Energy storage system and control method and controller thereof

Abstract

The invention discloses an energy storage system and a control method and a controller thereof, the energy storage system comprises a hybrid inverter and a battery system, the hybrid inverter is suitable for being connected with the battery system, and the control method of the energy storage system comprises the following steps: obtaining the type of the hybrid inverter; under the condition that the parameters of the battery system are matched with the type, the hybrid inverter is controlled to work; wherein the parameter is used for representing the output voltage of the battery system. Therefore, according to the method, whether the parameters of the battery system and the type of the hybrid inverter are matched or not can be automatically judged based on the parameters of the battery system and the type of the hybrid inverter, and the hybrid inverter is controlled to work under the condition that the parameters of the battery system are matched with the type, so that manual participation is reduced, and the application cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of energy storage system technology, and in particular to a control method for an energy storage system, a controller, and an energy storage system. Background Technology

[0002] Currently, the energy storage system market offers a variety of product forms. For example, based on form, they can be divided into integrated units and split units; based on the number of AC output phases, they can be divided into single-phase inverter products and three-phase inverter products; and based on the voltage range of the energy storage battery, they can be divided into low-voltage battery products and high-voltage battery products.

[0003] Due to the diversity of products in energy storage systems, customers need to place orders by category when ordering products, and installers also need to manually identify and determine compatibility during the installation process. As a result, a lot of manpower, material resources and financial resources are required to build energy storage systems. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, the first objective of this invention is to propose a control method for an energy storage system. After a hybrid inverter is connected to a battery system, the method can automatically determine whether the two are compatible based on the parameters of the battery system and the type of the hybrid inverter. If the parameters and type of the battery system are determined to be compatible, the method controls the operation of the hybrid inverter, thereby reducing manual intervention and lowering application costs.

[0005] The second objective of this invention is to provide a controller.

[0006] The third objective of this invention is to provide an energy storage system.

[0007] To achieve the above objectives, a first aspect of the present invention provides a control method for an energy storage system, the energy storage system including a hybrid inverter and a battery system, the hybrid inverter being adapted to be connected to the battery system, the control method for the energy storage system including: obtaining the type of the hybrid inverter; and controlling the operation of the hybrid inverter when the parameters of the battery system match the type; wherein the parameters are used to characterize the output voltage of the battery system.

[0008] According to an embodiment of the present invention, a control method for an energy storage system includes a hybrid inverter and a battery system. The hybrid inverter is adapted to be connected to the battery system. The method obtains the type of the hybrid inverter and controls the operation of the hybrid inverter when the parameters of the battery system match the type. The parameters characterize the output voltage of the battery system. Therefore, after the hybrid inverter and battery system are connected, the method can automatically determine whether they match based on the parameters of the battery system and the type of the hybrid inverter. If the parameters of the battery system match the type, the method controls the operation of the hybrid inverter, thereby reducing manual intervention and lowering application costs.

[0009] In addition, the control method for the energy storage system according to the above embodiments of the present invention may also have the following additional technical features:

[0010] According to one embodiment of the present invention, the battery system is a high-voltage battery system, which includes multiple high-voltage battery modules connected in series. The control method of the energy storage system further includes: acquiring attribute parameters of the multiple high-voltage battery modules; and determining whether the parameters and type of the battery system match based on the attribute parameters; wherein the attribute parameters include the number of multiple high-voltage battery modules / total output voltage.

[0011] According to one embodiment of the present invention, the type includes single-phase or three-phase. Determining whether the parameters and type of the battery system match based on attribute parameters includes: determining that the parameters and type of the battery system match when the attribute parameters are greater than or equal to a first parameter threshold and less than a second parameter threshold, and the type is single-phase; determining that the parameters and type of the battery system match when the attribute parameters are greater than or equal to the second parameter threshold and less than or equal to a third parameter threshold; and determining that the parameters and type of the battery system match when the attribute parameters are greater than the third parameter threshold and less than or equal to a fourth parameter threshold, and the type is three-phase; wherein the first parameter threshold < the second parameter threshold < the third parameter threshold < the fourth parameter threshold.

[0012] According to one embodiment of the present invention, multiple high-voltage battery modules have the same voltage level. When the attribute parameters include quantity, the control method of the energy storage system further includes: obtaining the voltage level of the high-voltage battery modules; and determining a first parameter threshold, a second parameter threshold, a third parameter threshold, and a fourth parameter threshold based on the voltage level and type.

[0013] According to one embodiment of the present invention, the battery system is a low-voltage battery system, which includes a low-voltage battery and a first DC-DC (Direct Current-Direct Current) module. The control method of the energy storage system further includes: sending a type to the first DC-DC module so that the first DC-DC module outputs a target voltage based on the type, so that the parameters of the battery system match the type.

[0014] According to one embodiment of the present invention, the type includes single-phase or three-phase. In the case of single-phase, the target voltage is greater than or equal to a first voltage threshold and less than or equal to a third voltage threshold; in the case of three-phase, the target voltage is greater than or equal to a second voltage threshold and less than or equal to a fourth voltage threshold; wherein, if the first DC-DC module does not receive the type, the target voltage is greater than or equal to the second voltage threshold and less than or equal to the third voltage threshold; wherein, the first voltage threshold < the second voltage threshold < the third voltage threshold < the fourth voltage threshold.

[0015] According to one embodiment of the present invention, the first DC-DC module determines its own switching frequency and / or gain based on its type, wherein the gain is the ratio of the output voltage to the input voltage of the first DC-DC module.

[0016] To achieve the above objectives, a second aspect of the present invention provides a controller, including a memory, a processor, and a control program for an energy storage system stored in the memory and executable on the processor. When the processor executes the control program for the energy storage system, it implements the above-described control method for the energy storage system.

