Battery-management-system power supply circuit of energy storage system, and energy storage valve and energy storage station

Abstract

The present application belongs to the technical field of power electronics. Provided are a battery-management-system power supply circuit of an energy storage system, and an energy storage valve and an energy storage station. When an energy storage sub-module (10) where battery management systems in the battery-management-system power supply circuit are located works normally, and when the energy storage sub-module (10) where the battery management systems are located is bypassed, an energy storage sub-module (10'), other than the energy storage sub-module (10) where the battery management systems are located, is selected to supply power to the battery management systems, such that the problem of battery modules (Bat) in the bypassed energy storage sub-module (10) being over-discharged due to continuous consumption caused by the battery management systems is ameliorated. Furthermore, all the battery management systems in the energy storage sub-module (10) are further controlled to be powered by batteries of electric cabinets (100) where the battery management systems are located, such that electric quantities of the electric cabinets (100) in the same energy storage sub-module (10) are uniform.

Description

Battery management system power supply circuit, energy storage valve and energy storage station of energy storage system

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of the People's Republic of China on July 31, 2023, with application number 202310954598.7 and invention name “Battery management system power supply circuit, energy storage valve and energy storage station for energy storage system”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application belongs to the field of power electronics technology, and in particular relates to a battery management system power supply circuit, an energy storage valve, and an energy storage station of an energy storage system. Background Art

[0003] In conventional high-voltage, direct-mounted energy storage systems, the battery management system (BMS) draws power from the battery modules within the cabinet. This creates a problem: for example, when a storage submodule is bypassed due to a fault, its battery modules may remain idle for extended periods of time due to a variety of factors, including maintenance cycles. However, due to the safety and reliability requirements of high-voltage, direct-mounted energy storage systems, battery module monitoring must not be lost, meaning the battery management system (BMS), which performs battery monitoring functions, must always be powered. Therefore, after the storage submodule is bypassed, the idle battery modules, due to the continued consumption of the BMS, may experience deep over-discharge, causing irreversible damage to the batteries and wasting battery cells.

[0004] Application Contents

[0005] In view of the above problems, the present application provides a battery management system power supply circuit, energy storage valve and energy storage station for an energy storage system, aiming to solve the problem that static battery modules in related energy storage systems may suffer from deep over-discharge and irreversible damage due to continuous consumption of the battery management system.

[0006] In a first aspect, an embodiment of the present application provides a battery management system power supply circuit for an energy storage system, wherein the energy storage system includes multiple energy storage sub-modules and a DC bus connected to each energy storage sub-module. The battery management system power supply circuit includes:

[0007] a first power supply module, connected to the battery module, and configured to supply power to the battery management system based on the power of the battery module;

[0008] The second power supply module is connected to the DC bus and is used to supply the battery management system with electric energy based on the DC bus, wherein the electric energy of the DC bus comes from an energy storage submodule other than the energy storage submodule where the battery management system is located in the energy storage system.

[0009] In the technical solution of the embodiment of the present application, two power supply modes are provided for the battery management system. When the battery module is normally stationary, an energy storage submodule other than the energy storage submodule in which the battery management system is located can be selected for the battery management system to power the battery management system, thereby improving the problem of deep over-discharge of the stationary battery module due to continuous consumption of the battery management system.

[0010] In some embodiments, the system further includes a power supply selection module connected to the first power supply module, the second power supply module, and the battery management system, wherein the power supply selection module is configured to:

[0011] When the energy storage submodule where the battery management system is located is operating normally, selecting the first power supply module to supply power to the battery management system;

[0012] When the energy storage submodule where the battery management system is located is bypassed, the second power supply module is selected to supply power to the battery management system.

[0013] In the technical solution of the embodiment of the present application, a power supply selection module is used to select a battery module to power the battery management system, or an energy storage submodule other than the energy storage submodule where the battery management system is located is selected to power the battery management system, so as to improve the problem that the battery module in the bypassed energy storage submodule may be over-discharged due to continuous consumption of the battery management system.

[0014] In some embodiments, the battery module is connected to a battery management system in the same electrical cabinet through a first power supply module and supplies power to the battery management system.

[0015] In the technical solution of the embodiment of the present application, the battery management systems of each electrical cabinet of the same energy storage submodule are powered by the battery modules of the respective electrical cabinets, thereby improving the uniformity of the power of the batteries of the electrical cabinets of the same energy storage submodule.

