Bolt safety monitoring system based on pulse period and data acquisition method

Abstract

The invention discloses a bolt safety monitoring system based on a pulse period and a data acquisition method, and belongs to the technical field of bolt monitoring, the bolt safety monitoring system comprises a detection unit, a time-delay switch circuit module, a control module, a communication module and a cloud server, the detection unit is connected with the time-delay switch circuit module, the time-delay switch circuit module is connected with the control module, and the control module is connected with the cloud server. The control module is connected with the communication module, and the communication module is in wireless communication connection with the cloud server. Through the mode, the invention discloses the electronic switch circuit based on the pulse period and combined with the time delay and the sensing network, bolt looseness information can be efficiently acquired, redundant data are reduced, and the precision and reliability of a monitoring system are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of bolt monitoring, and particularly relates to a bolt safety monitoring system and a data acquisition method based on pulse period. Background Art

[0002] At present, with the global strong promotion of the development of clean energy, photovoltaic power generation has become an important development direction in the energy field due to its advantages such as green and sustainable. With the continuous expansion of the construction scale of photovoltaic power stations, the number of photovoltaic components has increased sharply, and its stability and safety have become increasingly critical. Photovoltaic components are mainly fixed by bolts. These bolts are exposed to the outdoor complex environment for a long time and are affected by various harsh factors such as strong wind, vibration, sudden temperature change, and humidity erosion. For the monitoring of the safety status of bolts in photovoltaic components, it mostly relies on manual regular inspections. However, manual inspections not only have low efficiency and are greatly affected by subjective factors of inspectors, but also it is very difficult to achieve comprehensive, detailed, and timely detection when facing large-area photovoltaic power stations, and it is extremely easy to miss bolts with potential safety hazards.

[0003] For example, patent CN119165398A discloses a fault location system for a photovoltaic power station. The fault location system for the photovoltaic power station includes a starting power supply VCC1, a detection power supply VCC2, resistors R0, R7, several first automatic voltage dividing circuits, several multiplexers U, several traversing circuit units, a panel sensor, a bracket sensor, and a short-circuit location circuit.

[0004] However, its technology has the following problems. It relies on the RC delay time to collect the bolt loosening state, but fails to consider the problem that the error of the capacitor in practice is as high as 10%. According to the RC delay formula t = -RC * ln[(V - V s ) / V], it can be seen that the delay time is closely related to the capacitor. The increase in the capacitor value directly leads to the increase in the delay time. Therefore, relying on the delay time to collect bolt data has an error accumulation phenomenon, which is prone to cause repeated data collection or data redundancy, and then leads to the reduction of the system detection capacity.

[0005] Based on this, the present invention designs a bolt safety monitoring system and a data acquisition method based on pulse period to solve the above problems. Summary of the Invention

[0006] In view of the above-mentioned drawbacks of the prior art, the present invention provides a bolt safety monitoring system and a data acquisition method based on pulse period.

[0007] To achieve the above object, the present invention is realized through the following technical solutions:

[0008] A bolt safety monitoring system based on pulse period, comprising a detection unit, the detection unit is connected to a delay switch circuit module, and both the delay switch circuit module and the communication module are connected to a control module;

[0009] The detection unit is used to convert the tightening and loosening states of the bolts of the photovoltaic module pressing blocks and the nuts of the brackets into electrical signals and upload them to the delay switch circuit module;

[0010] The delay switch circuit module automatically adjusts the data acquisition time by using the charging and discharging characteristics of the capacitor in the RC delay circuit to adjust the pulse period. By adjusting the working states of multiplexer U1 and multiplexer U2, dynamic path switching of the delay switch circuit module is performed. There are multiple delay switch circuit modules and they are connected in series in sequence to form a polling mechanism to access and obtain the data of the detection unit;

[0011] The control module, through the ADC of the control chip, acquires the voltage value, and calculates the equivalent resistance of each detection unit according to the voltage division principle. A data sequence is formed through the access order of the polling mechanism of the delay switch circuit module. This data sequence can establish a position relationship database in combination with the bolt starting point without manually setting the position number tediously. Among them, the control module can control the on and off of the detection power supply of the sensing network composed of multiple delay switch circuits. When the power supply is started, the sensing network circuit starts to operate. The bolt state information of each detection unit is collected in sequence through the ADC. After the data collection is completed and uploaded, the power supply is disconnected, and the capacitor in the delay switch circuit module starts to discharge to avoid residual charge affecting the detection of the next cycle. Then the power supply is restarted and the cycle repeats, realizing 24-hour all-weather monitoring of the bolts in the photovoltaic power station.

[0012] Furthermore, the detection unit includes a pressing block detection unit for monitoring the loosening conditions of two bolts on the single board edge of the photovoltaic module and a bracket detection unit for monitoring the loosening conditions of eight bolts on the photovoltaic bracket;

[0013] The pressing block detection unit includes two pressing block sensor modules connected in series;

[0014] The bracket detection unit includes eight bracket sensor modules connected in parallel; both the pressing block sensor module and the bracket sensor module are connected to the delay switch circuit module;

[0015] The pressing block sensor module is used to convert the tightening and loosening state of the bolts of the photovoltaic module pressing blocks into electrical signals; and upload the data information to the delay switch circuit module;

[0016] The bracket sensor module is used to convert the tightening and loosening state of the bracket nuts into electrical signals and upload the data information to the delay switch circuit module.