[0017] According to the controller of the present invention, when the processor executes the control program of the energy storage system, the above-described control method of the energy storage system is implemented. Based on the above control method, it is possible to automatically determine whether the battery system parameters and the hybrid inverter type are matched, and control the hybrid inverter to work when it is determined that the battery system parameters and type are matched, thereby reducing manual intervention and lowering application costs.

[0018] To achieve the above objectives, a third aspect of the present invention provides an energy storage system, comprising: a battery system; a hybrid inverter adapted to be connected to the battery system, the hybrid inverter further comprising a controller; wherein the controller is used to acquire the type of the hybrid inverter and control the operation of the hybrid inverter when the parameters of the battery system match the type; wherein the parameters are used to characterize the output voltage of the battery system.

[0019] According to an embodiment of the energy storage system of the present invention, a hybrid inverter is adapted to be connected to a battery system. The hybrid inverter further includes a controller, which is used to acquire the type of the hybrid inverter and control the operation of the hybrid inverter when the parameters of the battery system match the type. The parameters characterize the output voltage of the battery system. Thus, the energy storage system can automatically determine whether the battery system parameters and the hybrid inverter type match, and control the operation of the hybrid inverter when it is determined that the battery system parameters and type match, thereby reducing manual intervention and lowering application costs.

[0020] In addition, the energy storage system according to the above embodiments of the present invention may also have the following additional technical features:

[0021] According to one embodiment of the present invention, the battery system is a high-voltage battery system, which includes multiple high-voltage battery modules connected in series, and the hybrid inverter is adapted to connect the multiple high-voltage battery modules; the controller is further configured to acquire attribute parameters of the multiple high-voltage battery modules, and determine whether the parameters and type of the battery system match based on the attribute parameters; wherein, the attribute parameters include the number of multiple high-voltage battery modules / total output voltage.

[0022] According to one embodiment of the present invention, the battery system is a low-voltage battery system, which includes a low-voltage battery and a first DC-DC module connected to the low-voltage battery. A hybrid inverter is adapted to connect to the first DC-DC module. The controller is further configured to send a type to the first DC-DC module so that the first DC-DC module outputs a target voltage based on the type, so that the parameters of the battery system match the type.

[0023] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the architecture of an energy storage system in related technologies. Figure 1 ;

[0025] Figure 2 This is a schematic diagram of the architecture of an energy storage system in related technologies. Figure 2 ;

[0026] Figure 3 This is a schematic diagram of the architecture of an energy storage system in related technologies. Figure 3 ;

[0027] Figure 4 This is a connection diagram of an energy storage system according to an embodiment of the invention;

[0028] Figure 5 This is a connection diagram of an energy storage system according to an embodiment of the invention, where the battery system is a high-voltage battery system.

[0029] Figure 6 This is a connection diagram of an energy storage system according to an embodiment of the present invention, in the case where the battery system is a low-voltage battery system;

[0030] Figure 7 This is a schematic diagram of the architecture of an energy storage system according to a specific embodiment of the present invention;

[0031] Figure 8 This describes the relationship between different input voltage levels applicable to different inverters according to an embodiment of the present invention;

[0032] Figure 9 A flowchart of a control method for an energy storage system according to an embodiment of the present invention;

[0033] Figure 10 This is a schematic diagram of the architecture of an energy storage system when the battery system is a high-voltage battery system, according to an embodiment of the present invention;

[0034] Figure 11 This is a schematic diagram of the architecture of an energy storage system when the battery system is a low-voltage battery system, according to an embodiment of the present invention;

[0035] Figure 12 A circuit diagram of a first DC-DC module according to a specific embodiment of the present invention;

[0036] Figure 13 This is a schematic diagram illustrating the relationship between the output voltage and switching frequency of a first DC-DC module according to a specific embodiment of the present invention.

[0037] Figure 14 This is a flowchart of a control method according to a specific embodiment of the present invention when the battery system is a high-voltage battery system;

[0038] Figure 15 This is a flowchart of a control method for an energy storage system when the battery system is a low-voltage battery system, according to another specific embodiment of the present invention;

[0039] Figure 16 This is a control flowchart of a first DC-DC module according to a specific embodiment of the present invention;

[0040] Figure 17 This is a block diagram of a controller according to an embodiment of the present invention;

[0041] Figure 18 This is a connection diagram of an energy storage system according to an embodiment of the present invention. Detailed Implementation

[0042] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0043] The control method, controller, and energy storage system of the energy storage converter proposed in the embodiments of the present invention are described below with reference to the accompanying drawings.

[0044] As a new type of clean energy, wind and solar energy will become the absolute main energy source in the future. However, due to the discontinuous, unstable and uncontrollable characteristics of renewable energy power generation such as wind and solar power, large-scale grid connection will seriously impact the safe and stable operation of the grid. Therefore, energy storage technology, as one of the important supporting technologies, is an important means to smooth out the fluctuations of new energy and reduce the impact of large-scale new energy access on the grid.

[0045] Currently, the residential photovoltaic and energy storage market offers a wide variety of product forms. In terms of form, they can be divided into integrated units and split units; in terms of the number of AC output phases, they can be divided into single-phase products and three-phase products; and in terms of the voltage range of the energy storage battery, they can be divided into low-voltage battery products and high-voltage battery products. The types are numerous and each has its own advantages.

[0046] Throughout the entire lifecycle of a photovoltaic energy storage system, including product development, sales, and maintenance, all stakeholders, including suppliers, customers, and installers, desire a product that is compatible with a wider range of application scenarios to facilitate storage, management, and maintenance. Currently, most system architectures on the market cannot meet the requirement of adapting high-voltage and low-voltage battery systems to the same inverter. Customers need to place orders separately, and significant human, material, and financial resources are required for transportation, storage, and management.

