Energy management method, device and system, energy storage system and readable storage medium

Abstract

The present invention proposes an energy management method, device, and system, an energy storage system, and a readable storage medium. The energy management method is used for an energy storage converter including a bus, a PV controller, a DC-DC bidirectional converter, and an ACDC bidirectional converter. The method includes: obtaining the operating mode of the energy storage converter; obtaining the input power of the PV controller, the first operating power of the off-grid load, the second operating power of the energy storage battery pack, and the third operating power of the power grid; determining the power state of the energy storage system based on the input power, the first operating power, the second operating power, and the third operating power; and controlling the bus voltage through one of the PV controller, the DC-DC bidirectional converter, and the ACDC bidirectional converter according to a voltage control strategy corresponding to the operating mode and power state. In this way, the operating modules of the energy storage converter are decoupled and independently controlled, and the bus voltage is maintained by only a single module at any time, reducing the complexity of the energy storage system control logic and improving the reliability of the energy storage system.

Description

Technical Field

[0001] The present invention relates to the field of household energy storage technology, and in particular to an energy management method, device and system, an energy storage system and a readable storage medium. Background Art

[0002] Currently, traditional home energy storage systems use a logical judgment approach to control energy, characterized by integrated control logic. In this type of logical judgment energy system solution, each operating condition requires a separate logic block to debug and test, making software writing and debugging difficult, and increasing the complexity and debugging difficulty of the control logic. Furthermore, this integrated control logic can cause cascading failures if a single component fails, reducing the reliability and stability of the system. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0004] To this end, a first aspect of the present invention is to propose an energy management method.

[0005] A second aspect of the present invention is to provide an energy management device.

[0006] A third aspect of the present invention is to provide an energy management system.

[0007] A fourth aspect of the present invention is to provide an energy storage system.

[0008] A fifth aspect of the present invention is to provide a readable storage medium.

[0009] In view of this, according to one aspect of the present invention, an energy management method is proposed, which is applied to an energy storage converter in an energy storage system. The energy storage converter includes a bus and a PV controller, a DCDC bidirectional converter and an ACDC bidirectional converter connected to the bus. The energy management method includes: obtaining the working mode of the energy storage converter; obtaining the input power of the PV controller, and obtaining the first working power of the off-grid load connected to the energy storage converter, the second working power of the energy storage battery pack, and the third working power of the power grid; determining the power state of the energy storage system according to the input power, the first working power, the second working power and the third working power; and controlling the bus voltage through one of the PV controller, the DCDC bidirectional converter and the ACDC bidirectional converter according to the voltage control strategy corresponding to the working mode and the power state.

[0010] The energy management method provided by the present invention is applied to an energy storage converter in an energy storage system, which includes a busbar and a PV (Photo Voltaic) controller, a DCDC (Direct Current-Direct Current) bidirectional converter, and an ACDC (Alternating Current-Direct Current) bidirectional converter connected to the busbar respectively.

[0011] Specifically, in the energy management method provided by the present invention, during the operation of the energy storage converter, the operating mode of the energy storage converter is obtained, the input power of the PV controller is obtained, and the first operating power of the off-grid load connected to the energy storage converter, the second operating power of the energy storage battery pack, and the third operating power of the power grid are obtained. Furthermore, based on the obtained input power, first operating power, second operating power, and third operating power, the power state of the energy storage system is determined, and this power state can be used to indicate the power flow in the energy storage system. Furthermore, based on the voltage control strategy corresponding to the above-mentioned operating mode and power state, the bus voltage is controlled by one of the PV controller, the DCDC bidirectional converter, and the ACDC bidirectional converter. In this way, the operating modules of the energy storage converter are decoupled and independently controlled, and the bus voltage is controlled and maintained by only a single module at any time, reducing the complexity and debugging difficulty of the energy storage system control logic and improving the reliability and stability of the energy storage system operation.

[0012] The energy management method according to the present invention may also have the following additional technical features:

[0013] In some technical solutions, optionally, the first working power includes off-grid load power, the second working power includes battery charging power and battery discharging power, and the third working power includes grid on-grid power and grid off-grid power. The power state of the energy storage system is determined based on the input power, the first working power, the second working power and the third working power, including: when the input power is greater than the sum of the off-grid load power and the battery charging power, and the current is transmitted unidirectionally from the grid to the energy storage converter, the power state is determined to be the first state, in which the input power is limited; when the input power is greater than the sum of the off-grid load power and the battery charging power, and the current is between the grid and the energy storage converter, the power state is determined to be the first state. In the case of bidirectional transmission between the power supply and the grid, the power state is determined to be the second state, in which part of the input power is transmitted to the grid; when the input power is less than the sum of the off-grid load power and the grid on-grid power, or when the sum of the input power and the grid off-grid power is less than the off-grid load power, the power state is determined to be the third state, in which the energy storage battery pack transmits power to the energy storage converter; when the sum of the input power and the battery discharge power is less than the off-grid load power, or when the input power is less than the sum of the off-grid load power and the battery charging power, the power state is determined to be the fourth state, in which the grid transmits power to the energy storage converter.

[0014] In this technical solution, based on different working conditions, the above-mentioned first working power may specifically include off-grid load power, the second working power may specifically include battery charging power and battery discharging power, and the third working power may specifically include grid-on power and grid-off power.

[0015] On this basis, in the process of determining the power state of the energy storage system based on the input power, first operating power, second operating power, and third operating power of the PV controller, when the input power is greater than the sum of the off-grid load power and the battery charging power, and the current is transmitted unidirectionally from the grid to the energy storage converter, that is, when the input power is greater than the sum of the off-grid load power and the battery charging power, and the energy storage converter is in anti-backflow mode and does not allow grid feed, the power state of the energy storage system is determined to be the first state. In the first state, the input power of the PV controller is limited. Furthermore, when the input power is greater than the sum of the off-grid load power and the battery charging power, and the current is transmitted bidirectionally between the grid and the energy storage converter, that is, when the input power is greater than the sum of the off-grid load power and the battery charging power, and the energy storage converter is not in anti-backflow mode and allows grid feed, the power state is determined to be the second state. In the second state, the energy storage converter transmits all the remaining power of the PV controller to the grid. Furthermore, when the input power is less than the sum of the off-grid load power and the grid power, or when the sum of the input power and the grid power is less than the off-grid load power, the power state is determined to be the third state. In the third state, the energy storage battery pack transmits power to the energy storage inverter. Furthermore, when the sum of the input power and the battery discharge power is less than the off-grid load power, or when the input power is less than the sum of the off-grid load power and the battery charging power, the power state is determined to be the fourth state. In the fourth state, the grid transmits power to the energy storage inverter. In this way, the design of the anti-backflow logic takes into account whether regional policies allow for grid access, and also considers the direction of energy flow in the system when there is no grid and sufficient photovoltaic power. This ensures the normal flow of energy in the energy storage system and determines the power state of the energy storage system as a whole, without having to determine the power state of each module one by one.

[0016] In some technical solutions, optionally, the operating mode includes a first operating mode. In the first operating mode, the bus voltage is controlled by one of a PV controller, a DCDC bidirectional converter, and an ACDC bidirectional converter according to a voltage control strategy corresponding to the operating mode and the power state, including: in a first state, the bus voltage is controlled at a first voltage value by the PV controller; in a second state, the bus voltage is controlled at a second voltage value by the ACDC bidirectional converter; in a third state, the bus voltage is controlled at a third voltage value by the DCDC bidirectional converter; in a fourth state, the bus voltage is controlled at a fourth voltage value by the ACDC bidirectional converter; wherein the first voltage value is greater than the second voltage value, the second voltage value is greater than the third voltage value, and the third voltage value is greater than the fourth voltage value.