[0017] Further, the pressing block sensor module includes a sensor housing, a rotating rod, a bottom plate, a buckle, a fixing screw, a fixing nut and a gasket, and the fixing screw is in threaded connection with the fixing nut;

[0018] There are two buckles, fixing screws and fixing nuts respectively located on the left and right sides of the sensor housing;

[0019] A circular notch is opened at the middle top of the sensor housing, the rotating rod is located in the circular notch, electrode notches are respectively opened on the front and rear sides of the circular notch at the top of the sensor housing, three U-shaped notches are opened at the inner top of the sensor housing, and straight notches are respectively opened on the left and right sides of the top of the sensor housing;

[0020] A flat-blade is opened at the top of the rotating rod, a gasket is sleeved on the rotating rod, and the bottom of the rotating rod is fixedly connected with a hexagonal prism;

[0021] The lower end of the bottom plate is fixedly connected with a curved side wall, a threaded hole is opened in the middle inside the bottom plate, a threaded groove is opened on the side wall of the rotating rod, and the threaded hole is in threaded connection with the threaded groove on the side wall of the rotating rod;

[0022] A convex block is fixedly installed on the inner side of the bottom of the buckle, a hexagonal notch is opened at the bottom of the buckle, the hexagonal notch accommodates the fixing nut, and the fixing screw is in threaded connection with the fixing nut through the hexagonal notch.

[0023] Further, the bracket sensor module includes a nut cap, a screw cap and a cap; the nut cap includes a hexagonal cavity and a first cylinder, one end of the hexagonal cavity is fixedly connected with the first cylinder, a notch is opened on the wall of the first cylinder, a clamping edge is fixedly installed at one end of the notch, and two rib rings are fixedly installed inside the first cylinder.

[0024] Further, the nut cap further includes a second cylinder, a threaded groove is opened on the inner wall of the second cylinder, a screw cap hole is opened inside the second cylinder, the side wall of the second cylinder is fixedly connected with two sector-shaped clamping edges, one end of the second cylinder is fixedly installed with a third cylinder, and grooves are opened on both sides of the third cylinder; a cap hole is opened at the top of the cap.

[0025] Further, the distance between the two sector-shaped clamping edges is greater than the thickness of one rib ring.

[0026] Further, the delay switch circuit module includes a resistor R1, a capacitor C, a multiplexer U1 and a multiplexer U2; the resistor R1 and the capacitor C are connected in series to the ground, the multiplexer U1 is used as a power supply terminal, the multiplexer U2 is used as a detection terminal, the VCC terminals of the multiplexer U1 and the multiplexer U2 are both connected to a 5V power supply, and the GNDs of the multiplexer U1 and the multiplexer U2 are both grounded.

[0027] Further, the D terminal of the multiplexer U1 is connected to the power supply, the SEL terminal is connected to both the resistor R1 and the capacitor C, the S2 terminal serves as the power supply to connect the VCC of the multiplexer U1 in the next group of delay switch circuit modules, the D terminal of the multiplexer U1, and the VCC of the multiplexer U2. The S1 terminal is connected to the grounding resistor R2, and the grounding resistor R2 is grounded. The function of the grounding resistor R1 is to stabilize the voltage of the S1 terminal, and the S1 terminal is also connected to the SEL terminal of U2.

[0028] Further, the D terminal of the multiplexer U2 is connected to the sampling resistor Rd, the sampling resistor Rd is connected to the power supply, the S2 terminal of the multiplexer U2 is connected to the detection unit through the resistor R3, and the S1 terminal of the multiplexer U2 is connected to the D terminal of the multiplexer U2 in the next group of delay switch circuit modules.

[0029] Further, the method of dynamic path switching is as follows:

[0030] When the impedance of the capacitor C in the delay switch circuit module is 0, the voltage is low;

[0031] The SEL terminal of the multiplexer U1 receives a low level, and the D terminal is conducted with the S1 terminal;

[0032] The SEL terminal of the multiplexer U2 receives a high level, the D terminal is conducted with the S2 terminal, and the adc port of the single-chip microcomputer is used for acquisition, and the effective resistance value R of the detection unit is calculated ed Information, the calculation formula is:

[0033] R ed =R d ×U / (V cc -U);

[0034] R d is the resistance value of the sampling resistor, R ed is the equivalent resistance value of the detection unit, U is the voltage value collected from R d to the ground during the sampling process, V cc is the power supply voltage.

