Photovoltaic power station wireless monitoring system, child node device and main node device

Abstract

The invention relates to the technical field of communication, and provides a photovoltaic power station wireless monitoring system, child node equipment and main node equipment. The photovoltaic power station wireless monitoring system comprises a child node device and a main node device. Wherein the sub-node equipment is used for monitoring the operation state of each internal component of the photovoltaic power station to obtain the operation data of each internal component of the photovoltaic power station, and sending the operation data of each internal component of the photovoltaic power station to the main node equipment; every two child node devices are connected with each other in a Bluetooth mode to form a child node mesh network; the main node equipment is used for receiving the operation data sent by the sub-node equipment, and if the operation data is correctly transmitted, the operation state of the photovoltaic power station is obtained through summarizing according to the operation data so as to carry out wireless monitoring on the photovoltaic power station; and the main node equipment is connected with the sub-node equipment in a Bluetooth form. By adopting the wireless monitoring system for the photovoltaic power station, the communication transmission cost and the construction cost of the wireless monitoring system for the photovoltaic power station can be reduced.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and particularly to a wireless monitoring system for a photovoltaic power station, a sub-node device, and a main-node device. Background Art

[0002] Currently, distributed photovoltaic power generation technologies are deployed in many locations such as remote areas, coastal islands, the sea, rooftops, and vacant plots of residents. However, distributed photovoltaic power stations are scattered, and the form of electrical energy output is unstable. It is necessary to monitor the photovoltaic power station in real time to improve the power generation, operation reliability, and economy of the photovoltaic power station.

[0003] Currently, two communication transmission methods, wired and wireless, are mainly used to monitor photovoltaic power stations. However, the wired communication transmission method has a high cost, great wiring difficulty, and complex construction technology, resulting in great construction difficulty. The wireless communication transmission method mainly uses wireless 4G and 5G base station technologies, which also have a high cost, long construction period, and difficult maintenance, and are not suitable for monitoring photovoltaic power stations in remote areas. Summary of the Invention

[0004] Based on this, it is necessary to provide a wireless monitoring system for a photovoltaic power station, a sub-node device, and a main-node device in view of the above technical problems.

[0005] In a first aspect, this application provides a wireless monitoring system for a photovoltaic power station, including:

[0006] A sub-node device, configured to monitor the operating status of each internal component of the photovoltaic power station, obtain the operating data of each internal component of the photovoltaic power station, and send the operating data of each internal component of the photovoltaic power station to the main-node device; the sub-node devices are connected to each other pairwise in the form of Bluetooth to form a sub-node mesh network;

[0007] The main-node device is configured to receive the operating data sent by the sub-node device. If the operating data is transmitted correctly, then based on the operating data, summarize to obtain the operating status of the photovoltaic power station to perform wireless monitoring on the photovoltaic power station; the main-node device is connected to the sub-node device in the form of Bluetooth.

[0008] In one embodiment, the sub-node device sending the operating data of each internal component of the photovoltaic power station to the main-node device specifically includes:

[0009] Dividing the operating data of each internal component of the photovoltaic power station into several data blocks;

[0010] Calculating the parity check bit of each data block to obtain the first parity check bits corresponding to the several data blocks;

[0011] Send the several data blocks and the first parity check bits corresponding to the several data blocks to the master node device.

[0012] In one embodiment, after receiving the operation data sent by the slave node device, the master node device is further configured to:

[0013] Recalculate the parity check bits of the received several data blocks to obtain second parity check bits of the several data blocks;

[0014] Compare the first parity check bits and the second parity check bits of the several data blocks;

[0015] When the first parity check bits and the second parity check bits of the several data blocks are consistent, it is confirmed that the operation data is transmitted correctly.

[0016] In one embodiment, during the communication process between the master node device and the slave node device, the master node device monitors the signal-to-noise ratio of the current master node communication channel according to a first preset time;

[0017] If the signal-to-noise ratio of the current master node communication channel is lower than a preset signal-to-noise ratio threshold, rescan the preset frequency band to detect the interference conditions of each Bluetooth communication channel, and calculate the signal-to-noise ratio of each Bluetooth communication channel;

[0018] Select the Bluetooth communication channel with the highest signal-to-noise ratio as the current master node communication channel according to the signal-to-noise ratios of the Bluetooth communication channels; the current master node communication channel is used for communication between the master node device and the slave node device.

[0019] In one embodiment, during the communication process between the master node device and the slave node device, the master node device sends a synchronization signal to the slave node device according to a second preset time;

[0020] The slave node device performs clock calibration according to the received synchronization signal.