[0017] In this technical solution, the operating mode of the energy storage converter may specifically include a first operating mode. On this basis, when the power state of the energy storage system is the first state, the bus voltage is controlled at a first voltage value by the PV controller. When the power state of the energy storage system is the second state, the bus voltage is controlled at a second voltage value by the ACDC bidirectional converter. Furthermore, when the power state of the energy storage system is the third state, the bus voltage is controlled at a third voltage value by the DCDC bidirectional converter. Furthermore, when the power state of the energy storage system is the fourth state, the bus voltage is controlled at a fourth voltage value by the ACDC bidirectional converter. The second voltage value is less than the first voltage value, the third voltage value is less than the second voltage value, and the fourth voltage value is less than the third voltage value.

[0018] In some technical solutions, optionally, the operating mode also includes a second operating mode. In the second operating mode, the bus voltage is controlled by one of the PV controller, the DCDC bidirectional converter and the ACDC bidirectional converter according to the voltage control strategy corresponding to the operating mode and the power state, including: in the first state, the bus voltage is controlled at a first voltage value by the PV controller; in the second state, the bus voltage is controlled at a second voltage value by the ACDC bidirectional converter; in the third state, the bus voltage is controlled at a fourth voltage value by the DCDC bidirectional converter; in the fourth state, the bus voltage is controlled at a third voltage value by the ACDC bidirectional converter.

[0019] In this technical solution, the operating mode of the energy storage converter may further include a second operating mode. On this basis, when the power state of the energy storage system is the first state, the bus voltage is controlled at a first voltage value by the PV controller. Furthermore, when the power state of the energy storage system is the second state, the bus voltage is controlled at a second voltage value by the ACDC bidirectional converter. Furthermore, when the power state of the energy storage system is the third state, the bus voltage is controlled at a fourth voltage value by the DCDC bidirectional converter. Furthermore, when the power state of the energy storage system is the fourth state, the bus voltage is controlled at the third voltage value by the ACDC bidirectional converter.

[0020] In some technical solutions, optionally, the working mode also includes a third working mode. In the third working mode, the working mode of the energy storage converter is switched between the first working mode and the second working mode according to the mode switching instruction. In the third working mode, the bus voltage is controlled by one of the PV controller, the DCDC bidirectional converter and the ACDC bidirectional converter according to the voltage control strategy corresponding to the working mode and the power state, including: controlling the bus voltage by one of the PV controller, the DCDC bidirectional converter and the ACDC bidirectional converter according to the voltage control strategy corresponding to the working mode and the power state corresponding to the mode switching instruction.

[0021] In this technical solution, the operating mode of the energy storage converter can further include a third operating mode. In this third operating mode, the operating mode of the energy storage converter switches between the first operating mode and the second operating mode according to a mode switching instruction. Furthermore, in the third operating mode, the actual operating mode of the energy storage converter is determined based on the mode switching instruction. The bus voltage is then controlled using one of a PV controller, a DC-DC bidirectional converter, and an ACDC bidirectional converter based on the voltage control strategy corresponding to the actual operating mode and power state.

[0022] In this way, under various operating modes, the energy storage converter only needs to control the voltage level of the bus voltage of each module and limit the power of the solar panel or photovoltaic panel to complete the energy management of the entire energy storage system. This greatly simplifies the complexity of the energy management logic and makes it easier to reduce the computing power of the embedded system so that the above energy management logic can be deployed on chips with lower power consumption and computing power, reducing energy management costs. At the same time, it makes it easier to free up more computing time for processing other performance indicators, thereby improving the response speed of the energy storage system and improving product quality.

[0023] In some technical solutions, optionally, the energy management method also includes: when the energy storage converter is not connected to the grid, controlling the bus voltage through the DCDC bidirectional converter, providing energy to the energy storage battery pack and the off-grid load through the PV controller, and the ACDC bidirectional converter serving as an off-grid inverter to provide energy to the off-grid load.

[0024] In this technical solution, when the energy storage converter is not connected to the grid, the PV controller does not control the bus voltage. Instead, it serves only to maintain the energy needs of the energy storage battery pack and off-grid loads. The ACDC bidirectional converter acts as an off-grid inverter to provide energy to the off-grid loads. Furthermore, the DCDC bidirectional converter controls the bus voltage, for example, by keeping it at 220V or another voltage value to ensure stable operation of the off-grid inverter.

[0025] According to a second aspect of the present invention, an energy management device is proposed, which is applied to an energy storage converter in an energy storage system. The energy storage converter includes a bus and a PV controller, a DCDC bidirectional converter, and an ACDC bidirectional converter connected to the bus. The energy management device includes: an acquisition unit for acquiring the operating mode of the energy storage converter; the acquisition unit is also used to acquire the input power of the PV controller, and acquire the first operating power of the off-grid load connected to the energy storage converter, the second operating power of the energy storage battery pack, and the third operating power of the power grid; a processing unit for determining the power state of the energy storage system based on the input power, the first operating power, the second operating power, and the third operating power; and a control unit for controlling the bus voltage through one of the PV controller, the DCDC bidirectional converter, and the ACDC bidirectional converter according to a voltage control strategy corresponding to the operating mode and the power state.

[0026] The energy management device provided by the present invention is applied to an energy storage converter in an energy storage system. The energy storage converter includes a busbar and a PV controller, a DCDC bidirectional converter, and an ACDC bidirectional converter respectively connected to the busbar.

[0027] Specifically, the energy management device provided by the present invention includes an acquisition unit, a processing unit, and a control unit. During the operation of the energy storage converter, the acquisition unit acquires the operating mode of the energy storage converter, the input power of the PV controller, and the first operating power of the off-grid load connected to the energy storage converter, the second operating power of the energy storage battery pack, and the third operating power of the power grid. Furthermore, the processing unit determines the power state of the energy storage system based on the acquired input power, first operating power, second operating power, and third operating power. This power state can be used to indicate the power flow in the energy storage system. Furthermore, the control unit controls the bus voltage through one of the PV controller, the DCDC bidirectional converter, and the ACDC bidirectional converter according to the voltage control strategy corresponding to the above-mentioned operating mode and power state. In this way, the operating modules of the energy storage converter are decoupled and independently controlled. At any time, the bus voltage is controlled and maintained by only a single module, reducing the complexity and debugging difficulty of the energy storage system control logic and improving the reliability and stability of the energy storage system.

[0028] According to a third aspect of the present invention, an energy management system is provided, comprising a processor and a memory. The memory stores a program or instruction executable on the processor. When executed by the processor, the program or instruction implements the steps of the energy management method described in any of the above-described technical solutions. Therefore, the energy management system provided in the third aspect of the present invention possesses all the beneficial effects of the energy management method described in any of the above-described technical solutions in the first aspect, and will not be further elaborated here.

[0029] According to a fourth aspect of the present invention, an energy storage system is provided, comprising: an energy storage converter; and the energy management system described in the third aspect, connected to the energy storage converter. The energy storage system described in the fourth aspect includes the energy management system described in the third aspect. Therefore, the energy storage system described in the fourth aspect possesses all the beneficial effects of the energy management system described in the third aspect, and will not be further elaborated here.

[0030] According to a fifth aspect of the present invention, a readable storage medium is provided. The readable storage medium stores a program or instructions. When executed by a processor, the program or instructions implement the energy management method described in any of the above-mentioned technical solutions. Therefore, the readable storage medium provided in the fifth aspect of the present invention possesses all the beneficial effects of the energy management method described in any of the above-mentioned technical solutions in the first aspect, and will not be further elaborated here.

