Anti-Countercurrent Method, System and Device for Photovoltaic System Based on Intelligent Internet-of-Things Meter

Abstract

The present invention relates to a method, system and device for preventing reverse current in a photovoltaic system based on an intelligent Internet of Things meter. The method for preventing reverse current includes the following processes: Step 1: Obtain the rated power generation capacity P of the photovoltaic system N . Collect the real-time output power P of the intelligent Internet of Things meter and the real-time power generation capacity P of the photovoltaic system pv , and set the reverse current prevention threshold P set . Step 2: Calculate the maximum active power P that the photovoltaic system is allowed to output max . When P≥P set , P max = P N . When P<P set , P max = P pv -(P set -P)P set / P. Step 3: Send a maximum active power command to the photovoltaic system so that the photovoltaic system generates electricity according to the real-time power generation capacity P pv = P max . By communicating the intelligent Internet of Things meter with the inverter and the user load respectively, the present invention can, while measuring the user's electricity consumption, match the power generation amount of the power generation module with the load amount of the user load in real time, avoid the generation of excess electricity in the photovoltaic system, and does not require additional installation of reverse current prevention equipment, having the advantages of low cost and strong timeliness.

Description

Technical Field

[0001] The present invention relates to a photovoltaic system, and in particular to a method for preventing reverse current in a photovoltaic system based on an intelligent IoT meter, a system for preventing reverse current in a photovoltaic system based on an intelligent IoT meter, a device for preventing reverse current in a photovoltaic system based on an intelligent IoT meter, and a photovoltaic system for preventing reverse current based on an intelligent IoT meter. Background Art

[0002] For a completely self-consumed photovoltaic power generation project, the generated electric energy is not allowed to be sent to the grid side. When the power generation of the photovoltaic system is sufficient, all user loads are powered by the photovoltaic power generation. When the power generation of the photovoltaic system is less than the power consumption of the user load, the user load is powered by both the photovoltaic power generation and the grid. When the power generation of the photovoltaic system is higher than the power consumption required by the current load, the electric energy generated on the photovoltaic side will be fed back to the grid side.

[0003] In view of the above situation, at present, many projects use photovoltaic reverse current prevention devices to meet the requirement of preventing reverse current. However, installing a photovoltaic reverse current device requires purchasing equipment separately, which not only occupies installation space but also increases equipment costs. Existing methods for preventing reverse current have problems of untimely response and low regulation efficiency in practical applications because they cannot collect the power consumption of the load and the output power of the inverter in real time. How to provide a low-cost and fast-response method for preventing reverse current has become an urgent problem to be solved. Summary of the Invention

[0004] Based on this, in view of the problem that it is difficult to balance low cost and timeliness when the existing photovoltaic system deals with the reverse current risk, it is necessary to provide a method, a system and a device for preventing reverse current in a photovoltaic system based on an intelligent IoT meter.

[0005] The present invention is implemented by the following scheme: A method for preventing reverse current in a photovoltaic system based on an intelligent IoT meter, the method for preventing reverse current includes the following processes:

[0006] Step 1: Obtain the rated power generation P of the photovoltaic system N . Collect the real-time output power P of the intelligent IoT meter and the real-time power generation P of the photovoltaic system pv , and set the reverse current prevention threshold P set .

[0007] Step 2: Calculate the maximum active power P that the photovoltaic system is allowed to output max , and the specific calculation method is as follows:

[0008] Ⅰ. When P≥P set , adjust the maximum active power P max to the rated power generation P N , that is, P max = P N .

[0009] II. When P < P set , the ratio of the real - time output power P of the intelligent IoT meter to the anti - reverse threshold P set is used as the difference coefficient, and the difference coefficient k is expressed as:

[0010] k = P / P set .

[0011] Calculate the active - power difference P offset according to the difference coefficient. The active - power difference P offset is expressed as:

[0012] P offset =(P set - P) / k.

[0013] Take the difference between the real - time power generation power P pv and the active - power difference P offset as the maximum active power P max . The maximum active power P max is expressed as:

[0014] P max =P pv - P offset .

[0015] Step 3: Send a maximum active - power command to the photovoltaic system so that the photovoltaic system generates electricity according to the real - time power generation power P pv =P max .