[0021] In one embodiment, during the communication process between the slave node device and the master node device, the slave node device obtains a frequency hopping sequence according to an initial frequency and a frequency step value;

[0022] When the slave node device detects congestion or interference on the slave node communication channel, switch the frequency of the slave node communication channel according to the frequency hopping sequence.

[0023] In one embodiment, one of the slave node devices obtains the weighted propagation delay times of the slave node devices according to a weighting coefficient and the propagation delay times of the slave node devices;

[0024] One of the sub-node devices determines a forwarding node device among the sub-node devices according to the received signal strength and weighted propagation delay time of each sub-node device;

[0025] One of the sub-node devices transmits the operation data collected at its end to the master node device through the forwarding node device.

[0026] In one embodiment, the master node device serves as the central node device of the photovoltaic power station, communicates with the upper system, and uploads the operation status of the photovoltaic power station to the cloud monitoring platform.

[0027] In a second aspect, the present application also provides a sub-node device, which is the sub-node device included in the wireless monitoring system of the photovoltaic power station.

[0028] In a third aspect, the present application also provides a master node device, which is the master node device included in the wireless monitoring system of the photovoltaic power station.

[0029] The above-mentioned wireless monitoring system of the photovoltaic power station includes sub-node devices and a master node device. The sub-node devices are used to monitor the operation status of each internal component of the photovoltaic power station, obtain the operation data of each internal component of the photovoltaic power station, and send the operation data of each internal component of the photovoltaic power station to the master node device; the sub-node devices are pairwise connected to each other in the form of Bluetooth to form a sub-node mesh network; the master node device is used to receive the operation data sent by the sub-node devices. If the operation data is transmitted correctly, the operation status of the photovoltaic power station is summarized according to the operation data to wirelessly monitor the photovoltaic power station; the master node device is connected to the sub-node devices in the form of Bluetooth. The communication methods between the master node device and the sub-node devices and between the sub-node devices and the sub-node devices in the present application are all Bluetooth communications, without the need for wiring or the construction of base stations, which can reduce the communication transmission cost and construction cost of the wireless monitoring system of the photovoltaic power station. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments of the present application or related technologies. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0031] Figure 1 It is an application environment diagram of the wireless monitoring system of the photovoltaic power station in one embodiment;

[0032] Figure 2Schematic diagram of the process of sending the operation data of each internal component of a photovoltaic power station to the master node device in an embodiment;

[0033] Figure 3 Schematic diagram of the process of confirming the correct transmission of operation data in an embodiment;

[0034] Figure 4 Schematic diagram of the process of adaptive adjustment of the master node communication channel in another embodiment;

[0035] Figure 5 Schematic diagram of the process of clock calibration of the slave node device in an embodiment. Detailed implementation manners

[0036] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0037] The wireless monitoring system of a photovoltaic power station provided by an embodiment of the present application can be applied to an application environment as Figure 1 shown. Among them, the slave node devices 102 are pairwise connected to each other in the form of Bluetooth to form a slave node mesh network; the master node device is connected to the slave node devices in the form of Bluetooth. The data storage system can store the data that the master node device 104 needs to process. The data storage system can be integrated on the server 104. The slave node devices 102 can monitor the operation status of each internal component of the photovoltaic power station, obtain the operation data of each internal component of the photovoltaic power station, and send the operation data of each internal component of the photovoltaic power station to the master node device 104; the master node device 104 can receive the operation data sent by the slave node devices 102. If the operation data is transmitted correctly, the operation status of the photovoltaic power station can be summarized according to the operation data to wirelessly monitor the photovoltaic power station.

[0038] In an exemplary embodiment, as Figure 2 shown, a wireless monitoring system of a photovoltaic power station is provided. The wireless monitoring system of the photovoltaic power station includes slave node devices and a master node device. Among them, the slave node devices are used to monitor the operation status of each internal component of the photovoltaic power station, obtain the operation data of each internal component of the photovoltaic power station, and send the operation data of each internal component of the photovoltaic power station to the master node device; the slave node devices are pairwise connected to each other in the form of Bluetooth to form a slave node mesh network; the master node device is used to receive the operation data sent by the slave node devices. If the operation data is transmitted correctly, the operation status of the photovoltaic power station can be summarized according to the operation data to wirelessly monitor the photovoltaic power station; the master node device is connected to the slave node devices in the form of Bluetooth.

[0039] The wireless monitoring system of a photovoltaic power station may include sub-node devices and a master-node device. Among them, the sub-node devices are connected in a mesh mode, that is, the sub-node devices are pairwise connected to each other in the form of Bluetooth to form a sub-node mesh network, which can realize multi-hop transmission of operation data; the master-node device and the sub-node devices can be connected in a star networking mode, that is, the master-node device and the sub-node devices are connected in the form of Bluetooth.