[0031] Additional aspects and advantages of the invention will become apparent from the description which follows, or may be learned by practice of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0033] Figure 1 A schematic diagram showing a flow chart of an energy management method according to an embodiment of the present invention is shown;

[0034] Figure 2 A schematic diagram showing the working process of a PV controller according to an embodiment of the present invention is shown;

[0035] Figure 3 A schematic diagram showing the working process of a DCDC bidirectional converter according to an embodiment of the present invention is shown;

[0036] Figure 4 A schematic diagram showing the working process of the ACDC bidirectional converter according to an embodiment of the present invention is shown;

[0037] Figure 5 The figure shows a schematic structural diagram of an energy storage converter in the related art;

[0038] Figure 6 A schematic structural diagram of an energy storage converter according to an embodiment of the present invention is shown;

[0039] Figure 7 shows a structural block diagram of an energy management device according to an embodiment of the present invention;

[0040] Figure 8 shows a structural block diagram of an energy storage management system according to an embodiment of the present invention;

[0041] Figure 9 shows a structural block diagram of an energy storage system according to an embodiment of the present invention;

[0042] Figure 10 A schematic structural diagram of a household energy storage system according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0043] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present invention and the features therein can be combined with each other without conflict.

[0044] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0045] The following combination Figures 1 to 10 , the energy management method, device and system, energy storage system and readable storage medium provided in the embodiments of the present application are described in detail through specific embodiments and their application scenarios.

[0046] In one embodiment of the present invention, an energy management method is proposed. The method is applied to an energy storage converter in an energy storage system. The energy storage converter includes a busbar and a PV controller connected to the busbar, a DCDC bidirectional converter, and an ACDC bidirectional converter. Figure 1 As shown, the energy management method may specifically include the following steps 102 to 108:

[0047] Step 102, obtaining the operating mode of the energy storage converter;

[0048] Step 104: obtaining the input power of the PV controller, as well as the first operating power of the off-grid load connected to the energy storage converter, the second operating power of the energy storage battery pack, and the third operating power of the grid;

[0049] Step 106, determining a power state of the energy storage system according to the input power, the first operating power, the second operating power, and the third operating power;

[0050] Step 108 : Control the bus voltage through one of the PV controller, the DCDC bidirectional converter, and the ACDC bidirectional converter according to a voltage control strategy corresponding to the operating mode and power state.

[0051] The energy management method provided by the present invention is applied to the PCS (Power Conversion System, energy storage converter) in the energy storage system, such as Figure 6As shown, the energy storage converter includes a busbar and a PV controller, a DCDC bidirectional converter and an ACDC bidirectional converter respectively connected to the busbar.

[0052] Among them, such as Figure 5 and Figure 6 As shown, the PV controller can be connected to a solar panel or photovoltaic panel to transfer energy from the solar panel to the energy storage inverter. The ACDC bidirectional converter can be connected to the grid and off-grid loads to exchange energy between the energy storage inverter and the grid or off-grid loads. The DCDC bidirectional converter can be connected to an energy storage battery pack to exchange energy between the energy storage inverter and the battery pack.

[0053] Specifically, in the energy management method provided by the present invention, during the operation of the energy storage converter, the operating mode of the energy storage converter is obtained, the input power of the PV controller is obtained, and the first operating power of the off-grid load connected to the energy storage converter, the second operating power of the energy storage battery pack, and the third operating power of the power grid are obtained. Furthermore, based on the obtained input power, first operating power, second operating power, and third operating power, the power state of the energy storage system is determined, and this power state can be used to indicate the power flow in the energy storage system. Furthermore, based on the voltage control strategy corresponding to the above-mentioned operating mode and power state, the bus voltage is controlled by one of the PV controller, the DCDC bidirectional converter, and the ACDC bidirectional converter. In this way, the operating modules of the energy storage converter are decoupled and independently controlled, and the bus voltage is controlled and maintained by only a single module at any time, reducing the complexity and debugging difficulty of the energy storage system control logic and improving the reliability and stability of the energy storage system operation.

[0054] The working modes of the energy storage converter may specifically include self-generation and self-use mode, battery priority mode, and peak shaving and valley filling mode.

[0055] Furthermore, when controlling bus voltage, based on different operating conditions, the bus voltage includes four ascending voltage levels: 220V, 240V, 260V, and 280V. The higher the bus voltage level, the more energy-sufficient the energy storage system is, while the lower the bus voltage level, the less energy the energy storage system has, requiring energy flow restriction. By determining the difference between bus voltage levels, a preset bus can be set, facilitating rapid identification of the optimal point during project development, maximizing efficiency and minimizing losses. This improves the reliability and availability of the energy storage system and facilitates project development and subsequent maintenance.

[0056] Furthermore, in the energy management method provided by the present invention, at any time, the bus voltage is controlled and maintained by only a single module, and the ability of other modules to maintain the bus voltage is limited by their respective control loops to an integrated shallow saturation state. When the energy of the energy storage system changes, the control loop of each module quickly responds to the change and maintains the bus voltage, ensuring the normal flow of energy in the energy storage system, and the power state of the entire energy storage system will be determined without having to determine the power state of each module in turn. In this way, on the one hand, the various modules of the energy storage converter are decoupled, and when a module fails, the energy storage converter can also work normally, without causing unknown chain failures, thereby improving the reliability of the energy storage system; on the other hand, by using the control loop to automatically switch instead of logical judgment, the sudden change and switching of the set value of the energy storage system can be reduced, thereby reducing the risk of energy storage system jitter, increasing the hysteresis loop overhead, reducing logical switching, and improving the stability of the energy storage system.

[0057] In addition, the energy management method provided by the present invention has a wide range of applications and can be directly copied and used in other energy storage scenario projects, which can greatly improve project development efficiency and shorten project cycles.

[0058] In some embodiments of the present invention, optionally, the first operating power includes off-grid load power, the second operating power includes battery charging power and battery discharging power, and the third operating power includes grid on-grid power and grid off-grid power. The above step 106 may specifically include the following steps 106a to 106d:

[0059] Step 106a: When the input power is greater than the sum of the off-grid load power and the battery charging power, and the current is transmitted unidirectionally from the grid to the energy storage converter, determining that the power state is the first state;

[0060] Step 106b: when the input power is greater than the sum of the off-grid load power and the battery charging power, and current is transmitted bidirectionally between the grid and the energy storage converter, determining that the power state is the second state;

[0061] Step 106c: When the input power is less than the sum of the off-grid load power and the grid on-grid power, or when the sum of the input power and the grid off-grid power is less than the off-grid load power, determine that the power state is the third state;

[0062] Step 106d: When the sum of the input power and the battery discharge power is less than the off-grid load power, or when the input power is less than the sum of the off-grid load power and the battery charge power, determine that the power state is the fourth state;

[0063] Among them, in the first state, the input power is limited; in the second state, part of the input power is transmitted to the power grid; in the third state, the energy storage battery pack transmits power to the energy storage converter; in the fourth state, the power grid transmits power to the energy storage converter.

[0064] In this embodiment, based on different working conditions, the above-mentioned first working power may specifically include off-grid load power, the second working power may specifically include battery charging power and battery discharging power, and the third working power may specifically include grid on-grid power and grid off-grid power.

[0065] On this basis, in the process of determining the power state of the energy storage system based on the input power, first operating power, second operating power, and third operating power of the PV controller, when the input power is greater than the sum of the off-grid load power and the battery charging power, and current is transmitted unidirectionally from the grid to the energy storage converter, that is, when the input power is greater than the sum of the off-grid load power and the battery charging power, and the energy storage converter is in anti-backflow mode and does not allow grid feeding, the power state of the energy storage system is determined to be the first state. In the first state, the input power of the PV controller is limited.

