阅读说明：本技术 一种基于压电陶瓷微形变图像检测的电压测量装置及方法 (Voltage measuring device and method based on piezoelectric ceramic micro-deformation image detection ) 是由 翟少磊 罗奕 程富勇 贾南疆 张林山 方正云 段怡 何潇 李月梅 闫永梅 杨莉 于 2021-01-07 设计创作，主要内容包括：本发明示出一种基于压电陶瓷微形变图像检测的电压测量装置及方法,涉及电力检测技术领域。解决了现有OVT技术测量电压时运行不可靠、价格不低廉的问题。本发明示出的电压测量装置,包括：背光单元设置在压电陶瓷模块的一侧；采集单元设置在压电陶瓷模块的另一侧；压电陶瓷模块上设置有可拆卸的压电陶瓷片、电极和基座,电极设置在压电陶瓷片的上下两端。本发明利用压电陶瓷的逆压电效应,基于压电陶瓷微形变的图像识别模块,以非接触式的图像传感器取代了高成本的机械传感器,结合图像处理技术,计算压电陶瓷片受电后的微形变投影面积,进而实现直流电压的高精度测量。它具有成本低、准确度高、稳定性强等特点,满足智能电网对设备数字化的要求。(The invention discloses a voltage measuring device and method based on piezoelectric ceramic micro-deformation image detection, and relates to the technical field of power detection. The problems of unreliable operation and low price in voltage measurement of the existing OVT technology are solved. The voltage measuring device shown in the invention comprises: the backlight unit is arranged on one side of the piezoelectric ceramic module; the acquisition unit is arranged on the other side of the piezoelectric ceramic module; the piezoelectric ceramic module is provided with a detachable piezoelectric ceramic piece, electrodes and a base, and the electrodes are arranged at the upper end and the lower end of the piezoelectric ceramic piece. The invention utilizes the inverse piezoelectric effect of the piezoelectric ceramic, the image identification module based on the piezoelectric ceramic micro-deformation, replaces a high-cost mechanical sensor with a non-contact image sensor, and combines an image processing technology to calculate the micro-deformation projection area of the piezoelectric ceramic piece after power is received, thereby realizing the high-precision measurement of the direct current voltage. The method has the characteristics of low cost, high accuracy, strong stability and the like, and meets the requirements of the intelligent power grid on equipment digitization.)

1. A voltage measuring device based on piezoelectric ceramic micro-deformation image detection is characterized by comprising: the device comprises a backlight unit (1), an acquisition unit (2), an image recognition module (3), a piezoelectric ceramic module (4) and a control unit (5);

the backlight unit (1) is arranged on one side of the piezoelectric ceramic module (4) and is configured to: providing a backlight source;

the acquisition unit (2) is arranged on the other side of the piezoelectric ceramic module (4) and is configured to: acquiring a deformation projection image;

the piezoelectric ceramic module (4) is provided with a detachable piezoelectric ceramic piece (41), electrodes (42) and a base (43), the electrodes (42) are arranged at the upper end and the lower end of the piezoelectric ceramic piece (41), and the electrodes (42) are arranged at the upper end of the base (43);

the output end of the acquisition unit (2) is connected with the input end of the image identification module (3);

the backlight unit (1), the acquisition unit (2), the image recognition module (3) and the piezoelectric ceramic module (4) are respectively electrically connected with the control unit (5).

2. Voltage measurement device according to claim 1, characterized in that said acquisition unit (2) comprises: a lens (21) and an image sensor (22);

the output end of the lens (21) is connected with the input end of the image sensor (22);

the output end of the image sensor (22) is connected with the input end of the image recognition module (3).

3. The voltage measurement device of claim 1, further comprising: a chassis (6);

the base (43) is arranged on the chassis (6), the backlight unit (1) is arranged on the chassis (6) through a first fixing part (61), and the image recognition module (3) is arranged on the chassis (6) through a second fixing part (62).

4. The voltage measurement device of claim 1, further comprising: a communication unit (7),

the input end of the communication unit (7) is connected with the output end of the image recognition module (3).