[0040] The sub-node devices can monitor the operating status of each internal component of the photovoltaic power station, obtain the operation data of each internal component of the photovoltaic power station, and send the operation data of each internal component of the photovoltaic power station to the master-node device.

[0041] Each internal component of the photovoltaic power station may include an inverter, an electricity meter, and a busbar box. The sub-node devices may be Bluetooth sensors installed on each internal component of the photovoltaic power station.

[0042] The sub-node devices can monitor the operating status of each internal component of the photovoltaic power station, obtain the operation data of each internal component of the photovoltaic power station. For example, the output power, current, voltage, and temperature of the inverter can be obtained.

[0043] The sub-node devices can send the operation data of each internal component of the photovoltaic power station to the master-node device based on the parity bit re-coding verification method to ensure error-free transmission of the operation data.

[0044] The master-node device can receive the operation data sent by the sub-node devices. If the operation data is transmitted correctly, it can summarize the operating status of the photovoltaic power station based on the operation data to wirelessly monitor the photovoltaic power station.

[0045] The master-node device may be an edge computing gateway or a controller of the photovoltaic power station.

[0046] After receiving the operation data sent by the sub-node devices, the master-node device can perform parity bit re-coding verification on the operation data to determine whether the operation data is transmitted correctly. If the operation data is transmitted correctly, it can summarize the operating status of the photovoltaic power station based on the operation data to wirelessly monitor the photovoltaic power station.

[0047] In the above wireless monitoring system of the photovoltaic power station, the communication methods between the master-node device and the sub-node devices and between the sub-node devices are both Bluetooth communications, without the need for wiring or building a base station, which can reduce the communication transmission cost and construction cost of the wireless monitoring system of the photovoltaic power station.

[0048] In one embodiment, the steps for the sub-node devices to send the operation data of each internal component of the photovoltaic power station to the master-node device are as follows Figure 2Shown as follows: Step S201, divide the operation data of each internal component of the photovoltaic power station into several data blocks; Step S202, calculate the parity check bits of each data block to obtain the first parity check bits corresponding to several data blocks; Step S203, send several data blocks and the first parity check bits corresponding to several data blocks to the master node device.

[0049] The sub-node device can divide the operation data of each internal component of the photovoltaic power station into several data blocks; can calculate the parity check bits of each data block to obtain the first parity check bits corresponding to several data blocks; can send several data blocks and the first parity check bits corresponding to several data blocks to the master node device, so that the master node device performs parity bit re-code check on the operation data to determine whether the operation data is transmitted correctly, thereby ensuring error-free transmission of the operation data.

[0050] In one embodiment, after receiving the operation data sent by the sub-node device, the master node device is further configured to execute the steps as Figure 3 shown: Step S301, re-calculate the parity check bits of several received data blocks to obtain the second parity check bits of several data blocks; Step S302, compare the first parity check bits and the second parity check bits of several data blocks; Step S303, when the first parity check bits and the second parity check bits of several data blocks are consistent, it is confirmed that the operation data is transmitted correctly.

[0051] After receiving the operation data sent by the sub-node device, the master node device can perform a parity bit re-code check on the operation data to determine whether the operation data is transmitted correctly. Specifically, it can re-calculate the parity check bits of several received data blocks to obtain the second parity check bits of several data blocks; can compare the first parity check bits and the second parity check bits of several data blocks; when the first parity check bits and the second parity check bits of several data blocks are consistent, it is confirmed that the operation data is transmitted correctly; when the first parity check bits and the second parity check bits of several data blocks are inconsistent, it is confirmed that the operation data is transmitted incorrectly.

[0052] In this embodiment, after receiving the operation data sent by the sub-node device, the master node device re-calculates the parity check bits of several received data blocks to obtain the second parity check bits of several data blocks; when the first parity check bits and the second parity check bits of several data blocks are consistent, it is confirmed that the operation data is transmitted correctly, thereby ensuring error-free transmission of the operation data.

[0053] In one embodiment, during the communication between the master node device and the slave node device, the master node device monitors the signal-to-noise ratio (SNR) of the current master node communication channel at a first preset time; if the SNR of the current master node communication channel is lower than the preset SNR threshold, the master node device re-scans the preset frequency band to detect the interference conditions of each Bluetooth communication channel, and calculates the SNR of each Bluetooth communication channel; based on the SNR of each Bluetooth communication channel, the Bluetooth communication channel with the highest SNR is selected as the current master node communication channel; the current master node communication channel is used for the communication between the master node device and the slave node device.

[0054] Before establishing the link of the wireless monitoring system for the photovoltaic power station, three frequency channels can be preset, which are respectively used for the link and network data transmission, positioning data transmission or emergency communication between the master node device and the slave node device.