[0016] The above anti - reverse method, through the communication between the intelligent IoT meter and the inverter and the user load respectively, while measuring the user's electricity consumption, matches the power generation amount of the power generation module with the load amount of the user load in real time, avoids the generation of excess electricity in the photovoltaic system, and prevents the reverse flow of the generated electricity of the photovoltaic power generation to the grid side, and is applicable to the system of user - side photovoltaic power generation without grid connection.

[0017] In one embodiment, the real - time output power P of the intelligent IoT meter is collected by the following method: The intelligent IoT meter queries the communication protocol adapted to each intelligent electrical device, and then issues a meter - reading command to each intelligent electrical device according to the adapted communication protocol, and then conducts data interaction with each intelligent electrical device to obtain the real - time power consumption of each intelligent electrical device. The total power consumption of all intelligent electrical devices is the real - time output power P.

[0018] In one embodiment, the real - time power generation power P pv of the photovoltaic system is collected by the following method: The intelligent IoT meter issues a meter - reading command to the inverter of the photovoltaic system according to the pre - stored communication protocol, and then conducts data interaction with the inverter to obtain the power output in real time by the inverter as the real - time power generation power Ppv 。

[0019] The present invention also provides a reverse current prevention system for a photovoltaic system based on an intelligent IoT meter. The reverse current prevention system includes a collection module, an operation module, and an execution control module.

[0020] The collection module is used to collect the real-time output power P of the intelligent IoT meter and the real-time power generation power P of the photovoltaic system pv 。

[0021] The operation module is used for: (1), setting a reverse current prevention threshold P according to the real-time output power P and the real-time power generation power P pv Set the reverse current prevention threshold P set 。(2), calculating the maximum active power P that the photovoltaic system is allowed to output according to the real-time output power P and the real-time power generation power P pv And the rated power generation power P of the photovoltaic system N Calculate the maximum active power P that the photovoltaic system is allowed to output max Among them, when P≥P set When, P max =P N 。When P<P set When, P max =P pv -(P set -P)P set / P. And

[0022] The execution control module is used to control the photovoltaic system to generate electricity according to the maximum active power output by the operation module.

[0023] The present invention also provides a reverse current prevention device for a photovoltaic system based on an intelligent IoT meter. The reverse current prevention device includes a memory, a processor, and a computer program stored on the memory and executable on the processor. The feature is that each functional module in the reverse current prevention device is deployed in the manner of the above-mentioned reverse current prevention system of the photovoltaic system based on an intelligent IoT meter. When the processor executes the computer program, the steps of the above-mentioned reverse current prevention method of the photovoltaic system based on an intelligent IoT meter are realized, and in a photovoltaic system without Internet access, the power generation power of the photovoltaic system is dynamically adjusted according to the power consumption of the load to avoid the photovoltaic system generating excess electricity.

[0024] The present invention also provides a reverse current prevention photovoltaic system based on an intelligent IoT meter. The photovoltaic system includes a power generation module, an inverter, a load, an intelligent IoT meter, and a power collection terminal. The power generation module is used to convert solar energy into electrical energy. The inverter is used to convert the unstable electrical energy output by the power generation module into stable electrical energy with a preset voltage and transmit the stable electrical energy to the power grid. The load is connected to the output end of the power grid. The intelligent IoT meter is used to collect the electrical energy output by the inverter and the electrical energy consumed by the load in real time. The feature is that the photovoltaic system further includes:

[0025] The power acquisition terminal is used to calculate the maximum active power that the photovoltaic system is allowed to output according to the real-time power consumption of the load and the real-time power generation of the power generation module, and then dynamically adjust the real-time power generation of the power generation module according to the maximum active power to avoid the generation of excess electricity in the photovoltaic system. The maximum active power is calculated by the following method: When P≥P set , P max =P N . When P<P set , P max =P pv -(P set -P)P set / P.

[0026] In one embodiment, the intelligent IoT meter queries the real-time output power of the inverter by the following method: The intelligent IoT meter sends a meter reading instruction to the inverter according to the pre-stored communication protocol, and then conducts data interaction with the inverter to obtain the real-time output power of the inverter.

