A gateway device and system for a distributed photovoltaic power generation system and a communication method

Abstract

The application provides a gateway device and system for a distributed photovoltaic power generation system and a communication method, comprising a master control module, a downlink communication module, a data processing module, and an uplink communication module, which can support multi-protocol compatibility, high integration, high reliability, and deep fusion Internet of Things technology. The application can improve compatibility and integration: unified conversion of multi-brand device bottom layer data into IEC104 standard protocol, breaking heterogeneous barriers; high integration hardware architecture greatly reduces device volume, realizing seamless embedding with field circuit breakers. Optimize deployment efficiency: built-in one-key configuration logic, automatically identify online devices and dynamically generate polling lists through active broadcast handshake, eliminating manual entry hassle and significantly reducing field implementation cost. Safeguard system security: establish an abnormal interruption triggering mechanism, skip regular polling when monitoring data is out of limit, real-time priority transmission of alarm messages, realize second-level response to power station risks, and reduce device damage rate.

Description

Technical Field

[0001] This invention relates to the field of gateway technology, and in particular to a gateway device and system and communication method for a distributed photovoltaic power generation system. Background Technology

[0002] In existing technologies, with the continuous expansion of photovoltaic power plant scale, the types and number of equipment have increased dramatically, resulting in a massive amount of data. Traditional monitoring and management methods face numerous challenges:

[0003] Insufficient protocol compatibility: Different brands of photovoltaic equipment (such as inverters, combiner boxes, etc.) use different communication protocols. Existing gateways often only support one or a few protocols, resulting in poor system compatibility and difficulty in achieving comprehensive data collection and equipment management.

[0004] Low integration: Traditional gateways have relatively simple functions, usually focusing only on data collection or uploading, lacking effective data processing and system management capabilities, and their hardware structure is scattered, occupying a large space, which is not conducive to the compact layout of distributed photovoltaic systems.

[0005] Stability and reliability issues: In large-scale photovoltaic systems, the stability of data transmission is crucial. Existing gateways may experience data loss and communication interruptions when facing complex electromagnetic environments and prolonged operation, affecting the normal operation of the system.

[0006] Insufficient integration with the Internet of Things (IoT): With the development of IoT technology, the demand for remote monitoring of photovoltaic systems is increasing. However, the integration of existing gateways with IoT technology is low, making it difficult to meet the needs of intelligent management. Summary of the Invention

[0007] This invention provides a gateway device, system, and communication method for distributed photovoltaic (PV) power generation systems, enabling a novel PV smart gateway system that supports multi-protocol compatibility, high integration, high reliability, and deep integration with Internet of Things (IoT) technology. The specific solution is as follows:

[0008] A gateway system for a distributed photovoltaic (PV) power generation system includes: a main control module for performing system initialization and loading preset configuration parameters, including downlink device bus addresses and register mapping tables; a downlink communication module electrically connected to the main control module for performing half-duplex asynchronous serial communication with underlying PV devices and obtaining raw register data streams according to polling instructions generated by the main control module; a data processing module integrated into the main control module for parsing the raw register data streams, extracting physical quantity parameters according to the register mapping table, and performing message encapsulation to generate data packets to be uploaded; an uplink communication module electrically connected to the main control module for executing AT command sets to configure network access points and link parameters, and transmitting the data packets to be uploaded to a cloud platform via a wireless network; and a power supply module for converting external input power into the operating voltage required by the gateway devices.

[0009] A communication method for a gateway in a distributed photovoltaic power generation system includes the following steps:

[0010] S1: After the main control module starts, it retrieves the configuration information in the non-volatile memory and establishes a task list containing the device bus address, baud rate, and acquisition cycle; S2: According to the task list, the main control module sends a request frame containing the function code and register start address to the target underlying photovoltaic device through the downlink communication module; S3: The main control module receives the response frame returned by the underlying photovoltaic device, performs CRC verification on the response frame, and after the verification is successful, parses the original data value of each channel according to the preset offset and data length; S4: The parsed original data value is converted into an engineering quantity, and framed according to the ASDU application service data unit format, adding type identifier, transmission reason, and common address; S5: The main control module drives the uplink communication module to establish a TCP / IP connection through AT commands and sends the encapsulated IEC104 message to the specified cloud IP address.

