Wireless data acquisition system and method for photovoltaic intelligent combiner box

Abstract

The invention discloses a wireless data acquisition system and method for a photovoltaic intelligent combiner box, the system is composed of a sending end deployed in the combiner box and a data convergence and return terminal arranged in a centralized manner, and the sending end sends acquired operation data to the convergence terminal through a first wireless link by using a LoRa communication module; the processor in the terminal performs analysis, aggregation, compression and protocol conversion processing on the received multi-path data, and then uniformly uploads the data to a cloud management platform through a 4G / 5G cellular network module via a second wireless link, the method realizes local low-power-consumption, long-distance and high-penetration data collection through the LoRa technology, effectively overcomes the wiring problem of complex terrains, and improves the data collection efficiency. According to the invention, complex wired wiring is reduced, a high-reliability star-shaped network is constructed, the deployment and operation and maintenance cost is remarkably reduced, and an efficient and stable intelligent data acquisition solution is provided for a photovoltaic power station.

Description

Technical Field

[0001] This invention belongs to the field of intelligent operation and maintenance technology for photovoltaic power plants, and in particular, it is a data acquisition system and method for photovoltaic intelligent combiner boxes based on LoRa wireless communication technology. Background Technology

[0002] As an important component of clean energy, photovoltaic power generation continues to expand in scale, and the demand for intelligent operation and maintenance of power plants is becoming increasingly prominent.

[0003] In photovoltaic power plants, the combiner box is a key device connecting photovoltaic strings and inverters. It mainly undertakes the function of collecting multiple DC currents and monitoring the operating status of the strings. Real-time and reliable data acquisition of the combiner box is the foundation for ensuring the efficient and safe operation of the power plant. Therefore, developing a stable and efficient data acquisition system is of great significance for improving the overall management level of photovoltaic power plants.

[0004] Currently, data acquisition in photovoltaic combiner boxes mainly relies on wired and wireless technologies, but both have certain limitations.

[0005] The mainstream solution uses RS485 communication combined with the MODBUS-RTU protocol, which requires all combiner boxes to be connected to the communication acquisition unit in a "daisy-chain" topology via shielded twisted-pair cables. This method has obvious drawbacks in actual deployment: First, when constructing in complex terrain (such as mountains and water areas), the cabling often needs to be detoured or excavated, and the cables need to be buried in conduits or installed in cable trays, resulting in high engineering difficulty, long cycle, and high cost; Second, the presence of a large number of cables and connectors increases the line failure rate, and the subsequent maintenance cost and difficulty also increase.

[0006] To overcome the shortcomings of wired cabling, existing technologies have attempted to use wireless modules such as Bluetooth, WiFi, or GPRS. However, Bluetooth and WiFi have short transmission distances, making it difficult to meet the coverage needs of the vast areas of photovoltaic power plants. While cellular network technologies such as GPRS can achieve long-distance transmission, their high power consumption is not conducive to the long-term stable operation of the system. More importantly, to extend the coverage area, these wireless solutions usually require multi-level repeater networking, which not only significantly increases hardware costs, deployment complexity, and total system power consumption, but also introduces a fatal problem: each repeater becomes a potential point of failure. The failure of any node will cause the loss of data in all downstream combiner boxes, resulting in a decrease in the overall availability of the system. In addition, the cascading forwarding of data also brings a significant transmission delay.

[0007] In summary, existing technologies struggle to achieve a good balance across multiple key dimensions, including ease of construction, system reliability, remote transmission capability, and power consumption control. Therefore, there is an urgent need in this field for a novel data acquisition solution that can simultaneously meet the following improvement objectives:

[0008] (1) Completely eliminates complex wiring, reduces construction and maintenance costs, and easily adapts to various complex terrains;

[0009] (2) Build a highly reliable wireless network to avoid large-scale data interruption caused by the failure of a single node and improve the overall availability of the system;

[0010] (3) Achieve an organic combination of low power consumption and long-distance transmission, ensuring stable data transmission back to the cloud while extending the service life of the equipment;

[0011] (4) It has good scalability and flexibility, and can be easily adapted to photovoltaic power plants of different sizes. Summary of the Invention

[0012] To address the problems of complex wiring, low reliability, high power consumption, and poor scalability in the aforementioned background technologies, this invention proposes a wireless data acquisition system and method for photovoltaic intelligent combiner boxes. The aim is to completely eliminate complex wiring by constructing a hybrid network architecture that combines local long-distance low-power communication with remote cellular network backhaul, significantly improving system reliability and maintainability, and meeting the application requirements of large-scale photovoltaic power plants for efficient, stable, and flexible data acquisition systems.