5. The voltage measurement device of claim 4, further comprising: a cloud centre (8),

the output end of the communication unit (7) is electrically connected with the cloud center (8).

6. Voltage measurement device according to claim 1, characterized in that the backlight unit (1) is backlit by a non-monochromatic light source.

7. The voltage measurement device of claim 2, wherein the image sensor (22) employs a Complementary Metal-Oxide-Semiconductor (CMOS) sensor as the image sensor.

8. The voltage measurement device according to claim 2 or 4, further comprising: a power supply unit (9),

the power supply unit (9) is respectively connected with the backlight unit (1), the image sensor (22), the image recognition module (3), the communication unit (7) and the power ends of the control unit (5).

9. The voltage measurement device of claim 2, 3 or 4, further comprising: a shell (10) which is provided with a plurality of grooves,

the backlight unit (1), the lens (21), the first fixing part (61) and the second fixing part (62) are arranged outside the shell (10), and the control unit (5), the image recognition module (3) and the communication unit (7) are arranged inside the shell (10);

the housing (10) is arranged on the chassis (6) by means of a third fixing part (63).

10. A voltage measurement method based on piezoelectric ceramic micro-deformation image detection, which is applied to the method of any one of the above claims 1-9, and is characterized by comprising the following steps:

the backlight unit provides a backlight source;

under the backlight source, the acquisition unit acquires a deformation projection image of the piezoelectric ceramic piece;

the image identification module detects a micro-deformation variable of the deformation projection image;

calculating voltage values at two ends of the piezoelectric ceramic piece according to the micro-deformation variable of the deformation projection image;

and acquiring the voltage value of the high-voltage end of the piezoelectric ceramic piece according to the voltage value and the voltage division ratio.

Technical Field

The invention relates to the technical field of power detection, in particular to a voltage measuring device and method based on piezoelectric ceramic micro-deformation image detection.

Background

High-voltage direct-current transmission is used as a high-capacity and long-distance transmission technology, and plays an important role in the propulsion process of the global energy Internet. With the development of the smart power grid in China and the application and popularization of technologies such as high-voltage flexible direct-current transmission, large-scale wind power plant grid connection and the like, the flexible direct-current system control and protection device meets the requirements for quicker and more accurate response, and therefore the high-voltage direct-current and voltage measuring device needs to have the characteristics of high reliability, high speed, high precision and the like. The measurement of high-voltage direct-current voltage is the basis of the wide promotion of the intelligent power grid and direct-current transmission, and is an important premise for realizing the state monitoring and the electric energy metering of the intelligent power grid.

In the prior art, a high-voltage direct-current voltage measuring device mainly adopts a resistance-capacitance voltage division principle, and good frequency response is ensured through the consistency of resistance-capacitance time constants of an upper arm and a lower arm of a voltage divider. However, in practical design, due to the influence of stray capacitance and parasitic inductance, the resistance-capacitance parameters of the upper arm and the lower arm are difficult to match, so that the voltage division ratio changes along with the frequency of a measured signal; meanwhile, the secondary output is generally an analog signal, is transmitted through a cable and is easy to interfere, or the response speed cannot be guaranteed when the signal is acquired on site. The conventional related measurement method of direct current Voltage is gradually replaced by a novel sensing technology with the advantages of small volume, light weight, high accuracy, large dynamic range and the like, such as an Optical Voltage Transformer (OVT), due to the defects of large volume, heavy weight, narrow dynamic range and the like. The dynamic range is large, the measurement frequency band is wide and the detection precision is high during the OVT measurement; the structure is relatively simple, the size is relatively smaller, and the weight is light; the method has the advantages of digital output quantity, convenience in remote control of optical fiber communication and the like. Currently, OVT is not only a novel voltage detection device for power systems, which is a controversial research in various countries in the world, but also is recognized as a development direction of transformer technology in the industry.