[0035] To better achieve the purpose of the present invention, the present invention also provides a data acquisition method based on the pulse period, including the following steps:

[0036] Step 1, input parameters k and s, and initialize variables m = 0, n = 0;

[0037] K is the number of block detection units and bracket detection units in the photovoltaic string, s is the number of photovoltaic strings in the photovoltaic array, n is the ordinal number of the current detected block detection unit and bracket detection unit, and m is the ordinal number of the current detected photovoltaic string;

[0038] Step 2, collect the voltage information of the entire sensing network at a frequency of every 10 milliseconds;

[0039] Step 3: In each data acquisition process, first calculate the equivalent resistance value R of the current circuit ed ;

[0040] Step 4: Compare the currently acquired equivalent resistance value R ed with the preset threshold value R z to determine their magnitudes, or compare the recorded n with the input parameter k;

[0041] Step 5: If R ed < R z or n ≤ k, the system will continue data acquisition and compare the current equivalent resistance value R ed with the equivalent resistance value collected last time ;

[0042] If then record the current equivalent resistance value, update the value of the recorded n, perform the increment operation on n (n++), and at the same time, update the equivalent resistance value of the last time to the equivalent resistance value, that is

[0043] Then, determine whether the remainder of n divided by 3 is equal to 1 (n % 3 == 1) to decide the storage location of the data, achieving the classification and filing of the data and optimizing the recording process;

[0044] If n % 3 = 1, record the current data in the bracket dataset and return to Step 2;

[0045] If n % 3 ≠ 1, store the data in the briquette dataset and return to Step 2;

[0046] If then the system will skip this record and return to Step 2;

[0047] Step 6: If R ed ≥ R z or n > k, the system will switch to the next photovoltaic string for detection and perform the increment operation on m (m++);

[0048] Step 7: When the detection of all photovoltaic strings is completed, the system will check the relationship between m and s;

[0049] If m > s, all the recorded data will be uploaded to the cloud server through communication means such as 4G modules, and the data acquisition process will officially end. The system will retain all the recorded resistance information for subsequent analysis and fault diagnosis.

[0050] If m ≤ s, the system will continue data acquisition and return to Step 2.

[0051] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Through the unique design of the pressure block sensor and the bracket sensor, the present invention can accurately sense the loosening state of the bolt. The method of triggering the switch based on the mechanical structure change greatly improves the detection accuracy and reliability compared with the traditional sensor, effectively avoiding misjudgment caused by environmental interference;

[0052] 2. The electronic switch circuit based on time delay combined with the polling mechanism not only reduces signal interference and system power consumption, but also realizes efficient acquisition of the detection unit through dynamic path switching, optimizing the data acquisition process;

[0053] 3. The data acquisition method of the pulse period uses the different equivalent resistances of the odd-side pressure block detection unit, the even-side pressure block detection unit, and the bracket monitoring unit to form a period for data acquisition, improving the pertinence and effectiveness of the data, reducing the generation of redundant data, and at the same time improving the detection accuracy. It can timely detect potential bolt loosening hazards, and through the grouping record mechanism, it realizes the comprehensive monitoring of the states of all bolts of the photovoltaic module. The different types of detection units are effectively distinguished through resistance identification, facilitating data processing and analysis, and further improving the performance and practicality of the entire monitoring system. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0055] Figure 1 It is a connection block diagram of a bolt safety monitoring system based on a pulse period of the present invention;

[0056] Figure 2 It is a schematic diagram of the overall pressure block sensor of the present invention;

[0057] Figure 3 It is a front view of the pressure block sensor of the present invention with a part removed;

[0058] Figure 4 It is a schematic diagram of the interior of the housing of the pressure block sensor of the present invention;

[0059] Figure 5 It is a schematic diagram of the rotating rod of the pressure block sensor of the present invention;

[0060] Figure 6 It is a schematic diagram of the bottom plate of the pressure block sensor of the present invention;

[0061] Figure 7Schematic diagram of the briquetting sensor buckle of the present invention;

[0062] Figure 8 Schematic diagram of the overall bracket sensor of the present invention;

[0063] Figure 9 Schematic diagram of a part of the interior of the bracket sensor of the present invention removed;

[0064] Figure 10 Schematic diagram of the nut cap of the bracket sensor of the present invention;

[0065] Figure 11 Schematic diagram of the screw cap of the bracket sensor of the present invention;

[0066] Figure 12 Schematic diagram of the cap of the bracket sensor of the present invention;

[0067] Figure 13 Connection diagram of the time-delay switch circuit module of the present invention;

[0068] Figure 14 Distribution diagram of the board surface detection unit of the present invention;

[0069] Figure 15 Schematic diagram of the bracket and the board edge structure of the present invention;

[0070] Figure 16 Flow chart of a data acquisition method based on pulse period of the present invention;

[0071] Figure 17 Detection flow chart of the bolt safety monitoring system of the present invention.

[0072] The reference numerals in the figure respectively represent:

[0073] 1. Briquetting sensor module; 10. Sensor housing; 11. Rotating rod; 12. Bottom plate; 13. Buckle; 14. Fixing screw; 15. Fixing nut; 16. Gasket; 100. Straight groove; 101. Circular groove; 102. Electrode groove; 103. U-shaped groove; 110. Hexagonal prism; 111. Flat blade; 121. Curved side wall; 122. Threaded hole; 130. Convex block; 131. Hexagonal groove; 2. Bracket sensor module; 20. Nut cap; 21. Screw cap; 22. Cap; 200. Hexagonal cavity; 201. Ribbed ring; 202. Clamping edge; 210. Sector clamping edge; 211. Groove; 212. Screw cap hole; 220. Cap hole; 3. Wire; 4. Resistor; 5. Electrode. Detailed implementation manners

[0074] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0075] In the following description, the "left", "right", "front", "rear", "upper", and "lower" mentioned are oriented in the perspective direction of the front view.