[0047] Currently, products on the market are mainly divided into the following architectures:

[0048] 1) Architecture 1: Low-voltage battery + DC-DC converter + inverter, such as Figure 1 As shown. However, this architecture only supports low-voltage battery systems and cannot use high-voltage battery systems, resulting in high costs, weak competitiveness, and an inability to meet increasingly diverse customer needs;

[0049] 2) Architecture 2: Low-voltage battery + hybrid inverter, such as Figure 2 As shown. However, this architecture only supports low-voltage battery systems and cannot use high-voltage battery systems. In addition, the bidirectional two-stage DC-DC hybrid inverter is bulky and heavy, which cannot meet the needs of one person to install it independently, and the cost is high.

[0050] 3) Architecture 3: High-voltage battery + hybrid inverter, such as Figure 3 As shown. However, this architecture only supports high-voltage battery systems and cannot be adapted to low-voltage battery systems.

[0051] The above-mentioned architecture schemes cannot achieve compatibility between high-voltage and low-voltage battery systems (architecture 1, architecture 2, architecture 3), and for energy storage circuits, they cannot adaptively identify single-phase and three-phase inverters.

[0052] To address this, this application proposes a system architecture for an energy storage system that can be adapted to both high-voltage and low-voltage batteries. The hybrid inverter in this energy storage system can be adapted to either a low-voltage or high-voltage battery system using the same inverter. The energy storage system of this application will be described in detail below with reference to the accompanying drawings.

[0053] The present application will now be described in detail with reference to the accompanying drawings.

[0054] like Figure 4 As shown, in one embodiment of the present invention, the energy storage system 1000 includes a hybrid inverter 200 and a battery system 100, wherein the hybrid inverter 200 is adapted to be connected to the battery system 100.

[0055] Specifically, the energy storage system 1000 is a device or system for storing energy, which can store excess energy (such as thermal energy, kinetic energy, electrical energy, potential energy, chemical energy, etc.) and release it when needed. Taking the energy storage system 1000 as a photovoltaic energy storage system as an example, the DC side of the hybrid inverter 200 is connected to the photovoltaic modules and battery system 100, and the AC side of the hybrid inverter 200 is connected to the mains and AC power grid.

[0056] The hybrid inverter 200 can internally include an energy storage DC-DC module, a PV (Photovoltaic) conversion circuit module, an inverter circuit module, and a control sampling module. The hybrid inverter 200 can be either a single-phase inverter or a three-phase inverter. The operating performance of single-phase and three-phase inverters differs, leading to different application scenarios. For example, the output current types differ: a single-phase inverter outputs a single-phase current (only one phase), while a three-phase inverter outputs a current with three phases, providing a more stable and reliable power supply; the output power also differs: single-phase inverters typically have lower output power, suitable for low-power applications, while three-phase inverters have a wider output power range, suitable for high-power applications; and the applicable input voltage ranges differ as well.

[0057] The battery system 100 can be a high-voltage battery system or a low-voltage battery system. The high-voltage battery system consists of high-voltage batteries with a voltage greater than 1.5V, while the low-voltage battery system consists of low-voltage batteries with a voltage less than 1.5V.

[0058] Furthermore, in combination Figures 4-7As shown, taking the energy storage system 1000 as a photovoltaic energy storage system as an example, the DC side of the hybrid inverter 200 is connected to the photovoltaic module 300 and the battery system 100, while the AC side of the hybrid inverter 200 is connected to the load and the AC power grid (i.e., external power source). Both the photovoltaic module 300 and the battery system 100 are connected to the DC bus of the hybrid inverter 200. It can be understood that the battery system 100 can output electrical energy to power the load connected to the hybrid inverter 200, the AC power grid connected to the hybrid inverter 200 (i.e., external power source) can also charge the battery system 100, and the electrical energy output by the photovoltaic module 300 can also power the battery system 100.

[0059] The hybrid inverter 200 includes a second DC-DC module 210, a DC-AC module 220, and a third DC-DC module 230. The second DC-DC module 210 can be a two-stage unidirectional module, the DC-AC module 220 is a bidirectional inverter module, and the third DC-DC module 230 can be a PV Boost module. The DC power output from the photovoltaic module 300 is converted and output to the DC bus through the third DC-DC module 230.

[0060] When the battery system 100 is a high-voltage battery system, such as Figure 5 As shown, the high-voltage battery system includes a high-voltage battery 110, which is directly connected to the second DC-DC module 210. When the second DC-DC module 210 is in the start-up state, the energy in the high-voltage battery 110 can be output to the DC bus.

[0061] When the battery system 100 is a low-voltage battery system, such as Figure 6 As shown, the low-voltage battery system includes a low-voltage battery 120 and a first DC-DC module 130, wherein the first DC-DC module 130 can be a single-stage isolated DC module. When the hybrid inverter 200 is connected to the low-voltage battery system, the low-voltage battery 120 in the low-voltage battery system is first connected to the first DC-DC module 130, and then the first DC-DC module 130 is connected to the second DC-DC module 210 to complete the connection between the low-voltage battery system and the hybrid inverter 200. When both the first DC-DC module 130 and the second DC-DC module 210 are in the startup state, the energy in the low-voltage battery 120 can be output to the DC bus. A specific implementation example is... Figure 7 As shown.

[0062] When the DCAC module 220 supplies power to the load, the DCAC module 220 draws power from the DC bus and converts the output to the external load and / or power grid.

[0063] Therefore, the hybrid inverter 200 in the energy storage system 1000 can be adapted to both high-voltage and low-voltage battery systems, and the application technology of the first DC-DC module 130 in the low-voltage battery system is low, the development cycle is short, and the application cost is reduced.

