Intelligent combiner box monitoring system based on LoRa wireless communication

Abstract

The invention discloses a combiner box intelligent monitoring system based on LoRa wireless communication. A microcontroller is arranged in each combiner box and connected with a first LoRa communication module, a display screen, an operation key, an RS485 communication module, a signal detection module, an energy storage tripping module and a power module, and the microcontroller monitors the bus voltage of a photovoltaic string, the current, temperature and humidity of each branch, the state of a circuit breaker and the state of a lightning protection device in real time through the signal detection module. The first LoRa communication module communicates with the first LoRa communication module in real time to process a data transceiving problem; and when an abnormal condition is detected, an instruction signal is sent to the energy storage tripping module to execute a tripping action. And data or state query is carried out on the combiner box of a specific address at the client information query end through the second LoRa communication module. The system can realize real-time monitoring and control of a plurality of combiner boxes in a photovoltaic power station, and realizes remote, efficient and stable data transmission through a LoRa wireless communication technology, thereby improving the operation and maintenance efficiency and safety of the photovoltaic power station.

Description

Technical Field

[0001] The invention relates to a combiner box intelligent monitoring system based on LoRa wireless communication, belonging to the field of photovoltaic combiner boxes. Background Art

[0002] In recent years, the global photovoltaic industry has developed well. With the continuous advancement of photovoltaic technology and the continuous decline in costs, more and more countries and regions have begun to vigorously develop the photovoltaic industry. This has led to increasingly fierce competition in the international market. However, this has also brought more development opportunities and challenges to the photovoltaic industry.

[0003] Since most combiner box monitoring systems on the market currently use the traditional RS485 communication method, communication lines need to be set up between combiner boxes, inverters, box-type transformer systems, and communication management machines (or SCADA systems) to carry out data communication and control. This not only brings difficulties to construction, but also increases the line failure rate and various maintenance costs.

[0004] At the same time, the maximum transmission distance of RS-485 communication using cables is mainly affected by the transmission rate. At a transmission rate of 100kb / s, RS-485 can reach its maximum transmission distance, which is about 1200 meters. However, when the transmission rate increases, the transmission distance will decrease accordingly. For example, at a higher transmission rate, such as 10Mb / s, the transmission distance will be significantly shortened. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a combiner box intelligent monitoring system with integrated wireless LoRa communication function. The data transmission between the combiner box and external devices is carried out by wireless transmission, which reduces the on-site wiring links, effectively saves costs, improves the efficiency of installation and debugging, and greatly improves the flexibility and mobility of installation operations.

[0006] According to the technical solution provided by the present invention, the intelligent monitoring system for combiner boxes based on LoRa wireless communication is provided with a microcontroller in each combiner box, and the microcontroller is respectively connected to the first LoRa communication module, the display screen, the operation button, the RS485 communication module, the signal detection module, the energy storage trip module and the power module.

[0007] The microcontroller monitors the bus voltage of the photovoltaic string, the current of each branch, temperature, humidity, circuit breaker status, and lightning arrester status in real time through the signal detection module, and communicates with the first LoRa communication module in real time to handle data transmission and reception issues; when the system detects an abnormal situation, it sends a command signal to the energy storage tripping module to execute a tripping action, disconnect the bus main switch, and ensure the safety of the machine and connected equipment;

[0008] The customer information query end is connected to the second LoRa communication module. When the customer information query end queries the data or status of a combiner box at a specific address through the second LoRa communication module, the second LoRa communication module performs data parsing, encryption and format conversion on the query instruction, and sends the packaged data through the antenna; after receiving the instruction through the first LoRa communication module, the microcontroller in the combiner box parses the instruction, confirms that the slave address is consistent with the address set by the system, and after the verification code information is correct, the data to be queried is sent out through the first LoRa communication module; the second LoRa communication module receives the data instruction and parses it, and transmits the parsed data to the customer information query end;

[0009] The communication protocol format of the query instruction is: slave address + function code + register address + register quantity + check code, and the communication protocol format of the reply data instruction is: slave address + function code + number of bytes + register data + check code. The function codes here are all function codes representing queries.

[0010] In the above system, the operation buttons are used to set various system parameters, including bus voltage warning upper and lower limits, current warning upper and lower limits, temperature warning upper and lower limits, baud rate value, etc.

[0011] Furthermore, the LoRa communication module that issues queries or setting instructions is set as the master node, and the LoRa communication module that receives queries or setting instructions is set as the slave node. The data output between the LoRa master and slave nodes adopts the fixed-point transmission and transparent transmission reception mode. The master node adds the target address and target channel before sending the data. Only the slave node whose target address and channel match can receive the data sent by the master node.

