A load intelligent power distribution system capable of switching between on-grid and off-grid

Abstract

The present application discloses a load intelligent power distribution system capable of switching between on-grid and off-grid, comprising a power grid, an energy storage inverter, a battery, a photovoltaic inverter, a photovoltaic panel, a first load, a second load, a third load, a power distribution control module and a controllable switch; the controllable switch divides an AC bus into two ends; the second load is connected to one end of the AC bus via a second load detection module connected thereto, the third load is connected thereto via a third load detection module connected thereto, the photovoltaic inverter is connected thereto via a photovoltaic inverter detection module connected thereto, and the energy storage inverter; the first load is connected to the other end of the AC bus via a first load detection module connected thereto and the power grid; the power distribution control module communicates with the controllable switch, the energy storage inverter and each detection module respectively, and acquires system information and allocates energy of the load intelligent power distribution system; the present application solves the problems of complex wiring and pipe penetration of the distribution system, inability to accurately grasp the operating conditions, lack of unified management and low intelligence level.

Description

Technical Field

[0001] The present application relates to the technical field of electric energy management of energy storage systems, and in particular to a load intelligent power distribution system capable of switching between on-grid and off-grid operation. Background Art

[0002] In the mainstream power distribution system of photovoltaic energy storage inverters in the North American market, in order to ensure that important off-grid loads can continue to be powered when power is cut off, such as Figure 1 and Figure 2 As shown, these off-grid important loads are usually connected to the off-grid load interface of the power distribution device or the off-grid load interface of the off-grid distribution box separately, and then connected to the off-grid interface of the photovoltaic energy storage inverter; or the off-grid important loads are directly connected to the off-grid interface of the photovoltaic energy storage inverter; in addition, for the grid-connected loads that will not be powered when the power is off, these grid-connected loads need to be connected to the corresponding grid-connected load interfaces, and the grid-connected load interfaces are connected to the grid-connected interface of the photovoltaic energy storage inverter;

[0003] However, the existing connection method has the following disadvantages: (1) Complex wiring and pipe design: Since important loads that cannot be powered off need to be connected to the off-grid interface of the photovoltaic energy storage inverter through the off-grid load interface, or directly connected to the off-grid interface of the photovoltaic energy storage inverter, this process involves more sets of wiring and pipe threading, which is not only complicated to operate and increase the difficulty of installation, but may also lead to additional material consumption and labor costs; (2) Unable to accurately grasp the operating conditions of various parts of the system: In the existing connection method, the system cannot directly detect the output and operating status of the photovoltaic inverter, and cannot accurately grasp information such as photovoltaic power generation and load power consumption; (3) Lack of unified monitoring and management: When the system operates abnormally somewhere, it is easy to affect the normal use of other equipment, and the reliability and safety of the system are low; (4) Insufficient intelligence level: When switching between on-grid and off-grid, the power supply control response speed of different loads is slow;

[0004] In summary, the inverter distribution system in the North American market has problems such as complex wiring and pipe design, inability to accurately grasp the operating conditions of each part of the system, lack of unified monitoring and management, and insufficient intelligence level. Further improvements are needed in its design and functions. Summary of the invention

[0005] In order to solve the problems in existing power distribution systems, such as complex wiring and pipe design, inability to accurately grasp the operating conditions of various parts of the system, lack of unified monitoring and management, and insufficient intelligence level, the present application provides a load intelligent distribution system that can be switched on and off the grid.

[0006] The present application provides a load intelligent power distribution system capable of switching between on-grid and off-grid operation, and adopts the following technical solution: the system includes a power distribution device, a power grid, an energy storage inverter, a battery, a photovoltaic inverter, a photovoltaic panel, a first load, a second load, and a third load; the first load, the second load, and the third load have different power usage strategies when they are on-grid and off-grid;

[0007] The power distribution device includes a first load detection module, a second load detection module, a third load detection module, a photovoltaic inverter detection module, a power distribution control module and a controllable switch;

[0008] The controllable switch is connected to the AC bus and divides the AC bus into a first end and a second end; the second load is connected to the first end of the AC bus through the second load detection module; the third load is connected to the first end of the AC bus through the third load detection module; one end of the photovoltaic inverter is connected to the photovoltaic panel, and the other end is connected to the first end of the AC bus through the photovoltaic inverter detection module; one end of the energy storage inverter is connected to the battery, and the other end is connected to the first end of the AC bus; the first load is connected to the second end of the AC bus through the first load detection module, and the power grid is connected to the second end of the AC bus;

[0009] The first load detection module, the second load detection module, the third load detection module, the photovoltaic inverter detection module, the controllable switch and the energy storage inverter are all communicatively connected to the power distribution control module; the power distribution control module is used to obtain load intelligent power distribution information and allocate energy of the load intelligent power distribution system.

[0010] By adopting the above technical solution, on the one hand, detection modules corresponding to different types of loads are set in the power distribution device. In the AC coupling scenario, the detection modules corresponding to each part are integrated to realize independent management of each part, and different types of loads are uniformly connected to the AC bus. This not only simplifies the wiring process and reduces the connection of AC lines and communication lines between the load and the inverter, but also enables the power distribution control module to communicate with each part to obtain the operating status of each part respectively. It has functions such as voltage and current monitoring, fault diagnosis, remote monitoring and energy management, realizes unified management, and significantly improves the safety, reliability and operation and maintenance efficiency of the system. And respond to and handle potential problems in a timely manner to prevent abnormal equipment from affecting the normal operation of the system; on the other hand, the first load that stops being used when the power is cut off and the power grid are connected to one end of the AC bus, and the second load and the third load that still need to be used when the power is cut off are connected to the other end of the AC bus, and they are separated by a controllable switch in the middle. Combined with the processing of the distribution control module, it is more convenient to switch the system between grid and off-grid, with a fast response speed, ensuring a smooth transition between grid and off-grid states, and solving the problems of complex wiring and pipe design in the existing distribution system, the inability to accurately grasp the operating conditions of various parts of the system, the lack of unified monitoring and management, and insufficient intelligence.