[0064] Furthermore, for the input ports of hybrid inverters connected to high-voltage or low-voltage battery systems, different types of inverters have different applicable input voltage ranges, such as... Figure 8 As shown, the applicable input voltage range for a single-phase inverter is V1≤V≤V3, and the applicable input voltage range for a three-phase inverter is V2≤V≤V4, where V1<V2<V3<V4. Here, [V1, V2) is the input voltage range applicable only to single-phase inverters, (V3, V4) is the input voltage range applicable only to three-phase inverters, and [V2, V3] is the input voltage range applicable to both.

[0065] Because single-phase inverters have lower DC bus voltages while three-phase inverters have higher DC bus voltages, the energy storage modules used with single-phase and three-phase inverters differ in the relevant technology architecture. This necessitates separate development, production, warehousing, transportation, sales, and maintenance, significantly increasing application costs. Therefore, this application proposes a control method for an energy storage system to achieve automatic matching and identification between the battery system and the hybrid inverter, reducing manual intervention, improving work efficiency, and lowering application costs.

[0066] The control method of the energy storage system of this application will be described in detail below with reference to the accompanying drawings.

[0067] like Figure 9 As shown, the control method for the energy storage system in this embodiment of the invention may include:

[0068] S1, obtain the type of hybrid inverter;

[0069] S2 controls the operation of the hybrid inverter when the parameters and type of the battery system are matched; the parameters are used to characterize the output voltage of the battery system.

[0070] Specifically, the type of hybrid inverter can be determined by identifying the preset single-phase and three-phase identification flags. For example, the flag bit of a single-phase inverter is flag_single=1, and the flag bit of a three-phase inverter is flag_three=1.

[0071] Matching the battery system parameters with the type means that the battery system's output voltage is within the applicable range of the input voltage corresponding to the type of hybrid inverter. These battery system parameters can be the total output voltage of the battery system, or controllable parameters that determine the total output voltage, such as switching frequency and the number of battery modules. During application, a preset mapping relationship between the battery system parameters and the hybrid inverter type can be established in advance. After installation, a table can be directly consulted to determine if a match is found. Alternatively, after installation, the parameter range corresponding to the type can be calculated in real time based on feedback information to determine if the battery system parameters are within that range, thus determining whether the battery system parameters match the type. There are no specific restrictions on the method used.

[0072] Taking the total output voltage of the battery system as an example, the applicable input voltage range for a single-phase inverter is V1≤V≤V3, and the applicable input voltage range for a three-phase inverter is V2≤V≤V4, where V1<V2<V3<V4. Specifically... Figure 8 As shown, when the total output voltage is within the range of V1-V2, it is determined that the total output voltage of the battery system is within the applicable range of the input voltage of the single-phase inverter. If it is determined that the type of the hybrid inverter is single-phase, it is considered that the battery system and the type of the hybrid inverter are matched, and the hybrid inverter is controlled to start working. If it is determined that the type of the hybrid inverter is three-phase, it is considered that the battery system and the type of the hybrid inverter are not matched, the hybrid inverter is controlled to not work, and a reminder signal can be issued at the same time.

[0073] This embodiment can automatically determine whether the hybrid inverter and the battery system are compatible based on the parameters of the battery system and the type of the hybrid inverter after the hybrid inverter is connected. If the parameters and type of the battery system are determined to be compatible, the hybrid inverter is controlled to work, thereby reducing manual intervention and lowering application costs.

[0074] In one embodiment of the present invention, the battery system is a high-voltage battery system, which includes multiple high-voltage battery modules connected in series. The control method of the energy storage system further includes: acquiring attribute parameters of the multiple high-voltage battery modules; and determining whether the parameters of the battery system match the type of the hybrid inverter based on the attribute parameters. The attribute parameters include the number of multiple high-voltage battery modules / total output voltage.

[0075] like Figure 10 As shown, the high-voltage battery system and the hybrid inverter have a power interface POWER and a communication interface COM. The high-voltage battery system and the hybrid inverter realize power transmission and communication through the power interface POWER and the communication interface COM.

[0076] Specifically, for high-voltage battery systems, different voltage output levels can be achieved by cascading different numbers of high-voltage battery modules. Thus, the attribute parameters of multiple high-voltage battery modules can be the number of high-voltage battery modules in the high-voltage battery system. The total output voltage of the high-voltage battery system can be characterized by the number of high-voltage battery modules, or the total output voltage of multiple high-voltage battery modules in the high-voltage battery system can be directly used as the attribute parameter to determine whether the total output voltage of the high-voltage battery system matches the applicable range of the input voltage corresponding to the type of hybrid inverter. If they match, the hybrid inverter is controlled to work.

[0077] In a high-voltage battery system, if the voltage level of each high-voltage battery module is 'a', then a single-phase inverter can be configured with m1-m3 modules, and a three-phase inverter can be configured with m2-m4 modules, where m1 < m2 < m3 < m4. Therefore, [m1, m2) represents the range of modules that can be configured for a single-phase inverter, (m3, m4) represents the range of modules that can be configured only for a three-phase inverter, and [m2, m3] represents the range of modules that can be configured for both types of inverters.

[0078] Taking the number of multiple high-voltage battery modules as an example, if the number of multiple high-voltage battery modules is in the range [m1, m2), then if the hybrid inverter is of single-phase type, it is considered that the parameters of the battery system match the type of the hybrid inverter, and the hybrid inverter is controlled to work; if the hybrid inverter is of three-phase type, it is considered that the parameters of the battery system do not match the type of the hybrid inverter, the hybrid inverter is controlled not to work, and a reminder is issued.

[0079] In one embodiment of the present invention, the hybrid inverter type includes single-phase or three-phase. Based on attribute parameters, determining whether the battery system parameters match the type includes: determining that the battery system parameters match the type when the attribute parameters are greater than or equal to a first parameter threshold and less than a second parameter threshold, and the type is single-phase; determining that the battery system parameters match the type when the attribute parameters are greater than or equal to the second parameter threshold and less than or equal to a third parameter threshold; and determining that the battery system parameters match the type when the attribute parameters are greater than the third parameter threshold and less than or equal to a fourth parameter threshold, and the type is three-phase; wherein the first parameter threshold < the second parameter threshold < the third parameter threshold < the fourth parameter threshold.

