A method for controlling switching of on-grid and off-grid energy storage batteries and an energy storage battery system

Abstract

The present application provides a method for controlling switching between an on-grid and off-grid energy storage battery and an energy storage battery system. The method is applied to the system. The energy storage battery system includes a control unit, a first energy storage unit, and a second energy storage unit. The control unit includes a mains detection module, a switch module, and a control module. The first energy storage unit includes a photovoltaic power generation module, a grid-connected module, and a first energy storage battery. The second energy storage unit includes an off-grid module and a second energy storage battery. The method includes: the control unit obtains real-time monitoring data of the power grid and the power of the first energy storage battery and the second energy storage battery; based on the real-time monitoring data, a stability detection result of the power grid is determined, and the real-time monitoring data, the stability detection result, and the power of the first energy storage battery and the second energy storage battery are respectively input into a decision tree model, and a switching control result and an operation control result are output to control the energy storage battery system to perform on-grid and off-grid switching and load operation, thereby intelligently performing on-grid and off-grid switching to ensure a stable supply of household electricity.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage battery systems, and in particular to a method for controlling switching between on-grid and off-grid energy storage batteries and an energy storage battery system. Background Art

[0002] With the rapid development and popularization of clean energy, energy storage battery systems are playing an increasingly important role in home and industrial applications. These systems are able to use renewable energy sources such as solar and wind power to charge and release electricity when needed to supply electricity demand. Their use not only improves the flexibility and stability of the power system, but also helps reduce energy costs and carbon emissions, so they have attracted much attention.

[0003] However, current energy storage battery systems still face some challenges in practical applications. One of the most prominent issues is the system's inability to respond to power outages. Traditional energy storage battery systems usually require manual intervention to switch to off-grid mode and lack intelligent control and automated management, which results in the system being unable to respond to power outages in a timely manner, thus affecting the continuity and stability of household electricity supply. Summary of the invention

[0004] In view of this, the purpose of the present application is to provide an on-grid and off-grid energy storage battery switching control method and an energy storage battery system, which can intelligently perform on-grid and off-grid switching based on the real-time situation of the power grid status and the mains power supply, so as to ensure the continuity and stability of household power supply.

[0005] An on-grid and off-grid energy storage battery switching control method provided in an embodiment of the present application is applied to an energy storage battery system, wherein the energy storage battery system comprises a control unit, a first energy storage unit and a second energy storage unit, wherein the first energy storage unit and the second energy storage unit are respectively connected to the control unit, and the control unit is connected to a mains power grid; the control unit comprises a mains power detection module, a switch module and a control module; the first energy storage unit comprises a photovoltaic power generation module, a grid-connected module and a first energy storage battery; the second energy storage unit comprises an off-grid module and a second energy storage battery; the method comprises:

[0006] The control unit obtains real-time monitoring data during power supply of the power grid, the power of the first energy storage battery in the first energy storage unit, and the power of the second energy storage battery in the second energy storage unit;

[0007] Based on the real-time monitoring data, determining a stability detection result of the power supply status of the power grid;

[0008] Input the real-time monitoring data, the stability detection result, the power of the first energy storage battery, the power of the first energy storage battery, and the power of the second energy storage battery into the nodes corresponding to the pre-built decision tree model respectively;

[0009] The decision tree model processes the real-time monitoring data, the stability detection results, the power of the first energy storage battery and the power of the second energy storage battery, outputs a switching control result for the energy storage battery system and an operation control result for the load, and controls the switching module in the control unit, the grid-connected module in the first energy storage unit, and the off-grid module of the second energy storage unit to switch based on the switching control result, and controls the operation of the load based on the operation control result.

[0010] In some embodiments, in the on-grid and off-grid energy storage battery switching control method, determining the stability detection result of the power supply state of the power grid based on the real-time monitoring data includes:

[0011] Preprocessing the real-time monitoring data to obtain preprocessed real-time monitoring data;

[0012] Based on the pre-processed real-time monitoring data, a plurality of mains power characteristics characterizing the mains power supply status are obtained; the mains power characteristics include the real-time monitoring data directly used as the mains power characteristics, and the mains power characteristics obtained after processing at least one real-time monitoring data;

[0013] Inputting the plurality of mains power features into a pre-trained isolation forest model, wherein the isolation forest model processes each mains power feature and calculates anomaly scores of data points in each mains power feature;

[0014] Based on the abnormal scores of the data points in each mains power feature, it is determined whether there are abnormal data points in the mains power feature to determine the stability detection result of the power supply state of the power grid.

[0015] In some embodiments, in the on-grid and off-grid energy storage battery switching control method, the isolation forest model processes each mains power feature and calculates the abnormal score of the data point in each mains power feature, including:

[0016] The isolation forest model processes each mains power feature and constructs a tree structure until the number of data points of the mains power feature included in each leaf node in the isolation forest model is less than a first preset threshold, or the isolation forest model reaches a maximum depth of the tree;

[0017] For each data point of each mains power feature, calculate the path length of the data point in the isolation forest model; the path length is the number of edges passed from the root node to the data point;

[0018] According to the path length of the data point, the anomaly score of the data point in each mains power feature is calculated; the shorter the path length, the lower the anomaly score; the longer the path length, the higher the anomaly score.

[0019] In some embodiments, in the on-grid and off-grid energy storage battery switching control method, the real-time monitoring data is preprocessed to obtain the preprocessed real-time monitoring data; including:

[0020] Normalizing different types of real-time monitoring data to obtain normalized real-time monitoring data;

[0021] Outliers in the normalized real-time monitoring data are screened out to obtain preprocessed real-time monitoring data.

[0022] In some embodiments, in the on-grid and off-grid energy storage battery switching control method, the decision tree model processes the real-time monitoring data, the stability detection result, the power of the first energy storage battery and the power of the second energy storage battery, and outputs the switching control result for the energy storage battery system and the operation control result for the load, including:

[0023] The decision tree model determines whether the real-time monitoring data is normal;

[0024] If yes, the real-time monitoring data is recorded normally; if no, whether the power supply status of the power grid is stable is determined in combination with the stability detection result;

[0025] Determine whether the power supply state of the power grid is stable. If so, control the switch module in the control unit to close to maintain the grid-connected operation state between the energy storage battery system and the power grid; if not, control the switch module to disconnect to switch to the off-grid operation state of the energy storage battery system and the power grid;

[0026] For the off-grid operation state, based on the power of the first energy storage battery and the power of the second energy storage battery in the energy storage battery system, the switching control results for the grid-connected module in the first energy storage unit and the off-grid module of the second energy storage unit and the operation control results for the load in the off-grid operation state are determined.

[0027] In some embodiments, in the on-grid and off-grid energy storage battery switching control method, the off-grid operation state is determined based on the power of the first energy storage battery and the power of the second energy storage battery in the energy storage battery system to determine the switching control result for the on-grid module in the first energy storage unit and the off-grid module of the second energy storage unit in the off-grid operation state, and the operation control result for the load, including:

[0028] For the off-grid operation state, determine the power evaluation result of the first energy storage battery of the first energy storage unit, and determine the power evaluation result of the second energy storage battery of the second energy storage unit, and based on the power evaluation results of the first energy storage battery and the second energy storage battery, determine the switching control result for the grid-connected module in the first energy storage unit and the off-grid module of the second energy storage unit, and the operation control result for the load;

[0029] Among them, the switching control result is to control the first energy storage unit to independently supply power off the grid, or to control the first energy storage unit and the second energy storage unit to jointly supply power off the grid; the operation control result of the load is to operate the load normally or shut down part of the load.

[0030] In some embodiments, in the on-grid and off-grid energy storage battery switching control method, the power evaluation result of the first energy storage battery of the first energy storage unit and the power evaluation result of the second energy storage battery of the second energy storage unit are determined for the off-grid operation state, and based on the power evaluation results of the first energy storage battery and the second energy storage battery, the switching control result for the on-grid module in the first energy storage unit and the off-grid module of the second energy storage unit and the operation control result for the load are determined; including:

[0031] For the off-grid operation state, determining whether the power of the first energy storage battery in the first energy storage unit is greater than a second preset threshold;

[0032] If the power of the first energy storage battery is greater than the second preset threshold, the grid-connected module in the first energy storage unit is started, and the power of the first energy storage battery in the first energy storage unit in the off-grid operation state is monitored in real time to see whether it is greater than the third preset threshold;

[0033] When the power of the first energy storage battery is greater than a third preset threshold, determining that the first energy storage unit is independently powered, and determining that the operation control result of the load is to maintain normal operation of the load;

[0034] If the power level of the first energy storage battery is less than or equal to the second preset threshold, or the power level of the first energy storage battery is greater than the third preset threshold, the off-grid module in the second energy storage unit is started at the same time, and the power level of the second energy storage battery in the second energy storage unit is monitored in real time to see whether it is greater than the fourth preset threshold;

[0035] When the power of the second energy storage battery is greater than a fourth preset threshold, determining that the operation control result of the load is to maintain normal operation of the load;

[0036] When the power level of the second energy storage battery is less than or equal to a fourth preset threshold, the operation control result of the load is determined to keep the first preset load running and shut down other loads.