[0011] In a specific implementation scheme, the system further includes a first monitoring module and a current transformer; the current transformer is installed on an AC bus between the controllable switch and the power grid;

[0012] The first monitoring module is connected to the AC bus between the current transformer and the power grid; the first monitoring module is also communicatively connected to the current transformer and the power distribution control module respectively.

[0013] By adopting the above technical solution, a first monitoring module and a current transformer are added, and the first monitoring module obtains the voltage and current of the corresponding node and transmits them to the power distribution control module, which facilitates the power distribution control module to manage the system.

[0014] In a specific possible implementation scheme, the power distribution control module obtains the first power consumption of the first load through the first load detection module, obtains the second power consumption of the second load through the second load detection module, obtains the third power consumption of the third load through the third load detection module, and obtains the photovoltaic power generation power of the photovoltaic panel through the photovoltaic inverter detection module; and also obtains the remaining battery power of the battery by communicating with the energy storage inverter;

[0015] The power distribution control module allocates energy of the load intelligent power distribution system based on the system on-grid or off-grid status, the first power consumption, the second power consumption, the third power consumption, the photovoltaic power generation power, and the remaining battery power.

[0016] By adopting the above technical solution, the power distribution control module allocates energy in a targeted manner when the system is in different on-grid and off-grid states based on the system on-grid and off-grid states, combined with the power consumption of each load, the photovoltaic power generation and the remaining battery power, to achieve power supply control for different types of loads under on-grid and off-grid switching.

[0017] In a specific feasible implementation scheme, the power distribution control module obtains the first grid voltage information of the first node through the first monitoring module, and also directly obtains the second grid voltage information of the first node; wherein the first node is an intermediate node between the controllable switch and the grid;

[0018] The power distribution control module determines the grid state based on the first grid voltage information and / or the second grid voltage information, controls the controllable switch to close when the grid is normal, so that the system enters a grid-connected state, and controls the controllable switch to open when the grid is abnormal, so that the system enters an off-grid state.

[0019] By adopting the above technical solution, the power distribution control module first obtains the voltage information of the first node to determine whether it can be connected to the grid. If the grid is normal, the controllable switch is closed and the system is connected to the grid; if the grid is abnormal, the controllable switch is disconnected and the system is off the grid. The controllable switch plays a protective role, further improving the safety of the system.

[0020] In a specific possible implementation scheme, when the system is in a grid-connected state, the power distribution control module determines whether the current time is in the working time of the third load;

[0021] If yes, the power distribution control module marks the first load, the second load and the third load as loads to be powered; if no, the power distribution control module marks the first load and the second load as loads to be powered;

[0022] The power distribution control module determines whether the power generation of the photovoltaic panel can meet the power demand of the load to be powered based on the power consumption of the load to be powered and the photovoltaic power generation power;

[0023] If yes, the power distribution control module controls the photovoltaic panel to supply power to the load to be powered, and stores the remaining energy of the system into the battery and / or outputs it to the power grid;

[0024] If not, the power distribution control module controls the photovoltaic panel to supply power to the load to be powered based on the remaining power of the battery and a preset power replenishment strategy, and uses the battery and / or the power grid to dynamically supplement the energy required by the load to be powered; or controls the photovoltaic panel to supply power to part of the load to be powered.

[0025] By adopting the above technical solution, when the system is in a grid-connected state, the first load is included in the system's loads to be powered, and photovoltaic panels are preferentially used to provide energy for the system. When the energy of the photovoltaic panels is insufficient, the remaining battery power and the power replenishment strategy are further combined to consider using batteries and / or the power grid to dynamically supplement the energy required by the system, or consider only powering part of the load, and comprehensively consider factors such as electricity costs and actual load conditions to allocate the energy of the load intelligent distribution system.

[0026] In a specific implementation scheme, when the system is in an off-grid state, the power distribution control module determines whether the current time is in the working time of the third load;

[0027] If yes, the power distribution control module marks the second load and the third load as loads to be powered; if no, the power distribution control module marks the second load as a load to be powered;

[0028] The power distribution control module determines whether the power generation of the photovoltaic panel can meet the power demand of the load to be powered based on the power consumption of the load to be powered and the photovoltaic power generation power;

[0029] If yes, the power distribution control module controls the photovoltaic panel to supply power to the load to be powered, and stores the remaining energy of the system into the battery;

[0030] If not, the power distribution control module controls the photovoltaic panel and / or the battery to power part of the loads to be powered based on the remaining power of the battery; or controls the photovoltaic panel to power the loads to be powered and uses the battery to dynamically supplement the energy required by the loads to be powered.

[0031] By adopting the above technical solution, when the system is in an off-grid state, the system disconnects the power supply to the first load, and similarly gives priority to using photovoltaic panels to provide energy. When the energy of the photovoltaic panels is insufficient, further combined with the remaining power of the battery, consider using photovoltaic panels and / or batteries to power part of the load, or consider using batteries to dynamically supplement energy while providing power with photovoltaic panels.

[0032] In a specific possible implementation scheme, the power distribution control module controls the photovoltaic panel and / or the battery to supply power to part of the loads to be powered based on the remaining power of the battery; or controls the photovoltaic panel to supply power to the loads to be powered, and uses the battery to dynamically supplement the energy required by the loads to be powered, specifically including:

[0033] If the remaining power of the battery is within the fourth power range, the power distribution control module controls the photovoltaic panel to supply power to the load to be powered, and uses the battery to dynamically supplement the energy required by the load to be powered;

[0034] If the remaining power of the battery is in the fifth power range, the power distribution control module selects part of the loads from the loads to be powered based on the preset load power usage priority, controls the photovoltaic panel to power the selected part of the loads, and uses the battery to dynamically supplement the energy required by the part of the loads;

[0035] If the remaining battery power is in the sixth power range, the power distribution control module selects part of the loads from the loads to be powered based on the preset load power usage priority, and controls the photovoltaic panel to supply power to the selected part of the loads.