[0066] For example, if the PV controller input power is 16 kW, the off-grid load power is 3 kW, the battery charging power is 3 kW, and the energy storage converter is in reverse flow mode, disallowing grid feed, the energy storage system's power state is determined to be in the first state, and the PV controller's input power is limited. Alternatively, if the PV controller input power is 16 kW, the off-grid load power is 3 kW, the battery charging power is 10 kW, and the energy storage converter is in reverse flow mode, disallowing grid feed, the energy storage system's power state is determined to be in the first state, and the PV controller's input power is limited.

[0067] Furthermore, when the input power is greater than the sum of the off-grid load power and the battery charging power, and current is transmitted bidirectionally between the grid and the energy storage converter, that is, when the input power is greater than the sum of the off-grid load power and the battery charging power, and the energy storage converter is not in reverse flow prevention mode and allows grid feeding, the power state is determined to be the second state. In the second state, the energy storage converter transmits all remaining power from the PV controller to the grid.

[0068] For example, when the PV controller's input power is 16 kW, the off-grid load's power is 3 kW, the battery charging power is 3 kW, and the energy storage converter is not in reverse flow mode, allowing grid feeding, the energy storage system's power state is determined to be the second state, and the remaining 10 kW of the PV controller's input power is fully fed to the grid. Alternatively, when the PV controller's input power is 16 kW, the off-grid load's power is 3 kW, the battery charging power is 10 kW, and the energy storage converter is not in reverse flow mode, allowing grid feeding, the energy storage system's power state is determined to be the second state, and the remaining 3 kW of the PV controller's input power is fully fed to the grid.

[0069] Furthermore, when the input power is less than the sum of the off-grid load power and the grid power, or when the sum of the input power and the grid power is less than the off-grid load power, the power state is determined to be a third state. In the third state, the energy storage battery pack transmits power to the energy storage converter.

[0070] For example, if the PV controller input power is 4 kW, the off-grid load power is 6 kW, and the grid power is 2 kW, the energy storage battery pack needs to discharge to supplement 4 kW of power. In this case, the energy storage system's power state is determined to be the third state. Alternatively, if the PV controller input power is 4 kW, the off-grid load power is 6 kW, and the grid power is 1 kW, the energy storage battery pack needs to discharge to supplement 1 kW of power. In this case, the energy storage system's power state is determined to be the third state.

[0071] Furthermore, when the sum of the input power and the battery discharge power is less than the off-grid load power, or when the input power is less than the sum of the off-grid load power and the battery charge power, the power state is determined to be a fourth state. In the fourth state, the grid transmits power to the energy storage converter.

[0072] For example, if the PV controller input power is 4 kW, the off-grid load power is 6 kW, and the battery discharge power is 1 kW, then the grid needs to supplement 1 kW of power. In this case, the energy storage system's power state is determined to be the fourth state. Alternatively, if the PV controller input power is 4 kW, the off-grid load power is 6 kW, and the battery charge power is 10 kW, then the grid needs to supplement 12 kW of power. In this case, the energy storage system's power state is determined to be the fourth state.

[0073] In this way, the anti-backflow logic is designed by considering whether the regional policy can be connected to the grid. The energy flow direction of the system when there is no grid and the photovoltaic power is sufficient is also considered, ensuring the normal flow of energy in the energy storage system and determining the power state of the energy storage system as a whole, without having to determine the power state of each module one by one.

[0074] Specifically, the above-mentioned off-grid loads may be household appliances such as refrigerators and washing machines that are mounted on the AC line when using the energy storage system. The energy required mainly comes from energy storage battery packs, solar panels or photovoltaic panels.

[0075] In some embodiments of the present invention, optionally, the working mode includes a first working mode. In the first working mode, step 108 may specifically include the following steps 108a to 108d:

[0076] Step 108a, in a first state, controlling the bus voltage to a first voltage value by the PV controller;

[0077] Step 108b: in the second state, controlling the bus voltage to a second voltage value through the ACDC bidirectional converter;

[0078] Step 108c: in the third state, controlling the bus voltage to a third voltage value through the DCDC bidirectional converter;

[0079] Step 108d: in the fourth state, controlling the bus voltage to a fourth voltage value through the ACDC bidirectional converter;

[0080] Among them, the second voltage value is smaller than the first voltage value; the third voltage value is smaller than the second voltage value; and the fourth voltage value is smaller than the third voltage value.

[0081] In this embodiment, the operating mode of the energy storage converter may specifically include a first operating mode, which may specifically be a self-generation and self-consumption mode. In the self-generation and self-consumption mode, the bus voltage levels of the modules in the energy storage converter may specifically be: PV controller (280V) > DCDC bidirectional converter (240V) > ACDC bidirectional converter (upper limit 260V, lower limit 220V).

[0082] On this basis, when the energy storage system's power state is in the first state, the bus voltage is controlled to a first voltage value by the PV controller. Specifically, the first voltage value may be 280V. For example, in self-generation and self-consumption mode, when the PV controller's input power is 16kW, the off-grid load's power is 3kW, the battery charging power is 3kW, and the energy storage converter is in reverse flow prevention mode, disabling grid feed, the PV controller's input power is limited, and the bus voltage is controlled to 280V by the PV controller.

[0083] Furthermore, when the energy storage system's power state is in the second state, the bus voltage is controlled to a second voltage value via the ACDC bidirectional converter. The second voltage value is less than the first voltage value, and the second voltage value may specifically be 260V. For example, in self-generation and self-consumption mode, when the PV controller's input power is 16kW, the off-grid load power is 3kW, the battery charging power is 3kW, and the energy storage converter is not in reverse flow mode, allowing grid feed, the remaining 10kW of the PV controller's input power is fully fed to the grid, and the bus voltage is controlled to 260V via the ACDC bidirectional converter.

[0084] Furthermore, when the energy storage system's power state is in the third state, the bus voltage is controlled to a third voltage value via the DCDC bidirectional converter. The third voltage value is lower than the second voltage value and can specifically be 240V. For example, in self-generation and self-consumption mode, with a PV controller input power of 4kW, an off-grid load power of 6kW, and a grid power of 2kW, the energy storage battery pack needs to discharge to supplement 4kW of power, and the bus voltage is controlled to 240V via the DCDC bidirectional converter.

[0085] Furthermore, when the energy storage system's power state is in the fourth state, the bus voltage is controlled to a fourth voltage value via the ACDC bidirectional converter. The fourth voltage value is lower than the third voltage value and may specifically be 220V. For example, in self-generation and self-consumption mode, with a PV controller input power of 4kW, an off-grid load power of 6kW, and a battery discharge power of 1kW, the grid needs to supplement 1kW of power offline. The bus voltage is controlled to 220V via the ACDC bidirectional converter.

[0086] In some embodiments of the present invention, optionally, the working mode further includes a second working mode. In the second working mode, step 108 may specifically include the following steps 108e to 108h:

[0087] Step 108e: in the first state, controlling the bus voltage to a first voltage value by the PV controller;

[0088] Step 108f, in the second state, controlling the bus voltage to a second voltage value through the ACDC bidirectional converter;

[0089] Step 108g: In the third state, the bus voltage is controlled to a fourth voltage value by the DCDC bidirectional converter;

[0090] Step 108h: In the fourth state, the bus voltage is controlled to a third voltage value through the ACDC bidirectional converter.