[0037] In some embodiments, in the on-grid and off-grid energy storage battery switching control method, real-time communication between the control unit of the energy storage battery system, the first energy storage unit, the second energy storage unit and the load is achieved based on the UDP local communication protocol.

[0038] In some embodiments, an energy storage battery system is further provided, the energy storage battery system comprising a control unit, a first energy storage unit and a second energy storage unit, the first energy storage unit and the second energy storage unit are respectively connected to the control unit, and the control unit is connected to the mains power grid; the control unit comprises a mains power detection module, a switch module and a control module; the first energy storage unit comprises a photovoltaic power generation module, a grid-connected module and a first energy storage battery; the second energy storage unit comprises an off-grid module and a second energy storage battery;

[0039] The control unit is used to obtain real-time monitoring data during power supply of the power grid, the power of the first energy storage battery in the first energy storage unit, and the power of the second energy storage battery in the second energy storage unit;

[0040] It is also used to determine the stability detection result of the power supply state of the power grid based on the real-time monitoring data;

[0041] It is also used to input the real-time monitoring data, the stability detection result, the power of the first energy storage battery, the power of the first energy storage battery, and the power of the second energy storage battery into the nodes corresponding to the pre-built decision tree model respectively;

[0042] The decision tree model is also used to process the real-time monitoring data, stability detection results, the power of the first energy storage battery and the power of the second energy storage battery, output a switching control result for the energy storage battery system and an operation control result for the load, and control the switching of the switch module in the control unit, the grid-connected module in the first energy storage unit, and the off-grid module of the second energy storage unit based on the switching control result, and control the operation of the load based on the operation control result.

[0043] In some embodiments, in the energy storage battery system, the switch module of the control unit is arranged between the power grid and the control module, so that after the switch module is disconnected, the energy storage battery system supplies power to the control module.

[0044] In an embodiment of the present application, a method for controlling switching between an on-grid and off-grid energy storage battery and an energy storage battery system are provided, which are applied to an energy storage battery system, wherein the energy storage battery system comprises a control unit, a first energy storage unit and a second energy storage unit, wherein the first energy storage unit and the second energy storage unit are respectively connected to the control unit, and the control unit is connected to a mains power grid; the control unit comprises a mains power detection module, a switch module and a control module; the first energy storage unit comprises a photovoltaic power generation module, a grid-connected module and a first energy storage battery; the second energy storage unit comprises an off-grid module and a second energy storage battery; the method comprises: the control unit obtains real-time monitoring data during power supply of the power grid, the power of the first energy storage battery in the first energy storage unit, and the power of the second energy storage battery in the second energy storage unit; based on the real-time monitoring data, determines a stability detection result of the power supply state of the power grid; processes the real-time monitoring data, the stability detection result, the power of the first energy storage battery and the second energy storage battery through a policy tree model The power of the energy storage battery is determined, and the switching control result for the energy storage battery system and the operation control result for the load are determined. Based on the switching control result, the switch module in the control unit, the grid-connected module in the first energy storage unit, and the off-grid module of the second energy storage unit are controlled to switch, and the operation of the load is controlled based on the operation control result; thereby, based on the real-time monitoring of the power grid state and the mains power supply, automatic judgment and response to power outages, instability, etc. of the power grid are made; and the switching of the first energy storage unit and / or the second energy storage unit in the energy storage battery system is further controlled, and other household load devices are informed to perform corresponding operations, so that the continuity and stability of the household power supply are guaranteed through the cooperation of the control module, the off-grid module and the grid-connected module in the energy storage battery system. The system can manage the power supply more intelligently, make full use of solar energy and battery energy storage systems, and combine the management of household loads to ensure the power demand of the household in the event of unstable mains power or power outage. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1 A flow chart of the on-grid and off-grid energy storage battery switching control method described in an embodiment of the present application is shown;

[0047] Figure 2 A schematic diagram of the structure of the energy storage battery system according to an embodiment of the present application is shown;

[0048] Figure 3A flow chart of a method for determining a stability detection result of a power supply state of a power grid according to an embodiment of the present application is shown;

[0049] Figure 4 A schematic diagram of the process of processing each mains power feature by the isolation forest model described in the embodiment of the present application is shown;

[0050] Figure 5 A flow chart of the decision tree model in an embodiment of the present application processing the real-time monitoring data, stability detection results, the power of the first energy storage battery and the power of the second energy storage battery is shown. DETAILED DESCRIPTION

[0051] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application only serve the purpose of explanation and description and are not used to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn in real proportion. The flowchart used in this application shows the operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowchart can be implemented out of sequence, and the steps without logical context can be reversed in order or implemented simultaneously. In addition, those skilled in the art can add one or more other operations to the flowchart under the guidance of the content of the present application, or remove one or more operations from the flowchart.

[0052] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0053] It should be noted that the term "comprising" will be used in the embodiments of the present application to indicate the existence of the features declared thereafter, but does not exclude the addition of other features.

[0054] With the rapid development and popularization of clean energy, energy storage battery systems are playing an increasingly important role in home and industrial applications. These systems are able to use renewable energy sources such as solar and wind power to charge and release electricity when needed to supply electricity demand. Their use not only improves the flexibility and stability of the power system, but also helps reduce energy costs and carbon emissions, so they have attracted much attention.

[0055] However, current energy storage battery systems still face some challenges in practical applications. One of the most prominent issues is the system's inability to respond to power outages. Traditional energy storage battery systems usually require manual intervention to switch to off-grid mode and lack intelligent control and automated management, which results in the system being unable to respond to power outages in a timely manner, thus affecting the continuity and stability of household electricity supply.

[0056] At present, although there are some control methods and system designs for on-grid and off-grid energy storage battery systems, they still have some limitations. For example, some systems use timer or threshold-based control strategies, lack real-time monitoring of the grid status and mains power supply, and therefore cannot make automatic judgments and responses to grid power outages. In addition, some systems use remote monitoring and control methods, but this method relies on Internet connection and has potential safety and reliability risks.

[0057] Based on this, in an embodiment of the present application, a method and system for switching control of an on-grid and off-grid energy storage battery is provided, which is applied to an energy storage battery system, wherein the energy storage battery system comprises a control unit, a first energy storage unit and a second energy storage unit, wherein the first energy storage unit and the second energy storage unit are respectively connected to the control unit, and the control unit is connected to a mains power grid; the control unit comprises a mains power detection module, a switch module and a control module; the first energy storage unit comprises a photovoltaic power generation module, a grid-connected module and a first energy storage battery; the second energy storage unit comprises an off-grid module and a second energy storage battery; the method comprises: the control unit obtains real-time monitoring data during power supply of the power grid, the power of the first energy storage battery in the first energy storage unit, and the power of the second energy storage battery in the second energy storage unit; based on the real-time monitoring data, determines the stability detection result of the power supply state of the power grid; the real-time monitoring data, the stability detection result, the power of the first energy storage battery, the power of the first energy storage battery and the power of the second energy storage battery are respectively input into the nodes corresponding to the pre-constructed decision tree model; the decision The policy tree model processes the real-time monitoring data, stability detection results, the power of the first energy storage battery and the power of the second energy storage battery, outputs the switching control results for the energy storage battery system and the operation control results for the load, and controls the switch module in the control unit, the grid-connected module in the first energy storage unit, and the off-grid module of the second energy storage unit to switch based on the switching control results, and controls the operation of the load based on the operation control results, so as to make automatic judgments and responses to power outages, instability, etc. of the grid based on real-time monitoring of the grid state and the city power supply; and further controls the switching of the first energy storage unit and / or the second energy storage unit in the energy storage battery system, and informs other household load devices to perform corresponding operations, so as to ensure the continuity and stability of household power supply through the cooperation of the control module, the off-grid module and the grid-connected module in the energy storage battery system, and the system can manage the power supply more intelligently, make full use of solar energy and battery energy storage systems, and combine the management of household loads to ensure the power demand of the household when the city power is unstable or out of power.

[0058] Please refer to Figure 1 and Figure 2 , Figure 1 A flow chart of the on-grid and off-grid energy storage battery switching control method described in an embodiment of the present application is shown; Figure 2The schematic diagram of the structure of the energy storage battery system described in the embodiment of the present application is shown; the energy storage battery system includes a control unit, a first energy storage unit and a second energy storage unit, the first energy storage unit and the second energy storage unit are respectively connected to the control unit, and the control unit is connected to the mains power grid; the control unit includes a mains detection module 205, a switch module 204 and a control module 201; the first energy storage unit includes a photovoltaic power generation module 208, a grid-connected module 202 and a first energy storage battery 206; the second energy storage unit includes an off-grid module 203 and a second energy storage battery 207; please refer to Figure 1 , the method comprises the following steps S101-S104:

[0059] S101, the control module 201 obtains real-time monitoring data during the power supply process of the power grid, the power of the first energy storage battery 206 in the energy storage battery system connected to the grid-connected module 202, and the power of the second energy storage battery 207 in the energy storage battery system connected to the off-grid module 203;

[0060] S102, determining a stability detection result of the power supply state of the power grid based on the real-time monitoring data;

[0061] S103, inputting the real-time monitoring data, stability detection results, the power of the first energy storage battery 206 and the power of the second energy storage battery 207 into the nodes corresponding to the pre-built decision tree model respectively;

[0062] S104, the decision tree model processes the real-time monitoring data, the stability detection results, the power of the first energy storage battery 206 and the power of the second energy storage battery 207, outputs a switching control result for the energy storage battery system and an operation control result for the load, and controls the switching of the grid-connected module 202, the off-grid module 203, and the switch module 204 based on the switching control result, and controls the operation of the load based on the operation control result.