[0036] In a specific feasible implementation scheme, the power distribution control module obtains the voltage and current values ​​of the load end, the grid end, the photovoltaic output end and the battery end through the first monitoring module, the first load detection module, the second load detection module, the third load detection module and the photovoltaic inverter detection module; and based on the voltage and current values ​​of the load end, the grid end, the photovoltaic output end and the battery end, identifies system abnormalities and performs corresponding protection actions.

[0037] By adopting the above technical solution, the voltage and current of various parts of the system are summarized through the power distribution control module. When an abnormality occurs somewhere, the power distribution control module can respond and protect in time, thereby improving system safety and having the advantage of lower cost.

[0038] In a specific implementation scheme, the first load detection module identifies an abnormality of the first load by acquiring first current information and first voltage information of the first load, and performs a corresponding protection action;

[0039] The second load detection module identifies an abnormality of the second load by acquiring second current information and second voltage information of the second load, and performs a corresponding protection action;

[0040] The third load detection module identifies an abnormality of the third load by acquiring third current information and third voltage information of the third load, and performs a corresponding protection action;

[0041] The photovoltaic inverter detection module identifies the abnormality of the photovoltaic inverter by acquiring the fourth current information and the fourth voltage information of the output terminal of the photovoltaic inverter, and performs a corresponding protection action.

[0042] By adopting the above technical solution and integrating relevant protection circuits in each detection module, the advantage of faster response speed is achieved.

[0043] In a specific embodiment, the first load, the second load and the third load each include one or more loads.

[0044] In summary, the technical solution of this application includes at least the following beneficial technical effects:

[0045] 1. Efficient integration and control: By setting up detection modules corresponding to different types of loads in the distribution device, in the AC coupling scenario, by integrating the corresponding detection modules of each part, the independent management of each part is realized, and different types of loads are uniformly connected to the AC bus, which not only simplifies the wiring process and reduces the connection of AC lines and communication lines between the load and the inverter, but also the distribution control module communicates with each part to obtain the operation status of each part respectively. It has functions such as voltage and current monitoring, fault diagnosis, remote monitoring and energy management, realizes unified management, significantly improves the safety, reliability and operation and maintenance efficiency of the system, can respond to and handle potential problems in a timely manner, and avoid abnormal equipment affecting the normal operation of the system, and solves the problems of complex wiring and pipe design in the existing distribution system, inability to accurately grasp the operation status of each part of the system, and lack of unified monitoring and management;

[0046] 2. Intelligent grid-connected and off-grid switching: The first load that stops being used when the power is cut off is connected to the grid at one end of the AC bus, and the second load and the third load that still need to be used when the power is cut off are connected to the other end of the AC bus, and they are separated by a controllable switch in the middle. Combined with the processing of the distribution control module, it makes the system grid-connected and off-grid switching more convenient and responsive, ensuring a smooth transition between the grid-connected and off-grid states, providing users with a seamless power usage experience; and solving the problem of insufficient intelligence level of the existing distribution system. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a connection structure diagram of a power distribution system in the prior art;

[0048] Figure 2 It is another connection structure schematic diagram of the power distribution system in the prior art;

[0049] Figure 3 This is a schematic diagram of the connection structure of the load intelligent power distribution system in the embodiment of the present application;

[0050] Figure 4 It is a schematic diagram of the main process of system energy allocation in the on-grid and off-grid states in the embodiment of the present application;

[0051] Figure 5 It is a schematic diagram of the corresponding energy allocation process in the embodiment of the present application in the grid-connected state when the power generation of the photovoltaic panel cannot meet the power demand of the load to be powered;

[0052] Figure 6It is a schematic diagram of the corresponding energy allocation process when the power generation of the photovoltaic panel cannot meet the power demand of the load to be powered in the on-grid and off-grid states in the embodiment of the present application.

[0053] Description of reference numerals:

[0054] 1. Power distribution device; 11. First load detection module; 12. Second load detection module; 13. Third load detection module; 14. Photovoltaic inverter detection module; 15. Power distribution control module; 16. Controllable switch; 17. First monitoring module; 18. Current transformer; 19. Manual switch; 2. Power grid; 3. Energy storage inverter; 4. Battery; 5. Photovoltaic inverter; 6. Photovoltaic panel; 7. First load; 8. Second load; 9. Third load. DETAILED DESCRIPTION

[0055] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0056] The present application embodiment provides a load intelligent power distribution system capable of switching between on-grid and off-grid. Figure 3 As shown, it includes a power distribution device 1, a power grid 2, an energy storage inverter 3, a battery 4, a photovoltaic inverter 5, a photovoltaic panel 6, a first load 7, a second load 8 and a third load 9; the first load 7, the second load 8 and the third load 9 have different power usage strategies when connected to or off the grid;

[0057] The power distribution device 1 includes a first load detection module 11, a second load detection module 12, a third load detection module 13, a photovoltaic inverter detection module 14, a power distribution control module 15 and a controllable switch 16; the controllable switch 16 can be a contactor.

[0058] The controllable switch 16 is connected to the AC bus and divides the AC bus into a first end and a second end; the second load 8 is connected to the first end of the AC bus through the second load detection module 12; the third load 9 is connected to the first end of the AC bus through the third load detection module 13; one end of the photovoltaic inverter 5 is connected to the photovoltaic panel 6, and the other end is connected to the first end of the AC bus through the photovoltaic inverter detection module 14; one end of the energy storage inverter 3 is connected to the battery 4, and the other end is connected to the first end of the AC bus; the first load 7 is connected to the second end of the AC bus through the first load detection module 11, and the power grid 2 is connected to the second end of the AC bus;

[0059] The first load detection module 11, the second load detection module 12, the third load detection module 13, the photovoltaic inverter detection module 14, the controllable switch 16 and the energy storage inverter 3 are all communicatively connected to the power distribution control module 15; the power distribution control module 15 is used to obtain load intelligent power distribution information and allocate energy of the load intelligent power distribution system.

