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

Abstract

The invention provides 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 comprising a bus, a PV controller, a DCDC bidirectional converter and an ACDC bidirectional converter. The method comprises the following steps: acquiring a working mode of the energy storage converter; obtaining the input power of the PV controller, the first working power of the off-grid load, 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 a voltage control strategy corresponding to the working mode and the power state. Therefore, the working module of the energy storage converter is decoupled and independently controlled, and the bus voltage is controlled and maintained only by a single module at any moment, so that the complexity of the control logic of the energy storage system is reduced, and the working reliability of the energy storage system is improved.

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] At present, in traditional household energy storage systems, energy is controlled by logical judgment, and its main feature is integrated control logic. In this type of logical judgment energy system solution, each working condition is a separate logic that needs to be debugged and tested, which makes software writing and debugging difficult, making the control logic more complex and difficult to debug. In addition, the above-mentioned integrated control logic will also cause chain failures when a single component of the system 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 inverter in an energy storage system. The energy storage inverter 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 inverter; obtaining the input power of the PV controller, and obtaining the first working power of the off-grid load connected to the energy storage inverter, 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; 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 inverter in an energy storage system, which includes a bus and a PV (Photo Voltaic) controller, a DCDC (Direct Current-Direct Current) bidirectional converter and an ACDC (Alternating Current-Direct Current) bidirectional converter respectively connected to the bus.

[0011] Specifically, in the energy management method provided by the present invention, during the operation of the energy storage inverter, the working mode of the energy storage inverter is obtained, the input power of the PV controller is obtained, and the first working power of the off-grid load connected to the energy storage inverter, the second working power of the energy storage battery pack, and the third working power of the power grid are obtained. Further, according to the obtained input power, the first working power, the second working power, and the third working power, the power state of the energy storage system is determined, and the power state can be used to indicate the power flow in the energy storage system. Further, according to the voltage control strategy corresponding to the above-mentioned working 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 working modules of the energy storage inverter are decoupled and independently controlled, and the bus voltage is controlled and maintained by only a single module at any time, which reduces the complexity of the control logic of the energy storage system and the difficulty of debugging, and improves the reliability and stability of the operation of the energy storage system.

[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-connected power and grid-offline power. The power state of the energy storage system is determined according to 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 inverter; 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 inverter.

[0014] In this technical solution, based on different working conditions, the 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 according to the input power, the first working power, the second working power and the third working 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 power 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 turns on the anti-reverse flow mode and does not allow feeding to the grid, 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. Further, 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 power 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 does not turn on the anti-reverse flow mode and allows feeding to the grid, 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 power 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. Wherein, in the third state, the energy storage battery pack transmits power to the energy storage inverter. Further, 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. Wherein, in the fourth state, the grid transmits power to the energy storage inverter. In this way, the anti-backflow logic is designed by considering whether the regional policy can be connected to the grid, and the energy flow direction of the system when there is no grid and the photovoltaic power is sufficient is also considered, which 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 the need to determine the power state of each module in turn.

[0016] In some technical schemes, optionally, the working mode includes a first working mode. In the first working mode, according to the voltage control strategy corresponding to the working mode and the power state, the bus voltage is controlled by one of the PV controller, the DCDC bidirectional converter and the ACDC bidirectional converter, 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 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.

[0017] In this technical solution, the working mode of the energy storage converter may specifically include a first working 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. Further, 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. Further, 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. Among them, 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 schemes, optionally, the working mode also includes a second working mode. In the second 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: 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 working mode of the energy storage converter may also specifically include a second working 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. Further, 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. Further, 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. Further, when the power state of the energy storage system is the fourth state, the bus voltage is controlled at a third voltage value by the ACDC bidirectional converter.

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

[0021] In this technical solution, the working mode of the energy storage converter may further include a third working mode, in which the working mode of the energy storage converter switches between the first working mode and the second working mode according to the mode switching instruction. On this basis, in the third working 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, the DCDC bidirectional converter and the ACDC bidirectional converter according to the voltage control strategy corresponding to the actual working mode and the power state.