[0076] Embodiment 1: In some embodiments, please refer to Figures 1-12 of the accompanying drawings of the specification. A bolt safety monitoring system based on pulse period includes a detection unit, a delay switch circuit module, a control module, a communication module, and a cloud server. The detection unit is connected to the delay switch circuit module, the delay switch circuit module is connected to the control module, the control module is connected to the communication module, and the communication module is wirelessly connected to the cloud server.

[0077] Preferably, the communication module uses a 4G module.

[0078] The detection unit is used to convert the tightening and loosening states of the bolts of the photovoltaic module pressing block and the bracket nut into electrical signals and upload them to the delay switch circuit module.

[0079] The detection unit includes a pressing block detection unit for monitoring the loosening of two bolts on the single board edge of the photovoltaic module and a bracket detection unit for monitoring the loosening of eight bolts on the photovoltaic bracket.

[0080] The pressing block detection unit includes two pressing block sensor modules 1 connected in series.

[0081] The bracket detection unit includes eight bracket sensor modules 2 connected in parallel. Both the pressing block sensor module 1 and the bracket sensor module 2 are connected to the delay switch circuit module.

[0082] The pressing block sensor module 1 is used to convert the tightening and loosening state of the bolts of the photovoltaic module pressing block into an electrical signal and upload the data information to the delay switch circuit module.

[0083] The bracket sensor module 2 is used to convert the tightening and loosening state of the bracket nut into an electrical signal and upload the data information to the delay switch circuit module.

[0084] The delay switch circuit module uses the charging and discharging characteristics of the RC delay circuit (Resistor-Capacitor Delay Circuit) to automatically adjust the data acquisition time to achieve the adjustment of the pulse period. By adjusting the working states of multiplexer U1 and multiplexer U2, the dynamic path switching of the delay switch circuit module is carried out. There are multiple delay switch circuit modules which are connected in series in sequence to form a polling mechanism to access and obtain the data of the sensor module;

[0085] The control module collects the voltage value through the ADC of the control chip, calculates the equivalent resistance of each detection unit according to the voltage division principle, and forms a data sequence (data set) through the access order of the polling mechanism of the delay switch circuit module. This data sequence can be combined with the starting point of the bolt to build a position relationship database without manually setting the position number tediously.

[0086] Among them, the control module can control the on-off of the detection power supply of the sensing network composed of multiple delay switch circuit switches. When the power is started, the sensing network circuit starts to operate. The bolt state information of each detection unit is collected in sequence through the ADC. After the data collection is completed and uploaded, the power is disconnected, and the capacitor in the delay switch circuit module starts to discharge to avoid the influence of residual charge on the detection of the next cycle. Then the power is restarted and the cycle repeats, realizing the all-weather 24-hour monitoring of the bolts in the photovoltaic power station.

[0087] The pressure block sensor module 1 includes a sensor housing 10, a rotating rod 11, a bottom plate 12, a buckle 13, fixing screws 14, fixing nuts 15 and gaskets 16. There are two of each of the buckle 13, fixing screws 14 and fixing nuts 15, which are respectively located on the left and right sides of the sensor housing 10;

[0088] As Figure 4 , a circular notch 101 is opened at the middle top of the sensor housing 10, and the rotating rod 11 is located in the circular notch 101;

[0089] Electrode notches 102 are respectively opened on the front and rear sides of the circular notch 101 at the top of the sensor housing 10, and the electrode notches 102 on both sides are used to fix the electrode 5;

[0090] Three U-shaped notches 103 are opened at the inner top of the sensor housing 10 for passing the wire 3;

[0091] Straight notches 100 are respectively opened on the left and right sides at the top of the sensor housing 10 for moving the buckle 13.

[0092] As Figure 5 , a flat head slot 111 is opened at the top of the rotating rod 11, a gasket 16 is sleeved on the rotating rod 11, and the bottom of the rotating rod 11 is fixedly connected to a hexagonal prism 110 for inserting into the pressure block bolt.

[0093] As Figure 6 shown in Figure 6 , the bottom plate 12 is used to close the bottom of the sensor housing 10. The lower end of the bottom plate 12 is fixedly connected to the curved side wall 121. The curved side wall 121 is used to fix the pressure block bolt. A threaded hole 122 is formed inside the middle of the bottom plate 12. A threaded groove is formed on the side wall of the rotating rod 11. The threaded hole 122 is threadedly connected to the threaded groove on the side wall of the rotating rod 11, thereby controlling the up and down movement of the rotating rod 11;

[0094] As Figure 7 shown in Figure 7 , it is the buckle 13. A convex block 130 is fixedly installed on the inner side of the bottom of the buckle 13, which is used to firmly clamp the edge of the pressure block; a hexagonal notch 131 is formed at the bottom of the buckle 13. The hexagonal notch 131 is threadedly connected to the fixing nut 15. The fixing screw 14 is threadedly connected to the top of the buckle 13;

[0095] Usage method of the pressure block sensor: As Figure 2 shown in Figure 2 , the electrode 5 is fixed in the electrode notch 102 at the top of the sensor housing 10, and the resistor 4 is fixed in the gap between the three U-shaped notches 103. Two electrodes 5 are wound around both ends of the resistor 4. Subsequently, two wires 3 are wound around these two electrodes 5 and then pass through the U-shaped notch 103 on the side wall to form a micro switch together with the gasket 16 on the rotating rod 11.