However, the OVT product mainly adopts an optical fiber sensor, the sensing head of the OVT product is easily affected by temperature and external environment disturbance, and the stability and reliability in long-term operation cannot be ensured. In addition, the pure optical fiber type photoelectric transformer has high price and poor measurement effect, and the market popularization of the OVT technology is severely restricted. Therefore, a new OVT technology with reliable operation, low price and high measurement accuracy is urgently needed.

Disclosure of Invention

Aiming at the technical problems in the prior art, the invention provides a voltage measuring device and method based on piezoelectric ceramic micro-deformation image detection, and solves the problems of unreliable operation and low price when the voltage is measured by the existing OVT technology.

The invention discloses a voltage measuring device based on piezoelectric ceramic micro-deformation image detection, which comprises: the device comprises a backlight unit, an acquisition unit, an image recognition module, a piezoelectric ceramic module and a control unit;

the backlight unit is arranged on one side of the piezoelectric ceramic module and is configured to: providing a backlight source;

the acquisition unit is arranged on the other side of the piezoelectric ceramic module and is configured to: acquiring a deformation projection image;

the piezoelectric ceramic module is provided with a detachable piezoelectric ceramic piece, electrodes and a base, the electrodes are arranged at the upper end and the lower end of the piezoelectric ceramic piece, and the electrodes are arranged at the upper end of the base;

the output end of the acquisition unit is connected with the input end of the image identification module;

the backlight unit, the acquisition unit, the image recognition module and the piezoelectric ceramic module are electrically connected with the control unit.

Specifically, the above structure has the following beneficial effects: the piezoelectric ceramic piece deforms due to the inverse piezoelectric effect, and the image recognition module detects the micro-deformation projection area of the piezoelectric ceramic piece by using an image recognition technology; the high-voltage direct current voltage is connected with two ends of an electrode after being subjected to voltage division treatment, and the electrode is connected with the input end of the piezoelectric ceramic piece; and further calculating the voltage values of the two ends of the ceramic chip, and acquiring the voltage value of the high-voltage end by combining the voltage division ratio. The structural design of the detachable piezoelectric ceramic piece realizes the function of replacement according to the size of the voltage to be measured.

In some embodiments, the acquisition unit comprises: a lens and an image sensor;

the output end of the lens is connected with the input end of the image sensor;

the output end of the image sensor is connected with the input end of the image recognition module.

In some embodiments, further comprising: a chassis; the chassis is provided with a base, the backlight unit is arranged on the chassis through a first fixing part, and the image recognition module is arranged on the chassis through a second fixing part.

In some embodiments, further comprising: and the input end of the communication unit is connected with the output end of the image recognition module. The communication unit transmits the voltage value data input by the image recognition microprocessor to the remote monitoring terminal to realize the remote monitoring of the high-voltage direct current voltage.

In some embodiments, further comprising: and the output end of the communication unit is electrically connected with the cloud center.

The cloud center is more flexible, the data center required by cloud computing is from the internet and evolves to an integrated platform, and therefore, the data center is continuous and integral from infrastructure to computing and application, and is related and adaptable to each other, different from the situation that the infrastructure of the traditional data center and software and hardware of an information system are separated.

In some embodiments, the backlight unit is backlit with a non-monochromatic light source.

Specifically, the above structure has the following beneficial effects: for accurate image-based measurement of object micro-deformation, transient light configurations are typically used. The invention adopts non-monochromatic backlight to obtain high-contrast images on the sensor, thereby fundamentally simplifying the task of target detection.

In some embodiments, the image sensor employs a Complementary Metal-Oxide-Semiconductor (CMOS) sensor as the image sensor.

Specifically, the above structure has the following beneficial effects: the image sensor realizes the digital processing of the piezoelectric ceramic chip image. In this example, the image sensor employs a complementary metal oxide semiconductor sensor. The CMOS technology is used for the image sensor, so that the measurement cost can be effectively reduced, an additional analog front-end circuit is not needed, direct digital output can be realized, and windowing can be used for carrying out pseudo-random access on pixel values.