[0016] In some embodiments, when the energy storage submodule where the battery management system is located is operating normally, the second power supply module is in a hot standby state.

[0017] In the technical solution of the embodiment of the present application, when the energy storage submodule operates normally, the second power supply module outputs voltage but not current, that is, does not output power, thereby optimizing the load power of the DC bus.

[0018] In some embodiments, the power supply selection module includes a first input terminal, a second input terminal, an output terminal, and a switching unit;

[0019] The first input end of the power supply selection module is connected to the output end of the first power supply module and the first end of the switching switch unit, the second input end of the power supply selection module is connected to the output end of the second power supply module and the second end of the switching switch unit, the third end of the switching switch unit is connected to the output end of the power supply selection module, the output end of the power supply selection module is connected to the power supply end of the battery management system, and the switching switch unit is used to control the switching between the first input end of the power supply selection module being connected to the output end and the second input end being connected to the output end.

[0020] In the technical solution of the embodiment of the present application, a switching switch module can be used to select the first input end of the power supply selection module to be connected to the output end or the second input end of the power supply selection module to be connected to the output end, so that different power supply modes can be actively or automatically selected for the battery management system, thereby solving the problem that the static battery module will be deeply over-discharged due to the continuous consumption of the battery management system, causing irreversible damage.

[0021] In some embodiments, the switching unit includes a first switching element, a first unidirectional conductor, and a second unidirectional conductor, one end of the first switching element serves as a first end of the switching unit, the other end of the first switching element is connected to an input end of the first unidirectional conductor, the input end of the second unidirectional conductor serves as a second end of the switching unit, and the output end of the first unidirectional conductor is connected to the output end of the second unidirectional conductor and serves as a third end of the switching unit.

[0022] The sum of the impedance of the first switching element and the impedance of the first one-way conductor is smaller than the impedance of the second one-way conductor.

[0023] In the technical solution of the embodiment of the present application, when the energy storage submodule is in normal operation, the first switch element of the power supply selection module is in a normally closed state. Since the impedance of the first switch element and the impedance of the first one-way conductor are added together and are less than the impedance of the second one-way conductor, when the energy storage submodule is in normal operation, the battery management system is powered by the battery module in the same electrical cabinet; when the energy storage submodule is bypassed, the first switch element is controlled to be disconnected, and at this time, power is taken from the DC bus (i.e., the energy storage submodule outside the energy storage submodule where the battery management system is located) to power the battery management system; in addition, the first one-way conductor and the second one-way conductor can also flow back to the output end of the power supply selection module, thereby providing anti-interference protection for the first and second power supply modules, and also improving the power supply stability of the battery management system. This structure of the switching switch module also enables the second power supply module to provide voltage to the second one-way conductor without outputting current when the energy storage submodule where the battery management system is located is operating normally, and is in a hot standby state.

[0024] In some embodiments, the first one-way conductor includes a first diode, and an anode and a cathode of the first diode serve as an input end and an output end of the first one-way conductor, respectively.

[0025] In the technical solution of the embodiment of the present application, a diode is used to implement the first unidirectional conductor, which has the function of preventing backflow while also having relatively low cost and loss.

[0026] In some embodiments, the second one-way conductor includes at least one more second diode than the first diode, and the positive and negative electrodes of the second diodes connected in series in the same direction are respectively connected to the input and output ends of the second one-way conductor.

[0027] In the technical solution of the embodiment of the present application, a diode is used to implement the second one-way conductor, which has the function of preventing backflow and has relatively low cost and loss. In addition, the number of the second diode is at least one more than the number of the first diode. This is to ensure that when the energy storage sub-module is operating normally, the battery management system is mainly powered by the battery module in the same electrical cabinet, and the first power supply module can also be maintained in a hot standby state.

[0028] In some embodiments, the energy storage submodule also includes a first controller, which is connected to the first switching element. The first controller is used to control the first switching element to close when the energy storage submodule where the battery management system is located is operating normally, and to control the first switching element to open when the energy storage submodule where the battery management system is located is bypassed.

[0029] In the technical solution of the embodiment of the present application, a first controller is actively used to control the on and off of the first switch element in the power supply selection module, thereby realizing the switching of the power supply mode of the battery management system. The control method is simple and reliable.