[0096] The fixing screw 14 passes through the buckle 13 and is fixed to the straight notches 100 on both sides of the top of the sensor housing 10 together with the fixing nut 15; the gasket 16 is fixed to the top of the rotating rod 11 with glue, and then is fixed by the thread on the threaded groove of the rotating rod 11 and the thread of the bottom plate 12. The bottom plate 12 seals the bottom of the sensor housing 10. The top of the rotating rod 11 passes through the circular notch 101 at the top of the sensor housing 10. At this time, the gasket 16 and the two electrodes 5 are not in contact, and the internal circuit of the sensor housing 10 is equivalent to a switch being off, and the resistor 4 can be detected; then align this overall sensor with the pressure block bolt on the plate edge, adjust the angle with a flat-blade 111 and insert it, and fix it by rotating the screw.

[0097] When the pressure block bolt is tightened, current flows through the resistor 4; when the pressure block bolt is loose, the rotating rod 11 moves upward, the gasket 16 contacts the electrode 5, and the resistor 4 is short-circuited.

[0098] As Figures 8-9 shown in Figures 8-9 , the bracket sensor module 2 includes a nut cap 20, a screw cap 21, and a cap 22;

[0099] As Figure 10 shown in Figure 10 , the nut cap 20 includes a hexagonal cavity 200 and a first cylinder; one end of the hexagonal cavity 200 is fixedly connected to the first cylinder;

[0100] The hexagonal cavity 200 is used to accommodate the hexagonal nut at the bracket;

[0101] A notch is provided on the first cylindrical wall, and a clamping edge 202 is fixedly installed at one end of the notch. The clamping edge 202 is used to close the ribbed ring 201;

[0102] Two ribbed rings 201 are fixedly installed inside the first cylinder;

[0103] Such as Figure 11 , the nut cap 20 further includes a second cylinder. A threaded groove is provided on the inner wall of the second cylinder for fixing at the root of the support screw;

[0104] Such as Figure 11 , a screw cap hole 212 is provided inside the second cylinder for fixing the electrode 5. Since the support screw is grounded, the electrode 5 and the support screw can form a microswitch;

[0105] The side wall of the second cylinder is fixedly connected to two sector clamping edges 210, and the distance between the two sector clamping edges 210 is greater than the thickness of one ribbed ring 201.

[0106] A third cylinder is fixedly installed at one end of the second cylinder, and grooves 211 are provided on both sides of the third cylinder;

[0107] Such as Figure 12 , a cap hole 220 is provided at the top of the cap 22 for passing the wire 3.

[0108] Usage method of the support sensor: Such as Figure 9 , the electrode 5 passes through the screw cap hole 212. One end of the resistor 4 is wound around the electrode 5 and the other end is connected to the external wire 3. The wire 3 passes through the cap hole 220; Insert the screw cap 21 into the nut cap 20 so that the hexagonal openings at the ports of the screw cap 21 and the nut cap 20 are flush. Rotate the screw cap 21 to align it with the support screw, ensuring that the screw cap 21 can rotate smoothly in cooperation with the support screw. Then use the nut cap 20 to seal the clamping edge 202 at the opening to drive the screw cap 21 to rotate further until the screw cap 21 reaches a preset rotation angle. At this time, the screw cap 21 is in a nearly tightened state.

[0109] Then, adjust the angle of the nut cap 20 and rotate the nut cap 20 counterclockwise by 60 degrees. At this time, the sector clamping edge 210 of the nut cap 20 changes from the direction close to the screw cap 21 to the direction away from the screw cap 21. The nut cap 20 is sleeved on the support nut. The screw cap 21 continues to rotate until it is tightened. The sector clamping edge 210 of the screw cap 21 enters between the two ribbed rings 201 of the nut cap 20 or catches the ribbed ring 201. Finally, cover the cap 22 on the screw cap 21.

[0110] All the support structures of the photovoltaic module can conduct electricity. Ground the support. When the support nut is tightened, the electrode 5 inside the screw cap 21 contacts the support screw. At this time, current flows through the resistor 4 inside the screw cap 21, and the microswitch is in the conducting state; when the support nut is loose, the nut cap 20 rotates 300 degrees, then drives the screw cap 21 to rotate, and the conductive screw separates from the support screw, and the microswitch is in the off state.

[0111] Embodiment 2: In some embodiments, as Figure 13 shown, as a preferred embodiment of the present invention, the delay switch circuit module includes a resistor R1, a capacitor C, a multiplexer U1, and a multiplexer U2; the resistor R1 and the capacitor C are connected in series to the ground;

[0112] Two one - in - two multiplexers U1 and U2 are adopted; the multiplexer U1 serves as the power supply terminal, and the multiplexer U2 serves as the detection terminal. The VCC terminals of the multiplexer U1 and the multiplexer U2 are both connected to the 5V power supply, and the GNDs of the multiplexer U1 and the multiplexer U2 are both grounded.

[0113] The D terminal of the multiplexer U1 is connected to the power supply, the SEL terminal is connected to both the resistor R1 and the capacitor C, the S2 terminal serves as the power supply to connect the VCC of the multiplexer U1, the D terminal of the multiplexer U1, and the VCC of the multiplexer U2 in the next group of delay switch circuit modules. The S1 terminal is connected to the grounding resistor R2, and the grounding resistor R2 is grounded. The function of the grounding resistor R1 is to stabilize the voltage of the S1 terminal, and the S1 terminal is also connected to the SEL terminal of U2.

