Anti-inversion control system for energy storage inverter system and energy storage inverter system

Abstract

A kind of anti-backflow control system applied to energy storage inverter system and related equipment, anti-backflow control system includes inverter, first LORA module being connected with inverter communication, electric meter for collecting the power information between load and power grid, second LORA module being connected with electric meter, wherein first LORA module and second LORA module are configured as point-to-point communication between each other;First LORA module is used to receive power query instruction from inverter and forward to second LORA module, second LORA module is used to transmit received power query instruction to electric meter, and power information is sent to first LORA module, and first LORA module transmits power data to inverter.The utility model embodiment replaces traditional wired connection mode by the point-to-point wireless communication of first LORA module and second LORA module, realizes long-distance stable transmission power data, with the advantages of simplifying wiring construction, improving communication stability and anti-interference ability.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic energy storage inverter technology, specifically to an anti-backflow control system for an energy storage inverter system and an energy storage inverter system. Background Technology

[0002] In existing energy storage inverter systems, to prevent excess power from photovoltaic energy storage systems from flowing back into the grid, electricity meters are usually installed to monitor the grid power status in real time and adjust the inverter's output power accordingly to achieve anti-backflow control. Most existing electricity meters and inverters use RS485 bus for wired communication.

[0003] However, the existing RS485 wired connection method has many limitations in actual installation scenarios. When the user's distribution box is far away from the inverter installation location, the wiring construction is complicated and the wiring is inconvenient, which can easily lead to a long construction period and high cost. In addition, long-distance transmission has communication attenuation and interference problems.

[0004] Meanwhile, some alternative solutions use WiFi wireless communication, but this method is limited by the signal coverage radius, requires network configuration, has poor stability, and is difficult to adapt to complex electromagnetic environments such as wall obstruction, basements, or outdoors. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings and deficiencies of existing technologies by providing an anti-backflow control system for energy storage inverter systems, which has the advantages of simplifying wiring construction, improving communication stability, and enhancing anti-interference capabilities.

[0006] The technical solution is as follows:

[0007] A reverse current prevention control system for an energy storage inverter system includes:

[0008] Inverter;

[0009] The first LORA module is communicatively connected to the inverter;

[0010] Electricity meters are used to collect power information between the load and the power grid;

[0011] The second LORA module is communicatively connected to the electricity meter;

[0012] The first LORA module and the second LORA module are configured to communicate with each other in a point-to-point manner.

[0013] The first LORA module is used to receive a power query command from the inverter and forward it to the second LORA module. The second LORA module is used to transmit the received power query command to the meter and send the power information to the first LORA module. The first LORA module transmits the power data to the inverter.

[0014] Furthermore, the inverter is provided with a first communication interface, and the electricity meter is provided with a second communication interface. The first LORA module is connected to the inverter through the first communication interface, and the second LORA module is connected to the electricity meter through the second communication interface.

[0015] Furthermore, both the first communication interface and the second communication interface are RS485 communication interfaces.

[0016] Furthermore, the inverter is configured to receive the power data forwarded by the first LORA module and control the output power based on the power data.

[0017] Furthermore, the inverter is configured to periodically send power query commands to the electricity meter.

[0018] Furthermore, the first LORA module and the second LORA module are preset with communication parameters, which include spreading factor, bandwidth and coding rate.

[0019] Furthermore, the first LORA module and the second LORA module are installed indoors, and the wireless communication distance between the first LORA module and the second LORA module is not less than 2 kilometers.

[0020] On the other hand, this utility model also provides an energy storage inverter system, including the anti-reverse flow control system for the energy storage inverter system as described above.

[0021] This utility model embodiment uses point-to-point wireless communication between the first LORA module and the second LORA module to replace the traditional wired connection method, thereby achieving stable long-distance transmission of power data. It has the advantages of simplifying wiring construction, improving communication stability and anti-interference capabilities. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a circuit structure block diagram of an embodiment of the present utility model.