[0091] In this embodiment, the operating mode of the energy storage converter may further include a second operating mode, which may be a battery priority mode. In the battery priority mode, the bus voltage levels of the modules in the energy storage converter may be: PV controller (280V) > ACDC bidirectional converter (upper limit 260V, lower limit 240V) > DCDC bidirectional converter (220V).

[0092] On this basis, when the energy storage system's power state is in the first state, the bus voltage is controlled to a first voltage value by the PV controller. For example, in battery priority mode, if the PV controller input power is 16 kW, the off-grid load power is 3 kW, the battery charging power is 10 kW, and the energy storage converter is in reverse flow prevention mode and grid feed is not allowed, the PV controller input power is limited and the bus voltage is controlled to 280 V by the PV controller.

[0093] Furthermore, when the energy storage system's power state is in the second state, the bus voltage is controlled to a second voltage value via the ACDC bidirectional converter. For example, in battery priority mode, if the PV controller's input power is 16 kW, the off-grid load's power is 3 kW, the battery charging power is 10 kW, and the energy storage converter is not in reverse flow prevention mode, allowing grid feed, the remaining 3 kW of the PV controller's input power is fully fed to the grid, and the bus voltage is controlled to 260 V via the ACDC bidirectional converter.

[0094] Furthermore, when the energy storage system's power state is in the third state, the bus voltage is controlled to a fourth voltage value via the DCDC bidirectional converter. For example, in battery priority mode, if the PV controller input power is 4 kW, the off-grid load power is 6 kW, and the grid power is 1 kW, the energy storage battery pack needs to discharge to supplement 1 kW of power, and the DCDC bidirectional converter controls the bus voltage to 220V.

[0095] Furthermore, when the energy storage system's power state is in the fourth state, the bus voltage is controlled to a third voltage value via the ACDC bidirectional converter. For example, in battery priority mode, with a PV controller input power of 4 kW, an off-grid load power of 6 kW, and a battery charging power of 10 kW, the grid needs to supplement 12 kW of power offline. The ACDC bidirectional converter controls the bus voltage to 240 V.

[0096] In some embodiments of the present invention, optionally, the operating mode further includes a third operating mode. In the third operating mode, the operating mode of the energy storage converter switches between the first operating mode and the second operating mode according to the mode switching instruction. In the third operating mode, step 108 may specifically include the following step 108i:

[0097] Step 108i: Control the bus voltage through one of the PV controller, the DCDC bidirectional converter, and the ACDC bidirectional converter according to the operating mode corresponding to the mode switching instruction and the voltage control strategy corresponding to the power state.

[0098] In this embodiment, the operating mode of the energy storage converter may further include a third operating mode, which may be a peak shaving and valley filling mode. In this mode, the BMS (Battery Management System) in the energy storage system issues a mode switching instruction in real time based on changes in grid prices in different regions. The energy storage converter responds to the mode switching instruction by switching between the self-generation and self-use mode and the battery priority mode to achieve peak shaving and valley filling.

[0099] On this basis, in the peak shaving and valley filling mode, the actual working mode of the energy storage converter is determined according to the mode switching instruction, and then the bus voltage is controlled through one of the PV controller, DCDC bidirectional converter and ACDC bidirectional converter according to the voltage control strategy corresponding to the actual working mode and power state.

[0100] For example, when grid prices are high, the BMS in the energy storage system controls the energy storage converter to operate in self-generation and self-consumption mode, feeding electricity into the grid. At this time, the bus voltage is controlled using the voltage control strategy corresponding to self-generation and self-consumption mode. When grid prices are low, the BMS in the energy storage system controls the energy storage converter to operate in battery-priority mode, controlling the bus voltage using the voltage control strategy corresponding to battery-priority mode.

[0101] In this way, under various operating modes, the energy storage converter only needs to control the voltage level of the bus voltage of each module and limit the power of the solar panel or photovoltaic panel to complete the energy management of the entire energy storage system. This greatly simplifies the complexity of the energy management logic and makes it easier to reduce the computing power of the embedded system so that the above energy management logic can be deployed on chips with lower power consumption and computing power, reducing energy management costs. At the same time, it makes it easier to free up more computing time for processing other performance indicators, thereby improving the response speed of the energy storage system and improving product quality.

[0102] In some embodiments of the present invention, optionally, the energy management method may further include the following step 110:

[0103] Step 110: When the energy storage converter is not connected to the grid, the bus voltage is controlled by the DCDC bidirectional converter, and energy is provided to the energy storage battery pack and the off-grid load through the PV controller. The ACDC bidirectional converter serves as an off-grid inverter to provide energy to the off-grid load.

[0104] In this embodiment, when the energy storage converter is not grid-connected, the PV controller does not control the bus voltage. Instead, it serves only to maintain the energy needs of the energy storage battery pack and off-grid loads. The ACDC bidirectional converter acts as an off-grid inverter to provide energy to the off-grid loads. Furthermore, the DCDC bidirectional converter controls the bus voltage, for example, by controlling it to 220V or another voltage value to ensure stable operation of the off-grid inverter.

[0105] In summary, in the energy management method provided by the present invention, if Figure 2 As shown, the workflow of the PV controller may specifically include the following steps 202 to 214:

[0106] Step 202: The PV controller sets the bus voltage to 280V.

[0107] Step 204 , running the MPPT algorithm to track the maximum power point of the PV controller in real time;

[0108] Step 206, determine: the energy storage converter is grid-connected, if so, execute step 208, if not, execute step 214;

[0109] Step 208, determine whether the energy storage converter is in anti-backflow mode. If so, proceed to step 210; if not, proceed to step 212;

[0110] Step 210 , when the energy storage battery pack is fully charged and the input power of the PV controller is sufficient to maintain the off-grid load power, limiting the input power of the PV controller;

[0111] Step 212: When the energy storage battery pack is fully charged and the input power of the PV controller is sufficient to maintain the off-grid load power, all the remaining input power of the PV controller is fed into the grid;

[0112] In step 214 , the PV controller does not control the bus voltage, and provides energy to the energy storage battery pack and the off-grid load through the PV controller.

[0113] Among them, MPPT (Maximum Power Point Tracking).

[0114] Specifically, the PV controller is a way to utilize solar green energy. In order to maximize the energy utilization rate of the PV controller, no matter what working mode the energy storage converter is running in, the PV controller always operates stably at the maximum power point to provide energy. The energy use priority of the PV controller is the highest. In the energy management method provided by the present invention, the PV controller is set to control the bus voltage to a maximum value of 280V. When the energy of the PV controller is sufficient, that is, when the energy storage battery pack is fully charged and the input power of the PV controller is sufficient to maintain the off-grid load power, the bus voltage is maintained by the PV controller. The power of the PV controller can be limited according to user needs and actual working conditions.

[0115] Furthermore, in the energy management method provided by the present invention, if Figure 3 As shown, the workflow of the DCDC bidirectional converter may specifically include the following steps 302 to 310:

[0116] Step 302, determine: the energy storage converter is grid-connected, if so, execute step 304, if not, execute step 310;

[0117] Step 304, determine: the energy storage converter is in self-generation and self-use mode, if so, execute step 306, if not, execute step 308;

[0118] Step 306, controlling the bus voltage to 240V to provide grid power and off-grid load power;

[0119] Step 308: Control the bus voltage to 220V to provide an environment for the grid to charge the energy storage battery pack;

[0120] Step 310: Control the bus voltage at 220V to maintain stable operation of the offline inverter.