[0030] In some embodiments, the first controller is, for example, a submodule controller or a battery management controller. The controller of the energy storage submodule itself is used to implement the switching of the power supply mode of the battery management system, eliminating the need for a separate setting and saving costs.

[0031] In some embodiments, the first power supply module includes a first DC conversion circuit, an input end of the first DC conversion circuit is connected to the battery module, and an output end of the first DC conversion circuit is connected to the power supply selection module.

[0032] In the technical solution of the embodiment of the present application, an implementation of a first power supply module is provided.

[0033] In some embodiments, the second power supply module includes a second DC conversion circuit, an input end of the second DC conversion circuit is connected to the DC bus, and an output end of the second DC conversion circuit is connected to the power supply selection module.

[0034] In the technical solution of the embodiment of the present application, an implementation method of a second power supply module is provided, which uses a different DC conversion circuit from the first power supply module to improve reliability.

[0035] In a second aspect, an embodiment of the present application further provides an energy storage valve, which includes multiple energy storage sub-modules and a battery management system power supply circuit of the above energy storage system.

[0036] In the technical solution of the embodiment of the present application, when the energy storage submodule of the energy storage valve is operating normally, the battery module of the energy storage submodule is selected to power the battery management system. When the energy storage submodule is bypassed, an energy storage submodule other than the energy storage submodule where the battery management system is located is selected to power the battery management system, so as to improve the problem that the battery module in the bypassed energy storage submodule may be over-discharged due to continuous consumption of the battery management system.

[0037] In a third aspect, an embodiment of the present application further provides an energy storage station, which includes a plurality of energy storage sub-modules and a battery management system power supply circuit of the above energy storage system.

[0038] In the technical solution of the embodiment of the present application, when the energy storage sub-module of the energy storage station is operating normally, the battery module of the energy storage sub-module is selected to power the battery management system. When the energy storage sub-module is bypassed, an energy storage sub-module other than the energy storage sub-module where the battery management system is located is selected to power the battery management system, so as to improve the problem that the battery module in the bypassed energy storage sub-module may be over-discharged due to continuous consumption of the battery management system.

[0039] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0041] FIG1 is a schematic structural diagram of an energy storage system provided in one embodiment of the present application;

[0042] FIG2 is a schematic diagram of a power supply circuit of a battery management system of an energy storage system according to an embodiment of the present application;

[0043] FIG3 is a schematic structural diagram of an energy storage system provided in one embodiment of the present application;

[0044] FIG4 is a schematic diagram of a power supply circuit of a battery management system of an energy storage system according to an embodiment of the present application;

[0045] FIG5 is a schematic diagram of a power supply circuit of a battery management system of an energy storage system according to an embodiment of the present application;

[0046] FIG6 is a schematic diagram of a power supply circuit of a battery management system of an energy storage system according to an embodiment of the present application;

[0047] FIG7 is a schematic structural diagram of an energy storage submodule of an energy storage system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0048] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0050] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0051] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0052] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0053] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0054] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0055] Energy storage systems are broadly categorized into several technical approaches, including MMC (Modular Multilevel Converter) AC direct-mounted energy storage systems, DC direct-mounted energy storage systems, and AC cascaded energy storage systems. Compared to traditional energy storage technologies, direct-mounted energy storage systems offer higher voltage levels, larger capacities, and enhanced grid regulation and support capabilities, making them of significant research significance for new power systems primarily based on renewable energy.

[0056] However, current energy storage systems still face some challenges. For example, when the battery modules of the energy storage submodule are at rest, the battery management system can be powered redundantly by an external AC source. Alternatively, the battery management system can be put into low-power mode and equipped with a micro uninterruptible power supply (UPS) to maximize the safe rest time of the battery modules. However, in the energy storage field, insulating external AC cables is difficult and costly. Furthermore, using a UPS cannot completely solve the problem of battery over-discharge during rest due to issues such as the uncertainty of the initial charge before rest and the long maintenance cycle of the energy storage system.

[0057] According to some embodiments of the present application, FIG1 shows a schematic structural diagram of an energy storage system provided in one embodiment of the present application, and FIG2 shows a schematic structural diagram of a battery management system power supply circuit of an energy storage system provided in one embodiment of the present application. For ease of illustration, only portions relevant to this embodiment are shown, which are described in detail as follows:

[0058] Referring to Figure 1 , the energy storage system includes multiple energy storage submodules 10, each of which is connected in series to a DC power busbar Vbus+ / Vbus-. Power can be transmitted via the DC power busbar Vbus+ / Vbus- to each of the energy storage submodules 10, enabling charging and discharging of the energy storage submodules 10. It will be appreciated that when the energy storage submodules 10 are operating normally, the battery modules Bat therein are connected to the DC power busbar Vbus+ / Vbus-, enabling charging and discharging. When an energy storage submodule 10 fails, it is bypassed, and the battery modules Bat therein are placed into a static state.