[0024] Figure label:

[0025] 100. Inverter;

[0026] 200. First LoRa module;

[0027] 300. Second LoRa module;

[0028] 400. Electricity meter. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to the accompanying drawings.

[0030] This specific embodiment is merely an explanation of the present utility model and is not intended to limit the present utility model. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive element, but as long as they are within the scope of the claims of the present utility model, they are protected by patent law.

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0033] In existing technologies, photovoltaic energy storage systems typically achieve backflow prevention control through wired communication between the meter and the inverter. When the distribution box and the inverter are installed far apart, RS485 bus wiring is complex and costly, and long-distance transmission is susceptible to interference. Alternative solutions using WiFi communication have limited signal coverage, rely on network configuration, and lack stability in environments with wall obstructions or complex electromagnetic fields. For example, in factory or large residential settings, the inverter and meter may be installed in the basement and outdoors respectively, making it difficult for traditional communication methods to meet reliable transmission requirements.

[0034] To address the aforementioned issues, it is first necessary to eliminate the dependence of wired communication on physical cabling, while simultaneously avoiding the impact of environmental interference on wireless communication. To address the high cost of RS485 cabling, wireless communication should be considered as an alternative to wired connections. To address the limitations of WiFi in terms of limited coverage and poor stability, a wireless technology with strong penetration and long transmission distance needs to be selected. Furthermore, it is essential to ensure compatibility between the communication module and existing device interfaces, and to establish a stable bidirectional data transmission mechanism. Research into the characteristics of different wireless communication protocols reveals that LoRa technology offers advantages such as low power consumption and long-distance transmission, making it suitable for building point-to-point communication links in complex environments.

[0035] Therefore, this application proposes an anti-reverse current control system including an inverter, a first LORA module, an electricity meter, and a second LORA module. The first LORA module is communicatively connected to the inverter, and the second LORA module is communicatively connected to the electricity meter. The two LORA modules are configured to communicate point-to-point. The first LORA module forwards the inverter's power query command to the second LORA module, and the second LORA module transmits the power information collected by the electricity meter back to the inverter.

[0036] It should be noted that an inverter is a device that converts the direct current (DC) power from an energy storage device into alternating current (AC). Specifically, it can be implemented using a grid-connected inverter with power regulation capabilities, used to adjust the output power according to the grid conditions. The first LoRa module is a wireless communication unit connected to the inverter, specifically implemented using a LoRa terminal module supporting RS485 interface conversion, used to convert electrical signals into wireless signals for transmission. The meter is a metering device that monitors the power between the grid and the load, specifically implemented using a power parameter acquisition module supporting bidirectional communication, used to acquire grid-connected power data in real time. The second LoRa module is a wireless communication unit connected to the meter, specifically implemented using a receiver module matched with the first LoRa module, used to complete the conversion between wireless and electrical signals. Point-to-point communication refers to the direct wireless link established between two LoRa modules, specifically implemented by pre-setting identical communication parameters, used to ensure the exclusivity and stability of data transmission.

[0037] Specifically, the inverter sends a power query command to the first LORA module via the first communication interface. The first LORA module then transmits the command wirelessly to the second LORA module. The second LORA module transmits the command to the electricity meter via the second communication interface. After collecting real-time power data between the grid and the load, the electricity meter sends the data back to the first LORA module via the second LORA module. The first LORA module then feeds back the received power data to the inverter, which dynamically adjusts its output power based on this data to prevent backflow of electricity into the grid.

[0038] Compared to existing technologies, traditional RS485 wired solutions require physical cabling, while this solution completely eliminates the need for wiring through LoRa wireless communication, reducing construction complexity. Compared to WiFi's reliance on router networking, point-to-point communication requires no network configuration, avoiding delays and interference caused by signal relays. The long-distance transmission characteristics of the LoRa module are suitable for basement and outdoor scenarios, and spread spectrum technology enhances signal penetration, maintaining stable communication in complex electromagnetic environments.