[0114] The D terminal of the multiplexer U2 is connected to the sampling resistor Rd, the sampling resistor Rd is connected to the power supply, the S2 terminal of the multiplexer U2 is connected to the pressure block detection unit or the support detection unit through the resistor R3, and the S1 terminal of the multiplexer U2 is connected to the D terminal of the multiplexer U2 in the next group of delay switch circuit modules.

[0115] The dynamic path switching of the switch circuit module is manifested as the control module real - time adjusting the working states of the multiplexers U1 and U2 of the multiplexer, and the method to realize the dynamic path switching is:

[0116] When the power supply is started, the impedance of the capacitor C in the delay switch circuit module is 0, and the voltage is low;

[0117] The SEL terminal of the multiplexer U1 receives a low level, and the D terminal is conducted with the S1 terminal;

[0118] The SEL terminal of the multiplexer U2 receives a high level, the D terminal is conducted with the S2 terminal, and it is collected through the adc port of the single - chip microcomputer, and through the formula:

[0119] R ed =R d ×U / (V cc -U);

[0120] R d is the resistance value of the sampling resistor, and R ed is the equivalent resistance value of the detection unit. U is the voltage collected from R to ground during the sampling process, and V d is the power supply voltage. cc is the power supply voltage.

[0121] The equivalent resistance value R of the detection unit where this side is located can be calculated to obtain information; then, the impedance of the capacitor C in the delay switch circuit module increases with time, and the voltage also increases. The SEL terminal of the multiplexer U1 receives a high level, the D terminal is disconnected from the S1 terminal, and switches to conduct with the S2 terminal, acting as the power supply for the next group of delay switch circuit modules; at the same time, the SEL terminal of the multiplexer U2 becomes a low level, the D terminal is disconnected from the S2 terminal, and switches to conduct with the S1 terminal, and S1 is connected to the D terminal of the multiplexer U2 of the next group of delay switch circuit modules. ed In the delay switch circuit module, by utilizing the charge and discharge characteristics of the capacitor C, the acquisition time is automatically adjusted. This periodic circuit state switching is similar to the change period of a pulse signal. In the data acquisition method based on the pulse period, by adding resistors with different resistance values (R for the odd sides and 2R for the even sides) to the odd and even sides of the photovoltaic frame, a period is formed relying on these different equivalent resistance values, and the equivalent resistance value information of the internal circuit of the sensor is acquired, thereby realizing periodic data acquisition.

[0122] In the delay switch circuit module, by utilizing the charge and discharge characteristics of the capacitor C, the acquisition time is automatically adjusted. This periodic circuit state switching is similar to the change period of a pulse signal. In the data acquisition method based on the pulse period, by adding resistors with different resistance values (R for the odd sides and 2R for the even sides) to the odd and even sides of the photovoltaic frame, a period is formed relying on these different equivalent resistance values, and the equivalent resistance value information of the internal circuit of the sensor is acquired, thereby realizing periodic data acquisition.

[0123] Embodiment 3: In some embodiments, as Figure 16 shown, as a preferred embodiment of the present invention, a data acquisition method based on the pulse period includes the following steps:

[0124] Step 1: Input parameters k and s, and initialize variables m = 0 and n = 0;

[0125] K is the number of block detection units and bracket detection units in the photovoltaic string, s is the number of photovoltaic strings in the photovoltaic array, n is the ordinal number of the currently detected block detection unit and bracket detection unit, and m is the ordinal number of the currently detected photovoltaic string;

[0126] Step 2: Acquire the voltage information of the entire sensing network at a frequency of every 10 milliseconds;

[0127] Step 3: In each data acquisition process, first calculate the equivalent resistance value R of the current circuit ed ;

[0128] Step 4: Compare the currently acquired equivalent resistance value R ed with the preset threshold R z to determine the size, or compare the already recorded n with the input parameter k to determine the size;

[0129] Step Five: If R ed < R z or n ≤ k, the system will continue to collect data and compare the current equivalent resistance value R ed with the equivalent resistance value collected last time for comparison;

[0130] If then record the current equivalent resistance value, update the value of record n, perform the increment operation on n (n++), and at the same time, update the equivalent resistance value of the last time to the equivalent resistance value, that is

[0131] Next, determine whether the remainder of n divided by 3 is equal to 1 (n % 3 == 1) to determine the storage location of the data, realizing the classification and archiving of the data and optimizing the recording process;

[0132] If n % 3 = 1, record the current data in the bracket dataset and return to Step Two;

[0133] If n % 3 ≠ 1, store the data in the briquette dataset and return to Step Two;

[0134] If then the system will skip this record and return to Step Two;

[0135] Step Six: If R ed ≥ R z or n > k, the system will switch to the next photovoltaic string for detection and perform the increment operation on m (m++);

[0136] Step Seven: When the detection of all photovoltaic strings is completed, the system will check the relationship between m and s;

[0137] If m > s, all the recorded data will be uploaded to the cloud server through communication means such as 4G modules, and the data collection process will officially end. The system will retain all the recorded resistance information for subsequent analysis and fault diagnosis.