[0022] In this way, in various working modes, the energy storage inverter 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, which 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, thereby reducing the energy management cost. At the same time, it is 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 inverter 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 acts 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. The PV controller is only used to maintain the energy demand of the energy storage battery pack and the off-grid load, and the ACDC bidirectional converter acts as an off-grid inverter to provide energy for the off-grid load. In addition, the bus voltage is controlled by the DCDC bidirectional converter, such as controlling the bus voltage at 220V or other voltage values ​​through the DCDC bidirectional converter to ensure the 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 inverter in an energy storage system. The energy storage inverter 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, which is used to acquire the working mode of the energy storage inverter; the acquisition unit is also used to acquire the input power of the PV controller, and acquire the first working power of the off-grid load connected to the energy storage inverter, the second working power of the energy storage battery pack, and the third working power of the power grid; a processing unit, which is used to determine 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; a control unit, which is used to control 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.

[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 bus bar and a PV controller, a DCDC bidirectional converter and an ACDC bidirectional converter respectively connected to the bus bar.

[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 inverter, the acquisition unit acquires the working mode of the energy storage inverter, acquires the input power of the PV controller, and acquires the first working power of the off-grid load connected to the energy storage inverter, the second working power of the energy storage battery pack, and the third working power of the power grid. Further, the processing unit determines the power state of the energy storage system according to the acquired input power, the first working power, the second working power and the third working power, and the power state can be used to indicate the power flow in the energy storage system. Further, 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 working mode and power state. In this way, the working modules of the energy storage inverter are decoupled and independently controlled, and the bus voltage is controlled and maintained by only a single module at any time, which reduces the complexity and debugging difficulty of the control logic of the energy storage system and improves the reliability and stability of the energy storage system.

[0028] According to the third aspect of the present invention, an energy management system is proposed, comprising a processor and a memory, wherein the memory stores a program or instruction that can be run on the processor, and when the program or instruction is executed by the processor, the steps of the energy management method in any of the above technical solutions are implemented. Therefore, the energy management system proposed in the third aspect of the present invention has all the beneficial effects of the energy management method in any of the above technical solutions in the first aspect, which will not be repeated here.

[0029] According to the fourth aspect of the present invention, an energy storage system is proposed, comprising: an energy storage inverter; the energy management system in the technical solution of the third aspect above, connected to the energy storage inverter. The energy storage system proposed in the fourth aspect of the present invention includes the energy management system in the technical solution of the third aspect above. Therefore, the energy storage system proposed in the fourth aspect of the present invention has all the beneficial effects of the energy management system in the technical solution of the third aspect above, which will not be repeated here.

[0030] According to the fifth aspect of the present invention, a readable storage medium is provided, on which a program or instruction is stored, and when the program or instruction is executed by a processor, an energy management method as in any of the above technical solutions is implemented. Therefore, the readable storage medium provided in the fifth aspect of the present invention has all the beneficial effects of the energy management method in any of the technical solutions in the first aspect, and will not be described in detail here.

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

[0032] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following 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 A schematic diagram of the structure of an energy storage converter in the related art is shown;

[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 A structural block diagram of an energy management device according to an embodiment of the present invention is shown;

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

[0041] Fig. 9 A structural block diagram of an energy storage system according to an embodiment of the present invention is shown;

[0042] Fig.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 purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments 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 protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0045] Combine the following 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, which is applied to an energy storage converter in an energy storage system, wherein the energy storage converter includes a bus and a PV controller connected to the bus, 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 working mode of the energy storage converter;

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

[0049] Step 106, determining a 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;

[0050] Step 108 , 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 working mode and the 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 bus bar and a PV controller, a DCDC bidirectional converter and an ACDC bidirectional converter respectively connected to the bus bar.

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

[0053] Specifically, in the energy management method provided by the present invention, during the operation of the energy storage inverter, the working mode of the energy storage inverter is obtained, the input power of the PV controller is obtained, and the first working power of the off-grid load connected to the energy storage inverter, the second working power of the energy storage battery pack, and the third working power of the power grid are obtained. Further, according to the obtained input power, the first working power, the second working power, and the third working power, the power state of the energy storage system is determined, and the power state can be used to indicate the power flow in the energy storage system. Further, according to the voltage control strategy corresponding to the above-mentioned working 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 working modules of the energy storage inverter are decoupled and independently controlled, and the bus voltage is controlled and maintained by only a single module at any time, which reduces the complexity of the control logic of the energy storage system and the difficulty of debugging, and improves the reliability and stability of the operation of the energy storage system.