The CMOS sensor model is MT9M001STM from APTINA. An image recognition microprocessor in the image recognition module processes CMOS image data with physical resolution not conforming to measurement precision by adopting a linear interpolation algorithm so as to realize uniform distribution of pixel light sensitivity. The method adopts a linear interpolation algorithm to process the CMOS image data so as to realize the uniform distribution of the pixel light sensitivity, and further calculates the area value of the piezoelectric ceramic piece according to the pixel points.

In some embodiments, further comprising: and the power supply unit is respectively connected with the backlight unit, the image sensor, the image recognition module, the communication unit and the power supply end of the control unit.

In some embodiments, further comprising: the backlight unit, the lens, the first fixing part and the second fixing part are arranged outside the shell, and the control unit, the image recognition module and the communication unit are arranged inside the shell; the housing is disposed on the chassis via a third fixing member.

The invention also discloses a voltage measuring method based on piezoelectric ceramic micro-deformation image detection, which comprises the following steps: the backlight unit provides a backlight source;

under a backlight source, the acquisition unit acquires a deformation projection image of the piezoelectric ceramic piece;

the image identification module detects a micro-deformation variable of the deformation projection image;

calculating voltage values at two ends of the piezoelectric ceramic piece according to the micro-deformation variable of the deformation projection image;

and acquiring the voltage value of the high-voltage end of the piezoelectric ceramic piece according to the voltage value and the voltage division ratio.

According to the technical scheme, the embodiment of the invention has the following beneficial effects: the method adopts a non-contact measurement method, replaces an expensive mechanical sensor with a non-contact image sensor, is not influenced by temperature change, has the characteristics of low cost, high accuracy, strong stability and the like, and meets the requirements of an intelligent power grid on equipment digitization; meanwhile, the combination of the piezoelectric ceramic module and the image recognition module has flexibility and expandability, is convenient to replace and maintain, and can meet the requirements of direct-current voltage measurement of different levels.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic structural diagram of an embodiment of a voltage measurement apparatus based on piezoelectric ceramic micro-deformation image detection according to the present invention;

FIG. 2 is a schematic structural diagram of an image recognition module in a voltage measurement apparatus based on piezoelectric ceramic micro-deformation image detection according to the present invention;

fig. 3 is a schematic flow chart of a voltage measurement method based on piezoelectric ceramic micro-deformation image detection according to the present invention.

Detailed Description

In order to make the technical solutions in the embodiments of the present invention better understood and make the above objects, features and advantages of the embodiments of the present invention more comprehensible, the technical solutions in the embodiments of the present invention are described in further detail below with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of an embodiment of a voltage measurement device based on piezoelectric ceramic micro-deformation image detection according to the present invention. As shown in fig. 1, a voltage measuring apparatus based on piezoelectric ceramic micro-deformation image detection includes: the device comprises a backlight unit 1, an acquisition unit 2, an image recognition module 3, a piezoelectric ceramic module 4 and a control unit 5; the backlight unit 1 is disposed on one side of the piezoelectric ceramic module 4, and is configured to: providing a backlight source; the acquisition unit 2 is disposed on the other side of the piezoceramic module 4, and is configured to: acquiring a deformation projection image; the piezoelectric ceramic module 4 is provided with a detachable piezoelectric ceramic piece 41, electrodes 42 and a base 43, the electrodes 42 are arranged at the upper end and the lower end of the piezoelectric ceramic piece 41, and the electrodes 42 are arranged at the upper end of the base 43; the output end of the acquisition unit 2 is connected with the input end of the image identification module 3; the backlight unit 1, the acquisition unit 2, the image recognition module 3 and the piezoelectric ceramic module 4 are electrically connected with the control unit 5.

The image recognition module 3 includes an image recognition microprocessor for processing image information of coarse resolution to output a voltage measurement value of high precision. The edge detection results obtained using conventional image processing methods are related to the physical resolution of the image sensor used. For the result that the physical resolution does not accord with the measurement precision, the method adopts a linear interpolation algorithm to process the CMOS image data so as to realize the uniform distribution of the pixel light sensitivity, and further calculates the area value of the piezoelectric ceramic piece according to the pixel points.

