Flexible sensing device used in strong electric field and strong magnetic field and manufacturing method thereof

Abstract

The invention discloses a flexible sensing device used in a strong electric field and a strong magnetic field and a manufacturing method thereof, and the method comprises the steps: selecting miniature low-power-consumption components which comprise a pcb antenna, a wireless communication module, a main control chip, a battery and a flexible printed circuit board FPCB, and configuring a sensing device; performing PCB layout and welding on the components to obtain a first-stage FPCB; anti-interference structure design with a metasurface structure is carried out on the first-stage FPCB, a second-stage FPCB is obtained, packaging processing is carried out on the second-stage FPCB, and the flexible sensing device applied to the strong-electric-field and strong-magnetic-field environment is obtained; and carrying out a metasurface structure electromagnetic field shielding performance test and an overall anti-interference performance test on the flexible sensing device through the test platform. The flexible sensing device is good in flexibility, and accords with the scene application of a complex strong electric field and strong magnetic field environment in the power industry.

Description

Technical Field

[0001] The present invention belongs to the technical field of power transmission facility sensing, and relates to a flexible sensing device for use under strong electric and magnetic fields and a manufacturing method thereof. Background Art

[0002] There are many types of transmission facilities and substation facilities in the power industry, and the structures of various facilities are different. For example, the transmission line tension clamp is generally cylindrical in structure, and sometimes it may be slightly deformed due to construction and manufacturing reasons. For example, the end of the synthetic insulator is a cylindrical curved surface structure, and the ball head of the suspended disc or glass insulator is a spherical curved surface structure. The transformer terminal palms, mutual inductor connectors, bushing terminals, etc. in the substation facilities are all special-shaped curved surface structures. Conventional sensing devices are difficult to fully adapt to such structures, which seriously affects the accuracy of sensing measurements. Most power equipment, especially equipment with irregular structures, still lacks effective sensing devices.

[0003] Flexible sensors have high adaptability to irregular structure surfaces, can better adapt to complex surfaces and curved shapes, and are very advantageous in applications on irregularly shaped objects. However, existing flexible sensing devices are mostly used in ordinary industries or wearable industries. Due to the particularity of the power industry, most of the equipment to be sensed is high-voltage equipment, and electric and magnetic fields are prone to interfere with or even damage the sensing devices. In addition, power equipment is divided into multiple voltage levels. The structure size and electromagnetic field strength of equipment at different voltage levels are different. Even the equipment structures of different manufacturers at the same voltage level are different. The impact on the sensing device increases with the increase of the voltage level. Therefore, flexible sensing devices are easily affected by the electromagnetic field environment and are not applicable in the high voltage and strong magnetic field environment of the power industry. In addition, the existing electromagnetic protection means use metal shielding materials to seal all non-wireless communication units, while the wireless communication antenna is exposed outside the shielding material. The induced voltage will be introduced into the circuit board through the antenna, which will cause the circuit board, components, etc. to break down and be damaged, especially in a high-voltage environment of hundreds of thousands of volts, which is more prone to damage. Summary of the invention

[0004] In order to solve the deficiencies in the prior art, the present invention provides a flexible sensing device and a manufacturing method thereof for use in strong electric and magnetic fields, so as to realize effective sensing of power transmission and transformation equipment in the power industry.

[0005] The present invention adopts the following technical solution.