[0138] If m ≤ s, the system will continue to collect data and return to Step Two.

[0139] Example Four: In some embodiments, as Figures 14-15 shown, as a preferred embodiment of the present invention, the briquette detection unit is a detection module for monitoring the loosening of two bolts on each side of a single plate of a photovoltaic module, and its core structure is composed of two briquette sensors connected in series;

[0140] As Figure 14As shown in the figure, the briquette detection unit includes two briquette sensor modules 1. The two briquette sensors are connected in series and connected to the delay switch circuit module. In order to distinguish between odd sides and even sides, a resistor with a resistance value of R is connected in series on the briquette detection unit on the odd side, and a resistor with a resistance value of 2R is connected in series on the briquette detection unit on the even side. This method mainly collects the equivalent resistance value information of the detection unit. Depending on the different resistance values of the odd side and the even side, a cycle can be formed, and corresponding data can be collected through this cycle.

[0141] As Figure 15 shown in the figure, in order to comprehensively detect the status of all bolts of the photovoltaic module, the present invention adds a bracket detection unit in the distribution design. The arrangement of the bracket bolts is such that a bracket is provided for fixing every two photovoltaic panels. Generally, each bracket requires 8 bracket bolts. The bracket detection unit is used to monitor the looseness of 8 bolts on the photovoltaic bracket. Its core structure is composed of 8 bracket sensors connected in parallel;

[0142] In addition, in order to effectively distinguish the detection units of the plate edge and the bracket, this article specifically connects a resistor with a group value of 3R in series on each bracket edge as a clear identification mark.

[0143] Combined with the delay switch circuit module, the sensing network is an alternating cascade structure of "bracket detection unit + panel surface detection unit".

[0144] Embodiment 5: In some embodiments, as Figure 17 shown in the figure, in order to be able to monitor the bolt tightening status of the photovoltaic resistor 24 hours a day and all-weather, the control module controls the power on and off of the sensing network composed of the delay switch module and the detection unit. If the voltage is started, the sensing network uses the data acquisition method based on the pulse period to collect and process data, and then the data is uploaded. When the voltage is disconnected, the capacitor in the sensing network starts to discharge, and then the voltage is restarted, repeating in a cycle.

[0145] 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 foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements will not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A bolt safety monitoring system based on pulse period, characterized in that, It includes a detection unit, which is connected to a delay switch circuit module. The delay switch circuit module and the communication module are both connected to a control module; The detection unit is used to convert the tightening states of the bolts of the photovoltaic module pressing blocks and the nuts of the brackets into electrical signals and upload them to the delay switch circuit module; The delay switch circuit module automatically adjusts the data acquisition time using the charging and discharging characteristics of the capacitor in the RC delay circuit to adjust the pulse period. By adjusting the operating states of the multiplexer (U1) and the multiplexer (U2), dynamic path switching of the delay switch circuit module is performed. There are multiple delay switch circuit modules connected in series in sequence to form a polling mechanism to access and obtain the data of the detection unit; The control module collects the voltage value through the ADC of the control chip, calculates the equivalent resistance of each detection unit according to the voltage division principle, and forms a data sequence through the access order of the polling mechanism of the delay switch circuit module. This data sequence can establish a position relationship database in combination with the starting point of the bolts.

2. The bolt safety monitoring system based on pulse period according to claim 1, wherein The detection unit includes a pressing block detection unit for monitoring the loosening conditions of two bolts on the single board edge of the photovoltaic module and a bracket detection unit for monitoring the loosening conditions of eight bolts on the photovoltaic bracket; The pressing block detection unit includes two pressing block sensor modules (1) connected in series; The bracket detection unit includes eight bracket sensor modules (2) connected in parallel. Both the pressing block sensor module (1) and the bracket sensor module (2) are connected to the delay switch circuit module; The pressing block sensor module (1) is used to convert the tightening state of the bolts of the photovoltaic module pressing blocks into electrical signals and upload the data information to the delay switch circuit module; The bracket sensor module (2) is used to convert the tightening state of the bracket nuts into electrical signals and upload the data information to the delay switch circuit module.

3. The bolt safety monitoring system based on pulse period according to claim 2, characterized in that The pressing block sensor module (1) includes a sensor housing (10), a rotating rod (11), a bottom plate (12), a buckle (13), a fixing screw (14), a fixing nut (15) and a gasket (16). The fixing screw (14) is threadedly connected to the fixing nut (15); There are two buckles (13), fixing screws (14) and fixing nuts (15) respectively located on the left and right sides of the sensor housing (10); A circular notch (101) is opened at the middle top of the sensor housing (10). The rotating rod (11) is located in the circular notch (101). Electrode notches (102) are respectively opened on the front and back sides of the circular notch (101) at the top of the sensor housing (10). Three U-shaped notches (103) are opened at the inner top of the sensor housing (10). Straight notches (100) are respectively opened on the left and right sides of the top of the sensor housing (10); A flat head (111) is opened at the top of the rotating rod (11). A gasket (16) is sleeved on the rotating rod (11). The bottom of the rotating rod (11) is fixedly connected to a hexagonal prism (110); The lower end of the bottom plate (12) is fixedly connected to the curved side wall (121). A threaded hole (122) is formed inside the middle of the bottom plate (12). Threaded grooves are formed on the side wall of the rotating rod (11). The threaded hole (122) is in threaded connection with the threaded grooves on the side wall of the rotating rod (11). A convex block (130) is fixedly installed on the inner side of the bottom of the buckle (13). A hexagonal notch (131) is formed at the bottom of the buckle (13). The hexagonal notch (131) accommodates the fixing nut (15). The fixing screw (14) is in threaded connection with the fixing nut (15) through the hexagonal notch (131).