The working process is as follows: the backlight unit 1 provides a backlight source; under a backlight source, the acquisition unit 2 acquires a deformation projection image of the piezoelectric ceramic piece 41; the image identification module 3 detects the micro-deformation variable of the deformed projection image; calculating the voltage values at two ends of the piezoelectric ceramic piece 41 according to the micro-deformation variable of the deformation projection image; and acquiring the voltage value of the high-voltage end of the piezoelectric ceramic piece 41 according to the voltage value and the voltage division ratio.

Among them, the piezoelectric ceramic plate 41 is deformed by the inverse piezoelectric effect, and the projected image is deformed by different voltages. Specifically, the high voltage direct current voltage is divided and then connected to two ends of the electrode 42, the electrode 42 is connected to the input end of the piezoelectric ceramic plate 41, the electrode 42 is fixed on the base 43, and the base 43 is fixed on the chassis 6.

Optionally, the piezoelectric ceramic 41 has a diameter of 50mm and a thickness of 50 mm. The working process is as follows: when the high voltage of the dc bus is divided and then the voltage is reduced to a voltage range (for example, 1000V) that the piezoelectric ceramic plate 41 can bear, the piezoelectric ceramic plate 41 is deformed due to the inverse piezoelectric effect. The image recognition module 3 calculates the voltage values at the two ends of the piezoelectric ceramic piece 41 by detecting the micro-deformation projection area of the piezoelectric ceramic piece 41 by using an image processing technology, and acquires the voltage value at the high-voltage end by combining a voltage division ratio. The piezoelectric ceramic plate 41 can be replaced according to the voltage to be measured.

Preferably, the backlight unit 1, the pickup unit 2, and the piezoelectric ceramic module 4 are disposed on a coaxial line.

In some embodiments, the acquisition unit 2 comprises: a lens 21 and an image sensor 22; the output end of the lens 21 is connected with the input end of the image sensor 22; the output end of the image sensor 22 is connected with the input end of the image identification module 3.

In some embodiments, further comprising: a chassis 6; the chassis 6 is provided with a base 43, the backlight unit 1 is disposed on the chassis 6 by a first fixing member 61, and the image recognition module 3 is disposed on the chassis 6 by a second fixing member 62.

In some embodiments, further comprising: and the input end of the communication unit 7 is connected with the output end of the image recognition module 3.

In some embodiments, further comprising: and the output end of the communication unit 7 is electrically connected with the cloud center 8.

The output end of the communication unit can output measured voltage data to the remote control terminal, the remote control terminal can be a cloud center 8, the cloud center 8 is more flexible, a data center required by cloud computing is from the Internet and evolves towards an integrated platform, and therefore, the situation that software and hardware of a traditional data center infrastructure and an information system are separated is different, and the data center of the cloud computing is continuous and integral from the infrastructure to computing and application and is related and adaptable to each other.

In some embodiments, the backlight unit 1 is backlit with non-monochromatic light sources.

In some embodiments, the image sensor 22 employs a CMOS Complementary Metal-Oxide-Semiconductor (CMOS) sensor as the image sensor.

In some embodiments, further comprising: and the power supply unit 9, wherein the power supply unit 9 is respectively connected with the backlight unit 1, the image sensor 22, the image recognition module 3, the communication unit 7 and the power supply ends of the control unit 5.

In some embodiments, further comprising: the casing 10, the backlight unit 1, the lens 21, the first fixing member 61, and the second fixing member 62 are disposed outside the casing 10, and the control unit 5, the image recognition module 3, and the communication unit 7 are disposed inside the casing 10. The housing 10 is provided on the chassis 6 through the third fixing member 63.

During installation, the backlight unit 1, the acquisition unit 2 and the piezoelectric ceramic module 4 are arranged on a coaxial line by adjusting the position of the backlight unit 1, and then the backlight unit 1 is fixed to complete the arrangement of the measuring device.