[0060] It should be noted that the first load 7 may include one or more loads, the first load detection module 11 includes one or more first load detection submodules, and the first load detection submodules are connected to the loads in the first load 7 in a one-to-one correspondence;

[0061] Similarly, the second load 8 may also include one or more loads, and the second load detection module 12 includes one or more second load detection submodules, and the second load detection submodules are connected to the loads in the second load 8 in a one-to-one correspondence;

[0062] The third load 9 may also include one or more loads, and the third load detection module 13 includes one or more third load detection submodules, and the third load detection submodules are connected to the loads in the third load 9 in a one-to-one correspondence.

[0063] Furthermore, the first load 7, the second load 8 and the third load 9 are three types of loads with different power usage strategies. The third load 9 is, for example, a timed start load, that is, the power usage of the third load 9 is a load that is started at a time set by the user; the first load 7 is, for example, a common load, which represents a load that is not powered in an off-grid state; the second load 8 is an important load, which represents a load that can be powered according to the system energy situation in an off-grid state. The power usage priorities among the first load 7, the second load 8 and the third load 9 are also different.

[0064] The technical solution of this application has the following advantages:

[0065] Efficient integration and control: By setting up detection modules corresponding to different types of loads in the distribution device, in the AC coupling scenario, by integrating the corresponding detection modules of each part, the independent management of each part is realized, and different types of loads are uniformly connected to the AC bus, which not only simplifies the wiring process and reduces the connection of AC lines and communication lines between the load and the inverter, but also the distribution control module communicates with each part to obtain the operation status of each part separately. It has functions such as voltage and current monitoring, fault diagnosis, remote monitoring and energy management, and realizes unified management, which significantly improves the safety, reliability and operation and maintenance efficiency of the system, and can respond to and handle potential problems in a timely manner to avoid abnormal equipment affecting the normal operation of the system. It solves the problems of complex wiring and pipe design in the existing distribution system, the inability to accurately grasp the operation status of each part of the system, and the lack of unified monitoring and management;

[0066] Intelligent on-grid and off-grid switching: The first load that stops being used when the power is off is connected to the grid at one end of the AC bus, and the second load and the third load that still need to be used when the power is off are connected to the other end of the AC bus, and the two loads are separated by a controllable switch. Combined with the processing of the power distribution control module, it makes the on-grid and off-grid switching of the system more convenient and responsive, ensuring a smooth transition between on-grid and off-grid states, providing users with a seamless power usage experience; solving the problem of insufficient intelligence level of the existing power distribution system;

[0067] Flexible configuration and personalized needs: Users can flexibly define load wiring according to actual usage and the actual capacity of batteries and photovoltaic panels, and divide the load into the first load, the second load or the third load according to actual needs, so as to achieve differentiated management and ensure the continuous power supply of key equipment after power outage of the power grid, while avoiding the use of system power by unnecessary equipment and extending the use time of the second load;

[0068] Energy management and energy-saving strategies: Through the power distribution control module, the load can be intelligently connected and selectively powered according to parameters such as the remaining battery capacity (SOC) and the power generation of the photovoltaic panels. For example, when the overall energy input of the system is sufficient, loads such as electric vehicle charging, electric water heaters, and air conditioners can be started; when the overall energy input of the system decreases, the system can automatically shut down some loads to ensure the stable operation of more important loads. This energy management strategy not only improves energy efficiency, but also provides users with a more intelligent power solution.

[0069] Highly customizable policy settings: The system supports users to set different management strategies according to the on-grid and off-grid status, meeting the diverse needs of users in different scenarios. Whether it is optimized operation in on-grid mode or emergency power supply in off-grid mode, efficient management can be achieved through simple settings.

[0070] Therefore, the load intelligent distribution system of the present application provides users with a comprehensive, intelligent and reliable power solution. Whether they are home users or commercial users, users can obtain excellent power usage experience and can well meet the North American market's demand for photovoltaic energy storage systems.

[0071] In one possible implementation, refer to Figure 3 , the system further comprises a first monitoring module 17 and a current transformer 18; the current transformer 18 is installed on the AC bus between the controllable switch 16 and the power grid 2;

[0072] The first monitoring module 17 is connected to the AC bus between the current transformer 18 and the power grid 2 ; the first monitoring module 17 is also communicatively connected to the current transformer 18 and the power distribution control module 15 , respectively.

[0073] By adding the first monitoring module 17 and the current transformer 18 , the first monitoring module 17 obtains the voltage and current of the corresponding node and transmits the communication to the power distribution control module 15 , which facilitates the power distribution control module 15 to manage the system.

[0074] In a possible implementation, Figure 3 As shown, the system also includes a manual switch 19, which is connected to the AC bus between the current transformer 18 and the power grid 2, and is used to manually cut off the connection between the power grid 2 and the power distribution device 1; the manual switch 19 can be a circuit breaker.

[0075] The user can manually close or open the manual switch 19 to connect or disconnect the power distribution device to the power grid, thereby improving the safety of the system.

[0076] In a possible implementation, Figure 3 As shown, the power distribution control module 15 is connected to the AC bus between the controllable switch 16 and the power grid 2, and can be used to obtain voltage information of corresponding nodes.