[0063] In step S101, the control module 201 obtains real-time monitoring data during the power supply process of the power grid, the power of the first energy storage battery 206 in the energy storage battery system connected to the grid-connected module 202, and the power of the second energy storage battery 207 in the energy storage battery system connected to the off-grid module 203.

[0064] Please refer to Figure 2, the mains power grid is connected to the home power grid to supply power to the load devices of the home power grid. The energy storage battery system also includes a mains power detection module 205; the mains power detection module 205 is arranged between the power grid and the switch module 204; the first energy storage unit includes a photovoltaic power generation module 208, a grid-connected module 202 and a first energy storage battery 206, the grid-connected module 202 connects the photovoltaic power generation module 208 and the energy storage electricity, and the grid-connected module 202 is connected to the control module 201 of the control unit; the second energy storage unit includes an off-grid module 203 and a second energy storage battery 207, the off-grid module 203 is connected to the second energy storage battery 207, and the off-grid module 203 is connected to the control module 201.

[0065] The grid-connected module 202 is used to control the power supply of the first energy storage unit; the off-grid module 203 is used to control the power supply of the second energy storage unit.

[0066] The grid-connected module 202 and the off-grid module 203 are both connected to the household power grid to control the first energy storage unit and the second energy storage unit to supply power to the household power grid. At the same time, the output end of the grid-connected module 202 is also connected to the power grid, and the electric energy of the first energy storage unit is directly transmitted to the power grid. The main function of the first energy storage unit is to convert solar energy into electric energy, and transmit the converted electric energy to the mains power grid for use by other users; or input the electric energy into the household power grid for use by household loads; or take electricity from the power grid and store it in the energy storage battery; or store the converted electric energy in the first energy storage battery 206. The grid-connected module 202 is mainly composed of a grid-connected inverter, etc., which controls the power supply of the first energy storage unit, and directly transmits the excess electric energy to the mains power grid, the household power grid or stores it in the first energy storage battery 206.

[0067] The second energy storage unit of the off-grid module 203 is independent of the power grid and is equipped with energy storage batteries to store the electricity generated by the solar cell array so as to supply power to the load when needed. It should be noted that the second energy storage unit operates in an isolated island and has no grid connection function, so it cannot sell electricity.

[0068] However, please refer to Figure 2 If the mains power grid is cut off, but the mains power grid and the home grid are connected, the second energy storage battery 207 connected to the off-grid module 203 or the first energy storage battery 206 connected to the grid-connected module 202 will supply power to the grid while supplying power to the home load, that is, electric energy will flow back into the grid, so the power of the energy storage battery will be quickly discharged in a short time.

[0069] It should be noted that, in the battery energy storage system, the second energy storage battery 207 connected to the off-grid module 203 and the first energy storage battery 206 connected to the grid-connected module 202 are distinguished based on their functions, and can actually be the same or independent.

[0070] When the same energy storage battery is connected to the off-grid module 203 and the grid-connected module 202, since there is no need to purchase and maintain two independent battery systems, space can be saved, making the entire energy storage system more compact; at the same time, based on the control system in the energy storage battery system, it can operate efficiently and safely in different modes.

[0071] Based on this, in the embodiment of the present application, it is necessary to monitor the status of the mains power grid in real time. When the mains power grid is unstable and it is judged that there is a possibility of power outage in the mains power grid, the switch module 204 is used to disconnect the mains power grid from the home power grid, so that the energy storage battery system is in an off-grid operation mode, preventing the electric energy in the home power grid from flowing back into the grid, thereby ensuring the power demand of the home power grid.

[0072] That is to say, the AC power detection module 205 in the control unit collects real-time monitoring data during the power supply process of the power grid in real time, and sends the real-time monitoring data to the control module 201, so that the control module 201 obtains real-time monitoring data during the power supply process of the power grid.

[0073] In the embodiment of the present application, the switch module 204 is specifically an intelligent knife switch, which receives the switching control signal of the control module 201, and responds to the switching control signal to disconnect or connect, so that the mains power grid and the home power grid are disconnected or connected; when the mains power grid and the home power grid are disconnected, the energy storage battery system is in an off-grid operation state; when the mains power grid and the home power grid are connected, the energy storage battery system is in a grid-connected operation state; it is worth noting that the intelligent knife switch is in a normally closed state under normal circumstances, in which the mains power grid and the home power grid are connected.

[0074] The off-grid operation state refers to the state in which the home grid (or local grid) operates independently when the mains grid and the home grid are disconnected through a smart knife switch. The home grid no longer relies on the power supply of the mains grid, but relies on other energy sources, such as energy storage battery systems, solar power generation systems, etc. At this time, the home grid can be independently regulated according to its own needs and energy supply conditions; however, since it does not rely on a stable mains grid, the power supply of the home grid may be affected by factors such as the status of the energy storage system and weather, and there is a certain degree of instability.

[0075] The grid-connected operation state refers to the state in which the household power grid and the municipal power grid are connected through an intelligent knife switch, and the household power grid and the municipal power grid operate together. The power supply of the household power grid is jointly guaranteed by the municipal power grid and possible local energy systems (such as energy storage battery systems), and has high stability.

[0076] The mains power detection module 205 is used to collect real-time monitoring data during the process of the mains power grid supplying power to the household power grid. The real-time monitoring data includes voltage, current, current frequency, etc.

[0077] In the embodiment of the present application, for example, the AC power detection module 205 can be integrated into an intelligent knife switch to facilitate installation and spatial arrangement.

[0078] The control module 201 is a local control module 201, including a processor, a memory, and an input / output interface, so as to realize local control of the energy storage battery and off-grid, which is more real-time and stable.

[0079] The control module 201 can be independently configured or integrated into an intelligent knife switch.

[0080] In the step S102, a stability detection result of the power supply status of the power grid is determined based on the real-time monitoring data.

[0081] Specifically, the control module 201 determines a stability detection result of the power supply status of the power grid based on the real-time monitoring data.

[0082] In the embodiment of the present application, the stability detection result of the power supply status of the power grid is determined specifically by using an isolation forest model.

[0083] Please refer to Figure 3 , Figure 3 A flow chart of a method for determining the stability detection result of the power supply state of the power grid according to an embodiment of the present application is shown; the method for determining the stability detection result of the power supply state of the power grid based on the real-time monitoring data includes steps S301-S304:

[0084] S301, preprocessing the real-time monitoring data to obtain preprocessed real-time monitoring data;

[0085] S302, based on the pre-processed real-time monitoring data, obtaining a plurality of mains power characteristics characterizing the mains power supply status; the mains power characteristics include the real-time monitoring data directly used as the mains power characteristics, and the mains power characteristics obtained after processing at least one real-time monitoring data;

[0086] S303, inputting the plurality of mains power features into a pre-trained isolation forest model, wherein the isolation forest model processes each mains power feature and calculates anomaly scores of data points in each mains power feature;

[0087] S304: Based on the abnormal scores of the data points in each mains power feature, determine whether there are abnormal data points in the mains power feature to determine the stability detection result of the power supply status of the power grid.

[0088] In step S301, the real-time monitoring data is preprocessed to obtain the preprocessed real-time monitoring data, including:

[0089] Normalizing different types of real-time monitoring data to obtain normalized real-time monitoring data;

[0090] Outliers in the normalized real-time monitoring data are screened out to obtain preprocessed real-time monitoring data.

[0091] Data with different features are normalized. For example, voltage and frequency data can be scaled to the same range to avoid certain features having too much influence on local model training.

[0092] Use local communication protocols to monitor data in real time, quickly discover and handle outliers, and ensure data accuracy and reliability.

[0093] The abnormal values ​​in the normalized real-time monitoring data are screened out. Specifically, the abnormal values ​​are determined based on the historical monitoring data of the power grid status.

[0094] Exemplarily, based on the historical monitoring data of the power grid status, a preset threshold range for each type of real-time monitoring data is determined, and data exceeding the preset threshold range is regarded as an abnormal value.

[0095] In step S302, more features are extracted according to the characteristics of the mains, such as the fluctuation deviation rate, peak-to-valley value, total harmonic distortion (THD) of voltage and frequency, so as to enhance the expression and discrimination capabilities of the isolation forest model.

