array 223, and the optical fiber probe 231 is connected with the optical transmitter/receiver 4 through the optical fiber 3; The reflective array 223 is composed of a plurality of first reflective strips and a plurality of second reflective strips, wherein the emissivity of the first reflective strips is greater than the reflectivity of the second light-emitting strips, and the first reflective strips and the second reflective strips are alternately distributed in sequence .

The PCB circuit board 1 includes a board base 11, a metal lead 12, a voltage connector 13 and an optical fiber adapter 14, wherein the metal lead 12, the voltage connector 13 and the optical fiber adapter 14 are all located on the board base 11, and the metal leads 12 One end is connected to the voltage connector 13 , the other end of the metal lead 12 is connected to the conductive post 211 , the high voltage conductor to be tested is electrically connected to the voltage connector 13 , and the optical fiber 3 is connected to the optical fiber adapter 14 .

The base 21 is provided with a TSV hole, wherein the TSV hole is filled with a solid conductive material to form a conductive column 211; the cover 23 is provided with a mounting hole for installing the fiber probe 231, wherein the fiber probe 231 is fixed by an adhesive The optical fiber 3 is a single-mode optical fiber, a multi-mode optical fiber or an optical fiber bundle; the metal cantilever is a constant-section cantilever beam, a variable-section cantilever beam or a bending spring.

The high-voltage conductor to be tested is connected with the light transmitter/receiver 4 at the rear end through an optical fiber 3 . Completely cut off the high-voltage terminal and the back-end circuit to ensure the safety of personnel and equipment; the board base 11 is made of high-insulation materials to ensure that the board base 11 is not charged and does not leak during the measurement; the base 21, the micromirror 22 and the cover 23 are made of low temperature Direct bonding process connection.

The concrete working process of the present invention is:

The high-voltage conductor to be measured is electrically connected to the voltage connector 13, so that the high-voltage conductor to be measured and the conductive column 211 have the same voltage, and the conductive column 211 generates an electrostatic attraction to the metal cantilever, so that the metal cantilever is bent, because the upper surface of the metal cantilever is provided with The reflective array 223, the reflective array 223 is composed of a plurality of first reflective strips and second reflective strips distributed in turn, and the reflectivity of the first reflective strips is greater than that of the second reflective strips, when the metal cantilever is bent, the reflective array The 223 moves in the measuring laser beam, and can directly obtain the digital signal of 0-1 interval according to the change of the reflected light intensity. The data can be counted through the external counter, and the measurement of the voltage of the high-voltage conductor can be realized.

Claims (6)

1. A front-end digital MEMS micro-mirror high-voltage electrostatic sensor is characterized by comprising a PCB (printed circuit board) 1, an MEMS micro-mirror 2, an optical fiber 3 and a light emitting/receiving device 4; wherein, the MEMS micro-mirror (2) comprises a base (21), a micro-mirror (22) and a sealing cover (23), the micro-mirror (22) comprises a fixed frame and a metal cantilever, one end of the metal cantilever is fixed in the fixed frame, the other end of the metal cantilever is suspended, a sealing cover (23), the fixed frame, a base (21) and a PCB (printed circuit board) are sequentially fixed from top to bottom, a conductive column (211) is arranged on the base (21), a high-voltage conductor to be tested is electrically connected with the conductive column (211) through the PCB (1), a reflective array (223) is arranged on the upper surface of the metal cantilever, the reflective array (223) is positioned right above the conductive column (211), an optical fiber probe (231) is arranged on the sealing cover (23), the optical fiber probe (231) is positioned right above the reflective array (223), and the optical fiber probe (231) is connected with a light emitting/receiving device (4) through an optical fiber (3);

the reflecting array (223) is composed of a plurality of first reflecting strips and a plurality of second reflecting strips, wherein the emissivity of the first reflecting strips is larger than the reflectivity of the second light-emitting strips, and the first reflecting strips and the second reflecting strips are distributed in a staggered mode in sequence.

2. The front-end digital MEMS micro-mirror high-voltage electrostatic sensor according to claim 1, wherein the PCB circuit board (1) comprises a board base (11), a metal lead (12), a voltage connector (13) and an optical fiber adapter (14), wherein the metal lead (12), the voltage connector (13) and the optical fiber adapter (14) are all located on the board base (11), one end of the metal lead (12) is connected with the voltage connector (13), the other end of the metal lead (12) is connected with the conductive column (211), the high-voltage conductor to be tested is electrically connected with the voltage connector (13), and the optical fiber (3) is connected with the optical fiber adapter (14).

3. The front-end digital MEMS micro-mirror high-voltage electrostatic sensor according to claim 1, wherein the base (21) has a TSV opening, wherein the TSV opening is filled with a solid conductive material to form the conductive pillar (211).

4. The front-end digital MEMS micro-mirror high-voltage electrostatic sensor according to claim 1, wherein the cover (23) has a mounting hole for mounting the fiber probe (231), wherein the fiber probe (231) is fixed in the mounting hole by an adhesive.

5. The front-end digital MEMS micro-mirror high voltage electrostatic sensor according to claim 1, characterized in that the optical fiber (3) is a single mode fiber, a multimode fiber or a fiber bundle.

6. The front-end digital MEMS micro-mirror high-voltage electrostatic sensor as claimed in claim 1, wherein the metal cantilever is a constant-section cantilever beam, a variable-section cantilever beam or a bending spring.

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