[0080] Specifically, taking the number of high-voltage battery modules as an example, the threshold values ​​for the first parameter are m1, the second parameter is m2, the third parameter is m3, and the fourth parameter is m4, where m1 < m2 < m3 < m4.

[0081] Combination Figure 10As shown, assuming the high-voltage battery system includes n high-voltage battery modules, denoted as high-voltage battery module 1, high-voltage battery module 2, ..., high-voltage battery module n respectively. If m1≤n<m2, and the hybrid inverter is a single-phase inverter, then the parameters and type of the battery system are determined to match. If m2≤n≤m3, then the number of high-voltage battery modules is determined to be within the intersection range of the configurable module numbers for single-phase and three-phase inverters, and it is considered to be compatible with both types of inverters. In this case, regardless of the type of hybrid inverter, it is considered a match. If m3<n≤m4, and the type of hybrid inverter is a three-phase inverter, then the parameters of the battery system are determined to match the type of hybrid inverter.

[0082] In one embodiment of the present invention, multiple high-voltage battery modules have the same voltage level. When the attribute parameter includes quantity, the control method of the energy storage system further includes: obtaining the voltage level of the high-voltage battery modules; and determining a first parameter threshold, a second parameter threshold, a third parameter threshold, and a fourth parameter threshold based on the voltage level and type.

[0083] For example, when the voltage level of the high-voltage battery module is 'a', and the hybrid inverter type is single-phase, the number of configurable modules corresponding to the single-phase inverter can be determined as m1-m3 based on the applicable range and voltage level of the input voltage corresponding to the single-phase inverter, thus determining the first parameter threshold as m1 and the third parameter threshold as m3. When the hybrid inverter type is three-phase, the number of configurable modules corresponding to the three-phase inverter can be determined as m2-m4 based on the applicable range and voltage level of the input voltage corresponding to the three-phase inverter, thus determining the second parameter threshold as m2 and the fourth parameter threshold as m4.

[0084] In one embodiment of the present invention, combined with Figure 11 As shown, the battery system is a low-voltage battery system, which includes a low-voltage battery 120 and a first DC-DC module 130. The control method of the energy storage system further includes: sending a type to the first DC-DC module 110 so that the first DC-DC module 130 outputs a target voltage based on the type, so that the parameters of the battery system match the type.

[0085] Specifically, such as Figure 11As shown, the low-voltage battery 120 in the low-voltage battery system is first connected to the first DC-DC module 130, and then the first DC-DC module 130 is connected to the hybrid inverter to complete the connection between the low-voltage battery system and the hybrid inverter. When the first DC-DC module 130 is in the start-up state, it can output the energy in the low-voltage battery 120 to the hybrid inverter. The low-voltage battery system and the hybrid inverter have a power interface (POWER), a communication interface (COM), and a hardware signal interface. Specifically, the hybrid inverter is connected to the first DC-DC module 130 through the POWER interface, the COM interface, and the hardware signal interface. The second DC-DC module 120 can communicate with the first DC-DC module 130 via the COM interface, or it can communicate quickly via the hardware signal interface. The specific communication division can be determined according to the situation.

[0086] Therefore, after the first DC-DC module of the low-voltage battery system is connected to the hybrid inverter, the output of the first DC-DC module becomes the input of the hybrid inverter. After the low-voltage battery system is connected to the hybrid inverter, the hybrid inverter sends the type of the hybrid inverter to the first DC-DC module of the low-voltage battery system via the communication interface COM, such as sending a command with single / three-phase identification flags to the first DC-DC module.

[0087] The first DC-DC module identifies the received instructions to determine the type of hybrid inverter, determines the target voltage based on the applicable range of the input voltage corresponding to the type of hybrid inverter, and controls the low-voltage battery system to output the target voltage within the applicable range of the input voltage, so that the parameters of the low-voltage battery system match the type.

[0088] This embodiment utilizes a first DC-DC converter module to adaptively adjust the output voltage by identifying the type of the hybrid inverter, ensuring it falls within the applicable range of the hybrid inverter's input voltage to achieve optimal operating conditions. The first DC-DC converter module can be an LLC (Resonant Converter), DAB (Dual Active Bridge Converter), BUCK, BOOST, or other DC-DC conversion modules. By identifying the inverter type, the first DC-DC converter module adjusts its output voltage to match the inverter's optimal operating conditions.

[0089] In one embodiment of the present invention, the hybrid inverter type includes single-phase or three-phase. When the type is single-phase, the target voltage is greater than or equal to a first voltage threshold V1 and less than or equal to a third voltage threshold V3. When the type is three-phase, the target voltage is greater than or equal to a second voltage threshold V2 and less than or equal to a fourth voltage threshold V4. When the first DC-DC module does not receive the type, the target voltage is greater than or equal to the second voltage threshold V2 and less than or equal to the third voltage threshold V3. Wherein, the first voltage threshold V1 < the second voltage threshold V2 < the third voltage threshold V3 < the fourth voltage threshold V4.

[0090] Specifically, when the hybrid inverter is determined to be single-phase, the target voltage is set within the applicable range of the input voltage of the single-phase inverter, i.e., V1≤V≤V3; when the hybrid inverter is determined to be three-phase, the target voltage is set within the applicable range of the input voltage of the three-phase inverter, i.e., m2≤n≤m4. However, if the first DC-DC module does not receive the type, for example, if the instruction is not successfully recognized, the target voltage is set in the intersection area of ​​the applicable range of the input voltage of the single-phase inverter and the three-phase inverter, m2≤n≤m3. In this case, regardless of whether the hybrid inverter is single-phase or three-phase, the target voltage output by the first DC-DC module meets the input voltage requirements of the hybrid inverter.