[0121] Specifically, the DCDC bidirectional converter acts as an intermediate between the battery and the busbar, primarily responsible for charging and discharging the energy storage battery pack. Depending on the operating mode, the DCDC bidirectional converter automatically adjusts the busbar voltage level to achieve bidirectional energy flow from high to low. In self-generation mode, the DCDC bidirectional converter sets the busbar voltage to 240V; in battery-priority mode, the DCDC bidirectional converter sets the busbar voltage to 220V.

[0122] Furthermore, in the energy management method provided by the present invention, if Figure 4 As shown, the working process of the ACDC bidirectional converter may specifically include the following steps 402 to 410:

[0123] Step 402, determine whether the energy storage converter is grid-connected. If yes, go to step 404; if no, go to step 410;

[0124] Step 404, determine: the energy storage converter is in self-generation and self-use mode, if so, execute step 406, if not, execute step 408;

[0125] Step 406 , controlling the bus voltage upper limit to 260V and lower limit to 220V, so that energy from the PV controller and the energy storage battery pack flows to the grid or off-grid loads;

[0126] Step 408 , controlling the bus voltage upper limit to 260V and lower limit to 240V, so that the energy of the grid flows to the energy storage battery pack;

[0127] Step 410: Serving as an offline inverter to provide energy to off-grid loads.

[0128] Specifically, the ACDC bidirectional converter acts as an interface between the busbar, off-grid loads, and the grid. When energy flows to the off-grid loads or the grid, the ACDC bidirectional converter functions as an inverter, providing stable AC power. When energy flows from the grid to the busbar, the ACDC bidirectional converter functions as a rectifier, extracting grid energy to maintain the busbar and charge the energy storage battery pack. When the ACDC bidirectional converter functions as an inverter, it does not need to control the busbar voltage. When the busbar has sufficient power to maintain, stable inverter operation is possible. When the ACDC bidirectional converter functions as a rectifier, it adjusts the busbar voltage based on the operating mode. In self-generation and self-consumption mode, the ACDC bidirectional converter sets the busbar voltage upper limit to 260V and the lower limit to 220V. In battery priority mode, the ACDC bidirectional converter sets the busbar voltage upper limit to 260V and the lower limit to 240V. During normal operation of the energy storage converter, the real-time busbar voltage value remains stable within the above range. Furthermore, in off-grid mode, the ACDC bidirectional converter operates in output voltage control mode, and the bus voltage is controlled by the DCDC bidirectional converter. In grid-connected mode, the ACDC bidirectional converter operates in bus voltage control mode, and the power is controlled by the DCDC bidirectional converter.

[0129] In one embodiment of the present invention, an energy management device is also proposed, which is applied to an energy storage converter in an energy storage system. The energy storage converter includes a busbar and a PV controller connected to the busbar, a DCDC bidirectional converter, and an ACDC bidirectional converter. Figure 7 As shown, Figure 7 FIG. 7 is a block diagram showing a structure of an energy management device 700 according to an embodiment of the present invention. Specifically, the energy management device 700 may include the following: an acquisition unit 702, a processing unit 704, and a control unit 706:

[0130] An acquisition unit 702 is configured to acquire an operating mode of the energy storage converter;

[0131] The acquisition unit 702 is further configured to acquire the input power of the PV controller, and acquire the first operating power of the off-grid load connected to the energy storage converter, the second operating power of the energy storage battery pack, and the third operating power of the grid;

[0132] a processing unit 704, configured to determine a power state of the energy storage system according to the input power, the first operating power, the second operating power, and the third operating power;

[0133] The control unit 706 is configured to control the bus voltage through one of the PV controller, the DCDC bidirectional converter, and the ACDC bidirectional converter according to a voltage control strategy corresponding to the operating mode and power state.

[0134] The energy management device 700 provided in the embodiment of the present invention is applied to an energy storage converter in an energy storage system. The energy storage converter includes a busbar and a PV controller, a DCDC bidirectional converter, and an ACDC bidirectional converter respectively connected to the busbar.

[0135] Specifically, the energy management device 700 provided by the present invention includes an acquisition unit 702, a processing unit 704, and a control unit 706. During operation of the energy storage converter, the acquisition unit 702 acquires the operating mode of the energy storage converter, the input power of the PV controller, the first operating power of the off-grid load connected to the energy storage converter, the second operating power of the energy storage battery pack, and the third operating power of the power grid. Furthermore, the processing unit 704 determines the power state of the energy storage system based on the acquired input power, first operating power, second operating power, and third operating power. This power state can be used to indicate the power flow within the energy storage system. Furthermore, the control unit 706 controls the bus voltage using one of the PV controller, the DC-DC bidirectional converter, and the ACDC bidirectional converter based on the voltage control strategy corresponding to the aforementioned operating mode and power state. This decouples and independently controls the operating modules of the energy storage converter, allowing the bus voltage to be controlled and maintained by a single module at any given time. This reduces the complexity and debugging difficulty of the energy storage system's control logic and improves the reliability and stability of the energy storage system.

[0136] The working modes of the energy storage converter may specifically include self-generation and self-use mode, battery priority mode, and peak shaving and valley filling mode.

[0137] Furthermore, when controlling bus voltage, based on different operating conditions, the bus voltage includes four ascending voltage levels: 220V, 240V, 260V, and 280V. The higher the bus voltage level, the more energy-sufficient the energy storage system is, while the lower the bus voltage level, the less energy the energy storage system has, requiring energy flow restriction. By determining the difference between bus voltage levels, a preset bus can be set, facilitating rapid identification of the optimal point during project development, maximizing efficiency and minimizing losses. This improves the reliability and availability of the energy storage system and facilitates project development and subsequent maintenance.

[0138] In some embodiments of the present invention, optionally, the first working power includes off-grid load power, the second working power includes battery charging power and battery discharging power, and the third working power includes grid on-grid power and grid off-grid power. The processing unit 704 is specifically used to: when the input power is greater than the sum of the off-grid load power and the battery charging power, and the current is transmitted unidirectionally from the grid to the energy storage converter, determine that the power state is a first state, in which the input power is limited; when the input power is greater than the sum of the off-grid load power and the battery charging power, and the current is transmitted bidirectionally between the grid and the energy storage converter, determine that the power state is a first state. The state is the second state, in which part of the input power is transmitted to the grid; when the input power is less than the sum of the off-grid load power and the grid on-grid power, or when the sum of the input power and the grid off-grid power is less than the off-grid load power, the power state is determined to be the third state, in which the energy storage battery pack transmits power to the energy storage converter; when the sum of the input power and the battery discharge power is less than the off-grid load power, or when the input power is less than the sum of the off-grid load power and the battery charging power, the power state is determined to be the fourth state, in which the grid transmits power to the energy storage converter.

[0139] In some embodiments of the present invention, optionally, the operating mode includes a first operating mode, in which the control unit 706 is specifically used to: in a first state, control the bus voltage to a first voltage value through the PV controller; in a second state, control the bus voltage to a second voltage value through the ACDC bidirectional converter; in a third state, control the bus voltage to a third voltage value through the DCDC bidirectional converter; in a fourth state, control the bus voltage to a fourth voltage value through the ACDC bidirectional converter; wherein the second voltage value is less than the first voltage value, the third voltage value is less than the second voltage value, and the fourth voltage value is less than the third voltage value.

[0140] In some embodiments of the present invention, optionally, the operating mode also includes a second operating mode. In the second operating mode, the control unit 706 is specifically used to: in a first state, control the bus voltage to a first voltage value through the PV controller; in a second state, control the bus voltage to a second voltage value through the ACDC bidirectional converter; in a third state, control the bus voltage to a fourth voltage value through the DCDC bidirectional converter; in the fourth state, control the bus voltage to a third voltage value through the ACDC bidirectional converter.