[0013] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0014] A photovoltaic intelligent combiner box wireless data acquisition system includes a transmitter and a data aggregation and backhaul terminal.

[0015] The transmitting end is located inside the photovoltaic combiner box and includes a first communication module and a first antenna connected to the first communication module.

[0016] The data aggregation and backhaul terminal includes a second communication module, a cellular network communication module, and a processor.

[0017] The first communication module and the second communication module communicate via a first wireless link; the cellular network communication module is configured to establish communication with the cloud management platform via a second wireless link; the processor is connected to the second communication module and the cellular network communication module respectively, and is configured to process data from the second communication module and forward it through the cellular network communication module.

[0018] Furthermore, the first communication module is a LoRa communication module, the first antenna is an external antenna, and the second communication module is a LoRa concentrator module. This design utilizes the characteristics of LoRa technology, such as long transmission distance, strong penetration capability, and low power consumption, to effectively overcome the shielding effect of the metal enclosure of the combiner box, and realizes stable data acquisition of distributed combiner boxes in complex terrain without the need to lay any wired lines.

[0019] Furthermore, the cellular network communication module is a 4G or 5G communication module, enabling the system to reliably transmit data back to a remote cloud platform using a widely covered public cellular network, thus overcoming the limitations of private networks such as LoRa in wide-area interconnection.

[0020] Furthermore, the processor performs data compression and protocol conversion. Even further, the data compression involves packaging multiple data records into a single data set, which significantly reduces the amount of data transmitted over the cellular network, lowers traffic consumption and communication costs, and simultaneously completes the conversion from device-side protocol to cloud platform protocol, thereby improving system integration efficiency.

[0021] Correspondingly, a wireless data acquisition method for a photovoltaic smart combiner box includes the following steps:

[0022] S1. Collect the operating data of the photovoltaic combiner box through the transmitting end, and send the operating data to the data aggregation and backhaul terminal through the first wireless link;

[0023] S2. Receive the operation data through the data aggregation and feedback terminal, and process the operation data;

[0024] S3. The processed data is transmitted back to the cloud management platform via the second wireless link through the data aggregation and backhaul terminal.

[0025] The first wireless link is a LoRa wireless link, and the second wireless link is a cellular network.

[0026] Furthermore, the processing of the operational data includes parsing, verifying, and aggregating the data to ensure its integrity and accuracy.

[0027] Furthermore, the processing also includes compressing and protocol conversion of the aggregated data, which effectively improves data transmission efficiency.

[0028] Furthermore, the data is transmitted via scheduled reporting and / or event-triggered reporting. This flexible reporting mechanism can meet the periodic needs of routine monitoring and also report immediately when abnormal conditions such as equipment failure occur, thus achieving real-time and accurate monitoring of the power plant's status.

[0029] Compared with the prior art, the technical solution provided by the present invention has the following main advantages:

[0030] (1) The adoption of LoRa wireless communication completely replaces the traditional RS485 wired wiring, greatly simplifies the construction process, and reduces the installation difficulty and comprehensive costs of cables, pipes, and manpower in complex terrain.

[0031] (2) By using a star or centralized receiving network, each combiner box transmitter communicates directly with the data aggregation terminal, eliminating the need for a multi-level relay structure. This means that a failure of a single node only affects the device itself and will not cause large-scale data loss, thus fundamentally improving the overall availability and stability of the system.

[0032] (3) It makes full use of LoRa technology’s long-distance transmission capability under low power consumption, ensuring the long-term stable operation of the transmitting device. At the same time, through data compression and intelligent reporting strategies, it effectively controls the energy consumption and traffic of the cellular network, achieving the optimal balance between power consumption and performance in local and remote communication.