[0027] In one embodiment, the intelligent IoT meter communicates with the inverter via RS485.

[0028] In one embodiment, the intelligent IoT meter queries the real-time power consumption of the load by the following method: The intelligent IoT meter queries the communication protocol adapted to each intelligent electrical device in the load, and then sends a meter reading instruction to each intelligent electrical device according to the adapted communication protocol, and then conducts data interaction with each intelligent electrical device to obtain the real-time power consumption of each intelligent electrical device. The total power consumption of all intelligent devices is the real-time power consumption of the load.

[0029] In one embodiment, the power acquisition terminal communicates with the intelligent IoT meter via 4G or HPLC, and then obtains the real-time power consumption of the load and the real-time output power of the inverter.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. By communicating the intelligent IoT meter with the inverter and the user load respectively, the present invention matches the power generation of the power generation module with the load of the user load in real time while measuring the user's electricity consumption, avoiding the generation of excess electricity in the photovoltaic system, preventing the reverse flow of the generated photovoltaic power to the grid side, and being applicable to the system of user photovoltaic power generation without grid connection. Based on the existing photovoltaic system, the present invention uses an intelligent IoT meter for power regulation, without the need to install additional anti-reverse flow equipment, having the advantages of low cost and strong timeliness, and overcoming the problems of untimely response and low regulation efficiency existing in the anti-reverse flow methods of the existing photovoltaic systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1The flowchart of the anti - reverse current method for the photovoltaic system based on the intelligent IoT meter in Embodiment 1 of the present invention;

[0033] Figure 2 Adopt Figure 1 The structural schematic diagram of the anti - reverse current system of the anti - reverse current method for the photovoltaic system based on the intelligent IoT meter in

[0034] Figure 3 The structural schematic diagram of the anti - reverse current photovoltaic system based on the intelligent IoT meter in Embodiment 4 of the present invention;

[0035] Figure 4 Be Figure 3 The schematic diagram of the communication method of the photovoltaic system in Detailed implementation manners

[0036] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0037] It should be noted that when a component is referred to as being "installed on" another component, it can be directly on the other component or there may also be an intermediate component. When a component is considered to be "set on" another component, it can be directly set on the other component or there may be an intermediate component at the same time. When a component is considered to be "fixed to" another component, it can be directly fixed to the other component or there may be an intermediate component at the same time.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention in this specification are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The term "or / and" used herein includes any and all combinations of one or more of the related listed items.

[0039] Embodiment 1

[0040] Please refer to Figure 1, which is the step diagram of the anti-backflow method of the photovoltaic system based on the intelligent IoT meter in this embodiment. The anti-backflow method in this embodiment is applied to a photovoltaic system that does not connect to the grid. The photovoltaic system generally includes a grid-side architecture and a user-side architecture. Among them, the grid-side architecture includes an intelligent IoT meter and the grid. The user-side architecture includes a power generation module, an inverter, and a user load. The power generation module is used to convert solar energy into electrical energy. Since solar energy is unstable, the electrical energy generated by the power generation module is also unstable. The rectifier of the power generation module can convert the unstable alternating current into stable direct current. The inverter can convert the direct current into alternating current with a fixed voltage (such as 110V, 220V, or 380V, etc.), and then supply power to the user load. The intelligent IoT meter can collect the power output by the inverter and the power consumed by the user load. When the power generation of the power generation module is sufficient, the user load is fully powered by the power generation module. When the power generation of the power generation module is less than the power consumption of the user load, the user load is powered by the power generation module and the grid simultaneously. When the real-time power generation power of the power generation module is greater than the real-time power consumption power of the user load, the electrical energy generated by the power generation module cannot be fully consumed by the user load, so the photovoltaic system generates excess power, and there is a risk of backflow in the grid. Set the power direction at the intelligent IoT meter, set the power direction from the grid-side architecture to the user-side architecture as the positive direction P(+), and set the power direction from the user-side architecture to the grid-side architecture as the negative direction P(-). For the photovoltaic system in this embodiment, the negative direction is the backflow. The anti-backflow method of the photovoltaic system based on the intelligent IoT meter includes the following steps:

[0041] Step 1: Obtain the rated power generation power P of the photovoltaic system N . Collect the real-time output power P of the intelligent IoT meter and the real-time power generation power P of the photovoltaic system pv , and set the anti-backflow threshold P set . The real-time output power P of the intelligent IoT meter is collected by the following method: The intelligent IoT meter queries the communication protocol adapted to each intelligent electrical device, and then issues a meter reading instruction to each intelligent electrical device according to the adapted communication protocol, and then conducts data interaction with each intelligent electrical device to obtain the real-time power consumption of each intelligent electrical device. The total power consumption of all intelligent electrical devices is the real-time output power P. The intelligent IoT meter can communicate with intelligent electrical devices through Bluetooth or wi-sun communication. Under the DLT698.45 communication protocol, the intelligent IoT meter conducts data interaction with intelligent electrical devices. Intelligent electrical devices include smart home appliances, smart charging devices, etc.

[0042] The real-time power generation power P of the photovoltaic system pv is collected by the following method: The intelligent IoT meter issues a meter reading instruction to the inverter of the photovoltaic system according to the pre-stored communication protocol, and then conducts data interaction with the inverter to obtain the power output by the inverter in real time as the real-time power generation power P pv。The intelligent IoT meter is remotely connected to the inverter through the RS485 interface, and the real-time output power of the inverter is obtained by reading the register data in the inverter.

[0043] In this embodiment, the rated power generation of the photovoltaic system is 30kw, and the rated power level of the user load is 30kw. The real-time output power of the intelligent IoT meter is 22kw, and the real-time power generation of the photovoltaic system is 27kw. The anti-counterflow threshold is set to 25kw.

[0044] Step 2: According to the rated power generation P N , real-time output power P and real-time power generation P pv Calculate the maximum active power P max allowed to be output by the photovoltaic system, and the specific calculation method is as follows:

[0045] Ⅰ. When P ≥ P set , adjust the maximum active power P max to the rated power generation P N , that is, P max = P N .

[0046] Ⅱ. When P < P set , take the ratio of the real-time output power P of the intelligent IoT meter to the anti-counterflow threshold P set as the difference coefficient, and the difference coefficient k is expressed as:

[0047] k = P / P set .

[0048] In this embodiment, the difference coefficient k = 22 / 25 = 0.88.

[0049] Calculate the active power difference P offset according to the difference coefficient. The active power difference P offset is expressed as:

[0050] P offset = (P set - P) / k.

[0051] In this embodiment, the active power difference P offset = (25 - 22) / 0.88 = 3.41kw.

[0052] Take the difference between the real-time power generation P pv and the active power difference P offset as the maximum active power P max . The maximum active power P max is expressed as:

[0053] P max = P pv - Poffset .

[0054] In this embodiment, P max = 27 - 3.41 = 23.59 kw.

[0055] Step 3: Send a maximum active power command to the photovoltaic system so that the photovoltaic system generates electricity according to the real-time power generation power P pv = P max .

[0056] In order to make the adjustment of the power generation power of the photovoltaic system smoother, an adjustment coefficient can be set to dynamically adjust the power generation power of the photovoltaic system. Please refer to Table 1, which is a mapping relationship table between the adjustment coefficient and the maximum active power.

[0057] Table 1

[0058] Adjustment coefficient Adjusted differential coefficient <![CDATA[P offset > <![CDATA[P max > 0.9 0.9*0.88＝0.792 (25 - 22) / 0.792 = 3.79 kW 27 - 3.79 = 23.21 kW 0.8 0.8*0.88＝0.704 (25 - 22) / 0.704 = 4.26 kW 27 - 4.26 = 22.74 kW 0.7 0.7*0.88＝0.616 (25 - 22) / 0.616 = 4.87 kW 27 - 4.87 = 22.13 kW

[0059] As shown in Table 1, by sequentially setting the adjustment coefficients to 0.9, 0.8, and 0.7, the real-time power generation power of the photovoltaic system gradually decreases to achieve smooth adjustment of the power generation power.