[0059] Please refer to FIG. 2 , the power supply circuit of the battery management system of the energy storage system includes a first power supply module 110 and a second power supply module 120 .

[0060] The first power supply module 110 is connected to the battery module Bat and is used to provide a first power supply voltage based on the electric energy of the battery module Bat; the second power supply module 120 is connected to the DC bus V+ / V- and is used to supply the battery management system based on the electric energy of the DC bus V+ / V-; wherein the electric energy of the DC bus V+ / V- comes from an energy storage submodule 10' other than the energy storage submodule 10 where the battery management system is located in the energy storage system, and can also be considered as an energy storage submodule 10' other than the battery management system.

[0061] The battery module Bat includes one or more batteries. In this solution, the battery management system acts as a load, and the power provided to it by the first power supply module 110 and the second power supply module 120 can be equal. Alternatively, one of the first power supply module 110 and the second power supply module 120 can be selected to power the battery management system. When the DC bus V+ / V- is used to power the battery management system through the second power supply module 120, the energy of the DC bus V+ / V- comes from other energy storage submodules 10' and therefore does not consume the energy of the battery module Bat.

[0062] In the technical solution of the embodiment of the present application, when the energy storage sub-module 10 where the battery management system is located is operating normally, the battery module Bat of the energy storage sub-module 10 can be selected to power the battery management system. When the energy storage sub-module 10 where the battery management system is located is bypassed, the battery management system will be powered by the DC bus V+ / V- outside the energy storage sub-module 10 and in the energy storage system with other energy storage sub-modules 10', so as to improve the problem of over-discharge of the battery module Bat in the bypassed energy storage sub-module 10 due to continuous consumption of the battery management system.

[0063] According to some embodiments of the present application, FIG3 shows a schematic structural diagram of an energy storage system provided in one embodiment of the present application. In combination with FIG2 and FIG3 , for ease of illustration, only the parts related to this embodiment are shown, which are detailed as follows:

[0064] Each energy storage submodule 10, 10_1 ... 10_n in the energy storage system is connected in parallel to the DC bus V+ / V-. Therefore, when the energy storage submodule 10 containing the battery management system is bypassed, the other energy storage submodules 10_1 ... 10_n (i.e., the other energy storage submodules 10' in FIG. 2 ) can provide the required power to the DC bus V+ / V- through the second power supply module 120. This does not consume the power of the battery module Bat in the energy storage submodule 10 containing the battery management system, thus alleviating the problem of over-discharge caused by continuous consumption by the battery management system.

[0065] It can be understood that each energy storage submodule 10 is connected in parallel to the DC bus V+ / V- to collectively provide the required power for the DC bus V+ / V-, thereby maintaining consistent power levels for each energy storage submodule 10_1 ... 10_n. In some embodiments, a controllable switch can be provided between each energy storage submodule 10_1 ... 10_n in the parallel circuit of the DC bus V+ / V-. This allows each energy storage submodule 10 to be disconnected from the parallel DC bus V+ / V- during charging or discharging via the DC power supply bus Vbus+ / Vbus-, thereby preventing any impact on the charging or discharging of each energy storage submodule 10.

[0066] According to some embodiments of the present application, FIG4 shows a schematic diagram of the structure of a battery management system power supply circuit of an energy storage system provided in one embodiment of the present application. In conjunction with FIG1 and FIG4 , for ease of illustration, only the portion relevant to this embodiment is shown, which is detailed as follows:

[0067] The power supply selection module 130 is connected to the first power supply module 110, the second power supply module 120 and the battery management system, wherein the power supply selection module 130 is used to: when the energy storage submodule 10 where the battery management system is located is operating normally, select the first power supply module 110 to power the battery management system; when the energy storage submodule 10 where the battery management system is located is bypassed, select the second power supply module 120 to power the battery management system.