[0012] The above system also includes a remote control with a built-in third LoRa communication module, which is used to remotely configure system parameters; operate the remote control to enter the setting mode, select the system parameters to be set, enter the numerical value and the target address and channel, and after confirmation, send the configuration command through the third LoRa communication module. The microcontroller in the corresponding combiner box parses the command after receiving it and modifies the system parameters of the combiner box.

[0013] The configuration instruction format is target address+function code+register address+register data+check code, where the function code represents the set function code.

[0014] The system supports two wake-up methods. One is to detect the light intensity through a photosensor connected to the microcontroller. When the light intensity meets the requirements in the morning, the system switches from sleep mode to normal working mode. When the light intensity is lower than the threshold in the evening, the system switches from normal working mode to sleep mode. The other is wireless signal wake-up. The wake-up command is sent through the information query end or the remote control end to restore the system from sleep mode to normal working mode.

[0015] The system also has a carrier monitoring function. By setting the address of a combiner box system or remote control end to 0xFFFF, it can monitor the data of all combiner box systems under the same channel. During functional testing or after-sales service, it is used to view the operation status of other combiner box systems in real time.

[0016] The advantages of the present invention are:

[0017] The present invention is an intelligent system that uses LoRa technology to realize remote monitoring and data transmission of combiner boxes. It is a monitoring solution for photovoltaic power plants for remote data transmission. The system can realize real-time monitoring and control of multiple combiner boxes in photovoltaic power plants, and realize remote, efficient and stable data transmission through LoRa wireless communication technology, thereby improving the operation and maintenance efficiency and safety of photovoltaic power plants.

[0018] The system is suitable for photovoltaic power stations, wind farms and other occasions that require remote monitoring of multiple distributed energy equipment. It can effectively improve operation and maintenance efficiency and reduce operation and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a hardware structure block diagram of a single combiner box system of the present invention.

[0020] Figure 2 This is a schematic diagram of fixed-point data transmission and reception between LoRa master and slave nodes.

[0021] Figure 3 It is a schematic diagram of the intelligent monitoring and remote control configuration of the present invention. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0023] like Figure 1 As shown, the present invention can be upgraded based on the existing combiner box intelligent system, and complete new functions on the basis of realizing the basic functions of the combiner box. Each combiner box is equipped with a microcontroller (single chip microcomputer 2), and a first LoRa communication module 1, an LCD display screen 3, a touch button 4, an RS485 communication module 5, a signal detection module 6, an energy storage trip module 7, and a power module 8 connected thereto, mainly realizing that a single combiner box monitors the bus voltage of the photovoltaic string, monitors the current of multiple photovoltaic strings, and monitors the temperature, humidity, circuit breaker status, and lightning arrester status inside and outside the box in real time; when the box-type transformer system or the customer backend (collectively referred to as the customer information query end) queries the combiner box for data or status through LoRa wireless communication, the combiner box system will promptly reply the information to the box-type transformer system or the customer backend (SCADA system) through the LoRa wireless communication module.

[0024] The component modules of the combiner box system are introduced in detail below.

[0025] 1. LoRa communication module: installed inside the combiner box monitoring system to achieve long-distance wireless transmission of data.

[0026] 2. Microcontroller (single-chip computer) unit: used to monitor bus voltage, branch current, temperature, humidity, circuit breaker status, lightning arrester status, etc., detect whether there is a key signal input, drive the LCD screen display, communicate with the LoRa module in real time, handle data transmission and reception problems, and perform tripping actions when the system detects abnormal conditions.

[0027] 3. LCD display unit: used to display bus voltage, branch current, temperature, humidity, various status values, etc. in real time.

[0028] 4. Touch buttons: used to set various system parameters, such as bus voltage warning upper and lower limits, current warning upper and lower limits, baud rate value, etc.

[0029] 5. RS485 communication: In addition to the LoRa communication function, the system also retains the RS485 communication circuit and interface for access to other detection equipment or modules.

[0030] 6. Signal detection: used for real-time detection of circuit breaker status, lightning arrester status, temperature and humidity sensor data, etc.

[0031] 7. Energy storage tripping: When the system detects that the temperature, voltage, and current values ​​have reached the warning values, the system will take protective measures and disconnect the busbar main switch to ensure the power supply safety of the system and the subsequent box-type transformer system.

[0032] 8. Power module: used to handle system power supply issues, convert the system bus DC voltage to 12V, and then convert the 12V voltage to 5V and 3.3V, which are used to power the LoRa module, microcontroller module, etc. The system supports a wide voltage range, with an input voltage range of DC 5V to 24V, and is compatible with various specifications of combiner boxes.