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

[0055] Furthermore, when controlling the bus voltage, based on different working conditions, the bus voltage includes four voltage levels of 220V, 240V, 260V and 280V, which are ascending in sequence. Among them, the higher the voltage level of the bus voltage, the more sufficient the energy of the energy storage system, and the lower the voltage level of the bus voltage, the less energy the energy storage system has, and the energy flow needs to be restricted. In this way, once the difference between the voltage levels of the bus voltage is determined, the preset bus can be set, which is convenient for quickly finding the optimal point in project development, so that the efficiency is the highest and the loss is the lowest, which 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 inverter are decoupled, and when a certain module fails, the energy storage inverter can also work normally, and will not cause 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 less likely to occur, thereby reducing the risk of energy storage system jitter, increasing the overhead of the hysteresis loop, 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 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-connected power and grid-offline 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 the current is bidirectionally transmitted 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, determining 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, determining 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 inverter; in the fourth state, the power grid transmits power to the energy storage inverter.

[0064] In this embodiment, based on different working conditions, the 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-connected power and grid-offline power.

[0065] On this basis, in the process of 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 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 power 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 turns on the anti-reverse current mode and does not allow feeding to the grid, 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, when the input power of the PV controller is 16KW, the off-grid load power is 3KW, the battery charging power is 3KW, and the energy storage converter is in anti-reverse flow mode and does not allow grid feeding, the power state of the energy storage system is determined to be the first state, and the input power of the PV controller is limited. Alternatively, when the input power of the PV controller is 16KW, the off-grid load power is 3KW, the battery charging power is 10KW, and the energy storage converter is in anti-reverse flow mode and does not allow grid feeding, the power state of the energy storage system is determined to be the first state, and the input power of the PV controller 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 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 does not start the anti-reverse current 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 the remaining power of the PV controller to the grid.

[0068] For example, when the input power of the PV controller is 16KW, the off-grid load power is 3KW, the battery charging power is 3KW, and the energy storage converter does not start the anti-backflow mode and allows feeding into the grid, the power state of the energy storage system is determined to be the second state, and the remaining 10KW input power of the PV controller is fully fed into the grid. Alternatively, when the input power of the PV controller is 16KW, the off-grid load power is 3KW, the battery charging power is 10KW, and the energy storage converter does not start the anti-backflow mode and allows feeding into the grid, the power state of the energy storage system is determined to be the second state, and the remaining 3KW input power of the PV controller is fully fed into the grid.

[0069] Further, 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.

[0070] For example, when the input power of the PV controller is 4KW, the off-grid load power is 6KW, and the grid power is 2KW, the energy storage battery pack needs to discharge to supplement 4KW of power. At this time, the power state of the energy storage system is determined to be the third state. Alternatively, when the input power of the PV controller is 4KW, the off-grid load power is 6KW, and the grid power is 1KW, the energy storage battery pack needs to discharge to supplement 1KW of power. At this time, the power state of the energy storage system is determined to be the third state.

[0071] Further, 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 the fourth state, the power grid transmits power to the energy storage converter.

[0072] For example, when the input power of the PV controller is 4KW, the off-grid load power is 6KW, and the battery discharge power is 1KW, the grid needs to supplement 1KW of power offline, and at this time, the power state of the energy storage system is determined to be the fourth state. Alternatively, when the input power of the PV controller is 4KW, the off-grid load power is 6KW, and the battery charging power is 10KW, the grid needs to supplement 12KW of power offline, and at this time, the power state of the energy storage system is determined to be the fourth state.

[0073] In this way, the anti-backflow logic is designed by considering whether the regional policy can access the grid, and also considering the direction of energy flow when there is no grid and the photovoltaic power is sufficient, thus 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 in turn.