[0068] The power supply selection module 130 can be controlled manually or automatically. It is understood that when the energy storage submodule 10 is operating normally, the battery module Bat therein is connected to the DC power bus Vbus+ / Vbus-, enabling charging and discharging. When the energy storage submodule 10 fails, it is bypassed, the battery module Bat therein is placed in standby mode, and the energy storage submodule 10', which is not located in the battery management system, is selected to power the battery management system via the second power supply module 120.

[0069] In the technical solution of the embodiment of the present application, the power supply selection module 130 is used to select the battery module Bat to power the battery management system, or to select an energy storage submodule 10' other than the energy storage submodule 10 where the battery management system is located to power the battery management system, so as to improve the problem that the battery module Bat in the bypassed energy storage submodule 10 may be over-discharged due to continuous consumption of the battery management system.

[0070] According to some embodiments of the present application, in conjunction with FIG. 2 and FIG. 4 , for ease of explanation, only parts related to the present embodiment are shown, which are described in detail as follows:

[0071] The battery module Bat is connected to a battery management system in the same electrical cabinet 100 through the first power supply module 110 and supplies power to the battery management system.

[0072] Typically, an energy storage submodule 10 may include multiple electrical cabinets 100, each of which is equipped with a battery module Bat and a battery management system. The battery management system is typically configured to manage the battery modules Bat within the electrical cabinet 100 and to communicate with the outside world. Therefore, in this embodiment, when the energy storage submodule 10 is operating normally, the battery management systems of each electrical cabinet 100 of the same energy storage submodule 10 are powered by the battery modules Bat within their respective electrical cabinets 100 via the first power supply module 110, thereby improving the uniformity of the charge of the battery modules Bat of the electrical cabinets 100 of the same energy storage submodule 10.

[0073] In some embodiments, when the energy storage submodule 10, where the battery management system resides, is operating normally, the second power supply module 120 is in a hot standby state. When the energy storage submodule 10 is operating normally, the second power supply module 120 is in a hot standby state when it is outputting voltage but not current, that is, not outputting power. This optimizes the load power of the DC power busbars Vbus+ / Vbus-.

[0074] According to some embodiments of the present application, FIG5 shows a schematic diagram of the structure of the battery management system power supply circuit of the energy storage system provided by an embodiment of the present application. For ease of illustration, only the part related to this embodiment is shown, which is detailed as follows:

[0075] The power supply selection module 130 includes a first input terminal in1, a second input terminal in2, an output terminal out, and a switch unit 132;

[0076] The first input terminal in1 of the power supply selection module 130 is connected to the output terminal of the first power supply module 110 and the first terminal of the switching switch unit 132, the second input terminal in2 of the power supply selection module 130 is connected to the output terminal of the second power supply module 120 and the second terminal of the switching switch unit 132, the third terminal of the switching switch unit 132 is connected to the output terminal out of the power supply selection module 130, the output terminal out of the power supply selection module 130 is connected to the power supply terminal of the battery management system, and the switching switch unit 132 is used to select the first input terminal in1 of the power supply selection module 130 to be connected to the output terminal out or the second input terminal in2 of the power supply selection module 130 to be connected to the output terminal out.

[0077] The switching unit 132 may be an electronic switch with a single-pole double-throw (SPDT) function, used to select and switch on either the channel between the first input terminal in1 and the output terminal out, or the channel between the second input terminal in2 and the output terminal out. A manually or automatically controlled electronic switch, such as a SPDT switch, relay, or contactor, may be employed. Alternatively, an electronic device may be used to form different channel impedances, thereby allowing the current to automatically select different channels for output to the power supply terminal of the battery management system.

[0078] In the technical solution of the embodiment of the present application, different power supply modes can be actively or automatically selected for the battery management system to solve the problem that static battery modules may be deeply over-discharged due to continuous consumption of the battery management system, causing irreversible damage.

[0079] According to some embodiments of the present application, FIG6 shows a schematic diagram of the structure of the battery management system power supply circuit of the energy storage system provided by an embodiment of the present application. For ease of illustration, only the part related to this embodiment is shown, which is detailed as follows:

[0080] The switch unit 132 includes a first switch element S1 , a first unidirectional conductor D1 , and a second unidirectional conductor D2 .