[0011] Furthermore, in S2, the main control module adopts a one-click configuration logic: by traversing the bus addresses within a preset range and sending handshake signals, it automatically identifies online underlying photovoltaic devices and dynamically updates the task list.

[0012] Furthermore, after S4, an anomaly detection step is also included: the main control module compares the converted physical quantity parameters with the preset threshold range in real time. If the parameter exceeds the threshold, an interruption is immediately triggered and an anomaly alarm message is generated, and the preset upload cycle is skipped to perform real-time priority upload.

[0013] Furthermore, the physical quantity parameters include voltage, current, and temperature; the anomaly detection and identification include excessive voltage, current overload, or abnormal temperature conditions.

[0014] Furthermore, the data upload process in S5 supports both timed upload mode and real-time upload mode, and the main control module dynamically switches the upload frequency according to the configuration instructions issued by the cloud platform.

[0015] A gateway device for a distributed photovoltaic power generation system includes a main controller, a communication circuit board, a memory, and a system program that can run on the processor, which implements the aforementioned communication method when executing the computer program.

[0016] Furthermore, the main controller is a GD32F103RET6 microcontroller, and the communication circuit board includes an SP485 chip.

[0017] The beneficial effects of this invention are as follows:

[0018] Enhanced compatibility and integration: Unified conversion of underlying data from multiple brands of equipment into the IEC104 standard protocol breaks down heterogeneous barriers; highly integrated hardware architecture significantly reduces equipment size, enabling seamless integration with field circuit breakers.

[0019] Optimize deployment efficiency: Built-in one-click configuration logic automatically identifies online devices and dynamically generates a polling list through proactive broadcast handshake, eliminating tedious manual data entry and significantly reducing on-site implementation costs.

[0020] Ensuring system safety: Establishing an abnormal interruption triggering mechanism, when monitoring data exceeds the limit, skipping regular polling, and prioritizing the transmission of alarm messages in real time, achieving second-level response to power plant risks and reducing equipment damage rate. Attached Figure Description

[0021] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0022] Figure 1 This is a module framework diagram of the gateway system involved in the present invention;

[0023] Figure 2 This is a structural diagram of the power generation system of the photovoltaic integrated gateway involved in this invention;

[0024] Figure 3 This is a hardware configuration framework diagram of the gateway involved in the present invention;

[0025] Figure 4 This is a circuit connection schematic diagram of the 485 communication involved in the present invention;

[0026] Figure 5 This invention relates to a schematic diagram of the power supply for the peripheral circuit.

[0027] Figure 6 This is a flowchart illustrating the device polling process involved in the present invention.

[0028] Figure 7 The device data upload process involved in this invention

[0029] Figure 8 This is a diagram of the data collected by the gateway system involved in this invention;

[0030] Figure 9 This is a power consumption statistics diagram of the gateway system involved in the present invention; Detailed Implementation

[0031] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0032] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0033] This invention provides a gateway system for a distributed photovoltaic power generation system, comprising a main control module, a downlink communication module, a data processing module, an uplink communication module, and a power supply module, which is integrated into the field photovoltaic circuit breaker device in a pluggable structure.

[0034] I. Hardware Implementation Level

[0035] The main control module uses the GD32F103RET6 microcontroller as its computing core. Its internal FLASH storage area is divided into a boot area, a configuration parameter area, and a running code area. The configuration parameter area is used to persistently store the bus address table, register mapping table, and threshold list.

[0036] Downlink communication module based on Figure 4 The circuit shown leads the A and B differential lines of the SP485 chip to the terminal block. The DI and RO pins of the SP485 are connected to the UART_TXD and UART_RXD of the GD32F103RET6, respectively. The DE / RE transmit / receive enable pins are driven by the GPIO control pin R / T to achieve half-duplex switching: before sending a request frame, the GPIO is set high to put the SP485 into transmit mode; after transmission is completed, the GPIO is pulled low to enter receive mode to wait for a response frame.

[0037] The uplink communication module uses the YUGE CLM920_YV9 communication module, whose RXD / TXD pins are cross-connected with the second UART of the main controller. The main controller performs APN configuration, signal query and socket connection establishment on the module through the AT command set.