[0033] 9. Antenna 9: connected to the LoRa communication module, used to enhance the system communication signal and ensure that the communication distance between the master and slave nodes can reach more than 3KM.

[0034] like Figure 3 As shown, the figure includes photovoltaic strings a1~an, combiner box systems b1~bn, remote control g, and the second LoRa communication module c1 is connected to the SCADA system e or box transformer system f at the information query end through the switch d1 network.

[0035] The communication process is as follows: when the SCADA system e needs the parameters (such as voltage) in each combiner box system, it will issue a command to query the voltage in a combiner box at a specific address according to the agreed communication protocol format, such as: 01 (slave address) 03 (function code) 01 04 (register address) 00 01 (number of registers) C4 37 (check code). After the second LoRa communication module c1 receives the command to query the voltage value through the switch d1, it performs data encryption and format conversion internally and sends the data through the antenna. After the combiner box system b1 receives the command to query the voltage value, it parses the received command and confirms that the slave address 01 is consistent with the address set by the system, 03 represents the query function, and 01 04 is the register address for storing the voltage value. After verifying that the check code information is correct, the system sends the current voltage value through the first LoRa communication module. The protocol format for sending data instructions is: 01 (slave address) 03 (function code) 02 (number of bytes) 02BC (register data) B8 95 (check code). Similarly, the second LoRa communication module c1 receives and parses the data instruction, and transmits the voltage value 0x02bc to the SCADA system e and the box-type transformer system f through the MODBUS TCP protocol.

[0036] The present invention upgrades the traditional RS485 communication to LoRa wireless communication, adopts spread spectrum modulation technology, and brings a longer communication distance. It has stronger anti-interference ability, multiple transmission modes, and working frequency bands in 230 band, 400 band, 800 band, and 900 band, which can meet the use of different countries and regions around the world.

[0037] like Figure 2 As shown in the figure, the data output between the LoRa master and slave nodes adopts a fixed-point transmission and reception mode. Before sending data, the master node adds the target address and target channel before the data. Only the slave module with the matching target address and channel can receive the data sent by the master node.

[0038] The present invention also has a wake-up function: since this product mainly works under good light conditions during the day, the system is basically in a dormant state at night. The system supports two wake-up methods. One is to detect the light intensity through a photosensor. When the light meets the requirements in the morning, the system switches from the dormant state to the normal working state. When the light is very dim in the evening, the system switches from the normal working state to the dormant state. The other method is wireless signal air wake-up. Since this system contains a LoRa wireless communication module, when the system is in a dormant state, other communication modules (inverter end or handheld remote control) can issue a wake-up command to restore the system from the dormant state to the normal working state.

[0039] On the basis of the local configuration mode of the traditional system, the present invention adds a remote control function to configure the system parameters, avoiding the need to disconnect the power supply and unpack the configuration parameters on site. During on-site debugging or after-sales service, it is often necessary to configure the system parameters, such as setting the system bus voltage warning value of 1700V. When the value exceeds the warning protection state, the system enters the warning protection state by pressing the setting button on the matching remote control g, entering the setting mode, and then entering the voltage upper limit setting interface, adjusting the upper limit value to 1700V, and pressing the setting function key after the target address and channel are changed to the values ​​to be set, and sending the configuration instruction through the third LoRa communication module. After the corresponding junction box system receives the instruction, it parses the relevant information in the instruction and changes the local voltage value to 1700V. The configuration instruction is 01 (target address) 05 (function code) 01 04 (register address) 06A4 (register data) 8F EC (check code). 05 represents the setting function, 01 04 represents the register address for storing the voltage value, and 06A4 represents the voltage value.

[0040] The present invention has strong scalability: the system supports flexible multi-node access, and there are three situations in the later maintenance. One is that the capacity of the photovoltaic strings needs to be increased on site, which will result in the addition of an entire array of photovoltaic strings; the second is to add monitoring system nodes to an existing array; the third is to divide the original monitoring system nodes into other arrays; if encountering the above situations, the system can be flexibly constructed on site, and the installation location is convenient and flexible, and is not restricted by communication lines and communication addresses.

[0041] The system also has a carrier monitoring function. By setting the address of a combiner box system or remote control to 0xFFFF, it can monitor all data on the same channel. During functional testing or after-sales service, it can effectively view the operation status of other systems in real time.

[0042] In summary, the LoRa wireless communication-based combiner box intelligent monitoring system of the present invention has the following functional features:

[0043] 1. Remote monitoring: Through LoRa wireless communication technology, remote real-time monitoring of the combiner box is achieved without physical connection, reducing the complexity and cost of wiring. The monitoring center or cloud platform can remotely control the combiner box to perform parameter configuration, troubleshooting and other operations to improve operation and maintenance efficiency.