[0055] The master node device can scan the preset frequency band to detect the interference conditions of each Bluetooth communication channel, and calculate the signal-to-noise ratio (SNR) of each Bluetooth communication channel.

[0056] The master node device can use the Bluetooth communication channel with the highest SNR as the current master node communication channel based on the SNR of each Bluetooth communication channel.

[0057] During the communication between the master node device and the slave node device, the master node device can monitor the SNR of the current master node communication channel at a first preset time; if the SNR of the current master node communication channel is lower than the preset SNR threshold, the master node device can re-scan the preset frequency band to detect the interference conditions of each Bluetooth communication channel, and calculate the SNR of each Bluetooth communication channel; based on the SNR of each Bluetooth communication channel, the Bluetooth communication channel with the highest SNR can be re-selected as the current master node communication channel; the first preset time can be determined according to the actual situation, and the current master node communication channel is used for the communication between the master node device and the slave node device.

[0058] In this embodiment, during the communication between the master node device and the slave node device, the master node device monitors the SNR of the current master node communication channel at a first preset time; if the SNR of the current master node communication channel is lower than the preset SNR threshold, the master node device re-scans the preset frequency band to obtain the SNR of each Bluetooth communication channel, so as to select the Bluetooth communication channel with the highest SNR as the current master node communication channel, which optimizes the reliability of the communication between the master node device and the slave node device and the signal anti-interference ability.

[0059] In one embodiment, during the communication between the master node device and the slave node device, the master node device sends a synchronization signal to the slave node device according to a second preset time; the slave node device performs clock calibration based on the received synchronization signal.

[0060] During the communication between the master node device and the slave node device, the master node device sends a synchronization signal to the slave node device according to a second preset time; the slave node device performs clock calibration based on the received synchronization signal. The clock calibration is shown in Equation (1). The second preset time can be determined according to the actual situation.

[0061] (1)

[0062] In the formula, is the timestamp of the slave node device i, is the timestamp of the reference slave node device, is the clock difference between the slave node device i and the slave node device j.

[0063] In this embodiment, the slave node device performs clock calibration according to the received synchronization signal, which can synchronize the clocks of each slave node device to a unified standard, ensure the accurate synchronization of the clocks of each slave node device, and avoid the confusion of operation data caused by time deviation.

[0064] In one embodiment, during the communication between the slave node device and the master node device, the slave node device obtains a frequency hopping sequence according to the initial frequency and the frequency step value; when the slave node device detects congestion or interference in the slave node communication channel, it switches the frequency of the slave node communication channel according to the frequency hopping sequence.

[0065] During the communication between the slave node device and the master node device, the slave node device can perform frequency hopping in a pseudo-random mode and perform adaptive adjustment of the frequency of the slave node communication channel in combination with spectrum analysis to avoid congestion or interference in the slave node communication channel.

[0066] The slave node device can obtain a frequency hopping sequence according to the initial frequency and the frequency step value, as shown in Equation (2). Equation (2) can also be called the frequency hopping formula.

[0067] (2)

[0068] In the formula, is the i-th frequency in the frequency hopping sequence, is the initial frequency, is the frequency step value, is a random number generated by a pseudo-random number generator, dimensionless.

[0069] When the child node device detects congestion or interference in the child node communication channel, it can switch the frequency of the child node communication channel according to the frequency hopping sequence.

[0070] In this embodiment, during the communication process between the child node device and the master node device, the child node device obtains a frequency hopping sequence according to the initial frequency and the frequency step value; when the child node device detects congestion or interference in the child node communication channel, it switches the frequency of the child node communication channel according to the frequency hopping sequence, which can avoid congestion or interference in the child node communication channel.

[0071] In one embodiment, one of the child node devices obtains the weighted propagation delay time of each child node device according to the weighting coefficient and the propagation delay time of each child node device; one of the child node devices determines the forwarding node device among the child node devices according to the received signal strength and the weighted propagation delay time of each child node device; one of the child node devices transmits the operation data collected at its end to the master node device through the forwarding node device.

[0072] One of the child node devices can obtain the weighted propagation delay time of each child node device according to the weighting coefficient and the propagation delay time of each child node device; one of the child node devices can determine the forwarding node device among the child node devices according to the received signal strength and the weighted propagation delay time of each child node device, as shown in Equation (3).

[0073] (3)

[0074] In the formula, is the selected forwarding node device, is the received signal strength of child node device i, is the propagation delay time of child node device i, is the weighting coefficient. The weighting coefficient has a value range of [0.1, 1], and the value of the weighting coefficient can be adjusted according to the actual situation.