[0006] The first aspect of the present invention provides a method for manufacturing a flexible sensing device for use in strong electric and magnetic fields, comprising: Select miniature low-power components, including PCB antenna, wireless communication module, main control chip, battery, flexible circuit board FPCB, and configure sensor devices; Carry out PCB layout and soldering of components to obtain the first stage FPCB; The first-stage FPCB is designed with an anti-interference structure having a super surface structure to obtain a second-stage FPCB, including: after the first-stage FPCB is wrapped with an insulating layer, the first-stage FPCB wrapped with the insulating layer is placed in a mold, a silicone material is used for the first packaging, and then a polyester coating is uniformly sprayed on the surface of the silicone material, metal nickel is electroplated on the polyester coating, an iron layer is electroplated on the metal nickel, and nickel metal is electroplated on the iron layer to obtain the second-stage FPCB; at the same time, during the electroplating process, a laser-cut mask having a super surface structure is fixed at a position directly above the PCB antenna to manufacture the super surface structure; The second-stage FPCB is packaged and processed to obtain a flexible sensing device used in strong electric and magnetic field environments; The flexible sensing device is tested on the test platform for electromagnetic field shielding performance and overall anti-interference performance of the metasurface structure; The test platform includes a strong magnetic field environment simulation device, a high-voltage electric field environment simulation device, a square box with a hollow structure, a group of radio frequency communication transceiver modules, a magnetic field measuring instrument and an electric field measuring instrument; the square box is a hexahedron made of silicone material, and one side of it is detachable and set as a super surface structure; the group of radio frequency communication transceiver modules matches the transparent frequency band of the super surface structure; the strong magnetic field environment simulation device uses a series circuit composed of a large current generator and a wire to simulate a strong magnetic field environment; the high-voltage electric field environment simulation device simulates a high-voltage electric field environment through a series resonant AC withstand voltage test device; Conducting metasurface structure electromagnetic field shielding performance test and overall anti-interference performance test on the flexible sensing device, including: metasurface structure electric field shielding performance test based on electric field strength, metasurface structure magnetic field shielding performance test based on magnetic field strength, communication signal strength and packet loss rate, and overall anti-interference performance test based on communication signal strength and packet loss rate; The calculation process of the communication signal strength is: (1) The receiving end decomposes the received wireless signal into an IQ signal including in-phase and quadrature components, and uses a filter to filter the IQ signal; (2) Calculate the instantaneous power of each sampling point of the filtered IQ signal , based on instantaneous power Calculate the mean of a power series and standard deviation ; in ; In the formula, is every n sampling points of the in-phase component in the IQ signal, is every n sampling points of the orthogonal component in the IQ signal; (3) According to the average value of the power series and standard deviation Perform Gaussian distribution preprocessing on the instantaneous power to obtain the preprocessed power : , Among them, k is an adjustable parameter; (4) According to the power after preprocessing Calculate the communication signal strength: , , , in, is the total power after filtering; is the average power, and N is the number of sampling points of the signal.

[0007] Preferably, the wireless communication module selects a low-power zigbee chip with a high frequency of 2.4GHz; the main control chip selects a chip with standby, sleep and stop modes, and the current in the sleep mode is ≤1μA; the battery selects a button battery or a flexible special-shaped battery.

[0008] Preferably, the PCB layout of components includes: the main control chip, battery and peripheral circuits, wireless communication module, and sensor devices are arranged on one side of the central axis of the FPCB, the PCB antenna is arranged on the other side of the central axis of the FPCB, and the PCB antenna is arranged at the edge of the FPCB.

[0009] Preferably, the packaging process of the second-stage FPCB includes: placing the second-stage FPCB in a mold by using an injection molding process, and performing secondary packaging by using a silicone material.

[0010] Preferably, the process of the test platform testing the magnetic field shielding performance of the metasurface structure of the flexible sensing device includes: (1) Place the square box metasurface structure in direct contact with the wire of the strong magnetic field environment simulation device, place the magnetic field measuring instrument in the square box, and test the magnetic field intensity value of the hexahedron without the metasurface structure to be B1, and the magnetic field intensity value of the hexahedron with the metasurface structure to be B2. If , then proceed to (2); otherwise, it fails and the metasurface structure of the flexible sensing device is adjusted and retested; (2) The square box metasurface structure is directly contacted with the wires of the strong magnetic field environment simulation device, and the transmitting end of the radio frequency communication transceiver module is placed in the square box. The receiving end is 50 cm away from the square box. According to the wireless signal received by the receiving end, the receiving end communication signal strength RSSI1 and packet loss rate X1 of the hexahedron without the metasurface structure surface are calculated, and the receiving end communication signal strength RSSI2 and packet loss rate X2 of the hexahedron with the metasurface structure surface are calculated. If RSSI2>RSSI1, X2<X1 and X2≤5%, the magnetic field shielding performance of the metasurface structure is qualified. Otherwise, it is unqualified. The metasurface structure of the flexible sensing device is adjusted and retested.

[0011] Preferably, the process of the test platform testing the electric field shielding performance of the metasurface structure of the flexible sensing device is as follows: The square box metasurface structure is directly contacted with the wires of the high-voltage electric field environment simulation device, and the electric field tester is placed in the square box. The electric field strength value under the hexahedron without the metasurface structure is E1, and the electric field strength value under the hexahedron with the metasurface structure is E2. If E2<E1 and E2<1kV / m, the electric field shielding performance test of the metasurface structure is qualified; otherwise, it fails. The metasurface structure of the flexible sensing device is adjusted and retested.