[0044] 2. Real-time data transmission: LoRa technology supports low-power long-distance communication. The node can transmit the operating data of the combiner box to the LoRa gateway in real time, including key parameters such as current, voltage, and temperature.

[0045] 3. Fault warning: The system can monitor the working status of the combiner box in real time. Once an abnormality is found, a warning signal will be issued immediately for timely processing.

[0046] 4. High security: LoRa communication technology has encryption function to ensure the security of data transmission.

[0047] 5. Strong scalability: The system supports flexible multi-node access, which is convenient for future expansion of monitoring scope and functions. Monitoring nodes can be increased, reduced, or replaced according to the operation of the power station.

Claims

1. An intelligent monitoring system for combiner boxes based on LoRa wireless communication, each combiner box is equipped with a microcontroller, characterized in that: The microcontroller is respectively connected to the first LoRa communication module, the display screen, the operation button, the RS485 communication module, the signal detection module, the energy storage trip module and the power module. The microcontroller monitors the bus voltage of the photovoltaic string, the current of each branch, temperature, humidity, circuit breaker status, and lightning arrester status in real time through the signal detection module, and communicates with the first LoRa communication module in real time to handle data transmission and reception issues; when the system detects an abnormal situation, it sends a command signal to the energy storage tripping module to execute a tripping action, disconnect the bus main switch, and ensure the safety of the machine and connected equipment; The customer information query end is connected to the second LoRa communication module. When the customer information query end queries the data or status of a combiner box at a specific address through the second LoRa communication module, the second LoRa communication module performs data parsing, encryption and format conversion on the query instruction inside, and sends the packaged data through the antenna; after receiving the instruction through the first LoRa communication module, the microcontroller in the combiner box parses the instruction, confirms that the slave address is consistent with the address set by the system, and after the verification code information is correct, the data to be queried is sent out through the first LoRa communication module; The second LoRa communication module receives and parses the data instruction, and transmits the parsed data to the customer information query end; The communication protocol format of the query instruction is: slave address + function code + register address + register quantity + check code, and the communication protocol format of the reply data instruction is: slave address + function code + number of bytes + register data + check code. The function codes here are all function codes representing queries.

2. The intelligent monitoring system for combiner boxes based on LoRa wireless communication as claimed in claim 1, characterized in that: The operation buttons are used to set various system parameters, including bus voltage warning upper and lower limits, current warning upper and lower limits, temperature warning upper and lower limits, and baud rate value.

3. The intelligent monitoring system for combiner boxes based on LoRa wireless communication as claimed in claim 1, characterized in that: The LoRa communication module that issues a query or setting command is set as the master node, and the LoRa communication module that receives a query or setting command is set as a slave node. The data output between the LoRa master and slave nodes adopts a fixed-point transmission and transparent transmission reception mode. The master node adds the target address and target channel before sending the data. Only the slave node with the same target address and channel can receive the data sent by the master node.

4. The intelligent monitoring system for combiner boxes based on LoRa wireless communication as claimed in claim 1, characterized in that: It also includes a remote controller with a built-in third LoRa communication module, which is used for remotely controlling the configuration of system parameters; the remote controller is operated to enter the setting mode, the system parameters to be set are selected, the numerical values, the target address and the channel are input, and after confirmation, the configuration instructions are sent out through the third LoRa communication module. After receiving the instructions, the microcontroller in the corresponding combiner box parses them and modifies the system parameters of the combiner box.

5. The intelligent monitoring system for combiner boxes based on LoRa wireless communication as claimed in claim 4, characterized in that: The configuration instruction format is target address+function code+register address+register data+check code, where the function code represents the set function code.

6. The intelligent monitoring system for combiner boxes based on LoRa wireless communication as claimed in claim 1, characterized in that: The system supports two wake-up methods. One is to detect the light intensity through a photosensor connected to the microcontroller. When the light intensity meets the requirements in the morning, the system switches from sleep mode to normal working mode. When the light intensity is lower than the threshold in the evening, the system switches from normal working mode to sleep mode. The other is wireless signal wake-up. The wake-up command is sent through the information query end or the remote control end to restore the system from sleep mode to normal working mode.

7. The intelligent monitoring system for combiner boxes based on LoRa wireless communication as claimed in claim 1, characterized in that: The system has a carrier monitoring function. By setting the address of a combiner box system or remote control end to 0xFFFF, it can monitor the data of all combiner box systems under the same channel. During functional testing or after-sales service, it is used to view the operation status of other combiner box systems in real time.

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