[0074] Among them, the above-mentioned off-grid loads can specifically be household appliances such as refrigerators and washing machines 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, the above step 108 may specifically include the following steps 108a to 108d:

[0076] Step 108a, in a first state, controlling the bus voltage at a first voltage value by a 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 working mode of the energy storage converter may specifically include a first working mode, which may specifically be a self-generation and self-use mode. In the self-generation and self-use mode, the voltage level of the bus voltage of each module 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 power state of the energy storage system is the first state, the bus voltage is controlled at the first voltage value by the PV controller. The first voltage value can be specifically 280V. For example, in the self-generation and self-use mode, when the input power of the PV controller is 16KW, the off-grid load power is 3KW, the battery charging power is 3KW, and the energy storage converter is turned on the anti-reverse flow mode and does not allow grid feeding, the input power of the PV controller is limited, and the bus voltage is controlled at 280V by the PV controller.

[0083] Furthermore, when the power state of the energy storage system is in the second state, the bus voltage is controlled at a second voltage value through the ACDC bidirectional converter. The second voltage value is less than the first voltage value, and the second voltage value can be specifically 260V. For example, in the self-generation and self-use mode, when the input power of the PV controller is 16KW, the off-grid load power is 3KW, the battery charging power is 3KW, and the energy storage converter is not in the anti-reverse flow mode and allows feeding into the grid, the remaining 10KW input power of the PV controller is fully fed into the grid, and the bus voltage is controlled at 260V through the ACDC bidirectional converter.

[0084] Furthermore, when the power state of the energy storage system is the third state, the bus voltage is controlled at a third voltage value through the DCDC bidirectional converter. The third voltage value is less than the second voltage value, and the third voltage value may be specifically 240V. For example, in the self-generation and self-use mode, when the input power of the PV controller is 4KW, the off-grid load power is 6KW, and the grid power is 2KW, the energy storage battery pack needs to discharge to supplement 4KW of power, and the bus voltage is controlled at 240V through the DCDC bidirectional converter.

[0085] 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 fourth voltage value is less than the third voltage value, and the fourth voltage value may be specifically 220V. For example, in the self-generation and self-use mode, when the input power of the PV controller is 4KW, the off-grid load power is 6KW, and the battery discharge power is 1KW, the grid needs to supplement 1KW of power offline, and the bus voltage is controlled at 220V by 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, the above step 108 may specifically include the following steps 108e to 108h:

[0087] Step 108e, in the first state, controlling the bus voltage at 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, controlling the bus voltage to a fourth voltage value through 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 working mode of the energy storage converter may further include a second working mode, which may be a battery priority mode. In the battery priority mode, the voltage level of the bus voltage of each module 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 power state of the energy storage system is the first state, the bus voltage is controlled at the first voltage value through the PV controller. For example, in the battery priority mode, when the input power of the PV controller is 16KW, the off-grid load power is 3KW, the battery charging power is 10KW, and the energy storage converter is turned on the anti-reverse flow mode and does not allow grid feeding, the input power of the PV controller is limited, and the bus voltage is controlled at 280V through the PV controller.

[0093] Furthermore, when the power state of the energy storage system is the second state, the bus voltage is controlled at the second voltage value through the ACDC bidirectional converter. For example, in the battery priority mode, when the input power of the PV controller is 16KW, the off-grid load power is 3KW, the battery charging power is 10KW, and the energy storage converter is not in the anti-reverse flow mode and allows grid feeding, the remaining 3KW input power of the PV controller is fully fed to the grid, and the bus voltage is controlled at 260V through the ACDC bidirectional converter.

[0094] 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. For example, in the battery priority mode, when the input power of the PV controller is 4KW, the off-grid load power is 6KW, and the off-grid power of the grid is 1KW, the energy storage battery pack needs to discharge to supplement 1KW of power, and the bus voltage is controlled at 220V by the DCDC bidirectional converter.

[0095] 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. For example, in the battery priority mode, when the input power of the PV controller is 4KW, the off-grid load power is 6KW, and the battery charging power is 10KW, the grid needs to supplement 12KW of power, and the bus voltage is controlled at 240V by the ACDC bidirectional converter.

[0096] In some embodiments of the present invention, optionally, the working mode further 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 above step 108 may specifically include the following step 108i:

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

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

[0099] On this basis, in the peak shaving and valley filling mode, the actual working mode of the energy storage inverter 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 the grid price is high, the BMS in the energy storage system controls the energy storage converter to operate in the self-generation and self-use mode to feed the grid to buy electricity. At this time, the bus voltage is controlled by the voltage control strategy corresponding to the self-generation and self-use mode. When the grid price is low, the BMS in the energy storage system controls the energy storage converter to operate in the battery priority mode. At this time, the bus voltage is controlled by the voltage control strategy corresponding to the battery priority mode.