[0091] In one embodiment of the present invention, the first DC-DC module determines its own switching frequency and / or gain based on its type, wherein the gain is the ratio of the output voltage to the input voltage of the first DC-DC module.

[0092] Specifically, taking the circuit diagram of the first DC-DC module as an example... Figure 12 For example, the LLC topology serves as the main circuit of the first DC-DC module, and its output voltage can be adjusted by regulating the switching frequency of the circuit. Its input-output relationship formula is:

[0093] V0 = n * Gain * Vin

[0094] Where V0 represents the output voltage of the first DC-DC module, n represents the turns ratio of the LLC transformer, Gain represents the gain (i.e., amplification factor) of the LLC circuit, and Vin is the input voltage of the first DC-DC module, i.e., the output voltage of the low-voltage battery. Additionally, Gain is a function of the switching frequency f, and its relationship curve is shown below. Figure 13 As shown. In Figure 13In this configuration, the switching frequencies are f1 > f2 > f3 > f4, and the corresponding output voltage gains at these frequencies are G1, G2, G3, and G4, respectively. The output voltages of the first DC-DC module are V1, V2, V3, and V4, respectively. Therefore, by adjusting the voltage as described above, the switching frequency can be adjusted according to the applicable input voltage range of both single-phase and three-phase inverters to match the type of hybrid inverter.

[0095] Furthermore, since hybrid inverters can be either single-phase or three-phase inverters, adaptive identification and matching are required at the installation site after the hybrid inverter is connected to the battery system.

[0096] Specifically, after the battery system and hybrid inverter are installed, the staff presses the control button corresponding to the battery system to send an access signal to the hybrid inverter. The access signal is a signal with level transformation.

[0097] When the hybrid inverter detects a change in the electrical signal level at the port receiving the access signal, it determines that it has received the access signal from the battery system and performs the aforementioned motor control method.

[0098] Furthermore, the hybrid inverter can also determine whether an access signal has been received based on the duration of the control button press. For example, when the control button is pressed, the port electrical signal level goes high; when the control button is released, the port electrical signal level returns to low. The hybrid inverter starts timing when the port electrical signal level goes high and ends timing when it returns to low. If the timing reaches the set time, the button signal is considered valid, and an access signal from the battery system has been received; otherwise, the button signal is considered invalid, no access signal from the battery system has been received, and a feedback signal is sent to the after-sales APP to prompt the installer to press the button again.

[0099] It should be noted that, in addition to sending the battery system access signal to the hybrid inverter via hardware control buttons, a mobile app can also be used to send the battery system access signal to the hybrid inverter via the communication network. For example, when the communication connection is normal, staff can send corresponding control signals to the hybrid inverter via the network using the mobile app to control the entire power supply and energy storage system, enabling functions such as starting and stopping. However, when the network infrastructure is disrupted due to force majeure (such as war, weather, geological disasters, etc.), and control via the mobile app is not possible, staff can manually control the system using the control buttons to provide a reliable emergency response.

[0100] As a specific embodiment of the present invention, taking a photovoltaic energy storage system as an example, when the battery system is a high-voltage battery system, the attribute parameters of the multiple high-voltage battery modules are the number of high-voltage battery modules n, and the first parameter threshold, the second parameter threshold, the third parameter threshold, and the fourth parameter threshold are n1, n2, n3, and n4, respectively. The control method of this energy storage system is as follows: Figure 14 As shown, the following steps may be included:

[0101] S101, The photovoltaic energy storage system has been installed;

[0102] S102, the photovoltaic connection switch is closed, and the hybrid inverter is powered on and in standby mode;

[0103] S103, the hybrid inverter sends a communication request command to the high-voltage battery;

[0104] In this process, after the high-voltage battery system is connected to the hybrid inverter, the installer presses the corresponding control button to activate the high-voltage battery and identify the number n of battery modules. After receiving the button signal, the hybrid inverter starts executing S103.

[0105] The high-voltage battery receives a communication request command and sends back a response command, reporting the number of battery modules, n.

[0106] S104, the number n of battery modules acquired by the energy storage inverter;

[0107] S105, determine if the quantity n is greater than or equal to m1. If yes, proceed to step S106; otherwise, proceed to step S107.

[0108] S106, determine if n is less than m2. If yes, proceed to step S108; otherwise, proceed to step S110.

[0109] S107, It has been determined that the parameters and type of the battery system do not match.

[0110] S108. Determine whether the hybrid inverter is single-phase. If yes, proceed to step S109; otherwise, proceed to step S107.

[0111] S109, determine that the parameters and type of the battery system are matched, and control the operation of the hybrid inverter.

[0112] S110, determine if n is less than or equal to m3. If yes, proceed to step S109; otherwise, proceed to step S111.

[0113] S111, determine if n is less than or equal to m4. If yes, proceed to step S112; otherwise, proceed to step S107.

[0114] S112, determine whether the hybrid inverter is a three-phase inverter. If yes, proceed to step S109; otherwise, proceed to step S107.

[0115] As another specific embodiment of the present invention, taking a photovoltaic energy storage system as an example, when the battery system is a low-voltage battery system, the control method of the energy storage system is as follows: Figure 15 As shown, the following steps may be included:

[0116] S201, Energy storage system installation complete;

[0117] S202, the photovoltaic connection switch is closed, and the hybrid inverter is powered on and in standby mode;

[0118] S203, the hybrid inverter sends a communication request command to the first DC-DC module;

[0119] After the low-voltage battery system is connected to the hybrid inverter, the installer presses the button on the first DC-DC module. Upon receiving the button signal, the hybrid inverter begins to execute S203.