[0039] Through the above technical solution, this application achieves reliable wireless communication between the inverter and the electricity meter, solving the problem of difficult long-distance wiring and reducing installation and maintenance costs. The point-to-point communication mode avoids the impact of network fluctuations, ensures real-time power data transmission, enables the inverter to respond quickly to changes in grid conditions, and effectively prevents reverse current phenomena.

[0040] In an optional embodiment, the inverter may be an energy storage inverter with grid connection function, such as the SUN2000 series grid-connected energy storage inverter from Sungrow Power Supply Co., Ltd., which has output power regulation function, supports RS485 communication interface, and can realize reverse current suppression control according to the received grid power data.

[0041] In an optional embodiment, the first LORA module and the second LORA module may each adopt an EByte E32-900T30D LORA wireless communication module. This module is based on the Semtech SX1276 chip, supports RS485 interface input and output, has a communication frequency of 868 / 915MHz, and a theoretical communication distance of 5-8 kilometers in open environments. It has the ability to configure parameters such as spreading factor, bandwidth, and coding rate, and is suitable for point-to-point long-distance transmission.

[0042] In an optional embodiment, the meter may be an Acrel DTS1352 three-phase rail-mounted meter, which supports RS485 communication and Modbus protocol, and has real-time acquisition functions for parameters such as active power, reactive power, current, and voltage. It is suitable for power data monitoring in residential and small-scale photovoltaic energy storage scenarios.

[0043] This application further proposes that the inverter is provided with a first communication interface, the electricity meter is provided with a second communication interface, the first LORA module is connected to the inverter through the first communication interface, and the second LORA module is connected to the electricity meter through the second communication interface.

[0044] The first communication interface refers to the physical interface between the inverter and the first LORA module for data transmission, and the second communication interface refers to the physical interface between the meter and the second LORA module for data transmission.

[0045] In specific implementation, the inverter establishes a wired connection with the first LoRa module through the first communication interface, and the electricity meter establishes a wired connection with the second LoRa module through the second communication interface. The LoRa modules transmit power query commands and power data to each other via point-to-point wireless communication.

[0046] This application further proposes that both the first and second communication interfaces are RS485 communication interfaces.

[0047] The RS485 communication interface refers to a serial communication interface conforming to the RS485 standard. Specifically, it can be implemented using twisted-pair differential signal transmission, possessing common-mode interference immunity and suitable for data exchange between devices in industrial environments. In this embodiment, the RS485 standard serial communication interface is used for local communication between the inverter and the first LoRa module, and between the meter and the second LoRa module, ensuring the stability and reliability of data transmission between devices.

[0048] In practical implementation, the inverter establishes a local wired connection with the first LORA module via an RS485 communication interface, and the electricity meter establishes a local wired connection with the second LORA module via an RS485 communication interface. The RS485 interface is responsible for converting the inverter's power query command into an electrical signal and transmitting it to the first LORA module, while simultaneously converting the power information received by the second LORA module into a data format recognizable by the electricity meter. Since the RS485 interface offers stable transmission over short distances, and the LORA module handles long-distance wireless communication, the combination of the two avoids the construction problems of long-distance wired cabling and ensures the reliability of communication between local devices.

[0049] This application further proposes that the inverter is configured to receive power data forwarded by a first LORA module and control the output power based on the power data.

[0050] It should be noted that power data refers to the real-time power information between the load and the power grid collected by the electricity meter. Specifically, it can be transmitted to the inverter through point-to-point communication of the LORA module. The power data is used to reflect the power status of the power grid. Controlling the output power refers to the inverter dynamically adjusting its output power based on the received power data. Specifically, it can be achieved through the built-in power regulation algorithm, such as determining whether to limit the inverter's power generation based on the positive or negative value of the power grid.