[0101] In this way, in various working modes, the energy storage inverter 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, which 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, thereby reducing the energy management cost. At the same time, it is 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 connected to the grid, the PV controller does not control the bus voltage. The PV controller is only used to maintain the energy demand of the energy storage battery pack and the off-grid load, and the ACDC bidirectional converter acts as an off-grid inverter to provide energy for the off-grid load. In addition, the bus voltage is controlled by the DCDC bidirectional converter, such as controlling the bus voltage at 220V or other voltage values ​​by the DCDC bidirectional converter to ensure the 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 a bus voltage of 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 connected to the grid, if yes, execute step 208, if no, execute step 214;

[0109] Step 208, judging: whether the energy storage converter is in anti-backflow mode, if yes, executing step 210, if no, executing 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 of the PV controller, no matter what working mode the energy storage inverter is 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 at 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. Among them, 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 working process 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 yes, execute step 304, if no, execute step 310;

[0117] Step 304, determine: the energy storage converter is in the 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, controlling the bus voltage to 220V to provide an environment for the power grid to charge the energy storage battery pack;

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

[0121] Specifically, the DCDC bidirectional converter, as an intermediate between the battery and the bus, is mainly used to realize the charging and discharging of the energy storage battery pack. The DCDC bidirectional converter can automatically adjust the voltage level of the bus voltage according to different working modes to realize the bidirectional flow of energy from high to low. Among them, in the self-generation and self-use mode, the DCDC bidirectional converter sets the bus voltage to 240V, and in the battery priority mode, the DCDC bidirectional converter sets the bus 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: the energy storage converter is grid-connected, if yes, execute step 404, if no, execute step 410;

[0124] Step 404, determine: the energy storage converter is in the 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 the energy of the PV controller and the energy storage battery pack flows to the grid or off-grid load;

[0126] Step 408, controlling the bus voltage upper limit to 260V and lower limit to 240V, so that the energy of the power 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 interactive body between the bus, off-grid loads and the power grid. When energy flows to the off-grid load or the power grid, the ACDC bidirectional converter is used as an inverter to provide stable AC power; when energy flows from the power grid to the bus, the ACDC bidirectional converter is used as a rectifier to extract power from the power grid to maintain the bus for charging the energy storage battery pack. Among them, when the ACDC bidirectional converter acts as an inverter, it is not necessary for it to control the bus voltage. When the bus has sufficient support capacity to maintain, it can perform stable inverter operation. When the ACDC bidirectional converter acts as a rectifier, the ACDC bidirectional converter adjusts the bus voltage according to the working mode. Among them, in the self-generation and self-use mode, the ACDC bidirectional converter sets the bus voltage upper limit to 260V and the lower limit to 220V; in the battery priority mode, the ACDC bidirectional converter sets the bus voltage upper limit to 260V and the lower limit to 240V; when the energy storage converter operates normally, the real-time bus voltage value is 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 DCDC bidirectional converter performs power control.

[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 bus and a PV controller connected to the bus, a DCDC bidirectional converter, and an ACDC bidirectional converter. Figure 7 As shown, Figure 7 The energy management device 700 of the embodiment of the present invention is shown in the structural block diagram. The energy management device 700 may specifically include the following acquisition unit 702, processing unit 704 and control unit 706:

[0130] An acquisition unit 702 is used to acquire the working mode of the energy storage converter;

[0131] The acquisition unit 702 is further used to acquire the input power of the PV controller, and acquire 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 grid;

[0132] The processing unit 704 is used to determine 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;

[0133] The control unit 706 is used 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 working mode and the 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 bus and a PV controller, a DCDC bidirectional converter and an ACDC bidirectional converter respectively connected to the bus.

[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 the operation of the energy storage converter, the acquisition unit 702 acquires the working mode of the energy storage converter, acquires the input power of the PV controller, and acquires 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. Further, the processing unit 704 determines the power state of the energy storage system according to the acquired input power, the first working power, the second working power and the third working power, and the power state can be used to indicate the power flow in the energy storage system. Further, the control unit 706 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 working mode and power state. In this way, the working 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, which reduces the complexity and debugging difficulty of the control logic of the energy storage system and improves the reliability and stability of the energy storage system.