[0120] S204, the hybrid inverter sends an instruction with single-phase and three-phase identification flags to the first DC-DC module so that the first DC-DC module outputs a target voltage based on the type so that the parameters of the battery system match the type.

[0121] The first DC-DC module can output the target voltage based on the type, such as... Figure 16 The steps shown are as follows:

[0122] S301, the first DC-DC module receives the instruction and identifies the type;

[0123] S302, determine whether the type was successfully identified. If yes, proceed to step S303 if the type is single-phase, and proceed to step S306 if the type is three-phase; otherwise, proceed to step S307.

[0124] S303, determine that the applicable range of the input voltage of the single-phase inverter is V1≤V≤V3;

[0125] S304, limit the switching frequency of the first DC-DC module to within f3≤f≤f1; execute step S309;

[0126] S305, determine that the applicable range of the input voltage of the three-phase inverter is V2≤V≤V4;

[0127] S306, limit the switching frequency of the first DC-DC module to within f4≤f≤f2; execute step S309;

[0128] S307, determine the cross-range of the applicable input voltage range for single-phase inverters and three-phase inverters as V2≤V≤V3;

[0129] S308, limit the switching frequency of the first DC-DC module to within f3≤f≤f2; execute step S309;

[0130] S309, the first DC-DC module outputs the target voltage to match the parameters and type of the battery system.

[0131] Therefore, when the battery system is a high-voltage battery system, this embodiment can automatically determine whether it is compatible with the type of hybrid inverter by the number of high-voltage battery modules, eliminating the need to classify batteries in R&D, production, sales, and warehousing. When the battery system is a low-voltage battery system, the first DC-DC module can perform frequency regulation to adaptively identify the ideal operating range of single-phase and three-phase inverters, or control its own output voltage within the voltage range allowed by both single-phase and three-phase inverters. This allows the same low-voltage battery system to be compatible with both single-phase and three-phase inverters, standardizing products, greatly simplifying the production process, improving production efficiency, reducing inventory, and facilitating customer management and maintenance.

[0132] In summary, according to the control method of the energy storage system of the present invention, the energy storage system includes a hybrid inverter and a battery system, the hybrid inverter being adapted to connect to the battery system. The method obtains the type of the hybrid inverter and controls the operation of the hybrid inverter when the parameters of the battery system match the type; wherein the parameters characterize the output voltage of the battery system. Therefore, after the hybrid inverter and battery system are connected, this method can automatically determine whether they match based on the parameters of the battery system and the type of the hybrid inverter, and control the operation of the hybrid inverter when it is determined that the parameters and type of the battery system match, thereby reducing manual intervention and lowering application costs.

[0133] Corresponding to the above embodiments, the present invention also proposes a controller.

[0134] like Figure 17 As shown, the controller 300 of this embodiment includes a memory 310, a processor 320, and a control program for the energy storage system stored in the memory 310 and executable on the processor 320. When the processor 320 executes the control program for the energy storage system, it implements the above-mentioned control method for the energy storage system.

[0135] According to the controller of the present invention, when the processor executes the control program of the energy storage system, the above-described control method of the energy storage system is implemented. Based on the above control method, it is possible to automatically determine whether the battery system parameters and the hybrid inverter type are matched, and control the hybrid inverter to work when it is determined that the battery system parameters and type are matched, thereby reducing manual intervention and lowering application costs.

[0136] Corresponding to the above embodiments, the present invention also proposes an energy storage system.

[0137] like Figure 18 As shown, the energy storage system 1000 of this embodiment includes: a battery system 100; a hybrid inverter 200, which is adapted to be connected to the battery system 100, and the hybrid inverter 200 further includes a controller; wherein, the controller 300 is used to obtain the type of the hybrid inverter 200, and control the hybrid inverter 200 to operate when the parameters of the battery system 100 match the type; wherein, the parameters are used to characterize the output voltage of the battery system 100.

[0138] Energy storage system 1000 may include multiple hybrid inverters 200, such as Figure 8 and Figure 9 As shown, they are represented by hybrid inverter #1, hybrid inverter #2, hybrid inverter #3... hybrid inverter #n, respectively. Multiple hybrid inverters 200 are connected in parallel to achieve the function of parallel expansion of hybrid inverters 200, thereby increasing the grid-connected power and meeting different load requirements. It should be noted that the connecting lines in the diagram have been simplified; COM represents the communication signal.

[0139] In one embodiment of the present invention, the battery system 100 is a high-voltage battery system, which includes multiple high-voltage battery modules connected in series, and the hybrid inverter 200 is adapted to connect the multiple high-voltage battery modules; the controller 300 is further configured to acquire attribute parameters of the multiple high-voltage battery modules, and determine whether the parameters and types of the battery system 100 match based on the attribute parameters; wherein, the attribute parameters include the number of multiple high-voltage battery modules / total output voltage.

[0140] In one embodiment of the present invention, the battery system 100 is a low-voltage battery system, which includes a low-voltage battery and a first DC-DC module connected to the low-voltage battery. The hybrid inverter 200 is adapted to connect to the first DC-DC module. The controller 300 is further configured to send a type to the first DC-DC module so that the first DC-DC module outputs a target voltage based on the type, so that the parameters of the battery system match the type.

[0141] Therefore, the specific advantages of the energy storage system of this application are as follows:

[0142] 1. The same high-voltage battery system or the same low-voltage battery system can achieve compatibility and adaptation for single-phase inverters and three-phase inverters, and adaptive matching of single-phase and three-phase systems can be performed during installation;

[0143] 2. Reduce the number of product codes, significantly lowering production, warehousing, transportation, installation, and maintenance costs;

[0144] 3. The high-voltage battery features a modular design, and the number of modules adapts to single and three-phase inverters, eliminating the need for battery classification in R&D, production, sales, and warehousing.