[0075] One of the child node devices transmits the operation data collected at its end to the master node device through the forwarding node device.

[0076] In this embodiment, by the signal strength and propagation delay time of each child node device, the child node device with the best performance of signal strength and propagation delay time among the child node devices is determined as the forwarding node device, which can ensure the efficiency of operation data transmission.

[0077] In one embodiment, the master node device, as the central node device of the photovoltaic power station, communicates with the upper system and uploads the operation status of the photovoltaic power station to the cloud monitoring platform.

[0078] The master node device can serve as the central node device of a photovoltaic power station, communicate with the upper-level system, and upload the operating status of the photovoltaic power station to the cloud monitoring platform through Wi-Fi, LoRa, or 4G / 5G technology, so as to achieve cross-station data integration and intelligent scheduling of the operating status of each photovoltaic power station.

[0079] After receiving the operating status of the master node devices of each photovoltaic power station, the cloud monitoring platform can comprehensively analyze and schedule the operating status of the master node devices of each photovoltaic power station.

[0080] To better understand the wireless monitoring system of the photovoltaic power station introduced in the above embodiments, the following details an application embodiment of the wireless monitoring system of the photovoltaic power station of the present application.

[0081] With the substantial increase in social electricity consumption, distributed photovoltaic power generation technology, as an important supplementary power source, has the advantages of wide distribution and environmental friendliness, and has become the most widely used clean power generation technology at present. Currently, distributed photovoltaic power generation technology has more deployments in remote areas, coastal islands, the sea, rooftops, and vacant residential plots. However, distributed photovoltaic power stations are scattered in locations, and the form of power output is unstable, which brings certain difficulties to monitoring and control. It is necessary to monitor photovoltaic power stations in real time to improve the power generation, operating reliability, and economy of photovoltaic power stations.

[0082] The current power Internet of Things uses wired and wireless communication transmission methods to connect and communicate with distributed photovoltaic power stations. However, the wired transmission method requires laying cables during the transmission process. Therefore, the cost is relatively high, especially for the deployment of a large number of distributed photovoltaic power stations, and the wiring difficulty is relatively large, and the requirements for construction technology are also relatively complex, resulting in a large construction difficulty. Moreover, in the areas of distributed photovoltaic power stations with extreme environments or poor geographical conditions, due to the complex and changeable electromagnetic environment, the reliability of the lines is relatively poor, and signal interruption is likely to occur, making it difficult to meet the monitoring requirements. In contrast, using the wireless communication method, with radio waves as the control signal of the photovoltaic power station propagated by electromagnetic waves, to achieve wireless remote monitoring of the photovoltaic power station, the cost is relatively low, the line laying is simple, and it is not restricted by the geographical environment, and has the characteristics of being able to monitor at any time and place. Currently, the more commonly used is the wireless 4G and 5G base station technologies, but their network construction costs are high, the network construction cycle is long; and the base station site selection is difficult, the power consumption is high, and both require wired power supply and are difficult to maintain. Moreover, the coverage area is relatively small and cannot meet the interconnection between any two nodes. Especially for distributed photovoltaic power stations in remote areas, it is not suitable to use 4G and 5G base station technologies.

[0083] In summary, the existing wireless monitoring systems of photovoltaic power stations have the following problems:

[0084] (1) The cost of wired transmission is relatively high, the wiring is difficult, the construction process is complex, and the reliability of the line is poor in extreme environments or areas with poor geographical conditions, which is likely to cause signal interruption.

[0085] (2) The construction cost of wireless 4G and 5G base station technology networks is high, the cycle is long, the site selection is difficult, the power consumption is high, wired power supply is required, the maintenance is difficult, and the coverage area is small, which cannot meet the interconnection between any two nodes, especially not suitable for distributed photovoltaic power stations in remote areas.

[0086] In response to this, this embodiment proposes a wireless detection system for a photovoltaic power station based on Bluetooth communication. The wireless detection system for the photovoltaic power station includes sub-node devices and a main-node device. Among them, the sub-node devices are used to monitor the operating status of each internal component of the photovoltaic power station, obtain the operating data of each internal component of the photovoltaic power station, and send the operating data of each internal component of the photovoltaic power station to the main-node device; the sub-node devices are connected to each other in pairs in the form of Bluetooth to form a sub-node mesh network; the main-node device is used to receive the operating data sent by the sub-node devices. If the operating data is transmitted correctly, according to the operating data, the operating status of the photovoltaic power station is summarized to wirelessly monitor the photovoltaic power station; the main-node device is connected to the sub-node devices in the form of Bluetooth.