[0096] That is, the mains characteristics input into the isolation forest model include real-time monitoring data directly used as mains characteristics, such as voltage data, current data, etc.;

[0097] At the same time, it also includes the mains characteristics obtained after processing at least one real-time monitoring data, such as the fluctuation deviation rate, peak-to-valley value, total harmonic distortion (THD) of voltage and frequency, and statistical characteristics.

[0098] Specifically, the statistical features of the mains power characteristics include mean value, variance, kurtosis, skewness, extreme value, etc., and the local communication protocol is used to monitor and collect data in real time and calculate the statistical features.

[0099] The statistical calculation method of the statistical features in the voltage features is specifically described below.

[0100] Mean: The sum of all data divided by the number of data.

[0101] Example: Assume that there is a set of AC voltage data [220, 225, 218, 230, 222]. The average value is calculated as: Average value = (220 + 225 + 218 + 230 + 222) / 5 = 223 V.

[0102] Variance: The average of the squares of the differences between the data and the mean.

[0103] Example: Continuing to use the above mains voltage data, the steps to calculate the variance are as follows:

[0104] First calculate the average value: Average value = 223 V.

[0105] Then calculate the square of the difference between each data point and the mean: (220-223)^2, (225-223)^2, (218-223)^2, (230-223)^2, (222-223)^2; add the squared values ​​and divide by the number of data points to get the variance.

[0106] Kurtosis: The peak shape of the data distribution, which describes the degree of sharpness or flatness of the data distribution.

[0107] Skewness: The degree of skewness of data distribution, describing the asymmetry of data distribution.

[0108] Extrema: The maximum and minimum values ​​in the data.

[0109] Example: For the mains voltage data, just find the maximum and minimum values.

[0110] Periodic characteristics: including fluctuation period, peak-to-valley ratio, etc., real-time monitoring and data collection through local communication protocols to calculate periodic characteristics.

[0111] Fluctuation period: Fluctuation period is the periodic change of voltage data in time series. The fluctuation period can be calculated by finding the periodic repetitive pattern of data.

[0112] Peak-to-valley ratio: The peak-to-valley ratio is the ratio between the peak value and the valley value, which is used to describe the amplitude change of the data.

[0113] Example: For the voltage array data above, you can find the peak and valley values ​​and calculate the ratio between them.

[0114] Specifically, the isolation forest model processes each mains power feature and calculates the abnormal score of the data point in each mains power feature, including:

[0115] The isolation forest model processes each mains power feature and constructs a tree structure until the number of data points of the mains power feature included in each leaf node in the isolation forest model is less than a first preset threshold, or the isolation forest model reaches a maximum depth of the tree;

[0116] For each data point of each mains power feature, calculate the path length of the data point in the isolation forest model; the path length is the number of edges passed from the root node to the data point;

[0117] According to the path length of the data point, the anomaly score of the data point in each mains power feature is calculated; the shorter the path length, the lower the anomaly score; the longer the path length, the higher the anomaly score.

[0118] Please refer to Figure 4 , Figure 4 A schematic diagram of the process of processing each AC power feature by the isolation forest model described in an embodiment of the present application is shown; first, the AC power feature is used as a data set and input into the isolation forest model; multiple sub-sampling is performed to construct multiple isolated trees; the specific process of constructing a single isolated tree includes feature selection and data division until the growth stop condition is met.

[0119] Feature selection includes randomly selecting features and cutting values, randomly selecting feature subsets, and randomly selecting cutting features; partitioning data includes randomly selecting cutting values.

[0120] Randomly select features and cut values: For each isolated tree in the isolation forest model, at each node, a feature and a cut value are randomly selected to split the data into two parts;

[0121] Randomly select feature subsets: At each node, a subset is randomly selected from all features instead of selecting from all features. This helps reduce the selection space for each node and increase the diversity of the model.

[0122] Feature subset size: The size of the feature subset can be set according to the specific situation. Usually, a smaller subset size can be selected to increase randomness on each node.

[0123] Randomly select cutting features: Randomly select a feature from the selected feature subset as the cutting feature. This ensures that the cutting of each node is not fixed, increasing the diversity of the model;

[0124] Randomly select a cutting value: For the selected cutting feature, randomly select a cutting value to split the data into two parts. The cutting value is usually randomly selected within the value range of the feature.

[0125] Establish a tree structure: Repeat the above process and recursively establish the tree structure of the isolated tree until the growth stop condition is met, and an isolated tree is established: the growth stop condition is: the number of data points of the mains characteristics included in each leaf node is less than the first preset threshold, or the isolation forest model reaches the maximum depth of the tree.

[0126] Establish isolation tree 1...isolation tree n, thereby establishing an isolation forest.

[0127] For each data point of the mains voltage feature, calculate its path length in each tree. The path length is the number of edges from the root node to the data point. For example, suppose there is a set of mains voltage data [220, 225, 218, 230, 222], and build an isolation forest model consisting of multiple randomly generated decision trees (isolation trees).

[0128] First, insert this set of data into each tree and record the path length of each data point in each tree. The path length is the number of edges from the root node to the data point.

[0129] Suppose we have a simple Isolation Forest model with two trees:

[0130] The first tree: the cutting feature selected by the root node is voltage; the cutting value is 222; the left subtree node: data point [220, 218]; the right subtree node: data point [225, 230].

[0131] In this tree, the path lengths of the data points [220, 225, 218, 230, 222] are:

[0132] For data point 220: The length of the path from the root node to data point 220 is 2 (from the root node to the left subtree node, and then to data point 220).

[0133] For data point 225: The path length from the root node to data point 225 is 3 (from the root node to the right subtree node, and then to data point 225).

[0134] For data points 218, 230, and 222: These data points are not cut in the tree, so the path length is the height of the tree. In this example, the height of the tree is 1, so the path length is 1.

[0135] The second tree: the cutting feature selected by the root node is voltage; the cutting value is 225; the left subtree node: data points [220, 225, 218, 222]; the right subtree node: data point

[230] .

[0136] In this tree, the path lengths for the data points [220, 225, 218, 230, 222] are: For data points 220, 225, 218, and 222: These data points are never cut in the tree, so the path length is the height of the tree. In this example, the height of the tree is 2, so the path length is 2.

[0137] For data point 230: the length of the path from the root node to data point 230 is 2 (from the root node to the right subtree node, and then to data point 230).

[0138] Therefore, the path length of each data point in each tree can be obtained by counting the number of edges from the root node to the data point.

[0139] Calculate anomaly score: Calculate the anomaly score of each data point based on the path length. Generally, the shorter the path length (the faster it is isolated in the tree), the lower the anomaly score, indicating that the data point is more normal; conversely, the higher the anomaly score, the more abnormal the data point.

[0140] Based on the abnormality score of the data point in each mains power feature, it is determined whether there is an abnormal data point in the mains power feature to determine the stability detection result of the power supply state of the power grid. Exemplarily, according to the abnormality score, a threshold can be set to determine whether the data point is abnormal. Generally, a data point exceeding the threshold is considered to be an abnormal data point.

[0141] For better normalization and comparison, isolation forests usually refer to the outlier function S(x, n) to measure whether a data point x is an abnormal data point.

[0142] Given a data set containing n samples, the average path length c(n) of the tree is:

[0143] c(n)=2H(n-1) - 2(n-1)*(1 / n);

[0144] c(n)=2H(n-1) - 2(n-1)*(1 / n) = 2[ln(n-1)+0.57721] - 2(n-1)*(1 / n);

[0145] H refers to the harmonic number. The harmonic number H(n) represents the sum of the reciprocals of all natural numbers from 1 to n.

[0146] In the Isolation Forest Algorithm, the harmonic number is used to estimate the average search depth of a balanced binary tree. Intuitively, the larger the harmonic number, the greater the average depth of the tree.

[0147] H(n) = ∑(1 / i), (i from 1 to n); H(n) = ln(n) + Euler constant (0.57721) is used instead to simplify the calculation process, reduce calculation time and improve scalability.

[0148] Specifically, the precise calculation of the harmonic number (H(n)) requires the reciprocal and sum of each number from 1 to (n), which is a large amount of calculation, while the approximate formula only needs to calculate the logarithm and the addition of the constant, which significantly reduces the amount of calculation; when performing anomaly detection on large-scale data sets, the efficiency of constructing and calculating the isolation forest is very important. The use of the approximate formula can greatly reduce the time of calculating the path length normalization factor, thereby improving the efficiency of the entire algorithm; when the amount of data is large, it may become unrealistic to calculate the exact value of the harmonic number. The calculation of logarithmic functions and constants is very efficient and stable in modern computers, and is suitable for processing large-scale data.

[0149] The outlier function formula in Isolation Forest is: S(x, n) = 2^(-h(x) / (c(n) * ln(2))).