[0145] 4. The low-voltage battery system can operate through frequency regulation via the first DC-DC module, adaptively identifying the ideal operating range of single-phase and three-phase inverters, or controlling its own output voltage within the voltage range allowed by both single-phase and three-phase inverters. This allows the same low-voltage battery system to be compatible with both single-phase and three-phase inverters, standardizing the product, significantly simplifying the production process, improving production efficiency, reducing inventory, and facilitating customer management and maintenance.

[0146] 5. The overall cost of the solution is low, enhancing competitiveness.

[0147] It should be noted that for details not disclosed in the energy storage system of the embodiments of the present invention, please refer to the details disclosed in the control method of the energy storage system of the above embodiments of the present invention, which will not be repeated here.

[0148] According to an embodiment of the energy storage system of the present invention, a hybrid inverter is adapted to be connected to a battery system. The hybrid inverter further includes a controller, which is used to acquire the type of the hybrid inverter and control the operation of the hybrid inverter when the parameters of the battery system match the type. The parameters characterize the output voltage of the battery system. Thus, the energy storage system can automatically determine whether the battery system parameters and the hybrid inverter type match, and control the operation of the hybrid inverter when it is determined that the battery system parameters and type match, thereby reducing manual intervention and lowering application costs.

[0149] It should be noted that the logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device). For purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection with one or more wires (electronic device), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and portable compact disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0150] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0151] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above 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 one or more embodiments or examples.

[0152] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0153] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0154] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A control method for an energy storage system, characterized in that, The energy storage system includes a hybrid inverter and a battery system, the hybrid inverter being adapted to be connected to the battery system, and the method includes: Obtain the type of the hybrid inverter; The hybrid inverter is controlled to operate when the parameters of the battery system match the type; wherein the parameters are used to characterize the output voltage of the battery system.

2. The method according to claim 1, characterized in that, The battery system is a high-voltage battery system, which includes multiple high-voltage battery modules connected in series. The method further includes: Obtain the attribute parameters of multiple high-voltage battery modules; Based on the attribute parameters, it is determined whether the parameters of the battery system match the type; wherein, the attribute parameters include the number / total output voltage of the multiple high-voltage battery modules.

3. The method according to claim 2, characterized in that, The type includes single-phase or three-phase, and determining whether the parameters of the battery system match the type based on the attribute parameters includes: If the attribute parameter is greater than or equal to the first parameter threshold and less than the second parameter threshold, and the type is single-phase, it is determined that the parameters of the battery system match the type. If the attribute parameter is greater than or equal to the second parameter threshold and less than or equal to the third parameter threshold, it is determined that the parameters of the battery system match the type. If the attribute parameter is greater than the third parameter threshold and less than or equal to the fourth parameter threshold, and the type is three-phase, it is determined that the parameters of the battery system match the type. Wherein, the first parameter threshold < the second parameter threshold < the third parameter threshold < the fourth parameter threshold.

4. The method according to claim 3, characterized in that, The method further includes, where multiple high-voltage battery modules have the same voltage rating, and the attribute parameter includes the quantity: Obtain the voltage level of the high-voltage battery module; Based on the voltage level and the type, the first parameter threshold, the second parameter threshold, the third parameter threshold, and the fourth parameter threshold are determined.

5. The method according to claim 1, characterized in that, The battery system is a low-voltage battery system, which includes a low-voltage battery and a first DC-DC module. The method further includes: The type is sent to the first DC-DC module so that the first DC-DC module outputs a target voltage based on the type, thereby matching the parameters of the battery system with the type.

6. The method according to claim 5, characterized in that, The types include single-phase or three-phase. In the case of single-phase, the target voltage is greater than or equal to a first voltage threshold and less than or equal to a third voltage threshold; In the case of a three-phase system, the target voltage is greater than or equal to the second voltage threshold and less than or equal to the fourth voltage threshold. Wherein, if the first DC-DC module does not receive the type, the target voltage is greater than or equal to the second voltage threshold and less than or equal to the third voltage threshold; wherein, the first voltage threshold < the second voltage threshold < the third voltage threshold < the fourth voltage threshold.

7. The method according to claim 5 or 6, characterized in that, The first DC-DC module determines its own switching frequency and / or gain based on the type, wherein the gain is the ratio of the output voltage to the input voltage of the first DC-DC module.

8. A controller, characterized in that, The system includes a memory, a processor, and a control program for the energy storage system stored in the memory and executable on the processor. When the processor executes the control program for the energy storage system, it implements the control method for the energy storage system according to any one of claims 1-7.

9. An energy storage system, characterized in that, include: Battery system; A hybrid inverter adapted to be connected to the battery system, the hybrid inverter further comprising a controller for obtaining the type of the hybrid inverter and controlling the operation of the hybrid inverter when the parameters of the battery system match the type; wherein the parameters are used to characterize the output voltage of the battery system.

10. The energy storage system according to claim 9, characterized in that, The battery system is a high-voltage battery system, which includes multiple high-voltage battery modules connected in series, and the hybrid inverter is adapted to connect multiple high-voltage battery modules. The controller is further configured to acquire attribute parameters of the plurality of high-voltage battery modules, and determine whether the parameters of the battery system match the type based on the attribute parameters; wherein the attribute parameters include the number of the plurality of high-voltage battery modules / total output voltage.

11. The energy storage system according to claim 9, characterized in that, The battery system is a low-voltage battery system, which includes a low-voltage battery and a first DC-DC module connected to the low-voltage battery. The hybrid inverter is adapted to connect to the first DC-DC module. The controller is also configured to send the type to the first DC-DC module so that the first DC-DC module outputs a target voltage based on the type, so that the parameters of the battery system match the type.

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