[0077] In a possible implementation manner, the power distribution control module 15 obtains the first power consumption of the first load 7 through the first load detection module 11, obtains the second power consumption of the second load 8 through the second load detection module 12, obtains the third power consumption of the third load 9 through the third load detection module 13, and obtains the photovoltaic power generation power of the photovoltaic panel 6 through the photovoltaic inverter detection module 14; and also obtains the remaining battery power of the battery 4 by communicating with the energy storage inverter 3;

[0078] The power distribution control module 15 allocates energy of the load intelligent power distribution system based on the system on-grid and off-grid status, the first power consumption, the second power consumption, the third power consumption, the photovoltaic power generation power, and the remaining battery power.

[0079] It should be noted that when the power distribution control module 15 obtains the power consumption of different loads or the photovoltaic power generation of the photovoltaic panel, it can adopt a method of obtaining the corresponding voltage and current and calculating the corresponding power, or it can adopt a method of directly obtaining the power;

[0080] For example, the first load detection module 11 may obtain the first voltage information and the first current information of the first load 7, output the first voltage information and the first current information to the power distribution control module 15, and the power distribution control module 15 calculates the corresponding first power; or the first load detection module 11 obtains the first voltage information and the first current information of the first load 7, calculates the first power, and then outputs the first power to the power distribution control module 15;

[0081] Similarly, the power distribution control module 15 may also obtain the second power consumption, the third power consumption and the photovoltaic power generation power in the same manner, which will not be described in detail herein.

[0082] Through the above process, the power distribution control module 15 allocates energy in a targeted manner when the system is in different on-grid and off-grid states based on the system on-grid and off-grid states, combined with the power consumption of each load, the photovoltaic power generation and the remaining battery power, to achieve power supply control for different types of loads under on-grid and off-grid switching.

[0083] In a possible implementation manner, the power distribution control module 15 obtains the first grid voltage information of the first node through the first monitoring module 17; and / or,

[0084] The power distribution control module 15 directly obtains the second power grid voltage information of the first node; wherein the first node is an intermediate node between the controllable switch 16 and the power grid 2.

[0085] The power distribution control module 15 determines the grid state based on the first grid voltage information and / or the second grid voltage information, controls the controllable switch 16 to close when the grid is normal, so that the system enters the grid-connected state, and controls the controllable switch 16 to open when the grid is abnormal, so that the system enters the off-grid state;

[0086] Specifically, if the power distribution control module 15, based on the first grid voltage information and / or the second grid voltage information, if there is voltage at the first node and the voltage is stable, it means that the grid is normal, and therefore the controllable switch 16 is controlled to be closed; if there is no voltage at the first node, or there is voltage but the voltage is unstable, it means that the grid is abnormal, and therefore the controllable switch 16 is controlled to be disconnected.

[0087] That is to say, when determining the state of the power grid, the power distribution control module 15 can obtain the voltage at the first node through the first monitoring module 17, or directly obtain the voltage at the first node. Of course, in order to further improve the accuracy of the judgment of the power grid state, the power distribution control module 15 can combine the voltage information obtained through the first monitoring module 17 and the voltage information obtained directly to comprehensively determine the state of the power grid.

[0088] Through the above process, the power distribution control module 15 first obtains the voltage information of the first node to determine whether it can be connected to the grid. If the grid is normal, that is, there is a stable voltage, then the controllable switch 16 is closed and the system is connected to the grid; if the grid is abnormal, that is, there is no voltage or the voltage is unstable, then the controllable switch 16 is disconnected and the system is off the grid, and the controllable switch 16 plays a protective role to further improve the safety of the system.

[0089] In one possible implementation, combining Figure 4 , when the system is in a grid-connected state, the power distribution control module 15 determines whether the current time is in the working time of the third load 9;

[0090] If yes, the power distribution control module 15 marks the first load 7, the second load 8 and the third load 9 as loads to be powered; if no, the power distribution control module 15 marks the first load 7 and the second load 8 as loads to be powered;

[0091] The power distribution control module 15 determines whether the power generation of the photovoltaic panel 6 can meet the power demand of the load to be powered based on the power consumption of the load to be powered and the photovoltaic power generation power;

[0092] If yes, the power distribution control module 15 controls the photovoltaic panel 6 to supply power to the load to be powered, and stores the remaining energy of the system into the battery 4 and / or outputs it to the power grid 2;

[0093] If not, the power distribution control module 15 controls the photovoltaic panel 6 to supply power to the load to be powered based on the remaining power of the battery and the preset power replenishment strategy, and uses the battery 4 and / or the power grid 2 to dynamically supplement the energy required by the load to be powered; or controls the photovoltaic panel 6 to supply power to part of the load to be powered.

[0094] It should be noted that when the power generation of the photovoltaic panel 6 can meet the power demand of the load to be powered, the remaining energy of the system can be used to charge the battery 4, or it can be output to the power grid 2 to sell electricity, or both can be done at the same time. Technical personnel in this field can define it according to the local time period when electricity can be sold, the current remaining capacity of the battery 4 or user demand, and this application does not make any specific limitations on this.

[0095] Through the above process, when the system is in a grid-connected state, the first load is included in the system's loads to be powered, and the photovoltaic panel 6 is preferentially used to provide energy for the system. When the energy of the photovoltaic panel 6 is insufficient, the remaining battery power and the power replenishment strategy are further combined to consider using batteries and / or the power grid to dynamically replenish the energy required by the system, or consider only supplying power to part of the load, comprehensively considering factors such as electricity costs and actual load conditions, and deploying the energy of the load intelligent distribution system. The preset power replenishment strategy includes, for example, the current time electricity purchase price, a dynamic electricity price system, or user customization, and this application does not make specific restrictions on this.