[0087] Among them, the communication frequency selection and frequency hopping steps between the main-node device and the sub-node devices are as follows: The main-node device selects the best frequency channel based on spectrum analysis and signal-to-noise ratio, and dynamically adjusts the frequency for communication to avoid interference and channel congestion.

[0088] 1. The wireless detection system for the photovoltaic power station establishes a Bluetooth low-power transmission mechanism based on adaptive frequency hopping and coding technology:

[0089] 1.1 Adaptive frequency hopping algorithm:

[0090] Before establishing the link of the wireless monitoring system for the photovoltaic power station, 3 frequency channels can be preset, which are respectively used for link and network data transmission, positioning data transmission or emergency communication between the main-node device and the sub-node devices.

[0091] Frequency hopping can be performed in a pseudo-random mode, and adaptive adjustment of the communication channel is combined with spectrum analysis.

[0092] Spectrum analysis: Before establishing the link of the wireless monitoring system for the photovoltaic power station, the main-node device can perform spectrum scanning on the preset frequency band, detect the interference situation of each Bluetooth communication channel, and calculate the signal-to-noise ratio of each Bluetooth communication channel.

[0093] Frequency selection: According to the signal-to-noise ratio of each Bluetooth communication channel, select the Bluetooth communication channel with the highest signal-to-noise ratio as the current main-node communication channel.

[0094] The child node device can obtain a frequency hopping sequence based on the initial frequency and the frequency step value, as shown in Equation (2). Equation (2) can also be referred to as the frequency hopping formula.

[0095] (2)

[0096] In the formula, is the i-th frequency in the frequency hopping sequence, is the initial frequency, is the frequency step value, is a random number generated by a pseudo-random number generator, dimensionless.

[0097] In an actual photovoltaic power station, multiple child node devices can dynamically adjust the frequency according to this formula for data communication to avoid channel congestion.

[0098] The steps for adaptive adjustment of the main node communication channel are as Figure 4 shown: Step S401, during the communication process between the main node device and the child node device, the main node device can monitor the signal-to-noise ratio of the current main node communication channel at a first preset time; Step S402, if the signal-to-noise ratio of the current main node communication channel is lower than the preset signal-to-noise ratio threshold, the main node device can re-scan the spectrum of the preset frequency band, detect the interference situation of each Bluetooth communication channel, and calculate the signal-to-noise ratio of each Bluetooth communication channel; Step S403, the Bluetooth communication channel with the highest signal-to-noise ratio can be reselected as the current main node communication channel according to the signal-to-noise ratio of each Bluetooth communication channel; where the first preset time can be determined according to the actual situation, and the current main node communication channel is used for communication between the main node device and the child node device.

[0099] 1.2 Low-density parity-check coding parameters:

[0100] Low-density parity-check (LDPC) coding can be used for error correction of the communication channel. The code length of the low-density parity-check coding is 1024, and the code rate is 4 / 5. The parity-check matrix H of the low-density parity-check coding is generated by a sparse matrix and adopts the Gallager construction method. The decoding algorithm adopts the Belief Propagation algorithm.

[0101] 1.3 Non-standard advanced encryption algorithm:

[0102] A non-standard advanced (Advanced Encryption Standard, AES) encryption algorithm based on the optimization of the S-Box is adopted.

[0103] S-Box Optimization: Improve the S-Box of the Advanced Encryption Standard algorithm to increase its non-linearity and resistance to differential analysis.

[0104] Key Length: Adopt a 128-bit key.

[0105] Encryption Mode: Adopt the Counter (CTR) mode.

[0106] Among them, the networking and clock synchronization steps between the master node device and the slave node device are as follows: Under the coordination of the master node device, the slave node devices are networked through the star and Mesh network methods, and the master node device regularly sends synchronization signals to the slave node devices to ensure the accurate clock synchronization of each node device.

[0107] 2. Networking Technology Based on the Combination of Star and Mesh:

[0108] 2.1 Networking Method:

[0109] The slave node devices are networked in the Mesh mode to form a Mesh network to achieve multi-hop transmission of data.

[0110] The master node device and the slave node devices are networked in the star mode. The master node device serves as the central node and is responsible for communicating with the upper-level system.

[0111] 2.2 Clock Synchronization Mechanism:

[0112] During the communication process between the master node device and the slave node devices, the slave node devices need to perform clock calibration. The specific steps are as Figure 5 shown: Step S501, the master node device sends a synchronization signal to the slave node devices according to the second preset time; Step S502, the slave node devices adjust their own clocks according to the received synchronization signal to perform clock calibration. The second preset time can be determined according to the actual situation.

[0113] Clock Calibration: The slave node devices can perform clock calibration according to Equation (1).

[0114] (1)

[0115] In the formula, is the timestamp of slave node device i, is the timestamp of the reference slave node device, is the clock difference between slave node device i and slave node device j.