Fig. 2 is a schematic structural diagram of an image recognition module in a voltage measurement device based on piezoelectric ceramic micro-deformation image detection according to the present invention. In combination with the above structural features, as shown in fig. 2, the present invention provides another embodiment of a high-voltage dc voltage measuring apparatus based on piezoelectric ceramic micro-deformation image detection, comprising: the image recognition device comprises a shell 10, a first fixing part 61, a second fixing part 62, a power supply unit 9, a backlight unit 1, a lens 21, an image sensor 22, a control unit 5, an image recognition microprocessor and a communication unit 7. The backlight unit 1 and the lens 21 are respectively located at two sides of the piezoelectric ceramic plate 41, the output end of the lens 21 is connected with the input end of the image sensor 22, the output end of the image sensor 22 is connected with the input end of the image recognition microprocessor, and the output end of the image recognition microprocessor is connected with the input end of the communication unit 7. The power supply unit 9 is connected to the power supply terminals of the backlight unit 1, the image sensor 22, the image recognition microprocessor, the communication unit 7, and the control unit 5, respectively, and supplies power thereto. The control unit 5 is connected with the backlight unit 1, the image sensor 22 and the control end of the image recognition microprocessor to control the work of the image recognition microprocessor. The output end of the communication unit 7 can output the measured voltage data to the outside, the first fixing part 61 is positioned outside the shell 10, and the tail end of the first fixing part is provided with a backlight source. The backlight unit 1, the lens 21, the first fixing member 61 and the second fixing member 62 are located outside the housing 10, and the power supply unit 9, the control unit 5, the image recognition microprocessor and the communication unit 7 are fixed inside the housing 10. The backlight unit 1 and the housing 10 are fixed to the ground by the third fixing member 63.

The working process is as follows: the control unit 5 controls the backlight unit 1 to start the backlight source by outputting a control signal, the lens 21 and the image sensor 22 complete the digital processing of the micro-deformation projection image of the piezoelectric ceramic piece 41, and the image data is input into the image recognition microprocessor. The image recognition microprocessor realizes the uniform distribution of pixel light sensitivity by using a linear interpolation method, further obtains the pixel value of the projection area occupied by the piezoelectric ceramic piece 41 before and after the voltage is introduced, thereby solving the micro-deformation of the piezoelectric ceramic piece 41, calculates the voltage values at the two ends of the ceramic piece according to the deformation, and then obtains the voltage value at the high-voltage end by combining the voltage division ratio. The communication unit 7 transmits voltage value data input by the image recognition microprocessor to a remote monitoring terminal, and the remote control terminal can be a cloud center 8 to realize remote monitoring of high-voltage direct current voltage.

Fig. 3 is a schematic flow chart of a voltage measurement method based on piezoelectric ceramic micro-deformation image detection according to the present invention. As shown in figure 3 of the drawings,

s101, under a backlight source, a collecting unit collects deformation projection images of the piezoelectric ceramic plates;

s102, detecting a micro-deformation variable of the deformation projection image by an image identification module;

s103, calculating voltage values at two ends of the piezoelectric ceramic piece according to the micro-deformation variable of the deformation projection image;

s104, acquiring the voltage value of the high-voltage end of the piezoelectric ceramic piece according to the voltage value and the voltage division ratio.

In the embodiment, a non-contact measurement method is adopted, an expensive mechanical sensor is replaced by a non-contact image sensor, the temperature change is not influenced, the method has the characteristics of low cost, high accuracy, strong stability and the like, and the requirement of an intelligent power grid on equipment digitization is met; meanwhile, the combination of the voltage division module and the image identification module has flexibility and expandability, is convenient to replace and maintain, and can meet the requirements of direct-current voltage measurement of different levels.

While there have been shown and described what are at present considered the fundamental principles and essential features of the invention and its advantages, it will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, but is capable of other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art will be able to make the description as a whole, and the embodiments may be appropriately combined to form other embodiments as will be apparent to those skilled in the art.

The embodiments of the present invention are described in detail, and the embodiments are only examples of the general inventive concept, and should not be construed as limiting the scope of the present invention. Any other embodiments extended by the solution according to the invention without inventive step will be within the scope of protection of the invention for a person skilled in the art.