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

[0137] Furthermore, when controlling the bus voltage, based on different working conditions, the bus voltage includes four voltage levels of 220V, 240V, 260V and 280V, which are ascending in sequence. Among them, the higher the voltage level of the bus voltage, the more sufficient the energy of the energy storage system, and the lower the voltage level of the bus voltage, the less energy the energy storage system has, and the energy flow needs to be restricted. In this way, once the difference between the voltage levels of the bus voltage is determined, the preset bus can be set, which is convenient for quickly finding the optimal point in project development, so that the efficiency is the highest and the loss is the lowest, which 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-connected power and grid-offline 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 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 inverter; 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 inverter.

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

[0141] In some embodiments of the present invention, optionally, the working mode also includes a third working mode. In the third working mode, the working mode of the energy storage inverter is switched between the first working mode and the second working mode according to the mode switching instruction. In the third working 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 working 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 inverter 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 The structure block diagram of the energy management system 800 provided by the embodiment of the present invention is shown. The energy management system 800 includes:

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

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

[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 provided. Fig. 9 As shown, Fig. 9 The structure block diagram of the energy storage system 900 provided in the embodiment of the present invention is shown. The energy storage system 900 includes an energy storage converter 902 and the energy management system 800 in the above embodiment. Therefore, the energy storage system 900 has all the technical effects of the energy management system 800 in the above embodiment, which will not be described in detail here.

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

[0150] Furthermore, the energy storage inverter 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 inverter 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 inverter 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 for charging the energy storage battery pack.

[0152] Furthermore, the energy storage system 900 may also include a BMS (Battery Management System). The battery management system is used to monitor the voltage, current, temperature and other parameters of the energy storage battery pack in real time to ensure that the energy storage battery pack operates in a safe and efficient state. The battery management system can also be used to balance the charge and discharge of the energy storage battery pack to protect the energy storage battery pack from abnormal operating conditions such as overcharge, over discharge, short circuit, etc., thereby extending the service life of the energy storage battery pack.

[0153] Furthermore, EMS (Energy Management System) is an intelligent control system in the energy storage system, which is responsible for the management and scheduling of 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, electric 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 control strategy in the energy storage system 900 is the core of the entire energy storage device, which controls the energy flow direction and size of the energy storage system 900 in different working modes, thereby reasonably scheduling local energy to ensure the availability and economy of the home energy storage device. At the same time, the energy management control strategy also enables the home energy storage device to assist in the scheduling and supply of external power grid energy, providing support for the stability of the regional power grid.

[0155] Furthermore, in the energy storage system 900, solar panels or photovoltaic panels, as one of the energy sources, have been providing energy to the energy storage system 900, but their energy intensity will be affected by the light intensity and cannot be guaranteed to be stable at all times. As a stable energy supply for the energy storage system 900, the energy storage battery pack can both release energy and absorb energy. It 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 is widely used, and the laws and regulations of different regions determine whether the energy storage system 900 can deliver energy to the power grid, its energy management control logic becomes very complicated. The energy storage system 900 proposed in the present invention includes the above-mentioned energy management system 800, which can simplify the energy management control logic of the energy storage system 900.

[0156] In some embodiments, the energy storage system 900 is a household energy storage system, or a balcony photovoltaic energy storage system. Among them, the household energy storage system is usually relatively large, and its position after installation is relatively fixed and cannot be moved. The power capacity is relatively large, and the power provided is relatively large, which can meet the simultaneous use of most household electrical appliances; while the balcony photovoltaic energy storage system is relatively small and easy to carry and move. It can be moved according to the user's power demand, such as from the balcony to the garage or even outdoors, etc. The power capacity is relatively small, and the power provided is also relatively small, which can be used by some household electrical appliances.