[0060] The anti-backflow method of this embodiment, through the communication between the intelligent IoT meter and the inverter and the user load respectively, while measuring the user's electricity consumption, matches the power generation amount of the power generation module with the load amount of the user load in real time, avoids the generation of excess electricity in the photovoltaic system, and prevents the electricity generated by the photovoltaic power generation from flowing back to the grid side. It is applicable to the system of user photovoltaic power generation without grid connection.

[0061] Embodiment 2

[0062] Refer to Figure 2 , which is a schematic structural diagram of an anti-backflow system adopting the anti-backflow method of the photovoltaic system based on the intelligent IoT meter in Figure 1 . This embodiment provides an anti-backflow system for a photovoltaic system based on an intelligent IoT meter. The anti-backflow system includes an acquisition module, an operation module, and an execution control module.

[0063] The acquisition module is used to acquire the real-time output power P of the intelligent IoT meter and the real-time power generation power P of the photovoltaic system pv . The acquisition module can be an RS485 communication, Bluetooth communication module, 4G module, or wi-sun communication module. Among them, the intelligent IoT meter can communicate with the inverter of the photovoltaic system through the RS485 interface to achieve data interaction with the inverter. The intelligent IoT meter can communicate with the intelligent power consumption equipment at the user load end through Bluetooth communication or wi-sun communication. Among them, Bluetooth is suitable for short-distance communication, such as within a range of ten meters from the intelligent IoT meter. Wi-sun is used for medium and long-distance communication, such as within a range of 10 - 1000 meters from the intelligent IoT meter.

[0064] The operation module is used for: (1), according to the real-time output power P and the real-time power generation power P pv Set the anti-backflow threshold P set .

[0065] (2), according to the real-time output power P and the real-time power generation power P pv And the rated power generation power P of the photovoltaic system N Calculate the maximum active power P that the photovoltaic system is allowed to output max . Wherein, when P≥P set , adjust the maximum active power Pmax to the rated power generation power PN, that is, P max =P N . When P<P set , use the ratio of the real-time output power P of the intelligent IoT meter to the anti-backflow threshold P set as the difference coefficient, then the difference coefficient k is expressed as:

[0066] k = P / P set .

[0067] Calculate the active power difference P according to the difference coefficient offset , the active power difference P offset is expressed as:

[0068] P offset =(P set -P) / k.

[0069] Take the difference between the real-time power generation power P pv and the active power difference P offset as the maximum active power P max , then the maximum active power P max is expressed as:

[0070] P max =P pv -P offset .

[0071] In summary, the maximum active power P max is expressed as: P max =P pv -(P set -P)P set / P.

[0072] The execution control module is used to control the photovoltaic system to generate electricity according to the maximum active power output by the operation module.

[0073] Example 3

[0074] In order to implement the anti-countercurrent method of the photovoltaic system based on the intelligent IoT meter in Embodiment 1 and apply it to the existing photovoltaic system based on the intelligent IoT meter, so as to simplify the equipment installation process in practical applications and reduce the equipment installation cost, this embodiment provides an anti-countercurrent device for a photovoltaic system based on an intelligent IoT meter. The anti-countercurrent device includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the steps of the anti-countercurrent method of the photovoltaic system based on the intelligent IoT meter as described above are implemented, and further, in a photovoltaic system without Internet access, the power generation power of the photovoltaic system is dynamically adjusted according to the power consumption of the load to avoid the generation of excess power by the photovoltaic system.

[0075] The computer device can be a smart phone, a tablet computer, a notebook computer, a desktop computer, a rack server, a blade server, a tower server, or a cabinet server (including an independent server or a server cluster composed of multiple servers) that can execute programs. The computer device in this embodiment at least includes, but is not limited to, a memory and a processor that can communicate with each other through a system bus.

[0076] In this embodiment, the memory (i.e., the readable storage medium) includes flash memory, a hard disk, a multimedia card, a card-type memory (such as an SD or DX memory, etc.), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a magnetic memory, a magnetic disk, an optical disk, etc. In some embodiments, the memory can be an internal storage unit of the computer device, such as the hard disk or memory of the computer device. In other embodiments, the memory can also be an external storage device of the computer device, such as a plug-in hard disk equipped on the computer device, a Smart Media Card (SMC), a Secure Digital (SD) card, a Flash Card, etc. Of course, the memory can also include both the internal storage unit and the external storage device of the computer device. In this embodiment, the memory is generally used to store the operating system and various application software installed on the computer device. In addition, the memory can also be used to temporarily store various data that have been output or will be output.