[0012] Preferably, the test platform performs an overall anti-interference performance test on the flexible sensing device, including a magnetic field and electric field shielding performance test on the flexible sensing device as a whole; Among them, the magnetic field shielding performance test of the flexible sensing device as a whole includes: The flexible sensing device is directly contacted with the wire of the strong magnetic field environment simulation device, the receiving end of the radio frequency communication transceiver module is 50 cm away from the flexible sensing device, and the communication module of the flexible sensing device communicates with the receiving end of the radio frequency communication transceiver module as a transmitting end. The communication signal strength and packet loss rate of the receiving end are calculated according to the wireless signal received by the receiving end. If the communication signal strength of the receiving end is greater than the preset corresponding threshold value, and the packet loss rate is less than the preset corresponding threshold value, the overall magnetic field shielding performance test of the flexible sensing device is qualified, otherwise it is unqualified, and the structure of the flexible sensing device is adjusted and retested; The electric field shielding performance test of the flexible sensing device as a whole includes: The flexible sensing device is directly contacted with the wires of the high-voltage electric field environment simulation device. The receiving end of the radio frequency communication transceiver module is 50 cm away from the flexible sensing device. The communication module of the flexible sensing device acts as a transmitting end to communicate with the receiving end of the radio frequency communication transceiver module. The communication signal strength and packet loss rate of the receiving end are calculated according to the wireless signal received by the receiving end. If the communication signal strength of the receiving end is greater than the preset corresponding threshold value and the packet loss rate is less than the preset corresponding threshold value, the overall electric field shielding performance test of the flexible sensing device is qualified. Otherwise, it is unqualified and the structure of the flexible sensing device is adjusted and retested.

[0013] The second aspect of the present invention provides a flexible sensing device for use under strong electric and magnetic fields, comprising a PCB antenna, a wireless communication module, a main control chip, a battery, a flexible circuit board FPCB, a sensor device, an anti-interference structure and a packaging structure; wherein the PCB antenna, the wireless communication module, the main control chip, the battery, and the sensor device are arranged and welded on the FPCB; an anti-interference structure with a super surface structure is provided on the outside of the FPCB, and a packaging structure is provided on the outside of the anti-interference structure.

[0014] Compared with the prior art, the beneficial effects of the present invention include at least: The anti-interference and packaging processing design adopted by the flexible sensing device of the present invention has the properties of waterproof, heat-resistant, insulating, corona-proof, electromagnetic field shielding, and wireless communication signal transparency. It is suitable for application scenarios in complex strong electric field and strong magnetic field environments in the power industry. Based on the method of the present invention, various flexible sensing devices that meet the application of the power industry can be prepared according to monitoring needs.

[0015] In terms of anti-interference packaging processing, for the manufacture of flexible sensing devices in strong electric and magnetic field environments, the method of electroplating a metal protective layer on silicone is used to avoid the problems of inadequate wrapping of flexible anti-interference materials, and the deviation of the super-surface structure and the PCB antenna position affecting the shielding and communication performance, thereby improving the overall anti-interference performance of the flexible sensing device.

[0016] For the strong electric field and strong magnetic field shielding performance test, the conventional method mainly conducts wireless communication test in a darkroom, which is different from the actual scene of strong electric field and strong magnetic field of high-voltage lines, ignoring the influence of external power frequency electric field and magnetic field, and the existing darkroom laboratory cannot directly simulate the scene of strong electric field and strong magnetic field of high-voltage lines. Therefore, in order to ensure that the flexible sensing device can play a role in practical applications, the present invention proposes a targeted test platform and method. In addition, in the present invention, in view of the large measurement error existing in the conventional method of wireless communication quality testing, a method combining baseband IQ power integration method and Gaussian distribution preprocessing method is used to improve the accuracy of wireless communication measurement.

[0017] The flexible sensing device designed and manufactured by the present invention is used to test the electromagnetic field shielding performance and overall anti-interference performance of the metasurface structure, and a corresponding test platform is proposed. Test evaluation is performed based on indicators such as magnetic field strength, communication signal strength, and packet loss rate. The communication signal strength is calculated by combining the baseband IQ power integration method and the Gaussian distribution preprocessing method. This method improves the accuracy of power measurement by preprocessing the received signal and utilizing the characteristics of the Gaussian distribution. It can improve the accuracy of wireless communication signal strength calculation and reduce the influence of strong electric and magnetic fields generated by high voltage and high current in the conductor.

[0018] The flexible sensing device of the present invention is prepared by using a small, flexible device with good flexibility, and can be closely fitted with irregularly structured objects of power facilities to achieve accurate sensing. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the PCB layout of the present invention; Figure 2 It is a schematic diagram of the anti-interference protection of the present invention; The reference numerals are: 1-pcb antenna; 2-wireless communication module; 3-main control chip; 4-battery and peripheral circuit; 5-FPCB; 6-FPCB board with components welded; 7-high temperature resistant acetate tape; 8-flexible metamaterial; Figure 3 It is a strong magnetic field environment simulation device; Figure 4 It is a high voltage electric field environment simulation device. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The embodiments described in this application are only embodiments of a part of the present invention, rather than all embodiments. Based on the spirit of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present invention.