[0141] In some embodiments of the present invention, optionally, the operating mode also includes a third operating mode. In the third operating mode, the operating mode of the energy storage converter is switched between the first operating mode and the second operating mode according to the mode switching instruction. In the third operating mode, the control unit 706 is specifically used to: control the bus voltage through one of the PV controller, the DCDC bidirectional converter, and the ACDC bidirectional converter according to the operating mode corresponding to the mode switching instruction and the voltage control strategy corresponding to the power state.

[0142] In some embodiments of the present invention, optionally, the control unit 706 is also used to: when the energy storage converter is not connected to the grid, control the bus voltage through the DCDC bidirectional converter, provide energy to the energy storage battery pack and the off-grid load through the PV controller, and use the ACDC bidirectional converter as an off-grid inverter to provide energy to the off-grid load.

[0143] In one embodiment of the present invention, an energy management system is also proposed. Figure 8 As shown, Figure 8 FIG. 8 is a block diagram of an energy management system 800 according to an embodiment of the present invention. The energy management system 800 includes:

[0144] Memory 802 , where programs or instructions are stored;

[0145] The processor 804 implements the steps of the energy management method in any of the above embodiments when executing the above program or instruction.

[0146] The energy management system 800 provided in this embodiment includes a memory 802 and a processor 804. When the program or instructions in the memory 802 are executed by the processor 804, the steps of the energy management method in any of the above embodiments are implemented. Therefore, the energy management system 800 has all the beneficial effects of the energy management method in any of the above embodiments, which will not be repeated here.

[0147] Specifically, the memory 802 and the processor 804 may be connected via a bus or other means. The processor 804 may include one or more processing units, and the processor 804 may be a central processing unit (CPU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other chips.

[0148] In one embodiment of the present invention, an energy storage system is also proposed. Figure 9 As shown, Figure 9 FIG2 shows a block diagram of an energy storage system 900 according to an embodiment of the present invention. Energy storage system 900 includes an energy storage converter 902 and the energy management system 800 according to the above embodiment. Therefore, energy storage system 900 has all the technical effects of energy management system 800 according to the above embodiment, and will not be further described here.

[0149] The energy management system 800 is connected to the energy storage converter 902 .

[0150] Furthermore, the energy storage converter 902 may be specifically connected to an energy storage battery pack, a power grid, an off-grid load, a solar panel or a photovoltaic panel.

[0151] Furthermore, the energy storage converter 902 is used to control the charging and discharging process of the energy storage battery pack and perform AC-DC conversion. Specifically, the energy storage converter 902 can convert the DC power output by the energy storage battery pack into AC power for use by off-grid loads, or convert AC power into DC power to charge the energy storage battery pack.

[0152] Furthermore, the energy storage system 900 may also include a BMS (Battery Management System). This BMS monitors the voltage, current, temperature, and other parameters of the energy storage battery pack in real time to ensure safe and efficient operation. The BMS also balances the charge and discharge of the energy storage battery pack to protect it from abnormal operating conditions such as overcharging, over-discharging, and short circuits, thereby extending the service life of the battery pack.

[0153] Furthermore, the EMS (Energy Management System) is an intelligent control system in the energy storage system, responsible for managing and scheduling the entire energy storage system. The energy management system 800 is used for data collection, data analysis, and energy scheduling to ensure the energy balance and normal operation of the energy storage system 900. The energy management system 800 can also monitor the status of each module in the energy storage system 900 (such as PCS, BMS, electricity meter, fire protection, air conditioning, etc.) in real time, and intelligently allocate the energy in the energy storage system 900 according to the real-time operating status of each module in the energy storage system 900 and external environmental factors to achieve optimal scheduling. The energy management system 800 can also realize remote monitoring and intelligent operation to improve the operating efficiency and stability of the energy storage system 900.

[0154] Furthermore, the energy management and control strategy within energy storage system 900 is the core of the entire energy storage device. It controls the direction and amount of energy flow within the energy storage system 900 under different operating modes, thereby rationally dispatching local energy to ensure the availability and cost-effectiveness of the home energy storage device. Furthermore, the energy management and control strategy enables the home energy storage device to assist in dispatching and supplying energy from the external grid, providing support for regional grid stability.

[0155] Furthermore, in the energy storage system 900, solar panels or photovoltaic panels serve as one of the energy sources and continuously provide energy to the energy storage system 900. However, their energy intensity is affected by the intensity of light and cannot be guaranteed to be stable at all times. The energy storage battery pack serves as a stable energy supply for the energy storage system 900. It can both release and absorb energy and is the hub of energy regulation. By adjusting the energy output of the energy storage battery pack, the stability of the energy storage system 900 can be guaranteed. The power grid is the backup energy source for the entire energy storage system 900. Only when the energy storage system 900 is insufficient can it absorb energy from the power grid to ensure the stability of the energy storage system 900. In addition, since the energy storage system 900 has a wide range of uses and the laws and regulations of different regions determine whether the energy storage system 900 can transmit energy to the power grid, its energy management and control logic becomes very complex. The energy storage system 900 proposed in the present invention includes the above-mentioned energy management system 800, which can simplify the energy management and control logic of the energy storage system 900.

[0156] In some embodiments, energy storage system 900 is a home energy storage system or a balcony photovoltaic energy storage system. Home energy storage systems are typically relatively large, fixed in position after installation, and cannot be moved. They have a relatively large capacity and provide relatively high power, capable of simultaneously powering most household appliances. Balcony photovoltaic energy storage systems, on the other hand, are relatively small and easy to transport and move. They can be relocated based on user power needs, such as from a balcony to a garage or even outdoors. They have a relatively small capacity and provide relatively low power, capable of powering only a portion of household appliances.

[0157] For example, Figure 10 As shown, the home energy storage system includes a rooftop photovoltaic tile system, a hybrid inverter, a high-voltage battery, a smart distribution box, and a home energy management cloud. The rooftop photovoltaic tile system is connected to the smart distribution box. The rooftop photovoltaic tile system utilizes a string-connected system of curved photovoltaic tiles to fully utilize solar energy while preserving the home's aesthetic design. Furthermore, the smart distribution box serves as the energy dispatch center for the entire home energy storage system. Leveraging a powerful energy management system, it flexibly and intelligently manages energy distribution for the home energy storage system. Furthermore, the home energy management cloud includes a user app (Application) and a web interface that monitors the home energy storage system's real-time power output, usage, and energy conservation data. Furthermore, the high-voltage battery is connected to the hybrid inverter, which in turn is connected to the smart distribution box, which is then connected to the load and the grid. The home energy management cloud intelligently manages power from the grid, the rooftop photovoltaic tile system, and the high-voltage battery. Energy generated by the rooftop photovoltaic tile system can be delivered to the load, stored in the high-voltage battery for backup, or fed back to the grid in accordance with local regulations.

[0158] In one embodiment of the present invention, a readable storage medium is further provided, on which a program or instruction is stored, and when the program or instruction is executed by a processor, the steps of the energy management method in any of the above embodiments are implemented.

[0159] The readable storage medium provided in an embodiment of the present invention, when executed by a processor, stores a program or instruction that implements the steps of the energy management method described in any of the above embodiments. Therefore, the readable storage medium has all the beneficial effects of the energy management method described in any of the above embodiments, and no further description is given here.