[0077] The processor may be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other data processing chips in some embodiments. The processor is generally used to control the overall operation of a computer device. In this embodiment, the processor is used to run the program code stored in the memory or process data, thereby implementing the steps of the above anti-counterflow method for a photovoltaic system based on an intelligent IoT meter, and further implementing, in a photovoltaic system that is not connected to the Internet, dynamically adjusting the power generation power of the photovoltaic system according to the power consumption of the load to avoid the photovoltaic system generating excess electricity.

[0078] Embodiment 4

[0079] Please refer to Figure 3 , which is a schematic structural diagram of an anti-counterflow photovoltaic system based on an intelligent IoT meter in this embodiment. An anti-counterflow photovoltaic system based on an intelligent IoT meter, the photovoltaic system includes a power generation module, an inverter, a load, an intelligent IoT meter, and a power collection terminal.

[0080] The power generation module is used to convert solar energy into electrical energy. The inverter is used to convert the unstable electrical energy output by the power generation module into stable electrical energy with a preset voltage and transmit the stable electrical energy to the power grid. The power generation module is a power generation element composed of photovoltaic panels, that is, solar panels, and the solar panels use the photovoltaic effect at the semiconductor interface to directly convert light energy into electrical energy. The power generation module and the inverter together constitute a photovoltaic power generation device, which is the front-end device in the photovoltaic system for generating electrical energy.

[0081] The load is connected to the output end of the power grid. The load is the assembly of all electrical equipment on the user side. The total load of the power grid is also the total power consumption of all electrical equipment. The electrical energy output by the power generation module is used to supply power to the load. At night or in rainy weather, when the real-time power generation power of the power generation module is less than the power consumption of the load, the load uses the power grid for compensatory power supply. During the power consumption process of the load, the photovoltaic power generation device is always preferentially used for power supply.

[0082] Please refer to Figure 4 , which is Figure 3Schematic diagram of the communication method in the photovoltaic system. The intelligent IoT meter is used to collect the electrical energy output by the inverter and the electrical energy consumed by the load in real time. The intelligent IoT meter queries the real-time output power of the inverter through the following method: The intelligent IoT meter sends a meter reading instruction to the inverter according to the pre-stored communication protocol, and then conducts data interaction with the inverter to obtain the real-time output power of the inverter. In the photovoltaic system, the number of intelligent IoT meters may be more than one, and each intelligent IoT meter has more than one inverter downstream. By encoding the intelligent IoT meter and the inverter, when the intelligent IoT meter sends a meter reading instruction, it first performs encoding matching on each inverter, so that communication can be carried out between each intelligent IoT meter and the corresponding inverter through the pre-set communication protocol, avoiding communication anomalies. The photovoltaic inverter and the intelligent IoT meter can be remotely connected through the RS485 interface to achieve data interaction between the photovoltaic inverter and the intelligent IoT meter. Each intelligent IoT meter can interact with up to 255 photovoltaic inverters at the same time.

[0083] The intelligent IoT meter queries the real-time power consumption of the load through the following method: The intelligent IoT meter queries the communication protocol adapted to each intelligent electrical device in the load, and then sends a meter reading instruction to each intelligent electrical device according to the adapted communication protocol, and then conducts data interaction with each intelligent electrical device to obtain the real-time power consumption of each intelligent electrical device. The total power consumption of all intelligent devices is the real-time power consumption of the load. The intelligent IoT meter can communicate with the intelligent electrical devices at the user load end through Bluetooth communication or Wi-Sun communication. Among them, Bluetooth is suitable for short-distance communication, such as within a range of ten meters from the intelligent IoT meter. Wi-Sun is used for medium- and long-distance communication, such as within a range of 10 - 1000 meters from the intelligent IoT meter.