[0021] Embodiment 1 of the present invention provides a manufacturing method for a flexible sensing device for use in strong electric and magnetic fields, which mainly designs and manufactures the power consumption, PCB layout, anti-interference, and packaging of the sensing device, and specifically includes: Step 1: Select micro low-power components, including PCB antenna 1, wireless communication module 2, main control chip 3, battery, flexible circuit board FPCB5, and configure sensor devices; Further preferably, the low power consumption design scheme is as follows: The principle of component selection is mainly based on miniature and low power consumption. For example, the wireless communication module should choose a high-frequency 2.4GHz low-power zigbee chip; the current of the main control chip in sleep mode should be ≤1μA, and it should have low-power mode functions such as standby, sleep, and stop; battery selection: Option 1 chooses a small-sized button battery (diameter 16mm), and Option 2 chooses a flexible special-shaped battery for easy bending and deformation; The sensor device should be a MEMS or flexible device, and should be configured according to actual monitoring needs.

[0022] Step 2: PCB layout and soldering of components to obtain the first stage FPCB; Further preferably, the PCB layout scheme is as follows: When laying out the PCB, it is necessary to consider aspects such as the fit with the structural object during installation, the location of the wireless communication antenna, and shielding. The PCB layout is as follows Figure 1 As shown. The PCB layout follows the following principles: When selecting components, try to choose components with smaller size. The circuit connection of each component is completed according to the circuit design drawing when the FPCB5, i.e. the flexible circuit board, is processed. The PCB antenna 1 should be placed near the edge of the FPCB5. This layout takes into account the protection of the subsequent sensing device. The main control chip 3, battery and peripheral circuit 4, and wireless communication module 2 are arranged on one side of the central axis of the FPCB5. The sensor device should also be arranged in the left area as much as possible, and the PCB antenna 1 is arranged on the other side.

[0023] Step 3: Design the anti-interference structure of the first-stage FPCB and manufacture its anti-interference materials to obtain the second-stage FPCB; Further preferably, the anti-interference method and the anti-interference material manufacturing scheme are specifically as follows: Since the flexible sensing device is a wireless sensor without an external power line, the anti-interference of the flexible sensing device is protected by adding a metal layer to the outside of the FPCB board 6 (first-stage FPCB board) where components have been welded. It is necessary to consider not affecting the wireless communication of the flexible sensing device. In addition, it is also necessary to consider that when the device is abnormally damaged, it should not be flammable to avoid damaging power facilities. Anti-interference process methods such as Figure 2 As shown, the present invention requires that the sensor be made flexible for the scenario of special-shaped structure. In order to ensure that the sensor is still a flexible material after anti-interference protection, a metal protective layer is electroplated on the flexible shell, and a super surface structure is formed through a mask. Specifically: after the first-stage FPCB is wrapped with an insulating layer, a first packaging process is performed, including: using an injection molding process, placing the first-stage FPCB wrapped with an insulating layer in a mold, and using a silicone material for the first packaging; then electroplating a metal shielding layer with a super surface structure on the surface of the silicone, including: firstly, spraying a polyester coating evenly on the cleaned silicone surface to ensure coverage The entire first-stage FPCB is covered to increase the adhesion of the silicone surface, and then the polyester coating is first electroplated with metal nickel, and an iron layer with high conductivity and magnetic permeability is plated on the metal nickel, and then an anti-oxidation and anti-corrosion nickel metal is electroplated on the iron layer to obtain the second-stage FPCB; at the same time, during the electroplating process, the laser-cut mask with a super surface structure needs to be fixed just above the PCB antenna to facilitate the electroplating process of the metal shielding layer and manufacture the super surface structure; the insulating layer adopts high-temperature resistant acetate tape 7, which has good insulation, high temperature resistance, solvent resistance, anti-aging and other properties, and can withstand high temperatures of up to 180°C in a short period of time; The metal shielding layer uses flexible metamaterial 8 as the anti-interference material, specifically, a metal layer with a metasurface structure is directly electroplated on silica gel as the anti-interference layer to achieve metal shielding, and the material is structurally designed to have a wireless communication signal gain effect.

[0024] The structural part of the flexible metamaterial 8 is attached to the PCB antenna 1 of the device, that is, the metasurface structure of the metal shielding layer matches the position of the PCB antenna, and the metasurface structure is located directly above the PCB antenna, so that the wireless communication signal can be reliably transmitted through the metasurface.

[0025] Step 4: The second-stage FPCB is packaged and processed to obtain a flexible sensing device for use in strong electric and magnetic field environments.

[0026] Further preferably, the packaging processing scheme is as follows: The flexible sensing device is encapsulated with silicone material, and the hardness of silicone should be 50. Silicone material has the characteristics of waterproof, heat-resistant, insulating, and corona-proof, and can meet the high-voltage and outdoor environments of the power industry.