[0051] It should be noted that the process of the inverter controlling its output power based on the received power data relies on existing mature power regulation algorithms, such as power threshold judgment, PID closed-loop control, linear power point tracking, and state machine control. These power regulation algorithms are widely integrated into various commercial energy storage inverters, and this application does not propose any new improvements or innovations to these algorithms themselves. Those skilled in the art can utilize existing algorithm logic without creative effort to achieve dynamic adjustment of the inverter's output power, thereby facilitating the anti-reverse current control objective. The focus of this application is on utilizing a LoRa wireless communication module to achieve long-distance point-to-point data transmission between the inverter and the smart meter, thereby solving the problems of limited wired communication and difficult wiring in existing technologies.

[0052] Specifically, the inverter periodically acquires grid power information collected by the electricity meter through the first LORA module. When a negative grid power value is detected, it indicates a risk of backflow of electricity into the grid. At this time, the inverter will reduce its output power until the grid power returns to a non-negative state. By receiving power data in real time and dynamically adjusting the output, backflow can be effectively avoided.

[0053] This embodiment solves the problem of insufficient reliability of reverse flow control caused by communication method limitations in the prior art. It can stably transmit data and quickly respond to changes in power grid status in complex installation environments, thereby effectively preventing power backflow.

[0054] This application further proposes that the inverter be configured to periodically send power query commands to the electricity meter.

[0055] It should be noted that "periodic" refers to repeatedly executing the command sending operation at preset time intervals. This can be achieved using timer triggering or scheduling algorithms, such as setting the time interval to 30 seconds or 1 minute. By querying at a fixed frequency, real-time monitoring of the grid power status is ensured. The inverter's function in sending power query commands is to proactively obtain power change data between the grid and the load, thereby dynamically adjusting the output power and preventing backflow of power due to data update delays.

[0056] This application further proposes that the first LORA module and the second LORA module have preset communication parameters, including spreading factor, bandwidth, and coding rate. The spreading factor refers to the distribution of the signal over a wider frequency band through spread spectrum technology, which can be implemented by different spreading factor configurations to enhance communication anti-interference capability and increase transmission distance. The bandwidth refers to the frequency range occupied by the communication channel, which can be implemented by different bandwidth parameter configurations to balance data transmission rate and communication reliability. The coding rate refers to the ratio of effective information to redundancy check in the data stream, which can be implemented by forward error correction coding technology to improve data transmission accuracy and reduce bit error rate.

[0057] Specifically, in the anti-reverse current control system, the first LORA module and the second LORA module extend the signal spectrum through a preset spreading factor, and realize long-distance communication by utilizing low power consumption characteristics. At the same time, by adjusting the bandwidth parameter to match the noise level under different environments, and further combining the coding rate configuration, the collected power information is redundantly checked to ensure that the power data transmission between the meter and the inverter is complete and reliable.

[0058] Compared to existing technologies, conventional RS485 wired communication relies on physical line connections and is susceptible to line attenuation during long-distance deployments, while WiFi communication depends on network coverage and has weak anti-interference capabilities. This solution uses pre-configured LoRa communication parameters, achieving stable communication without relying on physical lines. It effectively suppresses multipath interference through spread spectrum technology, adapting to data transmission needs in basements or complex electromagnetic environments.

[0059] This application further proposes that the first LORA module and the second LORA module are installed indoors, and the wireless communication distance between the first LORA module and the second LORA module is not less than 2 kilometers.

[0060] Indoor installation refers to the deployment of LoRa modules within a building's interior space, specifically by fixing them to the inner wall of a distribution box or equipment cabinet, avoiding exposure to the outdoor environment. This feature ensures communication stability by reducing the module's susceptibility to external environmental factors such as rain and dust. It's important to note that while LoRa modules can be installed indoors, their communication capabilities are not limited to indoor scenarios. In open, unobstructed outdoor environments, the point-to-point wireless communication distance of LoRa modules can reach 5-15 kilometers or even longer, making them suitable for long-distance signal transmission in distributed scenarios across buildings, industrial parks, or rural areas.