[0157] For example, Fig.10 As shown, the home energy storage system includes a rooftop photovoltaic tile system, a hybrid inverter, a high-voltage battery, an intelligent distribution box, and a home energy management cloud. Among them, the rooftop photovoltaic tile system is connected to the intelligent distribution box, and the rooftop photovoltaic tile system specifically adopts a curved photovoltaic tile string connection method to fully utilize solar energy while retaining the aesthetic design of the family house. Further, the intelligent distribution box is the energy dispatching center of the entire home energy storage system. With its powerful energy management system, it flexibly and intelligently performs energy management and distribution of the home energy storage system. Further, the home energy management cloud includes a user APP (Application) and a WEB (network) terminal, which can monitor the real-time power output, usage, and power saving data of the home energy storage system. Further, the high-voltage battery is connected to the hybrid inverter, the hybrid inverter is connected to the intelligent distribution box, and the intelligent distribution box is connected to the load and the power grid. The power of the power grid, the rooftop photovoltaic tile system, and the high-voltage battery can be intelligently managed through the home energy management cloud. The power generated by the rooftop photovoltaic tile system can be delivered to the load, or stored in the high-voltage battery for standby, or the excess power can be fed back to the power grid in accordance with local regulations.

[0158] In one embodiment of the present invention, a readable storage medium is also 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 by the embodiment of the present invention can implement the steps of the energy management method in any of the above embodiments when the program or instruction stored therein is executed by the processor. Therefore, the readable storage medium has all the beneficial effects of the energy management method in any of the above embodiments, which will not be repeated 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 disk, 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 the description of this specification, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance unless otherwise clearly specified and limited; the terms "connection", "installation", "fixation" and the like should be understood in a broad sense, for example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0162] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[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 the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0164] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An energy management method, characterized in that: An energy storage converter applied to an energy storage system, the energy storage converter comprising a bus and a PV controller, a DCDC bidirectional converter and an ACDC bidirectional converter connected to the bus, the energy management method comprising: Obtaining the operating 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 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; According to a voltage control strategy corresponding to the operation mode and the power state, a bus voltage is controlled by one of the PV controller, the DCDC bidirectional converter, and the ACDC bidirectional converter.

2. The energy management method according to claim 1, characterized in that: The first working power includes off-grid load power, the second working power includes battery charging power and battery discharging power, the third working power includes grid on-grid power and grid off-grid power, and 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 includes: 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 power 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, 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 power grid transmits power to the energy storage inverter.

3. The energy management method according to claim 2, characterized in that: The working mode includes a first working mode, in which the bus voltage is controlled by one of the PV controller, the DCDC bidirectional converter and the ACDC bidirectional converter according to a voltage control strategy corresponding to the working 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 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; 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.

4. The energy management method according to claim 3, characterized in that: The working mode further includes a second working mode, in which the bus voltage is controlled by one of the PV controller, the DCDC bidirectional converter and the ACDC bidirectional converter according to a voltage control strategy corresponding to the working mode and the power state, including: In the first state, the bus voltage is controlled at the first voltage value by the PV controller; In the second state, the bus voltage is controlled at the second voltage value by the ACDC bidirectional converter; In the third state, the bus voltage is controlled at 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.

5. The energy management method according to claim 4, characterized in that: 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 a 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 a voltage control strategy corresponding to the working mode and the power state, including: According to the working mode corresponding to the mode switching instruction and the voltage control strategy corresponding to the power state, the bus voltage is controlled through one of the PV controller, the DCDC bidirectional converter and the ACDC bidirectional converter.

6. The energy management method according to any one of claims 1 to 5, 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 by the PV controller, and the ACDC bidirectional converter serves as an off-grid inverter to provide energy to the off-grid load.

7. An energy management device, characterized in that: An energy storage converter used in an energy storage system, the energy storage converter comprising a bus and a PV controller, a DCDC bidirectional converter and an ACDC bidirectional converter connected to the bus, the energy management device comprising: An acquisition unit, used for acquiring the working mode of the energy storage converter; The acquisition unit is further used to acquire the input power of the PV controller, and acquire the first working power of the off-grid load connected to the energy storage inverter, the second working power of the energy storage battery pack, and the third working power of the power grid; a processing unit, configured to determine a 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; A control unit is used 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 working mode and the power state.

8. 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 6 are implemented.

9. An energy storage system, characterized in that: include: Energy storage converter; The energy management system as claimed in claim 8, connected to the energy storage inverter.

10. 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 6 are implemented.

Images