[0084] The power collection terminal is used to calculate the maximum active power that the photovoltaic system is allowed to output according to the real-time power consumption of the load and the real-time power generation of the power generation module, and then dynamically adjust the real-time power generation of the power generation module according to the maximum active power to avoid the generation of excess electricity in the photovoltaic system.

[0085] The power collection terminal communicates with the intelligent IoT meter via 4G or HPLC, thereby obtaining the real-time power consumption of the load and the real-time output power of the inverter in real time. The power collection terminal first encodes each intelligent IoT meter, inverter, and intelligent power consumption device. The inverters or intelligent power consumption devices belonging to the same intelligent IoT meter downstream all adopt secondary encoding, and the encoding of the corresponding intelligent IoT meter is added to the front of the encoding of each inverter and intelligent power consumption device. Thus, when the power collection terminal issues a communication message, multiple instructions belonging to the same intelligent IoT meter are packed and sent to the intelligent IoT meter, and then the intelligent IoT meter communicates with the corresponding inverter or intelligent power consumption device separately to send each instruction to the corresponding inverter or intelligent power consumption device, realizing the communication between the intelligent IoT meter, inverter, and intelligent power consumption device.

[0086] Among them, the maximum active power is calculated by the following method:

[0087] When P ≥ P set , the maximum active power Pmax is adjusted to the rated power generation PN, that is, P max = P N . When P < P set , the ratio of the real-time output power P of the intelligent IoT meter to the anti-counterflow threshold P set is used as the difference coefficient, and the difference coefficient k is expressed as:

[0088] k = P / P set .

[0089] Calculate the active power difference P offset according to the difference coefficient. The active power difference P offset is expressed as:

[0090] P offset = (P set - P) / k.

[0091] Take the difference between the real-time power generation P pv and the active power difference P offset as the maximum active power P max , then the maximum active power P max is expressed as:

[0092] P max = P pv - P offset .

[0093] In summary, the maximum active power P max is expressed as: P max = P pv - (P set - P)P set / P.

[0094] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0095] The above-described embodiments only represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A method for preventing reverse current in a photovoltaic system based on an intelligent Internet of Things meter, which is used in a photovoltaic system that does not feed electricity back to the grid. The method dynamically adjusts the power generation of the photovoltaic system according to the power consumption of the load to avoid the generation of excess electricity by the photovoltaic system. It is characterized in that, The anti-counterflow method includes the following process: Step 1: Obtain the rated power generation P of the photovoltaic system N ; Collect the real-time output power P of the intelligent IoT meter and the real-time power generation P of the photovoltaic system pv , and set the anti-backflow threshold P set ; Step 2: According to the rated power generation P N , the real-time output power P, and the real-time power generation P pv calculate the maximum active power P that the photovoltaic system is allowed to output max , and the specific calculation method is as follows: Ⅰ. When P ≥ P set , adjust the maximum active power P max to the rated power generation P N , that is, P max = P N ; Ⅱ. When P < P set , take the ratio of the real-time output power P of the intelligent IoT meter to the anti-counterflow threshold P set as the difference coefficient, and the difference coefficient k is expressed as: k = P / P set ; Calculate the active power difference P according to the difference coefficient offset ; The active power difference P offset is expressed as: P offset = (P set - P) / k; Take the real-time power generation power P pv and the difference between the active power difference P offset as the maximum active power P max ; The maximum active power P max is expressed as: P max = P pv -P offset ; Step 3: Send a maximum active power command to the photovoltaic system so that the photovoltaic system generates electricity according to the real-time power generation power P pv = P max for power generation.

2. The anti-countercurrent method of the photovoltaic system based on the intelligent IoT meter according to claim 1, wherein In step one, the real-time output power P of the intelligent IoT meter is collected by the following method: the intelligent IoT meter queries the communication protocol adapted to each intelligent power consumption device, and then issues a meter reading instruction to each intelligent power consumption device according to the adapted communication protocol, and then conducts data interaction with each intelligent power consumption device to obtain the real-time power consumption of each intelligent power consumption device; the total power consumption of all the intelligent power consumption devices is the real-time output power P.