[0096] In one possible implementation, refer to Figure 5 The power distribution control module 15 controls the photovoltaic panel 6 to supply power to the load to be powered based on the remaining power of the battery and the preset power replenishment strategy, and uses the battery 4 and / or the power grid 2 to dynamically supplement the energy required by the load to be powered; or controls the photovoltaic panel 6 to supply power to part of the load to be powered separately, which can be done in the following ways:

[0097] If the remaining power of the battery is within the first power range, the power distribution control module 15 controls the photovoltaic panel 6 to supply power to the load to be powered, and uses the battery 4 to dynamically supplement the energy required by the load to be powered;

[0098] The first power range is, for example, above 50%, indicating that the remaining battery power is sufficient.

[0099] If the remaining power of the battery is within the second power range, and the current electricity purchase price does not exceed the first electricity price threshold, the power distribution control module 15 controls the photovoltaic panel 6 to supply power to the load to be powered, and uses the battery 4 and the power grid 2 to dynamically supplement the energy required by the load to be powered;

[0100] If the remaining power of the battery is within the second power range and the electricity purchase price exceeds the first electricity price threshold, the power distribution control module 15 controls the photovoltaic panel 6 to supply power to the load to be powered, and uses the battery 4 to dynamically supplement the energy required by the load to be powered;

[0101] Among them, the second power range is, for example, 10%-50%, indicating that the remaining battery power is relatively moderate at this time; the electricity purchase price does not exceed the first electricity price threshold, indicating that the electricity purchase price is relatively appropriate at this time; exceeding the first electricity price threshold, indicating that the electricity purchase price is relatively expensive at this time; the specific value of the first electricity price threshold can be flexibly set by technical personnel in this field according to the electricity price system in the actual area where the user is located, and this application does not make specific restrictions on this.

[0102] If the remaining power of the battery is within the third power range and the electricity purchase price does not exceed the first electricity price threshold, the power distribution control module 15 controls the photovoltaic panel 6 to supply power to the load to be powered, and uses the power grid 2 to dynamically supplement the energy required by the load to be powered;

[0103] If the remaining power of the battery is within the third power range and the electricity purchase price exceeds the first electricity price threshold, the power distribution control module 15 selects part of the loads from the loads to be powered based on the preset load power usage priority, and controls the photovoltaic panel 6 to supply power to the selected part of the loads;

[0104] The third power range is, for example, below 10%, which means that the remaining power of the battery is small at this time. If the battery continues to discharge, it may cause the battery to run out of power, thus affecting the battery life.

[0105] When the remaining battery power is within the third power range and the electricity purchase price exceeds the first electricity price threshold, it is neither suitable to use the battery to supplement the system energy nor to purchase electricity. Therefore, based on the load power priority, a part of the loads with higher power priority are selected from the loads to be powered, so that the photovoltaic panel 6 gives priority to supplying power to these more important loads.

[0106] In one possible implementation, combining Figure 4 , when the system is in an off-grid state, the first load 7 has no energy input, and the power distribution control module 15 determines whether the current time is in the working time of the third load 9;

[0107] If yes, the power distribution control module 15 marks the second load 8 and the third load 9 as loads to be powered; if no, the power distribution control module 15 marks the second load 8 as a load to be powered;

[0108] The power distribution control module 15 determines whether the power generation of the photovoltaic panel 6 can meet the power demand of the load to be powered based on the power consumption of the load to be powered and the photovoltaic power generation power;

[0109] If yes, the power distribution control module 15 controls the photovoltaic panel 6 to supply power to the load to be powered, and stores the remaining energy of the system into the battery 4;

[0110] If not, the power distribution control module 15 controls the photovoltaic panel 6 and / or the battery 4 to supply power to part of the loads to be powered based on the remaining power of the battery; or controls the photovoltaic panel 6 to supply power to the loads to be powered, and uses the battery 4 to dynamically supplement the energy required by the loads to be powered.

[0111] Through the above process, when the system is in an off-grid state, the system disconnects the power supply to the first load 7, and similarly gives priority to using the photovoltaic panel 6 to provide energy. When the energy of the photovoltaic panel 6 is insufficient, further combined with the remaining battery power, consider using the photovoltaic panel 6 and / or battery 4 to power part of the load, or consider using the battery 4 to dynamically supplement energy while the photovoltaic panel 6 is powering.

[0112] In one possible implementation, combining Figure 6 The power distribution control module 15 controls the photovoltaic panel 6 and / or the battery 4 to supply power to part of the loads to be powered based on the remaining power of the battery; or controls the photovoltaic panel 6 to supply power to the loads to be powered, and uses the battery 4 to dynamically supplement the energy required by the loads to be powered, which can be done in the following ways:

[0113] If the remaining power of the battery is in the fourth power range, the power distribution control module 15 controls the photovoltaic panel 6 to supply power to the load to be powered, and uses the battery 4 to dynamically supplement the energy required by the load to be powered;

[0114] If the remaining power of the battery is in the fifth power range, the power distribution control module 15 selects part of the loads from the loads to be powered based on the preset load power usage priority, controls the photovoltaic panel 6 to power the selected part of the loads, and uses the battery 4 to dynamically supplement the energy required by the part of the loads;

[0115] If the remaining battery power is in the sixth power range, the power distribution control module 15 selects part of the loads from the loads to be powered based on the preset load power usage priority, and controls the photovoltaic panel 6 to supply power to the selected part of the loads.

[0116] It should be noted that the fourth power range indicates that the remaining battery power is sufficient, the fifth power range indicates that the remaining battery power is moderate, and the sixth power range indicates that the remaining battery power is small; the fourth power range, the fifth power range and the sixth power range can be set according to the corresponding settings of the above-mentioned first power range, the second power range and the third power range, and can also be set to other values, and this application does not impose any restrictions on this.

[0117] In a possible implementation, the power distribution control module 15 obtains the voltage and current values ​​of the load end, the grid end, the photovoltaic output end and the battery end through the first monitoring module 17, the first load detection module 11, the second load detection module 12, the third load detection module 13 and the photovoltaic inverter detection module 14; and based on the voltage and current values ​​of the load end, the grid end, the photovoltaic output end and the battery end, identifies system abnormalities and performs corresponding protection actions.