[0038] Power supply module according to Figure 5The schematic diagram shows that the external 12V~24V DC input is stepped down to 5V by the TD1482AP switching power supply chip, and then regulated to 3.3V by the LDO, which supplies power to the main control module and the communication module respectively. The peripheral circuit of the TD1482AP includes an input filter capacitor, a freewheeling diode, an energy storage inductor, and an output feedback resistor voltage divider network to ensure that the voltage ripple is less than 100mV under the peak current of the communication module.

[0039] II. System Implementation Steps:

[0040] Step S1: After the gateway is powered on, the main control module enters the initialization phase, and completes the clock tree configuration and UART / GPIO / TIMER peripheral initialization in sequence. Then, it reads the device bus address, baud rate (default 9600bps), parity bit and acquisition period T from the FLASH configuration area to build a polling task list Task[N]={addr_i, reg_start_i, reg_len_i, period_i}.

[0041] Step S2: The main control module traverses the Task[N] in order, assembles a Modbus-RTU request frame for the current task i: [Slave_Addr | Func_Code(0x03 / 0x04) | Reg_Start_H / L | Reg_Len_H / L | CRC_L / H], sets the R / T control pin, and sends it out via UART_TXD.

[0042] In the one-click configuration scenario, the configuration software triggers the main controller to enter the scanning mode: the main controller traverses the address from 1 to 247 in increments, and sends a lightweight handshake frame (such as reading the device identification register 0x00) to each address. If a valid response is received within a 50ms timeout window, the address is registered in Task[N], otherwise it is skipped, thereby completing the automatic identification of online devices and dynamic updating of the task list.

[0043] Step S3: After the master UART_RXD receives the response frame, it triggers a DMA interrupt to write the data into the receive buffer Buf[]. First, it compares the consistency of Slave_Addr, then calculates the CRC16 based on the length of the response frame byte and compares it with the last two bytes of the frame. If the CRC check fails, it discards the data and retransmits the request (up to 3 retries). If the check passes, it slices the raw code value Raw_k from Buf[] according to the offset Offset_k and the byte length Len_k of each physical quantity in the register mapping table.

[0044] Step S4: Perform engineering quantity conversion on Raw_k according to the magnification Scale_k and bias Bias_k in the mapping table: Value_k = Raw_k × Scale_k + Bias_k to obtain physical quantities such as voltage (V), current (A), active power (kW), temperature (°C), etc.; then assemble the ASDU according to the IEC60870-5-104 protocol: fill in the type identifier TI (such as M_ME_NC_1 = 13 short floating-point telemetry), variable structure qualifier VSQ, transmission cause COT (period / burst), common address CA, and information object address IOA, and externally encapsulate the APCI to form a complete I-frame.

[0045] Abnormality detection: Before framing after the engineering quantity conversion, the master control compares Value_k with the threshold table [Min_k, Max_k]. If Value_k > Max_k or Value_k < Min_k (such as too high voltage, overloaded current, abnormal temperature), the alarm flag bit is set. When framing, the COT is modified to "spontaneous", and the current timing period is skipped, and immediately enter Step S5 for priority upload.

[0046] Step S5: The master control configures the APN through AT+CGDCONT, and establishes a long connection through AT+CIPSTART="TCP", <cloud IP>, <port>; after the connection is established, the assembled IEC104 I-frame is transparently transmitted through AT+CIPSEND, and the S-frame confirmation from the cloud is received, maintaining the send sequence number N(S) and receive sequence number N(R); if the link is abnormal, the master control starts the timers T1 / T2 / T3 for test frame U-frame handshake, and reconnects if it times out.

[0047] The cloud platform analyzes the received message according to the IEC104 protocol, stores each physical quantity in the database according to the IOA, and draws the operation curve and power statistics chart as shown in Figure 8 、 Figure 9 to achieve remote monitoring.

[0048] The advantages of the present invention are:

[0049] Break through the heterogeneous protocol barriers and improve the system compatibility and integration: Serial data of the Modbus-RTU protocol is collected through the downlink communication module, and the conversion to the IEC104 standard protocol is completed by using the built-in data processing module, realizing the underlying unified encapsulation of data of multi-brand and multi-type photovoltaic devices (such as inverters, busbar trunking systems). At the same time, based on the high-integration hardware architecture such as the GD32F103RET6 master control and SP485, the physical volume of the gateway is effectively compressed, enabling it to be directly and seamlessly embedded inside field devices such as distributed photovoltaic circuit breakers, optimizing the hardware layout space of the distributed photovoltaic system.