[0150] For example, suppose we have a data set containing 10 samples, where the path length of one data point is h(x)=5. The steps to calculate the outlier are as follows:

[0151] Step 1: Calculate the harmonic number H(9), H(9) = 1 + 1 / 2 + 1 / 3 + 1 / 4 + 1 / 5 + 1 / 6 + 1 / 7 +1 / 8 + 1 / 9 ≈ 2.82897

[0152] H(9)=ln(9)+0.57721=2.77443;

[0153] Step 2: Calculate the average path length c(10):

[0154] c(10) = 2 * 2.82897 - 2 * 9 / 10 ≈ 3.85794

[0155] c(10) = 2 * 2.77443 - 2 * 9 / 10 ≈ 3.74886

[0156] Step 3: Calculate the anomaly score S(x, 10):

[0157] S(x, 10) = 2^(-5 / (3.85794 * ln(2))) ≈ 0.2736

[0158] S(x, 10) = 2^(-5 / (3.74886 * ln(2))) ≈ 0.2635

[0159] In summary, the anomaly score results of H(n) = ∑(1 / i) and H(n) = ln(n) + Euler constant (0.57721) are similar, but the calculation speed has an advantage on the machine.

[0160] c(n)=2H(n-1)-2(n-1)*1 / n; the role of Euler's constant e is cited here. In actual calculations, in order to avoid the cost of calculating ln(2), the approximate value of Euler's constant e, 2.71828, is used instead. Therefore, the outlier function S(x, n) can be rewritten as:

[0161] ;

[0162] S(x, n) = 2^(-h(x) / (c(n) * 2.71828)).

[0163] Therefore, the meaning of the outlier function S(x, n) is as follows:

[0164] Normal data points usually have short path lengths, so the S(x, n) value is close to 1.

[0165] Outlier data points usually have longer path lengths, so the S(x, n) value is close to 0.

[0166] Optimization of the Isolation Forest Model: Parameter tuning, specifically monitoring the cross-validation results of the model in real time through the local communication protocol, adjusting the model parameters, and improving the generalization ability and prediction accuracy of the model.

[0167] The stability detection result is determined based on the abnormal data point. Specifically, when the abnormal data point meets the preset abnormal condition, the stability detection result is determined to be unstable.

[0168] The preset abnormal condition, exemplarily, is that the number of abnormal data points exceeds a fifth preset threshold.

[0169] In step S103, the real-time monitoring data, stability detection results, the power of the first energy storage battery 206, and the power of the second energy storage battery 207 are respectively input into the nodes corresponding to the pre-built decision tree model.

[0170] The stability detection result is the stability detection result output by the isolation forest model.

[0171] Here, it is also necessary to preprocess the real-time monitoring data to obtain preprocessed real-time monitoring data; then, based on the preprocessed real-time monitoring data, a variety of mains power characteristics that characterize the mains power supply status are obtained; the mains power characteristics include real-time monitoring data directly used as mains power characteristics, and mains power characteristics obtained after processing at least one real-time monitoring data. The processing of real-time monitoring data is the same as the preprocessing process of real-time monitoring data before inputting it into the isolation forest module, and will not be repeated here.

[0172] In the implementation of the present application, there are four characteristics, namely, real-time monitoring data, stability detection results, the power of the first energy storage battery 206, and the power of the second energy storage battery 207. Branches and nodes of the decision tree model are constructed based on these four characteristics, and a decision tree model is established so that the decision tree model can intelligently determine the switching control strategy for the smart knife switch, the off-grid module 203, the grid-connected module 202, and the load according to these four characteristics.

[0173] The decision tree algorithm is selected as the core algorithm of the intelligent switching strategy for the following reasons:

[0174] Strong interpretability: The decision tree model can intuitively explain the decision-making process and judgment basis. It is easy to understand and explain and is suitable for decision-making logic in embedded device environments.

[0175] Wide adaptability: The decision tree algorithm has good adaptability to various data types and feature types. It can process numerical, categorical and mixed features and is suitable for various AC power and battery data involved.

[0176] High computational efficiency: The computational complexity of the decision tree algorithm is relatively low, and the training speed is fast, which is suitable for scenarios where the computing resources of embedded devices are limited.

[0177] When constructing a decision tree model based on the four features of real-time monitoring data, stability detection results, the power of the first energy storage battery 206 and the power of the second energy storage battery 207, the design principles of nodes and branches are as follows:

[0178] Based on the real-time monitoring data, it is detected whether the power grid state is normal. If the data is normal, the real-time monitoring is recorded, otherwise it enters the mains stability judgment node. Specifically, based on the comparison results of the real-time monitoring data and the historical monitoring data, it is determined whether the power grid state is normal.

[0179] When judging the stability of the mains power, the stability detection result output by the isolation forest model is used to judge whether the power grid is stable. If it is stable, the energy storage battery system is kept in a grid-connected state, wherein the grid-connected module 202 operates normally. Otherwise, the intelligent power switch is started to disconnect the mains power grid and the home grid to prevent the energy storage battery in the home grid from flowing back into the grid, and the off-grid operation state of the energy storage battery system is started.

[0180] Start the off-grid operation state of the energy storage battery system, determine the battery power of the first energy storage battery 206 of the first energy storage unit, if the first energy storage battery 206 has sufficient power, start the grid-connected module 202, the first energy storage unit is the main power supply for the whole family, and the second energy storage unit is the auxiliary power supply, and priority is given to solar power generation to maintain the normal operation of the household equipment load, otherwise determine the power of the second energy storage battery 207 in the second energy storage unit.

[0181] If the second energy storage battery 207 in the second energy unit has sufficient power, the first energy storage unit and the second energy storage unit cooperate to supply power to maintain the normal operation of the household equipment load. Otherwise, the household's essential power loads are retained and other power-consuming equipment is turned off.

[0182] The training and optimization process of the decision tree model is as follows: Use historical data (i.e., mains stability judgment) to train and optimize the constructed decision tree model, adjust parameters and thresholds according to different scenarios and operating conditions, and improve the accuracy and stability of the model.

[0183] Please refer to Figure 5 , Figure 5 A flow chart showing the decision tree model according to the embodiment of the present application processing the real-time monitoring data, the stability detection result, the power of the first energy storage battery 206 and the power of the second energy storage battery 207; Figure 5 As shown,

[0184] The decision tree model processes the real-time monitoring data, the stability detection result, the power of the first energy storage battery 206 and the power of the second energy storage battery 207, and outputs a switching control result for the energy storage battery system and an operation control result for the load, including:

[0185] The decision tree model determines whether the real-time monitoring data is normal;

[0186] If yes, the real-time monitoring data is recorded normally; if no, whether the power supply status of the power grid is stable is determined in combination with the stability detection result;

[0187] Determine whether the power supply state of the power grid is stable. If so, control the switch module 204 in the control unit to close to maintain the grid-connected operation state between the energy storage battery system and the power grid; if not, control the switch module 204 to open to switch to the off-grid operation state of the energy storage battery system and the power grid;

[0188] For the off-grid operation state, based on the power of the first energy storage battery 206 and the power of the second energy storage battery 207 in the energy storage battery system, the switching control results for the grid-connected module 202 in the first energy storage unit and the off-grid module 203 of the second energy storage unit and the operation control results for the load in the off-grid operation state are determined.

[0189] The method for determining the switching control result of the grid-connected module 202 in the first energy storage unit and the off-grid module 203 in the second energy storage unit in the off-grid operation state and the operation control result of the load in the off-grid operation state based on the power of the first energy storage battery 206 and the power of the second energy storage battery 207 in the energy storage battery system includes:

[0190] For the off-grid operation state, determine the power evaluation result of the first energy storage battery 206 of the first energy storage unit, and determine the power evaluation result of the second energy storage battery 207 of the second energy storage unit, and based on the power evaluation results of the first energy storage battery 206 and the second energy storage battery 207, determine the switching control result for the grid-connected module 202 in the first energy storage unit and the off-grid module 203 of the second energy storage unit, and the operation control result for the load;

[0191] Among them, the switching control result is to control the first energy storage unit to independently supply power off the grid, or to control the first energy storage unit and the second energy storage unit to jointly supply power off the grid; the operation control result of the load is to operate the load normally or shut down part of the load.

[0192] The power evaluation result indicates whether the power of the energy storage battery is sufficient.

[0193] Specifically, for the off-grid operation state, determining the power evaluation result of the first energy storage battery 206 of the first energy storage unit, and determining the power evaluation result of the second energy storage battery 207 of the second energy storage unit, and based on the power evaluation results of the first energy storage battery 206 and the second energy storage battery 207, determining the switching control result for the grid-connected module 202 in the first energy storage unit and the off-grid module 203 of the second energy storage unit, and the operation control result for the load; including:

[0194] For the off-grid operation state, determining whether the power of the first energy storage battery 206 in the first energy storage unit is greater than a second preset threshold;

[0195] If the power of the first energy storage battery 206 is greater than the second preset threshold, the grid-connected module 202 in the first energy storage unit is started, and the power of the first energy storage battery 206 in the first energy storage unit in the off-grid operation state is monitored in real time to see whether it is greater than the third preset threshold;

[0196] When the power of the first energy storage battery 206 is greater than a third preset threshold, it is determined that the first energy storage unit is independently powered, and it is determined that the operation control result of the load is to maintain normal operation of the load;

[0197] If the power level of the first energy storage battery 206 is less than or equal to the second preset threshold, or the power level of the first energy storage battery 206 is greater than the third preset threshold, the off-grid module 203 in the second energy storage unit is started at the same time, and the power level of the second energy storage battery 207 in the second energy storage unit is monitored in real time to see whether it is greater than the fourth preset threshold;

[0198] When the power of the second energy storage battery 207 is greater than a fourth preset threshold, it is determined that the operation control result of the load is to maintain normal operation of the load;

[0199] When the power level of the second energy storage battery 207 is less than or equal to the fourth preset threshold, it is determined that the operation control result of the load is to keep the first preset load running and turn off other loads.