[0081] One end of the first switching element S1 is connected to the first input end in1 of the power supply selection module 130 as the first end of the switching switch unit 132, the other end of the first switching element S1 is connected to the input end of the first unidirectional conductor D1, the input end of the second unidirectional conductor D2 is connected to the second input end in2 of the power supply selection module 130 as the second end of the switching switch unit 132, the output end of the first unidirectional conductor D1 and the output end of the second unidirectional conductor D2 are connected to the output end out of the power supply selection module 130 as the third end of the switching switch unit 132; wherein the sum of the impedance of the first switching element S1 and the impedance of the first unidirectional conductor D1 is less than the impedance of the second unidirectional conductor D2.

[0082] The first switching element S1 can be an electronic switch such as a relay or contactor that can be operated to control the on / off of a circuit. The first unidirectional conductor D1 and the second unidirectional conductor D2 can be implemented using semiconductor devices, which can prevent current backflow and protect the power supply module when it is not outputting power. In addition, the sum of the impedance of the first switching element S1 and the impedance of the first unidirectional conductor D1 is set to be less than the impedance of the second unidirectional conductor D2. This allows the first supply voltage output by the first power supply module 110 to be output to the battery management system when the energy storage submodule 10 is operating normally, while the second supply voltage output by the second power supply module 120 is only in a hot standby state but does not consume power.

[0083] In the technical solution of the embodiment of the present application, when the energy storage sub-module 10 is in normal operating state, the first switch element S1 of the power supply selection module 130 is in a normally closed state. Since the impedance of the first switch element S1 and the impedance of the first unidirectional conductor D1 are added together and are less than the impedance of the second unidirectional conductor D2, when the energy storage sub-module 10 is in normal operating state, the battery management system is powered by the battery module Bat of the same electrical cabinet 100; when the energy storage sub-module 10 is bypassed, the control system controls the first switch element S1 to be disconnected, and at this time, power is taken from the DC bus V+ / V- to power the battery management system; in addition, the first unidirectional conductor D1 and the second unidirectional conductor D2 can also prevent the current from flowing back to the output end out of the power supply selection module 130, thereby providing anti-interference protection for the first and second power supply modules, and also improving the power supply stability of the battery management system.

[0084] In some embodiments, the first unidirectional conductor D1 includes a first diode, with the anode and cathode of the first diode serving as the input and output terminals of the first unidirectional conductor D1, respectively. Using a diode to implement the first unidirectional conductor D1 provides backflow prevention while also reducing cost and loss.

[0085] In some embodiments, the second unidirectional conductor D2 includes at least one more second diode than the first diodes. The positive and negative electrodes of each second diode connected in series in the same direction are connected to the input and output terminals of the second unidirectional conductor D2, respectively. The positive electrode of each second diode connected in series in the same direction corresponds to the anode of the first second diode in the current transmission direction, and the negative electrode of each second diode connected in series in the same direction corresponds to the cathode of the last second diode in the current transmission direction. The purpose of having at least one more second diode than the first diode is to ensure that the sum of the impedance of the first switching element S1 and the impedance of the first unidirectional conductor D1 is less than the impedance of the second unidirectional conductor D2.

[0086] In the technical solution of the embodiment of the present application, a diode is also used to implement the second unidirectional conductor D2, which has the function of preventing backflow and has relatively low cost and loss. In addition, the number of second diodes is at least one more than the number of first diodes for the purpose of ensuring that when the energy storage sub-module 10 is working normally, the battery management system is mainly powered by the battery module Bat in the same electrical cabinet 100, and the first power supply module 110 can also be maintained in a hot standby state.

[0087] According to some embodiments of the present application, FIG7 shows a schematic diagram of the structure of a battery management system power supply circuit of an energy storage system provided in one embodiment of the present application. In conjunction with FIG6 and FIG7 , for ease of illustration, only the portion relevant to this embodiment is shown, which is described in detail as follows:

[0088] The energy storage submodule 10 also includes a power circuit 101 and a first controller 102. The power circuit 101 is connected to the battery module Bat and the first controller 102. The first controller 102 is configured to output an activation signal and a deactivation signal. The power circuit 101 is configured to connect the battery module Bat to the energy storage submodule 10 in response to the activation signal, enabling normal operation of the energy storage submodule 10, and to disconnect the battery module Bat in response to the deactivation signal, enabling bypass of the energy storage submodule 10. Furthermore, the first controller 102 is connected to a first switching element S1. The first controller 102 is configured to control the first switching element S1 to close when the energy storage submodule 10, where the battery management system resides, is operating normally, and to control the first switching element S1 to open when the energy storage submodule 10, where the battery management system resides, is bypassed.