4. The bolt safety monitoring system based on pulse period according to claim 2, characterized in that The bracket sensor module (2) includes a nut cap (20), a screw cap (21) and a cap (22); the nut cap (20) includes a hexagonal cavity (200) and a first cylinder. One end of the hexagonal cavity (200) is fixedly connected to the first cylinder. A notch is formed on the wall of the first cylinder. A clamping edge (202) is fixedly installed at one end of the notch. Two rib loops (201) are fixedly installed inside the first cylinder. The nut cap (20) further includes a second cylinder. Threaded grooves are formed on the inner wall of the second cylinder. A screw cap hole (212) is formed inside the second cylinder. The side wall of the second cylinder is fixedly connected to two sector-shaped clamping edges (210). One end of the second cylinder is fixedly installed with a third cylinder. Grooves (211) are formed on both sides of the third cylinder; a cap hole (220) is formed at the top of the cap (22).

5. The bolt safety monitoring system based on pulse period according to claim 4, characterized in that, The lengths of the two rib loops (201) are both greater than the distance between the two clamping edges (202).

6. The bolt safety monitoring system based on pulse period according to claim 4, wherein, The distance between the two sector-shaped clamping edges (210) is greater than the thickness of one rib loop (201).

7. The bolt safety monitoring system based on pulse period according to claim 1, characterized in that, The delay switch circuit module includes a resistor (R1), a capacitor C, a multiplexer (U1) and a multiplexer (U2); the resistor (R1) and the capacitor C are connected in series to the ground. The multiplexer (U1) serves as a power supply terminal, and the multiplexer (U2) serves as a detection terminal. The VCC terminals of the multiplexer (U1) and the multiplexer (U2) are both connected to a 5V power supply, and the GNDs of the multiplexer (U1) and the multiplexer (U2) are both grounded.

8. The bolt safety monitoring system based on pulse period according to claim 7, characterized in that, The D terminal of the multiplexer (U1) is connected to the power supply. The SEL terminal is connected to both the resistor (R1) and the capacitor C. The S2 terminal serves as the power supply to connect the VCC of the multiplexer (U1) in the next group of delay switch circuit modules, the D terminal of the multiplexer (U1), and the VCC of the multiplexer (U2). The S1 terminal is connected to the grounding resistor (R2), and the grounding resistor (R2) is grounded. The S1 terminal is also connected to the SEL terminal of the multiplexer (U2). The D terminal of the multiplexer (U2) is connected to the sampling resistor Rd. The sampling resistor Rd is connected to the power supply. The S2 terminal of the multiplexer (U2) is connected to the detection unit through the resistor (R3). The S1 terminal of the multiplexer (U2) is connected to the D terminal of the multiplexer (U2) in the next group of delay switch circuit modules.

9. The bolt safety monitoring system based on pulse period according to claim 8, wherein, The method of dynamic path switching is as follows: When the impedance of the capacitor C in the delay switch circuit module is 0, the voltage is low; The SEL terminal of the multiplexer (U1) receives a low level, and the D terminal and the S1 terminal are conducted; The SEL terminal of the multiplexer (U2) receives a high level, the D terminal conducts with the S2 terminal, and the equivalent resistance R of the detection unit is collected through the adc port of the single-chip microcomputer and calculated ed information, and the calculation formula is: R ed = R d × U / (V cc - U); R d is the resistance value of the sampling resistor, R ed is the equivalent resistance value of the detection unit, U is the voltage value collected from R to ground during the sampling process d , and V cc is the power supply voltage.

10. A data acquisition method based on pulse period, which is used for the bolt safety monitoring system based on pulse period described in claim 9, is characterized in that, It includes the following steps: One, input parameters k and s, let m = 0, n = 0; Among them, k is the number of detection units in the photovoltaic string, s is the number of photovoltaic strings in the photovoltaic array, n is the ordinal number of the currently detected detection unit, and m is the ordinal number of the currently detected photovoltaic string; Second, collect voltage information; III. Calculate the equivalent resistance value R of the current circuit ed ; IV. Regarding the equivalent resistance value R ed and the preset threshold value R z perform a magnitude comparison, or compare the recorded n and k in terms of magnitude; V. If R ed <R z or n ≤ k, then compare R ed with the equivalent resistance value collected last time for comparison; If then record R ed and update the value of n, perform the increment operation on n, and at the same time, update Next, determine whether the remainder of n divided by 3 is equal to 1; If n % 3 = 1, record the data in the bracket dataset and return to step two; If n % 3 ≠ 1, store the data in the pressing block dataset and return to step two; If then directly return to step two; VI. If R ed ≥ R z or n > k, switch to the next photovoltaic string for detection and perform the increment operation on m; Seventh, when the detection of all photovoltaic strings is completed, check the relationship between m and s; If m > s, upload all the recorded data to the cloud server through the communication module; If m ≤ s, return to step two.

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