[0050] Optimize on-site commissioning processes and improve equipment adaptive configuration efficiency: A one-click configuration logic was designed at the front end of the data acquisition link, enabling gateway devices to proactively broadcast handshake signals to the bus environment and capture valid responses. This mechanism transforms the traditional workflow of manually verifying and entering device addresses one by one into an automated process where the gateway autonomously traverses, identifies, and dynamically generates a polling task list, significantly reducing the complexity of on-site deployment in power plants and the cost of manual intervention.

[0051] A multi-level response mechanism is established to ensure data real-time performance and system security: Real-time threshold comparison and interrupt triggering strategies are introduced into the data processing chain, making the regular periodic collection of power statistics data and the monitoring of abnormal states logically independent. When excessive voltage, current overload, or other limit-crossing conditions occur in the underlying input data, the system bypasses the regular polling timer and prioritizes calling the uplink communication module for real-time transmission of abnormal alarm messages. This allows the cloud platform to capture power plant risks with minimal latency, effectively reducing the probability of photovoltaic equipment downtime or damage.

[0052] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A gateway system for a distributed photovoltaic power generation system, characterized in that, include: The main control module is used to perform system initialization and load preset configuration parameters, including downlink device bus address and register mapping table; The downlink communication module is electrically connected to the main control module and is used to perform half-duplex asynchronous serial communication with the underlying photovoltaic equipment and obtain the raw register data stream according to the polling instructions generated by the main control module. The data processing module, integrated into the main control module, is used to parse the raw register data stream, extract physical quantity parameters according to the register mapping table, encapsulate messages, and generate data packets to be uploaded. The uplink communication module is electrically connected to the main control module and is used to execute AT command sets to configure network access points and link parameters, and to transmit the data packets to be uploaded to the cloud platform through the wireless network. The power supply module is used to convert the external input power into the operating voltage required by the gateway device.

2. A communication method for a gateway in a distributed photovoltaic power generation system, characterized in that, Includes the following steps: S1: After the main control module starts, it retrieves the configuration information in the non-volatile memory and establishes a task list containing the device bus address, baud rate and acquisition cycle. S2: According to the task list, the main control module sends a request frame containing the function code and register start address to the target underlying photovoltaic device through the downlink communication module; S3: Receive the response frame returned by the underlying photovoltaic device. The main control module performs CRC check on the response frame. After the check passes, it parses the original data value of each channel according to the preset offset and data length. S4: Perform engineering quantity conversion on the parsed raw data values, and frame them according to the ASDU application service data unit format, adding type identifier, transmission reason and common address; S5: The main control module drives the uplink communication module to establish a TCP / IP connection through AT commands, and sends the encapsulated IEC104 message to the specified cloud IP address.

3. The communication method according to claim 2, characterized in that, In S2, the main control module adopts a one-click configuration logic: by traversing the bus addresses within a preset range and sending handshake signals, it automatically identifies online underlying photovoltaic devices and dynamically updates the task list.

4. The communication method according to claim 3, characterized in that, Following S4, an anomaly detection step is also included: the main control module compares the converted physical quantity parameters with the preset threshold range in real time. If the parameter exceeds the threshold, an interruption is immediately triggered and an anomaly alarm message is generated, skipping the preset upload cycle and performing real-time priority upload.

5. The communication method according to claim 4, characterized in that, The physical parameters include voltage, current, and temperature; the anomaly detection and identification include excessive voltage, current overload, or abnormal temperature.

6. The communication method according to claim 2, characterized in that, The data upload process in S5 supports both timed upload mode and real-time upload mode. The main control module dynamically switches the upload frequency according to the configuration instructions issued by the cloud platform.

7. A gateway device for a distributed photovoltaic power generation system, characterized in that, It includes a main controller, a communication circuit board, a memory, and a system program that can run on the processor, which, when executing the computer program, implements the method according to any one of claims 2 to 6.

8. The gateway device for a distributed photovoltaic power generation system according to claim 1, characterized in that, The main controller is a GD32F103RET6 microcontroller, and the communication circuit board includes an SP485 chip.

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