[0027] The flexible sensing device is encapsulated by injection molding, that is, the entire flexible sensing device is placed in a mold and formed into a single piece with the silicone shell. The flexible sensing device manufactured by this method has good sealing performance, which can not only shield the interference of strong external electromagnetic fields, but also ensure the reliable transmission of wireless communication signals.

[0028] Embodiment 2 of the present invention provides a flexible sensing device for use in strong electric and magnetic fields, including a PCB antenna 1, a wireless communication module 2, a main control chip 3, a battery, an FPCB 5, a sensor device, an anti-interference structure and a packaging structure; Among them, the PCB antenna 1, wireless communication module 2, main control chip 3, battery and peripheral circuit 4, and sensor components are laid out and welded on FPCB5; A silicon protective layer and an electroplated base layer are provided on the outside of FPCB5, an anti-interference structure with a super surface structure is provided on the outside of the electroplated base layer, and a packaging structure is provided on the outside of the anti-interference structure.

[0029] The present invention is concerned with anti-interference performance testing of super-surface structures and anti-interference performance testing of flexible sensing devices as a whole.

[0030] Build a test platform: The test platform includes a strong magnetic field environment simulation device, a high-voltage electric field environment simulation device, and a six-sided (one side is detachable) hollow structure square box made of silicone material. The square box is a hexahedron with a silicone shell prepared by the same method as above. The metasurface structure is prepared by matching the size of the square box. The size of the detachable surface is known and can also be hung and disassembled.

[0031] Also prepare a set of radio frequency communication transceiver modules that match the transparent frequency band of the metasurface structure, a magnetic field meter, and an electric field meter.

[0032] The magnetic field meter and electric field meter store the magnetic field strength and electric field strength values, and the computer software records the received RF signal strength. A large current generator is used to simulate a strong magnetic field environment, and a series resonant AC withstand voltage test device ( Figure 4 The device shown) simulates a high voltage electric field environment.

[0033] Metasurface structure performance test: 1. The process of testing the magnetic field shielding performance of the metasurface structure is as follows: (1) Combine the box metasurface structure with Figure 3 The wires of the strong magnetic field environment simulation device shown in the figure are in direct contact, and the magnetic field measuring instrument is placed in the square box. The magnetic field intensity value under the hexahedron without the super surface structure surface is B1, and the magnetic field intensity value under the hexahedron with the super surface structure surface is B2. If the test result is unqualified, perform (2); otherwise, adjust the metasurface structure of the flexible sensing device and retest it.

[0034] (2) Combine the box metasurface structure with Figure 3 The wires of the strong magnetic field environment simulation device shown in the figure are in direct contact, and the radio frequency communication transmitter is placed in the square box (generally 2 cm away from the metasurface structure surface), and the receiving end is 50 cm away from the square box (can be selected according to application needs). According to the wireless signal received by the receiving end, the communication signal strength of the receiving end without the sixth surface is RSSI1, and the packet loss rate is X1. The communication signal strength of the receiving end under the hexahedron with the metasurface structure surface is RSSI2, and the packet loss rate is X2. When RSSI2>RSSI1, X2<X1 and X2≤5%, the magnetic field shielding performance of the metasurface structure is qualified, otherwise it is unqualified. The metasurface structure of the flexible sensing device is adjusted and retested.

[0035] In the above test, the current and voltage applied to the conductor are determined according to the voltage level of actual application (such as applying a current of 600A and a voltage of 220kV, etc.).

[0036] Further preferably, in order to improve the accuracy of wireless communication signal strength RSSI calculation and reduce the influence of strong magnetic field generated by large current in the conductor, the baseband IQ power integration method and Gaussian distribution preprocessing method are combined to calculate RSSI. This method improves the accuracy of power measurement by preprocessing the received signal and using the characteristics of Gaussian distribution.

[0037] (1) First, a filter is used to decompose the IQ (in-phase) component and the quadrature (Q) component of the wireless signal at the receiving end to accurately describe the state of the signal.

[0038] Filter the IQ signal, such as using a low-pass filter, to remove high-frequency noise (determined by the wireless communication frequency band of the sensing device).

[0039] (2) Calculate the instantaneous power of each sampling point: , Compute the mean and standard deviation of the power series: , , (3) Gaussian distribution preprocessing: Using the Gaussian distribution characteristics, data with power values ​​greater than a certain threshold (usually the mean minus a certain multiple of the standard deviation) can be extracted to reduce erroneous measurements caused by noise: , Here k is an adjustable parameter, usually ranging from 1 to 3.