[0033] (4) The system architecture supports the convenient addition, deletion or movement of combiner box nodes, which is easy to adapt to the dynamic changes in the scale of the power station. The edge computing capability of the data aggregation terminal reduces the burden on the cloud and provides a solid data foundation for the intelligent operation and maintenance of photovoltaic power stations.

[0034] In summary, this invention, through collaborative innovation in system architecture and communication methods, effectively solves the long-standing pain points of existing photovoltaic combiner box data acquisition technology in terms of engineering implementation, operational reliability, and overall cost, providing an efficient and reliable solution for the intelligent operation and maintenance of modern photovoltaic power plants. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the working process of the photovoltaic intelligent combiner box wireless data acquisition system of the present invention. Detailed Implementation

[0036] To enhance understanding of the present invention, the invention will be further described in detail below with reference to embodiments and accompanying drawings. These embodiments are only for explaining the invention and do not constitute a limitation on the scope of protection of the invention.

[0037] The core concept of the photovoltaic intelligent combiner box wireless data acquisition system and method provided by this invention is to construct a hybrid communication architecture that organically combines local low-power wide area network with remote cellular backhaul technology, thereby achieving significant optimization in terms of engineering deployment, system power consumption and transmission reliability.

[0038] like Figure 1 As shown, the system follows the following process in actual operation: First, each smart combiner box distributed in the photovoltaic array transmits the collected operating data to the nearest installed data aggregation and backhaul terminal via a LoRa wireless link through its internal integrated transmitter. Then, the terminal performs necessary processing and aggregation on the received data, and finally uploads it to the remote cloud management platform through a 4G or 5G cellular network, thereby realizing centralized monitoring and intelligent management of the entire power station's operating status.

[0039] As a key component for realizing wireless data transmission in the combiner box, the transmitter's core task is to deeply integrate the LoRa communication module with the combiner box itself. Specific implementation methods include hardware connection, power supply scheme, and antenna design.

[0040] In terms of hardware connectivity, the first communication module preferably adopts an industrial-grade LoRa communication module. This module connects to the existing intelligent monitoring unit inside the combiner box through its RS-485 interface, thereby stably acquiring operating data including the current, voltage, power, temperature, and various fault states of each string.

[0041] In terms of power supply, the LoRa communication module is directly powered by the power circuit inside the combiner box. Its typical operating voltage is DC 12V or 24V. This power supply method eliminates the need for a separate power supply, effectively simplifying the system structure and improving integration.

[0042] In terms of antenna design, in order to overcome the shielding effect of the metal enclosure of the combiner box on wireless signals, the first antenna is preferably an external antenna. This antenna is connected to the LoRa communication module through a low-loss RF feeder and leads out of the box through a waterproof connector on the enclosure wall. A preferred installation method is to use a magnetic base to firmly and conveniently attach the antenna to the metal surface on the top or side of the combiner box, thereby ensuring the best signal transmission effect.

[0043] The data aggregation and backhaul terminal plays the role of a data hub in the system, responsible for receiving, processing and remotely transmitting data.

[0044] In terms of hardware integration, the second communication module preferably adopts a multi-channel LoRa concentrator module, which is connected to the embedded main control board as a processor through the SPI interface. The cellular network communication module preferably adopts an LTE Cat.1 communication module, which is connected to the main control board through the UART interface. The selected embedded main control board should have lightweight edge computing capabilities, such as using an MCU based on the ARM Cortex-M core.

[0045] The terminal is equipped with two independent antenna systems: one omnidirectional antenna for receiving LoRa signals and the other a 4G or 5G antenna for cellular network communication.

[0046] Its workflow can be divided into three steps:

[0047] First, the data aggregation step is performed by the LoRa concentrator module, which continuously listens for and receives LoRa data packets sent by all transmitters within its coverage area;

[0048] After signal reception and demodulation are completed, the data processing step begins. The embedded main control board parses, verifies, and aggregates the demodulated data. The key feature of this process is that the main control board does not simply forward the data, but performs intelligent edge processing, including compressing multiple data records from multiple combiner boxes, for example, packaging them into a JSON array, and converting the original device protocol into an IoT protocol suitable for cloud platforms. This processing method significantly reduces the data traffic consumption of cellular networks.