[0116] This formula can ensure that the clocks of each slave node device can be synchronized to a unified standard, avoiding data chaos caused by time deviation.

[0117] 2.3 Node Selection Algorithm:

[0118] When the child node forwards data, it selects the forwarding node according to Equation (3).

[0119] (3)

[0120] In the formula, is the selected forwarding node device, is the received signal strength of the child node device i, is the propagation delay time of the child node device i, is the weighting coefficient. Among them, the weighting coefficient has a value range of [0.1, 1], and the value of the weighting coefficient can be adjusted according to the actual situation.

[0121] This formula can ensure the efficiency of the operation data transmission by optimizing the signal strength and delay time.

[0122] Among them, the data transmission and coding optimization steps between the master node device and the child node device are as follows: When transmitting data between node devices, low-density parity-check coding is used for channel error correction, and non-standard advanced encryption technology is used to ensure the security and integrity of the data.

[0123] 3. Data acquisition communication protocol based on multi-node device clock synchronization:

[0124] 3.1 Data marking:

[0125] Based on the clock synchronization of each child node device, time marking is performed on the communication and data transmission of the child node device, so that the transmitted data has the function of self-checking and self-identifying.

[0126] Time marking accuracy: accurate to the millisecond level.

[0127] 3.2 Data format:

[0128] The transmitted data format adopts the protocol header + data field + check code format.

[0129] Protocol header: contains information such as node identifier (Identity, ID), data type, and timestamp.

[0130] Data field: adopts the Extensible Markup Language (XML) format to describe the collected operation data of the photovoltaic power station.

[0131] Check code: adopts Hamming check to detect data transmission errors.

[0132] Among them, the positioning and error detection steps between the master node device and the slave node device are as follows: Node device positioning is carried out through double-sideband modulation and time slot coordination technology, and the reliability of network transmission is optimized by combining error detection and error correction technology to ensure accurate data transmission.

[0133] 4. Positioning technology based on double-sideband modulation signal:

[0134] 4.1 Positioning signal modulation:

[0135] The positioning signal is modulated by using double-sideband modulation (Bi-Phase Shift Keying, BPSK) technology.

[0136] Modulation formula:

[0137] (4)

[0138] Among them, is the modulation signal, is the signal amplitude, is the carrier frequency, is the phase, is the message signal.

[0139] 4.2 Time slot coordination:

[0140] Multiple slave node devices send positioning signals within different time periods. To avoid interference, a time slot coordination mechanism is adopted.

[0141] Time slot allocation formula:

[0142] (5)

[0143] Among them, is the transmission time slot of each node, is the total time period, is the number of nodes in the network.

[0144] 4.3 Positioning algorithm:

[0145] The positioning distance between node devices is calculated by the Time Difference Of Arrival (TDOA).

[0146] Distance calculation formula:

[0147] (6)

[0148] Among them, is the distance between node device i and node device j, is the signal propagation speed, is the time difference between node device i and node device j. is the time stamp of the reference node device.

[0149] 5. Bluetooth Low Energy Network Optimization Technology Based on Error Detection and Correction Technology:

[0150] 5.1 Low-Density Parity-Check (LDPC) Error-Correcting Code:

[0151] Introduce a Low-Density Parity-Check (LDPC) error-correcting code with a code length of 1024 and a code rate of 4 / 5.

[0152] At the Media Access Control (MAC) layer, use the low-density parity-check coding to suppress interference and improve the channel error-correcting ability.

[0153] 5.2 Data Verification:

[0154] Detect the operation data received by the master node device by using the parity bit re-coding based verification method to ensure error-free transmission.

[0155] Verification process:

[0156] The slave node device can divide the operation data of each internal component of the photovoltaic power station into several data blocks; can calculate the parity check bits of each data block to obtain the first parity check bits corresponding to several data blocks; can send several data blocks and the first parity check bits corresponding to several data blocks to the master node device.

[0157] After receiving the operation data sent by the slave node device, the master node device can perform parity bit re-coding verification on the operation data to determine whether the operation data is transmitted correctly. Specifically, it can re-calculate the parity check bits of the received several data blocks to obtain the second parity check bits of several data blocks; can compare the first parity check bits and the second parity check bits of several data blocks; when the first parity check bits and the second parity check bits of several data blocks are consistent, it is confirmed that the operation data is transmitted correctly; when the first parity check bits and the second parity check bits of several data blocks are inconsistent, it is confirmed that the operation data is transmitted incorrectly.