[0061] The wireless communication distance of no less than 2 kilometers refers to the stable coverage capability of the LORA module in typical buildings or semi-open environments, which can be achieved through spread spectrum modulation technology combined with a high-gain antenna. This feature enhances signal penetration and anti-interference capabilities, meeting the long-distance communication needs in cross-floor and cross-area scenarios and ensuring stable power data transmission. Taking the widely used LORA module based on the Semtech SX1276 / SX1278 chip as an example, even with a low-rate configuration of 125kHz bandwidth, spread spectrum factor SF12, and coding rate of 4 / 5, the point-to-point communication distance can stably reach 2 kilometers, even in office buildings or basements with multiple walls.

[0062] Specifically, when the first and / or second LoRa modules are configured for indoor installation, they can leverage the building structure to form a physical barrier, reducing the impact of external electromagnetic interference on wireless communication. After the first and second LoRa modules are connected to the inverter and the electricity meter respectively, they establish a point-to-point link using preset communication parameters. With a wireless communication distance exceeding 2 kilometers, even if the inverter and the distribution box are located in different buildings or on different floors, real-time power data transmission can still be maintained without relying on wired cabling or relay equipment.

[0063] In some implementations, the first LORA module and the second LORA module may each have an independent power supply circuit to provide a stable operating voltage for their respective internal circuits and connected communication interfaces. The independent power supply circuit may include a power management module, a DC-DC regulator, or an external independent power input port, etc., to improve module deployment flexibility and adapt to power supply requirements in distributed installation environments.

[0064] Compared to existing technologies, traditional RS485 wired solutions require cable laying in long-distance scenarios, resulting in high construction costs and easy aging of the lines; while WiFi communication is limited by its coverage radius and wall penetration ability, making it difficult to adapt to basements or complex building structures. This solution uses LoRa technology to achieve long-distance wireless transmission between indoors and outdoors, avoiding the wiring problems and overcoming the WiFi signal attenuation defect, thus improving the stability and adaptability of data interaction between the inverter and the smart meter.

[0065] This application further proposes an energy storage inverter system, including the aforementioned anti-reverse flow control system for the energy storage inverter system.

[0066] The above is only used to illustrate the technical solution of this utility model and not to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solution of this utility model, as long as they do not depart from the spirit and scope of the technical solution of this utility model, should be covered within the scope of the claims of this utility model.

Claims

1. A reverse current prevention control system for an energy storage inverter system, characterized in that, include: Inverter; The first LORA module is communicatively connected to the inverter; Electricity meters are used to collect power information between the load and the power grid; The second LORA module is communicatively connected to the electricity meter; The first LORA module and the second LORA module are configured to communicate with each other in a point-to-point manner. The first LORA module is used to receive a power query command from the inverter and forward it to the second LORA module. The second LORA module is used to transmit the received power query command to the meter and send the power information to the first LORA module. The first LORA module transmits the power data to the inverter.

2. The anti-reverse flow control system for an energy storage inverter system according to claim 1, characterized in that, The inverter is provided with a first communication interface, and the electricity meter is provided with a second communication interface. The first LORA module is connected to the inverter through the first communication interface, and the second LORA module is connected to the electricity meter through the second communication interface.

3. The anti-reverse flow control system for an energy storage inverter system according to claim 2, characterized in that, Both the first communication interface and the second communication interface are RS485 communication interfaces.

4. The anti-reverse flow control system for an energy storage inverter system according to claim 1, characterized in that, The inverter is configured to receive the power data forwarded by the first LORA module and control the output power based on the power data.

5. The anti-reverse flow control system for an energy storage inverter system according to claim 1, characterized in that, The inverter is configured to periodically send power query commands to the electricity meter.

6. The anti-reverse flow control system for an energy storage inverter system according to claim 2, characterized in that, The first LORA module and the second LORA module have preset communication parameters, which include spreading factor, bandwidth and coding rate.

7. The anti-reverse flow control system for an energy storage inverter system according to claim 2, characterized in that, The first LORA module and the second LORA module are installed indoors, and the wireless communication distance between the first LORA module and the second LORA module is not less than 2 kilometers.

8. An energy storage inverter system, characterized in that, Including the anti-reverse flow control system for energy storage inverter systems as described in any one of claims 1-7.

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