[0040] (4) Power calculation and RSSI calculation: Calculate the total filtered power: , Calculate the average power: , Convert to RSSI value (dBm): , 2. The process of testing the electric field shielding performance of the metasurface structure is as follows: The box metasurface structure is combined with Figure 4 The wires of the high-voltage electric field environment simulation device shown are in direct contact, and the electric field tester is placed in a square box (generally 2 cm away from the metasurface structure surface). The electric field strength value under the hexahedron without the metasurface structure surface is tested to be E1, and the electric field strength value under the hexahedron with the metasurface structure surface is E2. If E2<E1, and E2<1kV / m, the electric field shielding performance test of the metasurface structure is qualified, otherwise it is unqualified, and the metasurface structure of the flexible sensing device is adjusted and retested.

[0041] Flexible sensing device for overall anti-interference performance testing: 1. The overall magnetic field shielding performance test of the flexible sensing device includes: The flexible sensing device is connected to the distance Figure 3The wires of the strong magnetic field environment simulation device shown are direct, the receiving end of the radio frequency communication transceiver module is 50 cm away from the flexible sensing device, the communication module of the flexible sensing device communicates with the receiving end of the radio frequency communication transceiver module as a transmitting end, and the communication signal strength and packet loss rate of the receiving end are calculated according to the wireless signal received by the receiving end. If the communication signal strength and packet loss rate of the receiving end are better than the preset corresponding thresholds, the overall magnetic field shielding performance test of the flexible sensing device is qualified, otherwise it is unqualified, and the structure of the flexible sensing device is adjusted and retested; 2. The electric field shielding performance test of the flexible sensing device as a whole includes: The flexible sensing device Figure 4 The wires of the high-voltage electric field environment simulation device shown are in direct contact, and the magnetic field shielding performance test method is repeated. First, the wireless signal emitted by the flexible sensing device should be received normally, indicating that the flexible sensing device is operating normally, and then the communication signal strength and packet loss rate of the receiving end are calculated according to the wireless signal received by the receiving end. If the communication signal strength and packet loss rate of the receiving end are still better than the preset corresponding thresholds, the overall electric field shielding performance test of the flexible sensing device is qualified; otherwise, it is unqualified, and the structure of the flexible sensing device is adjusted and retested.

[0042] Compared with the prior art, the beneficial effects of the present invention include at least: The anti-interference and packaging processing design adopted by the flexible sensing device of the present invention has the properties of waterproof, heat-resistant, insulating, corona-proof, electromagnetic field shielding, and wireless communication signal transparency. It is suitable for application scenarios in complex strong electric field and strong magnetic field environments in the power industry. Based on the method of the present invention, various flexible sensing devices that meet the application of the power industry can be prepared according to monitoring needs.

[0043] In terms of anti-interference packaging processing, for the manufacture of flexible sensing devices in strong electric and magnetic field environments, the method of electroplating a metal shielding layer on silicone is used to avoid the problems of inadequate wrapping of flexible anti-interference materials, and the deviation of the super-surface structure and the PCB antenna position affecting the shielding and communication performance, thereby improving the overall anti-interference performance of the flexible sensing device.

[0044] For the strong electric field and strong magnetic field shielding performance test, the conventional method mainly conducts wireless communication test in a darkroom, which is different from the actual scene of strong electric field and strong magnetic field of high-voltage lines, ignoring the influence of external power frequency electric field and magnetic field, and the existing darkroom laboratory cannot directly simulate the scene of strong electric field and strong magnetic field of high-voltage lines. Therefore, in order to ensure that the flexible sensing device can play a role in practical applications, the present invention proposes a targeted test platform and method. In addition, in the present invention, in view of the large measurement error existing in the conventional method of wireless communication quality testing, a method combining baseband IQ power integration method and Gaussian distribution preprocessing method is used to improve the accuracy of wireless communication measurement.

[0045] The flexible sensing device designed and manufactured by the present invention is used to test the electromagnetic field shielding performance and overall anti-interference performance of the metasurface structure, and a corresponding test platform is proposed. Test evaluation is performed based on indicators such as magnetic field strength, communication signal strength, and packet loss rate. The communication signal strength is calculated by combining the baseband IQ power integration method and the Gaussian distribution preprocessing method. This method improves the accuracy of power measurement by preprocessing the received signal and utilizing the characteristics of the Gaussian distribution. It can improve the accuracy of wireless communication signal strength calculation and reduce the influence of strong electric and magnetic fields generated by high voltage and high current in the conductor.