[0158] The photovoltaic power station wireless monitoring system provided in this embodiment can optimize the reliability of wireless communication and the signal anti-interference ability through adaptive frequency hopping and low-density parity-check coding technology; can combine non-standard advanced encryption algorithm and parity check mechanism to ensure the security and integrity of the operation data transmission; can improve the transmission efficiency and positioning accuracy of the system through the combination of star and mesh networks, precise clock synchronization and high-efficiency positioning technology.

[0159] It should be understood that although the steps in the flowcharts involved in the above-described embodiments are sequentially shown according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear indication in this article, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-described embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or steps or stages in other steps.

[0160] In one embodiment, a sub-node device is further provided. The sub-node device is the sub-node device included in the wireless monitoring system of the photovoltaic power station introduced in the above embodiment.

[0161] In one embodiment, a master-node device is further provided. The master-node device is the master-node device included in the wireless monitoring system of the photovoltaic power station introduced in the above embodiment.

[0162] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0163] Those of ordinary skill in the art can understand that implementing all or part of the processes in the above embodiments can be accomplished by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the above embodiments. Among them, any reference to a memory, database, or other medium used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in this application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in this application can be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, data processing logics based on quantum computing, artificial intelligence (AI) processors, etc., without limitation.

[0164] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope recorded in this application.

[0165] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A wireless monitoring system for a photovoltaic power station, characterized in that: The system comprises: The sub-node device is used to monitor the operating status of each internal component of the photovoltaic power station, obtain the operating data of each internal component of the photovoltaic power station, and send the operating data of each internal component of the photovoltaic power station to the main node device; the sub-node devices are connected to each other in pairs through Bluetooth to form a sub-node mesh network; The master node device is used to receive the operating data sent by the sub-node device. If the operating data is transmitted correctly, the operating status of the photovoltaic power station is summarized based on the operating data to wirelessly monitor the photovoltaic power station. The master node device is connected to the sub-node device via Bluetooth.

2. The system according to claim 1, characterized in that The sub-node device sends the operation data of each internal component of the photovoltaic power station to the main node device, specifically including: Dividing the operation data of each internal component of the photovoltaic power station into a plurality of data blocks; Calculating a parity check bit of each data block to obtain a first parity check bit corresponding to the plurality of data blocks; The plurality of data blocks and first parity check bits corresponding to the plurality of data blocks are sent to a master node device.

3. The system according to claim 1, characterized in that After receiving the operation data sent by the sub-node device, the master node device is further used to: Recalculating parity bits of the received data blocks to obtain second parity bits of the data blocks; Comparing the first parity bits and the second parity bits of the plurality of data blocks; When the first parity check bits and the second parity check bits of the plurality of data blocks are consistent, it is confirmed that the running data transmission is correct.

4. The system according to claim 1, characterized in that During the communication between the master node device and the sub-node device, the master node device monitors the signal-to-noise ratio of the current master node communication channel according to a first preset time; If the signal-to-noise ratio of the current master node communication channel is lower than the preset signal-to-noise ratio threshold, re-scan the preset frequency band to detect the interference of each Bluetooth communication channel and calculate the signal-to-noise ratio of each Bluetooth communication channel; According to the signal-to-noise ratios of the Bluetooth communication channels, the Bluetooth communication channel with the highest signal-to-noise ratio is selected as the current master node communication channel; the current master node communication channel is used for communication between the master node device and the sub-node device.

5. The system according to claim 1, characterized in that During the communication between the master node device and the sub-node device, the master node device sends a synchronization signal to the sub-node device according to a second preset time; The sub-node device performs clock calibration according to the received synchronization signal.

6. The system according to claim 1, characterized in that During the communication between the sub-node device and the master node device, the sub-node device obtains a frequency hopping sequence according to an initial frequency and a frequency step value; When the sub-node device detects that the sub-node communication channel is congested or interfered, the frequency of the sub-node communication channel is switched according to the frequency hopping sequence.

7. The system according to claim 1, characterized in that One of the sub-node devices obtains the weighted propagation delay time of each sub-node device according to the weighted coefficient and the propagation delay time of each sub-node device; One of the sub-node devices determines a forwarding node device in each sub-node device according to the received signal strength and weighted propagation delay time of each sub-node device; One of the sub-node devices transmits the operation data collected locally to the main node device through the forwarding node device.

8. The system according to claim 1, characterized in that The master node device serves as the central node device of the photovoltaic power station, communicates with the host system, and uploads the operating status of the photovoltaic power station to the cloud monitoring platform.

9. A sub-node device, characterized in that: The sub-node device is a sub-node device included in the photovoltaic power station wireless monitoring system as described in claims 1 to 8.

10. A master node device, characterized in that: The master node device is the master node device included in the photovoltaic power station wireless monitoring system as described in claims 1 to 8.

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