[0200] The other loads are loads other than the first preset load.

[0201] It should be noted that during off-grid operation, it is necessary to determine in real time the power evaluation result of the first energy storage battery 206 of the first energy storage unit and the power evaluation result of the second energy storage battery 207 of the second energy storage unit, so as to determine the switching control result and the operation control result based on the two real-time power evaluation results.

[0202] Exemplarily, if a power failure occurs in the power grid during the day and the household power grid switches to an off-grid state, due to sufficient sunlight, the switching control result remains that the first energy storage unit independently supplies power off the grid; if sunlight is insufficient, the first energy storage unit independently supplies power off the grid, and after the amount of electricity stored in the first energy storage unit drops below a third preset threshold, the first energy storage unit and the second energy storage unit jointly supply power off the grid; when the amount of electricity in the second energy storage unit drops below a fourth preset threshold, the first preset load is controlled to operate, and other loads are turned off.

[0203] When the first energy storage unit and the second energy storage unit jointly supply power off the grid, the control module controls the first energy storage unit to supply power first. Therefore, it is only necessary to detect whether the power level of the second energy storage unit drops below the fourth preset threshold to determine whether to shut down other loads except the first preset load.

[0204] When the control module 201 collects the real-time monitoring data of the municipal power grid, the data of the off-grid module 203 and the grid-connected module 202, the data is input into the decision tree model for prediction and judgment, and the grid-connected or off-grid mode is intelligently switched according to the output results of the model. The local communication broadcast information notifies other devices to perform corresponding operations to ensure the continuity and stability of the household power supply.

[0205] In an embodiment of the present application, real-time communication between the control unit, the first energy storage unit, the second energy storage unit and the load of the energy storage battery system is achieved based on the UDP local communication protocol.

[0206] Specifically, the control module 201 and the mains detection module 205, the intelligent knife switch, the grid-connected module 202 and the off-grid module 203, and the home load in the energy storage battery system are implemented to interact with each other in real time. When the state of a device changes, a notification is broadcast to other devices to ensure that all devices can obtain the latest state information in a timely manner, thereby realizing real-time state updates. Broadcast messages are triggered according to specific conditions or events to realize linkage control between devices, such as triggering off-grid switching when the power grid is off, so that the home power grid is independent of the mains power grid.

[0207] The data frame transmitted by the UDP local communication protocol includes a frame start character, a frame type, a frame content, a frame check field, and a frame end character, as shown in Table 1 below.

[0208] Table 1

[0209]

[0210] Frame start character: AA55-2 bytes, used as the start mark of the frame to identify the beginning of the frame.

[0211] Protocol version: 1 byte - used to identify the version number of the protocol so that the receiver can recognize and process frames of different versions.

[0212] Frame type: 1 byte - used to distinguish different types of frames, such as data frames, control frames, and broadcast frames.

[0213] Frame content: Protobuf is used to encode and store the actual data content. Protobuf is a lightweight data serialization protocol that can efficiently serialize and deserialize structured data.

[0214] Frame check field: Based on the CRC32 algorithm, the frame check field is 2 bytes and is used to check the frame content to ensure the integrity and reliability of the data.

[0215] Frame end mark: CC33 (2 bytes) - used to identify the end of the frame.

[0216] Frame types include data frames, control frames, and broadcast frames;

[0217] Data frame: used to transmit actual data content.

[0218] Control frame: used to transmit control instructions or control information.

[0219] Broadcast frame: used for broadcast notifications or broadcast messages.

[0220] Protobuf content is explained as follows:

[0221] Data structuring: Protobuf allows you to define structured data and communicate using a defined message format, which ensures that the data structure is clear, easy to understand, and maintain.

[0222] Data serialization: Protobuf can serialize structured data into binary format, which can reduce the size of data transmission and improve transmission efficiency, especially suitable for network transmission or storage.

[0223] Cross-language support The message class generated by Protobuf can be used in multiple programming languages, so data exchange and communication between different systems can be realized, with good cross-platform and cross-language compatibility.

[0224] Version control: Protobuf allows you to specify the ordinal number of the field in the message definition, so that even if the message structure changes, compatibility can be maintained through the field ordinal number without destroying the existing data format.

[0225] The CRC32 algorithm can perform data integrity verification, with the advantages of high efficiency, low collision rate, and simple implementation.

[0226] Data integrity check: The CRC32 algorithm can check data to see if it has changed during transmission, thereby ensuring data integrity. This is very important when transmitting or storing data over a network to prevent data from being damaged or tampered with.

[0227] High efficiency: CRC32 algorithm is a fast and effective verification algorithm that can verify a large amount of data in a short time, so it is suitable for real-time data transmission and processing scenarios.

[0228] Low collision rate: The hash collision rate of the CRC32 algorithm is very low. Even when processing large amounts of data, it can maintain a high level of verification accuracy and effectively protect the integrity of the data.

[0229] Simple implementation: The implementation of the CRC32 algorithm is relatively simple and can be easily implemented in various programming languages. It takes up less computing resources and is therefore suitable for various embedded systems and high-performance computing environments. When CRC-16-IBM is used, the polynomial is X16+X15+X2+1.

[0230] The verification process of the CRC32 algorithm is as follows: the verification content is: AB CD EF; the initial value 0xFFFF is expressed in binary as: 1111 1111 1111 1111; each byte and the initial value are input into the CRC algorithm in bit sequence; and the CRC verification code is finally obtained: FC64.

[0231] The communication process of UDP local communication protocol:

[0232] The data sender constructs a frame and sends it; constructs a frame: encodes the data to be sent according to the Protobuf protocol, then adds the frame start symbol AA55, the protocol version number, the frame type, the frame check field CRC32, and finally adds the frame end symbol CC33 to obtain a complete frame; sends a frame: sends the constructed frame to the target device via the UDP protocol.

[0233] The data processing flow of the receiver is as follows: Receive data: listen to the UDP port and receive the data frame; parse the frame: extract the frame start character, protocol version number, frame type, frame content and frame check field, and verify the integrity of the frame; extract data: if the frame verification passes, parse the frame content and obtain the actual data in it.

[0234] In order to realize linkage control between devices, the embodiment of the present application introduces the UDP broadcast function, allowing the relevant devices in the on-grid and off-grid energy storage battery switching control method to notify other devices in real time through broadcast messages, thereby realizing collaborative operation between devices. The specific design is as follows:

[0235] UDP broadcast message content definition:

[0236] Broadcast messages include information such as device status updates, event notifications, and control instructions to ensure information synchronization and real-time response between devices.

[0237] Broadcast message sending and receiving mechanism:

[0238] Sender: When a device needs to send a broadcast message to other devices, it encapsulates the message in the broadcast message format and sends it to all devices in the LAN through the UDP broadcast address.

[0239] Receiver: All devices listen to the UDP broadcast address, and after receiving the broadcast message, they parse the message content and process it accordingly. Different operations can be performed according to the type and content of the message, such as updating status, executing commands, etc.

[0240] The on-grid and off-grid energy storage battery switching control method described in the embodiment of the present application can monitor the grid state and the mains power supply in real time, and make automatic judgments and responses to grid power outages, instability, and the like; and the first level controls the energy storage battery system as a whole to belong to the on-grid operation mode or the off-grid operation mode relative to the grid, and the second level controls the energy storage battery power of the first energy storage module and the second energy storage module in the energy storage battery system to achieve fine control of the first energy storage module and the second energy storage module in the energy storage battery system, thereby achieving on-grid and off-grid switching of the energy storage battery system at a finer granularity, so that the power of the energy storage battery system is reasonably utilized, and the third level informs other household load devices to perform corresponding operations according to the battery power of the off-grid module 203 and the on-grid module 202, so as to ensure that the power meets the household needs when the energy storage battery system is off-grid.

[0241] Based on the same inventive concept, an energy storage battery system corresponding to the on-grid and off-grid energy storage battery switching control method is also provided in the embodiment of the present application. Since the principle of solving the problem by the energy storage battery system in the embodiment of the present application is similar to the on-grid and off-grid energy storage battery switching control method in the embodiment of the present application, the implementation of the system can refer to the implementation of the method, and the repeated parts will not be repeated.

[0242] Please refer to Figure 2 , Figure 2 The structure diagram of the energy storage battery system according to the embodiment of the present application is shown.