[0046] The flexible sensing device of the present invention is prepared by using a small, flexible device with good flexibility, and can be closely fitted with irregularly structured objects of power facilities to achieve accurate sensing; In the first stage, the present invention wraps the FPCB with an insulating layer and then wraps the metal shielding layer with a super surface structure, taking into account the interference problem under the high voltage and strong magnetic field environment of electric power, and can realize effective protection and electromagnetic field shielding of the sensing device; the entire sensing device components are enclosed in the metal shielding layer with a super structure surface structure, and the metal shielding layer adopts a flexible super surface structure metal shielding material as an anti-interference material. The flexible super surface structure metal shielding material meets the flexibility requirements of the flexible sensing device, and the super surface structure avoids the situation that the wireless communication antenna will shield the electromagnetic wave signal of the communication in the shielding material, thereby making the wireless communication invalid, and realizes the transparency of the wireless communication signal, ensuring the stability of the wireless communication; when manufacturing the flexible super surface structure metal shielding material, by preparing the super surface structure on the metal fabric, it has the functions of flexibility, anti-interference, and wireless signal transparency, and the process adopts screen printing + laser cutting, which can not only realize the precise cutting of the super surface structure on the metal fabric, but also print the image through ink, and after laser cutting, the anti-interference material processing can be judged by checking the pattern shape to facilitate the inspection of the material preparation quality.

[0047] According to the application scenario, the present invention takes into account aspects such as waterproofing, temperature resistance, insulation, and corona protection. That is, silicone is used to encapsulate the sensing device as a whole, and there is no need to connect or paste the packaging shell, thereby improving the reliability of the sensing device in outdoor high-voltage and strong magnetic field environments.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for manufacturing a flexible sensing device for use in strong electric and magnetic fields, characterized in that: include: Select miniature low-power components, including PCB antenna, wireless communication module, main control chip, battery, flexible circuit board FPCB, and configure sensor devices; Carry out PCB layout and soldering of components to obtain the first stage FPCB; The first-stage FPCB is designed and manufactured with an anti-interference structure having a super surface structure to obtain a second-stage FPCB, including: after the first-stage FPCB is wrapped with an insulating layer, the first-stage FPCB wrapped with the insulating layer is placed in a mold, a silicone material is used for the first packaging, and then a polyester coating is uniformly sprayed on the surface of the silicone material, metal nickel is electroplated on the polyester coating, an iron layer is electroplated on the metal nickel, and nickel metal is electroplated on the iron layer to obtain the second-stage FPCB; at the same time, during the electroplating process, a laser-cut mask having a super surface structure is fixed at a position directly above the PCB antenna to manufacture the super surface structure; The second-stage FPCB is packaged and processed to obtain a flexible sensing device used in strong electric and magnetic field environments; The flexible sensing device is tested on the test platform for electromagnetic field shielding performance and overall anti-interference performance of the metasurface structure; The test platform includes a strong magnetic field environment simulation device, a high-voltage electric field environment simulation device, a square box with a hollow structure, a group of radio frequency communication transceiver modules, a magnetic field measuring instrument and an electric field measuring instrument; the square box is a hexahedron made of silicone material, and one side of it is detachable and set as a super surface structure; the group of radio frequency communication transceiver modules matches the transparent frequency band of the super surface structure; the strong magnetic field environment simulation device uses a series circuit composed of a large current generator and a wire to simulate a strong magnetic field environment; the high-voltage electric field environment simulation device simulates a high-voltage electric field environment through a series resonant AC withstand voltage test device; The said testing of the electromagnetic field shielding performance of the metasurface structure and the overall anti-interference performance of the flexible sensing device specifically includes: the electric field shielding performance test of the metasurface structure based on the electric field strength, the magnetic field shielding performance test of the metasurface structure based on the magnetic field strength, the communication signal strength and the packet loss rate, and the overall anti-interference performance test based on the communication signal strength and the packet loss rate; The calculation process of the communication signal strength is: (1) The receiving end decomposes the received wireless signal into an IQ signal including in-phase and quadrature components, and uses a filter to filter the IQ signal; (2) Calculate the instantaneous power of each sampling point of the filtered IQ signal , based on instantaneous power Calculate the mean of a power series and standard deviation ; in ; In the formula, is every n sampling points of the in-phase component in the IQ signal, is every n sampling points of the orthogonal component in the IQ signal; (3) According to the average value of the power series and standard deviation Perform Gaussian distribution preprocessing on the instantaneous power to obtain the preprocessed power : ， Among them, k is an adjustable parameter; (4) According to the power after preprocessing Calculate the communication signal strength: ， ， ， in, is the total power after filtering; is the average power, and N is the number of sampling points of the signal.

2. The method for manufacturing a flexible sensing device for use in strong electric and magnetic fields according to claim 1, characterized in that: The wireless communication module selects a low-power zigbee chip with a high frequency of 2.4GHz; the main control chip selects a chip with standby, sleep and stop modes, and the current in the sleep mode is ≤1μA; the battery selects a button battery or a flexible special-shaped battery.

3. The method for manufacturing a flexible sensing device for use in strong electric and magnetic fields according to claim 1, characterized in that: The PCB layout of components includes: the main control chip, battery and peripheral circuits, wireless communication module, and sensor devices are arranged on one side of the FPCB central axis, the PCB antenna is arranged on the other side of the FPCB central axis, and the PCB antenna is arranged at the edge of the FPCB.