[0118] Specifically, the power distribution control module 15 obtains the first grid current information of the first node through the first monitoring module 17, obtains the first current information and the first voltage information of the first load 7 through the first load detection module 11, obtains the second current information and the second voltage information of the second load 8 through the second load detection module 12, obtains the third current information and the third voltage information of the third load 9 through the third load detection module 13, and obtains the fourth current information and the fourth voltage information of the output end of the photovoltaic inverter 5 through the photovoltaic inverter detection module 14;

[0119] The power distribution control module 15 identifies system abnormalities and performs corresponding protection actions based on the first grid current information, the first current information, the second current information, the third current information, the fourth current information, the first grid voltage information, the first voltage information, the second voltage information, the third voltage information, and the fourth voltage information.

[0120] Specifically, when the power distribution control module 15 identifies the abnormality of the system, it can use the elimination method and the control variable method to find the abnormal equipment; for example, when the power distribution control module 15 identifies that there is leakage current in the system, it can disconnect the first load detection module 11, the second load detection module 12, the third load detection module 13, and the photovoltaic inverter detection module 14 from the system respectively to identify the abnormal location, and the abnormal location is one or more of the first load 7, the second load 8, the third load 9, or the photovoltaic inverter 5;

[0121] Furthermore, after determining the abnormal position, the elimination method and the control variable method are used to disconnect each device in the abnormal position from the system, and determine the specific abnormal device; for example, if the abnormal position is the first load 7, the switches in the first load detection module 11 that are connected to the loads in the first load 7 are disconnected respectively. By using the elimination method and the control variable method, the specific abnormal device can be identified, and then the abnormal device can be controlled to disconnect from the system to avoid affecting the normal operation of other devices.

[0122] It can be understood that the first load detection module 11, the second load detection module 12, the third load detection module 13 and the photovoltaic inverter detection module 14 can all include one or more switches, and each switch is connected to a corresponding device. For example, the switch in the first load detection module 11 is connected to the loads in the first load 7 in a one-to-one correspondence, the switch in the second load detection module 12 is connected to the loads in the second load 8 in a one-to-one correspondence, the switch in the third load detection module 13 is connected to the loads in the third load 9 in a one-to-one correspondence, and the switch in the photovoltaic inverter detection module 14 is connected to the sub-photovoltaic inverter in the photovoltaic inverter 5 in a one-to-one correspondence.

[0123] Therefore, the voltage and current of each part of the system are collected through the power distribution control module 15. When an abnormality occurs somewhere, the power distribution control module 15 can respond and protect in time, thereby improving the safety of the system. The method of using the elimination method and the control variable method has the advantage of low cost.

[0124] In a possible implementation manner, the first load detection module 11 identifies an abnormality of the first load 7 by acquiring first current information and first voltage information of the first load 7, and performs a corresponding protection action;

[0125] The second load detection module 12 identifies the abnormality of the second load 8 by acquiring the second current information and the second voltage information of the second load 8, and performs a corresponding protection action;

[0126] The third load detection module 13 identifies the abnormality of the third load 9 by acquiring the third current information and the third voltage information of the third load 9, and performs a corresponding protection action;

[0127] The photovoltaic inverter detection module 14 identifies the abnormality of the photovoltaic inverter 5 by acquiring the fourth current information and the fourth voltage information of the output end of the photovoltaic inverter 5, and performs a corresponding protection action.

[0128] For example, a circuit with a protection function such as a leakage switch can be integrated in the first load detection module 11. When a load in the first load 7 is abnormal, the first load detection module 11 can perform a protection action in time and automatically cut off the connection between the load and the AC bus.

[0129] The method of integrating relevant protection circuits in each detection module has the advantage of faster response speed.

[0130] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A load intelligent power distribution system capable of switching between on-grid and off-grid, characterized in that: The invention comprises a power distribution device (1), a power grid (2), an energy storage inverter (3), a battery (4), a photovoltaic inverter (5), a photovoltaic panel (6), a first load (7), a second load (8) and a third load (9); the first load (7), the second load (8) and the third load (9) have different power usage strategies when connected to or off the grid; The power distribution device (1) comprises a first load detection module (11), a second load detection module (12), a third load detection module (13), a photovoltaic inverter detection module (14), a power distribution control module (15) and a controllable switch (16); The controllable switch (16) is connected to the AC bus and divides the AC bus into a first end and a second end; the second load (8) is connected to the first end of the AC bus through the second load detection module (12); the third load (9) is connected to the first end of the AC bus through the third load detection module (13); one end of the photovoltaic inverter (5) is connected to the photovoltaic panel (6), and the other end is connected to the first end of the AC bus through the photovoltaic inverter detection module (14); one end of the energy storage inverter (3) is connected to the battery (4), and the other end is connected to the first end of the AC bus; the first load (7) is connected to the second end of the AC bus through the first load detection module (11), and the power grid (2) is connected to the second end of the AC bus; The first load detection module (11), the second load detection module (12), the third load detection module (13), the photovoltaic inverter detection module (14), the controllable switch (16) and the energy storage inverter (3) are all communicatively connected to the power distribution control module (15); the power distribution control module (15) is used to obtain load intelligent power distribution information and allocate energy of the load intelligent power distribution system.

2. The load intelligent power distribution system capable of switching between on-grid and off-grid according to claim 1, characterized in that: It also includes a first monitoring module (17) and a current transformer (18); the current transformer (18) is installed on the AC bus between the controllable switch (16) and the power grid (2); The first monitoring module (17) is connected to the AC bus between the current transformer (18) and the power grid (2); the first monitoring module (17) is also communicatively connected to the current transformer (18) and the power distribution control module (15), respectively.