[0243] The energy storage battery system includes a control unit, a first energy storage unit and a second energy storage unit, wherein the first energy storage unit and the second energy storage unit are respectively connected to the control unit, and the control unit is connected to the mains power grid; the control unit includes a mains power detection module 205, a switch module 204 and a control module 201; the first energy storage unit includes a photovoltaic power generation module 208, a grid-connected module 202 and a first energy storage battery 206; the second energy storage unit includes an off-grid module 203 and a second energy storage battery 207;

[0244] The control unit is used to obtain real-time monitoring data during the power supply process of the power grid, the power of the first energy storage battery 206 in the first energy storage unit, and the power of the second energy storage battery 207 in the second energy storage unit;

[0245] It is also used to determine the stability detection result of the power supply state of the power grid based on the real-time monitoring data;

[0246] It is also used to input the real-time monitoring data, stability detection results, the power of the first energy storage battery 206, the power of the first energy storage battery 206, and the power of the second energy storage battery 207 into the nodes corresponding to the pre-built decision tree model respectively;

[0247] It is also used to process the real-time monitoring data, stability detection results, the power of the first energy storage battery 206 and the power of the second energy storage battery 207 through the decision tree model, output a switching control result for the energy storage battery system and an operation control result for the load, and control the switch module 204 in the control unit, the grid-connected module 202 in the first energy storage unit, and the off-grid module 203 of the second energy storage unit to switch based on the switching control result, and control the load operation based on the operation control result.

[0248] In some embodiments, in the energy storage battery system, the switch module 204 of the control unit is arranged between the power grid and the control module 201, so that after the switch module 204 is disconnected, the energy storage battery system supplies power to the control module 201, the off-grid module 203 and the grid-connected module 202.

[0249] In some embodiments, the control module 201 is used to control the energy storage battery system, when determining the stability detection result of the power supply state of the power grid based on the real-time monitoring data:

[0250] Preprocessing the real-time monitoring data to obtain preprocessed real-time monitoring data;

[0251] Based on the pre-processed real-time monitoring data, a plurality of mains power characteristics characterizing the mains power supply status are obtained; the mains power characteristics include the real-time monitoring data directly used as the mains power characteristics, and the mains power characteristics obtained after processing at least one real-time monitoring data;

[0252] Inputting the plurality of mains power features into a pre-trained isolation forest model, wherein the isolation forest model processes each mains power feature and calculates anomaly scores of data points in each mains power feature;

[0253] Based on the abnormal scores of the data points in each mains power feature, it is determined whether there are abnormal data points in the mains power feature to determine the stability detection result of the power supply state of the power grid.

[0254] In some embodiments, the control unit of the energy storage battery system, when processing each mains power feature through the isolation forest model and calculating the abnormal score of the data point in each mains power feature, is specifically used to:

[0255] The isolation forest model processes each mains power feature and constructs a tree structure until the number of data points of the mains power feature included in each leaf node in the isolation forest model is less than a first preset threshold, or the isolation forest model reaches a maximum depth of the tree;

[0256] For each data point of each mains power feature, calculate the path length of the data point in the isolation forest model; the path length is the number of edges passed from the root node to the data point;

[0257] According to the path length of the data point, the anomaly score of the data point in each mains power feature is calculated; the shorter the path length, the lower the anomaly score; the longer the path length, the higher the anomaly score.

[0258] In some embodiments, the control unit of the energy storage battery system, when preprocessing the real-time monitoring data to obtain the preprocessed real-time monitoring data, is specifically used to:

[0259] Normalizing different types of real-time monitoring data to obtain normalized real-time monitoring data;

[0260] Outliers in the normalized real-time monitoring data are screened out to obtain preprocessed real-time monitoring data.

[0261] In some embodiments, the control unit of the energy storage battery system, when processing the real-time monitoring data, the stability detection result, the power of the first energy storage battery 206 and the power of the second energy storage battery 207 through the decision tree model, outputs the switching control result for the energy storage battery system and the operation control result for the load, is specifically used to:

[0262] The decision tree model determines whether the real-time monitoring data is normal;

[0263] If yes, the real-time monitoring data is recorded normally; if no, whether the power supply status of the power grid is stable is determined in combination with the stability detection result;

[0264] Determine whether the power supply state of the power grid is stable. If so, control the switch module 204 in the control unit to close to maintain the grid-connected operation state between the energy storage battery system and the power grid; if not, control the switch module 204 to open to switch to the off-grid operation state of the energy storage battery system and the power grid;

[0265] For the off-grid operation state, based on the power of the first energy storage battery 206 and the power of the second energy storage battery 207 in the energy storage battery system, the switching control results for the grid-connected module 202 in the first energy storage unit and the off-grid module 203 of the second energy storage unit and the operation control results for the load in the off-grid operation state are determined.

[0266] In some embodiments, the control unit of the energy storage battery system, when determining the switching control result for the grid-connected module 202 in the first energy storage unit and the off-grid module 203 of the second energy storage unit in the off-grid operation state and the operation control result for the load based on the power of the first energy storage battery 206 and the power of the second energy storage battery 207 in the energy storage battery system for the off-grid operation state, is specifically used to:

[0267] For the off-grid operation state, determine the power evaluation result of the first energy storage battery 206 of the first energy storage unit, and determine the power evaluation result of the second energy storage battery 207 of the second energy storage unit, and based on the power evaluation results of the first energy storage battery 206 and the second energy storage battery 207, determine the switching control result for the grid-connected module 202 in the first energy storage unit and the off-grid module 203 of the second energy storage unit, and the operation control result for the load;

[0268] Among them, the switching control result is to control the first energy storage unit to independently supply power off the grid, or to control the first energy storage unit and the second energy storage unit to jointly supply power off the grid; the operation control result of the load is to operate the load normally or shut down part of the load.

[0269] In some embodiments, the control unit of the energy storage battery system, when determining the power evaluation result of the first energy storage battery 206 of the first energy storage unit and the power evaluation result of the second energy storage battery 207 of the second energy storage unit for the off-grid operation state, and determining the switching control result for the grid-connected module 202 in the first energy storage unit and the off-grid module 203 of the second energy storage unit based on the power evaluation results of the first energy storage battery 206 and the second energy storage battery 207, and the operation control result for the load, is specifically used to:

[0270] For the off-grid operation state, determining whether the power of the first energy storage battery 206 in the first energy storage unit is greater than a second preset threshold;

[0271] If the power of the first energy storage battery 206 is greater than the second preset threshold, the grid-connected module 202 in the first energy storage unit is started, and the power of the first energy storage battery 206 in the first energy storage unit in the off-grid operation state is monitored in real time to see whether it is greater than the third preset threshold;

[0272] When the power of the first energy storage battery 206 is greater than a third preset threshold, it is determined that the first energy storage unit is independently powered, and it is determined that the operation control result of the load is to maintain normal operation of the load;

[0273] If the power level of the first energy storage battery 206 is less than or equal to the second preset threshold, or the power level of the first energy storage battery 206 is greater than the third preset threshold, the off-grid module 203 in the second energy storage unit is started at the same time, and the power level of the second energy storage battery 207 in the second energy storage unit is monitored in real time to see whether it is greater than the fourth preset threshold;

[0274] When the power of the second energy storage battery 207 is greater than a fourth preset threshold, it is determined that the operation control result of the load is to maintain normal operation of the load;

[0275] When the power level of the second energy storage battery 207 is less than or equal to the fourth preset threshold, it is determined that the operation control result of the load is to keep the first preset load running and turn off other loads.

[0276] In some embodiments, in the energy storage battery system, real-time communication between the control unit, the first energy storage unit, the second energy storage unit and the load of the energy storage battery system is achieved based on the UDP local communication protocol.

[0277] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, the specific working process of the system and device described above can refer to the corresponding process in the method embodiment, and will not be repeated in this application. In the several embodiments provided in this application, it should be understood that the disclosed system, device and method can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation. For example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

[0278] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0279] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0280] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a platform server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard drives, ROM, RAM, magnetic disks, or optical disks.