[0049] Finally, in the intelligent backhaul step, the processed data is transmitted to the cloud management platform efficiently and economically through the network connection established by the LTE Cat.1 module, using a combination of timed reporting and event-triggered reporting.

[0050] To facilitate a further understanding of the practical application of this invention, a specific implementation example is provided below.

[0051] Suppose a large photovoltaic power station is located in a hilly area with significant terrain undulations. The combiner boxes are scattered and some are located on the back of the hillside. If a traditional RS485 wired solution is used, the wiring construction will face the problem of detouring around the mountain or digging tunnels, resulting in high costs and long cycles. If a wireless solution requiring multi-level relays is used, the system reliability is difficult to guarantee.

[0052] After applying the solution of this invention, firstly, a LoRa transmitter with an external antenna is installed in each photovoltaic combiner box in accordance with the above preferred method. Then, a data aggregation and backhaul terminal is installed on a transformer substation platform with a relatively central location and good 4G signal in the power station area.

[0053] During system operation, the operating data of all combiner boxes are directly transmitted to the centralized data terminal in a single-hop manner through their respective LoRa transmitters. With the help of the long-distance diffraction and penetration capabilities of LoRa technology, even combiner boxes located on the back of a hillside can establish a stable connection with the terminal. The data aggregation and backhaul terminal compresses and converts the large amount of data collected, and then uploads it to the power plant cloud monitoring center through the 4G network.

[0054] The implementation of this solution completely avoids the excavation and laying of long-distance cable trenches during construction, resulting in rapid deployment and reduced total investment costs. In terms of reliability, due to the use of star topology and the absence of relay nodes, communication failures in a single combiner box will not affect other boxes, significantly improving the overall communication success rate of the system. Regarding operation and maintenance costs, LoRa's low power consumption means that the transmitting end receives almost no additional burden, while data compression technology significantly reduces the monthly data consumption of the cellular network, bringing considerable economic benefits to the long-term operation of the power station.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A wireless data acquisition system for a photovoltaic intelligent combiner box, characterized in that, include: Sending end and data aggregation and backhaul terminal; The transmitting end is located inside the photovoltaic combiner box, and it includes a first communication module and a first antenna connected to the first communication module; The data aggregation and backhaul terminal includes a second communication module, a cellular network communication module, and a processor; The first communication module and the second communication module communicate via a first wireless link; The cellular network communication module is configured to establish communication with the cloud management platform via a second wireless link; The processor is connected to both the second communication module and the cellular network communication module, and is configured to process data from the second communication module and forward it through the cellular network communication module.

2. The wireless data acquisition system according to claim 1, characterized in that, The first communication module is a LoRa communication module, and the first antenna is an external antenna; the second communication module is a LoRa concentrator module.

3. The wireless data acquisition system according to claim 1, characterized in that, The cellular network communication module is either a 4G communication module or a 5G communication module.

4. The wireless data acquisition system according to claim 1, characterized in that, The processor performs data compression and protocol conversion.

5. The wireless data acquisition system according to claim 4, characterized in that, The data compression involves packaging multiple data records into a single data set.

6. A wireless data acquisition method for a photovoltaic intelligent combiner box, characterized in that, The method includes: S1. Collect the operating data of the photovoltaic combiner box through the transmitting end, and send the operating data to the data aggregation and backhaul terminal through the first wireless link; S2. Receive the operation data through the data aggregation and feedback terminal, and process the operation data; S3. The processed data is transmitted back to the cloud management platform via the second wireless link through the data aggregation and backhaul terminal. The first wireless link is a LoRa wireless link, and the second wireless link is a cellular network.

7. The wireless data acquisition method according to claim 6, characterized in that, Processing the operational data includes parsing, validating, and aggregating the data.

8. The wireless data acquisition method according to claim 7, characterized in that, Processing the runtime data also includes compressing and protocol conversion of the aggregated data.

9. The wireless data acquisition method according to claim 8, characterized in that, The compression refers to packaging multiple data records into a single data set.

10. The wireless data acquisition method according to claim 6, characterized in that, Data is returned via scheduled reporting and / or event-triggered reporting.

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