4. The method for manufacturing a flexible sensing device for use in strong electric and magnetic fields according to claim 1, characterized in that: The packaging process of the second-stage FPCB includes: using an injection molding process to place the second-stage FPCB in a mold, and using a silicone material for secondary packaging.

5. The method for manufacturing a flexible sensing device for use in strong electric and magnetic fields according to claim 1, characterized in that: The process of testing the magnetic field shielding performance of the metasurface structure of the flexible sensing device on the test platform includes: (1) Place the square box metasurface structure in direct contact with the wire of the strong magnetic field environment simulation device, place the magnetic field measuring instrument in the square box, and test the magnetic field intensity value of the hexahedron without the metasurface structure to be B1, and the magnetic field intensity value of the hexahedron with the metasurface structure to be B2. If Then proceed to (2); otherwise, it fails and the metasurface structure of the flexible sensing device is adjusted and retested; (2) The square box metasurface structure is directly contacted with the wires of the strong magnetic field environment simulation device, and the transmitting end of the radio frequency communication transceiver module is placed in the square box. The receiving end is 50 cm away from the square box. According to the wireless signal received by the receiving end, the receiving end communication signal strength RSSI1 and packet loss rate X1 of the hexahedron without the metasurface structure surface are calculated, and the receiving end communication signal strength RSSI2 and packet loss rate X2 of the hexahedron with the metasurface structure surface are calculated. If RSSI2>RSSI1, X2<X1 and X2≤5%, the magnetic field shielding performance of the metasurface structure is qualified. Otherwise, it is unqualified. The metasurface structure of the flexible sensing device is adjusted and retested.

6. The method for manufacturing a flexible sensing device for use in strong electric and magnetic fields according to claim 1, characterized in that: The process of the test platform testing the electric field shielding performance of the metasurface structure of the flexible sensing device is as follows: The square box metasurface structure is directly contacted with the wires of the high-voltage electric field environment simulation device, and the electric field tester is placed in the square box. The electric field strength value under the hexahedron without the metasurface structure is E1, and the electric field strength value under the hexahedron with the metasurface structure is E2. If E2<E1 and E2<1kV / m, the electric field shielding performance test of the metasurface structure is qualified; otherwise, it fails. The metasurface structure of the flexible sensing device is adjusted and retested.

7. The method for manufacturing a flexible sensing device for use in strong electric and magnetic fields according to claim 1, characterized in that: The test platform performs an overall anti-interference performance test on the flexible sensing device, including a magnetic field and electric field shielding performance test on the flexible sensing device as a whole; Among them, the magnetic field shielding performance test of the flexible sensing device as a whole includes: The flexible sensing device is directly contacted with the strong magnetic field environment simulation device, the receiving end of the radio frequency communication transceiver module is 50 cm away from the flexible sensing device, and the communication module of the flexible sensing device communicates with the receiving end of the radio frequency communication transceiver module as a transmitting end. The communication signal strength and packet loss rate of the receiving end are calculated according to the wireless signal received by the receiving end. If the communication signal strength of the receiving end is greater than the preset corresponding threshold value, and the packet loss rate is less than the preset corresponding threshold value, the overall magnetic field shielding performance test of the flexible sensing device is qualified, otherwise it is unqualified, and the structure of the flexible sensing device is adjusted and retested; The electric field shielding performance test of the flexible sensing device as a whole includes: The flexible sensing device is directly contacted with the wires of the high-voltage electric field environment simulation device. The receiving end of the radio frequency communication transceiver module is 50 cm away from the flexible sensing device. The communication module of the flexible sensing device acts as a transmitting end to communicate with the receiving end of the radio frequency communication transceiver module. The communication signal strength and packet loss rate of the receiving end are calculated according to the wireless signal received by the receiving end. If the communication signal strength of the receiving end is greater than the preset corresponding threshold value and the packet loss rate is less than the preset corresponding threshold value, the overall electric field shielding performance test of the flexible sensing device is qualified. Otherwise, it is unqualified and the structure of the flexible sensing device is adjusted and retested.

8. A flexible sensing device for use in strong electric and magnetic fields, manufactured using the method described in any one of claims 1 to 7, characterized in that: It includes a pcb antenna, a wireless communication module, a main control chip, a battery, a flexible circuit board FPCB, a sensor device, an anti-interference structure and a packaging structure; wherein the pcb antenna, the wireless communication module, the main control chip, the battery, and the sensor device are arranged and welded on the FPCB; an anti-interference structure with a super surface structure is arranged outside the FPCB, and a packaging structure is arranged outside the anti-interference structure.

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