3. The anti-counterflow method of the photovoltaic system based on the intelligent IoT meter according to claim 1, characterized in that In step one, the real-time power generation power P of the photovoltaic system pv is collected by the following method: The intelligent IoT meter sends a meter reading instruction to the inverter of the photovoltaic system according to the pre-stored communication protocol, and then conducts data interaction with the inverter to obtain the power output by the inverter in real time as the real-time power generation power P pv .

4. An anti-backflow system for a photovoltaic system based on an intelligent IoT meter, which adopts the anti-backflow method for a photovoltaic system based on an intelligent IoT meter as described in any one of claims 1 to 3, characterized in that, The anti-counterflow system includes: A collection module, which is used to collect the real-time output power P of the intelligent IoT meter and the real-time power generation power P of the photovoltaic system pv ; An operation module, which is used for: (1), according to the real-time output power P and the real-time power generation power P pv Set the anti-backflow threshold P set ; (2), according to the real-time output power P and the real-time power generation power P pv And the rated power generation power P of the photovoltaic system N Calculate the maximum active power P that the photovoltaic system is allowed to output max ; where, when P≥P set , P max =P N ; when P<P set , P max =P pv -(P set -P)P set / P; and An execution control module, which is used to control the photovoltaic system to generate electricity according to the maximum active power output by the operation module.

5. An anti-backflow device for a photovoltaic system based on an intelligent IoT meter, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, Each functional module in the anti-counterflow device is deployed in the manner of the anti-counterflow system of the photovoltaic system based on the intelligent IoT meter as described in claim 4. When the processor executes the computer program, the steps of the anti-counterflow method of the photovoltaic system based on the intelligent IoT meter as described in any one of claims 1 to 3 are realized, and in a photovoltaic system without accessing the Internet, the power generation power of the photovoltaic system is dynamically adjusted according to the power consumption of the load to avoid the photovoltaic system generating excess electricity.

6. A photovoltaic system with anti-counterflow based on an intelligent IoT meter, which adopts the anti-counterflow method of the photovoltaic system based on the intelligent IoT meter as described in any one of claims 1 to 3. The photovoltaic system includes a power generation module, an inverter, a load, and an intelligent IoT meter; the power generation module is used to convert solar energy into electrical energy; the inverter is used to convert the unstable electrical energy output by the power generation module into stable electrical energy with a preset voltage and transmit the stable electrical energy to the power grid; the load is connected to the output end of the power grid; The intelligent IoT meter is used to collect the electric energy output by the inverter and the electric energy consumed by the load in real time; characterized in that The photovoltaic system further includes: A power collection terminal, which is used to calculate the maximum active power that the photovoltaic system is allowed to output according to the real-time power consumption of the load and the real-time power generation of the power generation module, and then dynamically adjust the real-time power generation of the power generation module according to the maximum active power to avoid the generation of excess electricity by the photovoltaic system; the maximum active power is calculated by the following method: when P≥P set , P max =P N ; When P < P set , P max = P pv - (P set - P)P set / P.

7. The anti-counterflow photovoltaic system based on the intelligent IoT meter according to claim 6, wherein, The intelligent IoT meter queries the real-time output power of the inverter by the following method: the intelligent IoT meter issues a meter reading instruction to the inverter according to the pre-stored communication protocol, and then conducts data interaction with the inverter to obtain the real-time output power of the inverter.

8. The anti-counterflow photovoltaic system based on the intelligent IoT meter according to claim 7, characterized in that, The intelligent IoT meter communicates with the inverter through RS485.

9. The anti-counterflow photovoltaic system based on the intelligent IoT meter according to claim 6, wherein, The intelligent IoT meter queries the real-time power consumption of the load by the following method: the intelligent IoT meter queries the communication protocol adapted to each intelligent power consumption device in the load, and then issues a meter reading instruction to each intelligent power consumption device according to the adapted communication protocol, and then conducts data interaction with each intelligent power consumption device to obtain the real-time power consumption of each intelligent power consumption device; The total power consumption of all intelligent devices is the real-time power consumption of the load.

10. The anti-counterflow photovoltaic system based on the intelligent IoT meter according to claim 6, characterized in that, The power acquisition terminal communicates with the intelligent IoT meter through 4G or HPLC to obtain the real-time power consumption of the load and the real-time output power of the inverter.

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