[0160] Specifically, the above-mentioned readable storage medium may include any medium capable of storing or transmitting information. Examples of readable storage media include electronic circuits, semiconductor memory devices, read-only memory (ROM), random access memory (RAM), compact disc read-only memory (CD-ROM), flash memory, erasable ROM (EROM), magnetic tape, floppy disk, optical disc, hard disk, optical fiber medium, radio frequency (RF) link, optical data storage device, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0161] In this specification, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance, unless otherwise expressly specified or limited. Terms such as "connect," "install," and "fix" should be interpreted broadly. For example, "connect" can refer to a fixed connection, a detachable connection, or an integral connection; and can be directly connected or indirectly connected through an intermediary. Those skilled in the art will understand the specific meanings of these terms in the present invention based on specific circumstances.

[0162] Throughout this specification, terms such as "one embodiment," "some embodiments," and "specific embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0163] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0164] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. An energy management method, characterized in that: An energy storage converter applied to an energy storage system includes a busbar and a PV controller, a DCDC bidirectional converter, and an ACDC bidirectional converter connected to the busbar. The energy management method includes: Obtaining an operating mode of the energy storage converter; Obtaining the input power of the PV controller, and obtaining a first operating power of an off-grid load connected to the energy storage converter, a second operating power of an energy storage battery pack, and a third operating power of a power grid; determining a power state of the energy storage system according to the input power, the first operating power, the second operating power, and the third operating power; controlling the bus voltage through one of the PV controller, the DCDC bidirectional converter, and the ACDC bidirectional converter according to a voltage control strategy corresponding to the operating mode and the power state; The first operating power includes off-grid load power, the second operating power includes battery charging power and battery discharging power, and the third operating power includes grid-connected power and grid-offline power. Determining the power state of the energy storage system based on the input power, the first operating power, the second operating power, and the third operating power includes: When the input power is greater than the sum of the off-grid load power and the battery charging power, and current is transmitted unidirectionally from the grid to the energy storage converter, determining that the power state is a first state, in which the input power is limited; When the input power is greater than the sum of the off-grid load power and the battery charging power, and current is bidirectionally transmitted between the grid and the energy storage converter, determining that the power state is a second state, in which part of the input power is transmitted to the grid; When the input power is less than the sum of the off-grid load power and the grid-connected power, or when the sum of the input power and the grid-offline power is less than the off-grid load power, determining that the power state is a third state, in which the energy storage battery pack transmits power to the energy storage converter; When the sum of the input power and the battery discharge power is less than the off-grid load power, or when the input power is less than the sum of the off-grid load power and the battery charging power, determining that the power state is a fourth state, in which the power grid transmits power to the energy storage converter; The operating mode includes a first operating mode. In the first operating mode, controlling the bus voltage through one of the PV controller, the DCDC bidirectional converter, and the ACDC bidirectional converter according to a voltage control strategy corresponding to the operating mode and the power state includes: In the first state, the bus voltage is controlled at a first voltage value by the PV controller; In the second state, the bus voltage is controlled at a second voltage value by the ACDC bidirectional converter; In the third state, the bus voltage is controlled to a third voltage value by the DCDC bidirectional converter; In the fourth state, the bus voltage is controlled to a fourth voltage value by the ACDC bidirectional converter; The first voltage value is greater than the second voltage value, the second voltage value is greater than the third voltage value, and the third voltage value is greater than the fourth voltage value.

2. The energy management method according to claim 1, characterized in that: The operating mode further includes a second operating mode. In the second operating mode, controlling the bus voltage through one of the PV controller, the DCDC bidirectional converter, and the ACDC bidirectional converter according to a voltage control strategy corresponding to the operating mode and the power state includes: In the first state, the bus voltage is controlled to the first voltage value by the PV controller; In the second state, the bus voltage is controlled to the second voltage value by the ACDC bidirectional converter; In the third state, the bus voltage is controlled to the fourth voltage value by the DCDC bidirectional converter; In the fourth state, the bus voltage is controlled to the third voltage value by the ACDC bidirectional converter.

3. The energy management method according to claim 2, characterized in that: The operating mode further includes a third operating mode. In the third operating mode, the operating mode of the energy storage converter switches between the first operating mode and the second operating mode according to a mode switching instruction. In the third operating mode, controlling the bus voltage through one of the PV controller, the DCDC bidirectional converter, and the ACDC bidirectional converter according to a voltage control strategy corresponding to the operating mode and the power state includes: The bus voltage is controlled by one of the PV controller, the DCDC bidirectional converter, and the ACDC bidirectional converter according to the operating mode corresponding to the mode switching instruction and the voltage control strategy corresponding to the power state.

4. The energy management method according to any one of claims 1 to 3, characterized in that: Also includes: When the energy storage converter is not connected to the grid, the bus voltage is controlled by the DCDC bidirectional converter, energy is provided to the energy storage battery pack and the off-grid load through the PV controller, and the ACDC bidirectional converter serves as an off-grid inverter to provide energy to the off-grid load.

5. An energy management device, characterized in that: An energy storage converter used in an energy storage system, the energy storage converter comprising a busbar and a PV controller, a DCDC bidirectional converter, and an ACDC bidirectional converter connected to the busbar, the energy management device comprising: an acquisition unit, configured to acquire an operating mode of the energy storage converter; The acquisition unit is further configured to acquire the input power of the PV controller, and acquire the first operating power of the off-grid load connected to the energy storage converter, the second operating power of the energy storage battery pack, and the third operating power of the grid; a processing unit, configured to determine a power state of the energy storage system according to the input power, the first operating power, the second operating power, and the third operating power; a control unit configured to control a bus voltage through one of the PV controller, the DCDC bidirectional converter, and the ACDC bidirectional converter according to a voltage control strategy corresponding to the operating mode and the power state; The first operating power includes off-grid load power, the second operating power includes battery charging power and battery discharging power, and the third operating power includes grid on-grid power and grid off-grid power. The processing unit is specifically configured to: When the input power is greater than the sum of the off-grid load power and the battery charging power, and the current is transmitted unidirectionally from the grid to the energy storage converter, the power state is determined to be a first state, in which the input power is limited; when the input power is greater than the sum of the off-grid load power and the battery charging power, and the current is transmitted bidirectionally between the grid and the energy storage converter, the power state is determined to be a second state, in which part of the input power is transmitted to the grid; when the input power is less than the sum of the off-grid load power and the grid on-grid power, or when the sum of the input power and the grid off-grid power is less than the off-grid load power, the power state is determined to be a third state, in which the energy storage battery pack transmits power to the energy storage converter; when the sum of the input power and the battery discharge power is less than the off-grid load power, or when the input power is less than the sum of the off-grid load power and the battery charging power, the power state is determined to be a fourth state, in which the grid transmits power to the energy storage converter; The operating mode includes a first operating mode. In the first operating mode, the control unit is specifically configured to: In the first state, the bus voltage is controlled at a first voltage value by the PV controller; in the second state, the bus voltage is controlled at a second voltage value by the ACDC bidirectional converter; in the third state, the bus voltage is controlled at a third voltage value by the DCDC bidirectional converter; in the fourth state, the bus voltage is controlled at a fourth voltage value by the ACDC bidirectional converter; wherein the first voltage value is greater than the second voltage value, the second voltage value is greater than the third voltage value, and the third voltage value is greater than the fourth voltage value.

6. An energy management system, characterized in that: The method comprises a processor and a memory, wherein the memory stores programs or instructions that can be run on the processor, and when the programs or instructions are executed by the processor, the steps of the energy management method according to any one of claims 1 to 4 are implemented.

7. An energy storage system, characterized in that: include: Energy storage converter; The energy management system according to claim 6, connected to the energy storage converter.

8. A readable storage medium, characterized in that: The readable storage medium stores a program or instruction, and when the program or instruction is executed by a processor, the steps of the energy management method according to any one of claims 1 to 4 are implemented.

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