3. The load intelligent power distribution system capable of switching between on-grid and off-grid according to claim 2 is characterized in that: The power distribution control module (15) obtains the first power consumption of the first load (7) through the first load detection module (11), obtains the second power consumption of the second load (8) through the second load detection module (12), obtains the third power consumption of the third load (9) through the third load detection module (13), and obtains the photovoltaic power generation of the photovoltaic panel (6) through the photovoltaic inverter detection module (14); and also obtains the remaining battery power of the battery (4) by communicating with the energy storage inverter (3); The power distribution control module (15) allocates energy of the load intelligent power distribution system based on the system on-grid and off-grid status, the first power consumption, the second power consumption, the third power consumption, the photovoltaic power generation power, and the remaining battery power.

4. The load intelligent power distribution system capable of switching between on-grid and off-grid according to claim 3 is characterized in that: The power distribution control module (15) obtains first grid voltage information of a first node through the first monitoring module (17), and also directly obtains second grid voltage information of the first node; wherein the first node is an intermediate node between the controllable switch (16) and the grid (2); The power distribution control module (15) determines the state of the power grid based on the first power grid voltage information and / or the second power grid voltage information, and controls the controllable switch (16) to close when the power grid is normal, so that the system enters a grid-connected state, and controls the controllable switch (16) to open when the power grid is abnormal, so that the system enters an off-grid state.

5. The load intelligent power distribution system capable of switching between on-grid and off-grid according to claim 3 is characterized in that: When the system is in a grid-connected state, the power distribution control module (15) determines whether the current time is in the working time of the third load (9); If yes, the power distribution control module (15) marks the first load (7), the second load (8) and the third load (9) as loads to be powered; if no, the power distribution control module (15) marks the first load (7) and the second load (8) as loads to be powered; The power distribution control module (15) determines whether the power generation of the photovoltaic panel (6) can meet the power demand of the load to be powered based on the power consumption of the load to be powered and the photovoltaic power generation; If so, the power distribution control module (15) controls the photovoltaic panel (6) to supply power to the load to be powered, and stores the remaining energy of the system in the battery (4) and / or outputs it to the power grid (2); If not, the power distribution control module (15) controls the photovoltaic panel (6) to supply power to the load to be powered based on the remaining power of the battery and a preset power replenishment strategy, and uses the battery (4) and / or the power grid (2) to dynamically supplement the energy required by the load to be powered; or controls the photovoltaic panel (6) to supply power to part of the load to be powered separately.

6. The load intelligent power distribution system capable of switching between on-grid and off-grid according to claim 3 is characterized in that: When the system is in an off-grid state, the power distribution control module (15) determines whether the current time is in the working time of the third load (9); If so, the power distribution control module (15) marks the second load (8) and the third load (9) as loads to be powered; if not, the power distribution control module (15) marks the second load (8) as a load to be powered; The power distribution control module (15) determines whether the power generation of the photovoltaic panel (6) can meet the power demand of the load to be powered based on the power consumption of the load to be powered and the photovoltaic power generation; If yes, the power distribution control module (15) controls the photovoltaic panel (6) to supply power to the load to be powered, and stores the remaining energy of the system in the battery (4); If not, the power distribution control module (15) controls the photovoltaic panel (6) and / or the battery (4) to supply power to part of the loads to be powered based on the remaining power of the battery; or controls the photovoltaic panel (6) to supply power to the loads to be powered, and uses the battery (4) to dynamically supplement the energy required by the loads to be powered.

7. The intelligent load distribution system capable of switching between on-grid and off-grid according to claim 6, characterized in that: The power distribution control module (15) controls the photovoltaic panel (6) and / or the battery (4) to supply power to a portion of the loads to be powered based on the remaining power of the battery; or controls the photovoltaic panel (6) to supply power to the loads to be powered, and uses the battery (4) to dynamically supplement the energy required by the loads to be powered, specifically including: If the remaining power of the battery is within a fourth power range, the power distribution control module (15) controls the photovoltaic panel (6) to supply power to the load to be powered, and uses the battery (4) to dynamically supplement the energy required by the load to be powered; If the remaining power of the battery is within the fifth power range, the power distribution control module (15) selects part of the loads from the loads to be powered based on the preset load power usage priority, controls the photovoltaic panel (6) to power the selected part of the loads, and uses the battery (4) to dynamically supplement the energy required by the part of the loads; If the remaining battery power is within the sixth power range, the power distribution control module (15) selects part of the loads to be powered based on the preset load power usage priority, and controls the photovoltaic panel (6) to supply power to the selected part of the loads.

8. The intelligent load distribution system capable of switching between on-grid and off-grid according to claim 2, characterized in that: The power distribution control module (15) obtains the voltage and current values ​​of the load end, the grid end, the photovoltaic output end and the battery end through the first monitoring module (17), the first load detection module (11), the second load detection module (12), the third load detection module (13) and the photovoltaic inverter detection module (14); and based on the voltage and current values ​​of the load end, the grid end, the photovoltaic output end and the battery end, identifies the abnormality of the system and performs corresponding protection actions.

9. The intelligent load distribution system capable of switching between on-grid and off-grid according to claim 1, characterized in that: The first load detection module (11) identifies an abnormality of the first load (7) by acquiring first current information and first voltage information of the first load (7), and performs a corresponding protection action; The second load detection module (12) identifies an abnormality of the second load (8) by acquiring second current information and second voltage information of the second load (8), and performs a corresponding protection action; The third load detection module (13) identifies an abnormality of the third load (9) by acquiring third current information and third voltage information of the third load (9), and performs a corresponding protection action; The photovoltaic inverter detection module (14) identifies abnormalities of the photovoltaic inverter (5) by acquiring fourth current information and fourth voltage information at the output end of the photovoltaic inverter (5), and performs corresponding protection actions.

10. The intelligent load distribution system capable of switching between on-grid and off-grid according to claim 1, characterized in that: The first load, the second load, and the third load each include one or more loads.

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