[0281] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for controlling switching between on-grid and off-grid energy storage batteries, characterized in that: Applied to an energy storage battery system, the energy storage battery system includes a control unit, a first energy storage unit and a second energy storage unit, the first energy storage unit and the second energy storage unit are respectively connected to the control unit, and the control unit is connected to the mains power grid; the control unit includes a mains power detection module, a switch module and a control module; the first energy storage unit includes a photovoltaic power generation module, a grid-connected module and a first energy storage battery; The second energy storage unit includes an off-grid module and a second energy storage battery; the method includes: The control unit obtains real-time monitoring data during power supply of the power grid, the power of the first energy storage battery in the first energy storage unit, and the power of the second energy storage battery in the second energy storage unit; Based on the real-time monitoring data, determining a stability detection result of the power supply status of the power grid; Input the real-time monitoring data, the stability detection result, the power of the first energy storage battery, the power of the first energy storage battery, and the power of the second energy storage battery into the nodes corresponding to the pre-built decision tree model respectively; The decision tree model processes the real-time monitoring data, the stability detection result, the power of the first energy storage battery and the power of the second energy storage battery, outputs a switching control result for the energy storage battery system and an operation control result for the load, and controls the switch module in the control unit, the grid-connected module in the first energy storage unit, and the off-grid module of the second energy storage unit to switch based on the switching control result, and controls the operation of the load based on the operation control result; The decision tree model processes the real-time monitoring data, the stability detection result, the power of the first energy storage battery and the power of the second energy storage battery, and outputs a switching control result for the energy storage battery system and an operation control result for the load, including: The decision tree model determines whether the real-time monitoring data is normal; If yes, the real-time monitoring data is recorded normally; if no, whether the power supply status of the power grid is stable is determined in combination with the stability detection result; Determine whether the power supply state of the power grid is stable. If so, control the switch module in the control unit to close to maintain the grid-connected operation state between the energy storage battery system and the power grid; if not, control the switch module to disconnect to switch to the off-grid operation state of the energy storage battery system and the power grid; For the off-grid operation state, based on the power of the first energy storage battery and the power of the second energy storage battery in the energy storage battery system, determine the switching control result for the grid-connected module in the first energy storage unit and the off-grid module of the second energy storage unit, and the operation control result for the load in the off-grid operation state; The method for determining the switching control result of the grid-connected module in the first energy storage unit and the off-grid module of the second energy storage unit and the operation control result of the load in the off-grid operation state based on the power of the first energy storage battery and the power of the second energy storage battery in the energy storage battery system includes: For the off-grid operation state, determine the power evaluation result of the first energy storage battery of the first energy storage unit, and determine the power evaluation result of the second energy storage battery of the second energy storage unit, and based on the power evaluation results of the first energy storage battery and the second energy storage battery, determine the switching control result for the grid-connected module in the first energy storage unit and the off-grid module of the second energy storage unit, and the operation control result for the load; Among them, the switching control result is to control the first energy storage unit to independently supply power off the grid, or to control the first energy storage unit and the second energy storage unit to jointly supply power off the grid; the operation control result of the load is to operate the load normally or shut down part of the load.

2. The on-grid and off-grid energy storage battery switching control method according to claim 1, characterized in that: Determining a stability detection result of the power supply state of the power grid based on the real-time monitoring data includes: Preprocessing the real-time monitoring data to obtain preprocessed real-time monitoring data; Based on the pre-processed real-time monitoring data, a plurality of mains power characteristics characterizing the mains power supply status are obtained; the mains power characteristics include the real-time monitoring data directly used as the mains power characteristics, and the mains power characteristics obtained after processing at least one real-time monitoring data; Inputting the plurality of mains power features into a pre-trained isolation forest model, wherein the isolation forest model processes each mains power feature and calculates anomaly scores of data points in each mains power feature; Based on the abnormal scores of the data points in each mains power feature, it is determined whether there are abnormal data points in the mains power feature to determine the stability detection result of the power supply state of the power grid.

3. The on-grid and off-grid energy storage battery switching control method according to claim 2 is characterized in that: The isolation forest model processes each mains power feature and calculates the anomaly score of the data point in each mains power feature, including: The isolation forest model processes each mains power feature and constructs a tree structure until the number of data points of the mains power feature included in each leaf node in the isolation forest model is less than a first preset threshold, or the isolation forest model reaches a maximum depth of the tree; For each data point of each mains power feature, calculate the path length of the data point in the isolation forest model; the path length is the number of edges passed from the root node to the data point; According to the path length of the data point, the anomaly score of the data point in each mains power feature is calculated; the shorter the path length, the lower the anomaly score; the longer the path length, the higher the anomaly score.

4. The on-grid and off-grid energy storage battery switching control method according to claim 2, characterized in that: Preprocessing the real-time monitoring data to obtain preprocessed real-time monitoring data; including: Normalizing different types of real-time monitoring data to obtain normalized real-time monitoring data; Outliers in the normalized real-time monitoring data are screened out to obtain preprocessed real-time monitoring data.

5. The on-grid and off-grid energy storage battery switching control method according to claim 1, characterized in that: The method comprises determining a power evaluation result of a first energy storage battery of a first energy storage unit and a power evaluation result of a second energy storage battery of a second energy storage unit for an off-grid operation state, and determining a switching control result for a grid-connected module in the first energy storage unit and an off-grid module in the second energy storage unit and an operation control result for a load based on the power evaluation results of the first energy storage battery and the second energy storage battery; comprising: For the off-grid operation state, determining whether the power of the first energy storage battery in the first energy storage unit is greater than a second preset threshold; If the power of the first energy storage battery is greater than the second preset threshold, the grid-connected module in the first energy storage unit is started, and the power of the first energy storage battery in the first energy storage unit in the off-grid operation state is monitored in real time to see whether it is greater than the third preset threshold; When the power of the first energy storage battery is greater than a third preset threshold, determining that the first energy storage unit is independently powered, and determining that the operation control result of the load is to maintain normal operation of the load; If the power level of the first energy storage battery is less than or equal to the second preset threshold, or the power level of the first energy storage battery is greater than the third preset threshold, the off-grid module in the second energy storage unit is started at the same time, and the power level of the second energy storage battery in the second energy storage unit is monitored in real time to see whether it is greater than the fourth preset threshold; When the power of the second energy storage battery is greater than a fourth preset threshold, determining that the operation control result of the load is to maintain normal operation of the load; When the power level of the second energy storage battery is less than or equal to a fourth preset threshold, the operation control result of the load is determined to keep the first preset load running and shut down other loads.

6. The on-grid and off-grid energy storage battery switching control method according to claim 1, characterized in that: Real-time communication between the control unit, the first energy storage unit, the second energy storage unit and the load of the energy storage battery system is achieved based on the UDP local communication protocol.

7. An energy storage battery system, characterized in that: The energy storage battery system includes a control unit, a first energy storage unit and a second energy storage unit, the first energy storage unit and the second energy storage unit are respectively connected to the control unit, and the control unit is connected to the mains power grid; the control unit includes a mains power detection module, a switch module and a control module; the first energy storage unit includes a photovoltaic power generation module, a grid-connected module and a first energy storage battery; the second energy storage unit includes an off-grid module and a second energy storage battery; The control unit is used to obtain real-time monitoring data during power supply of the power grid, the power of the first energy storage battery in the first energy storage unit, and the power of the second energy storage battery in the second energy storage unit; It is also used to determine the stability detection result of the power supply state of the power grid based on the real-time monitoring data; It is also used to input the real-time monitoring data, the stability detection result, the power of the first energy storage battery, the power of the first energy storage battery, and the power of the second energy storage battery into the nodes corresponding to the pre-built decision tree model respectively; It is also used to process the real-time monitoring data, the stability detection result, the power of the first energy storage battery and the power of the second energy storage battery through the decision tree model, output a switching control result for the energy storage battery system and an operation control result for the load, and control the switch module in the control unit, the grid-connected module in the first energy storage unit, and the off-grid module of the second energy storage unit to switch based on the switching control result, and control the operation of the load based on the operation control result; The decision tree model processes the real-time monitoring data, the stability detection result, the power of the first energy storage battery and the power of the second energy storage battery, and outputs a switching control result for the energy storage battery system and an operation control result for the load, including: The decision tree model determines whether the real-time monitoring data is normal; If yes, the real-time monitoring data is recorded normally; if no, whether the power supply status of the power grid is stable is determined in combination with the stability detection result; Determine whether the power supply state of the power grid is stable. If so, control the switch module in the control unit to close to maintain the grid-connected operation state between the energy storage battery system and the power grid; if not, control the switch module to disconnect to switch to the off-grid operation state of the energy storage battery system and the power grid; For the off-grid operation state, based on the power of the first energy storage battery and the power of the second energy storage battery in the energy storage battery system, determine the switching control result for the grid-connected module in the first energy storage unit and the off-grid module of the second energy storage unit, and the operation control result for the load in the off-grid operation state; The method for determining the switching control result of the grid-connected module in the first energy storage unit and the off-grid module of the second energy storage unit and the operation control result of the load in the off-grid operation state based on the power of the first energy storage battery and the power of the second energy storage battery in the energy storage battery system includes: For the off-grid operation state, determine the power evaluation result of the first energy storage battery of the first energy storage unit, and determine the power evaluation result of the second energy storage battery of the second energy storage unit, and based on the power evaluation results of the first energy storage battery and the second energy storage battery, determine the switching control result for the grid-connected module in the first energy storage unit and the off-grid module of the second energy storage unit, and the operation control result for the load; Among them, the switching control result is to control the first energy storage unit to independently supply power off the grid, or to control the first energy storage unit and the second energy storage unit to jointly supply power off the grid; the operation control result of the load is to operate the load normally or shut down part of the load.

8. The energy storage battery system according to claim 7, characterized in that: The switch module of the control unit is arranged between the power grid and the control module, so that after the switch module is disconnected, the energy storage battery system supplies power to the control module.

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