[0089] The first controller 102 is, for example, a submodule controller (SMC). Specifically, the SMC is used to monitor the operating status of the energy storage submodule 10, receive control information about the energy storage submodule 10 from the valve base controller (VBC) of the energy storage valve, manage the power circuit 101 of the energy storage submodule 10, control the activation and deactivation of each energy storage submodule 10, and transmit the status of the energy storage submodule 10 to the VBC. When the SMC detects a fault in an energy storage submodule 10, it bypasses the faulty energy storage submodule 10 and transmits the fault information to the VBC, ensuring that other energy storage submodules 10 continue to operate normally.

[0090] The first controller 102 is, for example, a battery management controller (BMC). The BMC communicates with the SMC and receives a signal from the SMC indicating that the energy storage submodule 10 is operating normally. The BMC controls the conduction of the first switch element S1 in the power supply selection module 130 and selects the first power supply module 110 to power the battery management system. The BMC receives a signal from the SMC indicating that the energy storage submodule 10 is operating in bypass mode. The BMC controls the disconnection of the first switch element S1 in the power supply selection module 130 and selects the second power supply module 120 to power the battery management system. This control method is simple and reliable.

[0091] 7 , in some embodiments, the power circuit 101 includes second switching elements T1 , T2 and an energy storage element C1 connected in parallel to the second switching elements T1 , T2 . The second switching elements T1 , T2 are connected to the first controller 102 .

[0092] There may be multiple second switching elements T1 and T2, and the multiple second switching elements T1 and T2 are connected in series and / or in parallel. The energy storage element C1 is connected in parallel with the multiple second switching elements T1 and T2 connected in series and / or in parallel. In a specific implementation, the multiple second switching elements T1 and T2 connected in series and / or in parallel include a full-bridge circuit or a half-bridge circuit. When the power circuit 101 is connected to the battery module Bat, the energy storage element C1 can be charged first, thereby reducing the impact of high current on the second switching elements T1 and T2 and improving the reliability of the energy storage submodule 10.

[0093] In the technical solutions of the embodiments of the present application, the power circuit 101 includes a half-bridge circuit or a full-bridge circuit. It should be noted that a half-bridge circuit is a power circuit 101 including two switching transistors, while a full-bridge circuit is a power circuit 101 including four switching transistors. A half-bridge circuit is low-cost and simple; a full-bridge circuit is high-cost and relatively complex. However, compared to a half-bridge circuit, a full-bridge circuit has less interference and higher reliability. This enables flexible configuration of the power circuit 101, increasing the design flexibility of the energy storage submodule 10.

[0094] In some embodiments, the first power supply module 110 includes a first DC conversion circuit, an input end of the first DC conversion circuit is connected to the battery module Bat, and an output end out of the first DC conversion circuit is connected to the power supply selection module 130. A simple and reliable implementation of the first power supply module 110 is provided.

[0095] In some embodiments, the second power supply module 120 includes a second DC conversion circuit, the input of the second DC conversion circuit being connected to the DC bus V+ / V-, and the output of the second DC conversion circuit being connected to the power supply selection module 130. This provides a simple and reliable embodiment of the second power supply module 120, which utilizes a different DC conversion circuit than the first power supply module 110, thereby improving reliability.

[0096] Second, embodiments of the present application further provide an energy storage valve comprising multiple energy storage submodules 10 and a battery management system power supply circuit for the energy storage system described above. In some embodiments, referring to FIG1 , multiple energy storage submodules 10 can be connected in series to a DC power supply busbar Vbus+ / Vbus-.

[0097] In the technical solution of the embodiment of the present application, when the energy storage submodule 10 of the energy storage valve is operating normally, the battery module Bat of the energy storage submodule 10 is selected to power the battery management system. When the energy storage submodule 10 is bypassed, the energy storage submodule 10' (see Figures 2 and 4) not located in the battery management system is selected to power the battery management system, so as to improve the problem of over-discharge of the battery module Bat in the bypassed energy storage submodule 10 due to continuous consumption of the battery management system.

[0098] Thirdly, embodiments of the present application further provide an energy storage station, comprising multiple energy storage submodules 10 and a battery management system power supply circuit for the energy storage system described above. In some embodiments, referring to FIG1 , multiple energy storage submodules 10 can be connected in series to a DC power busbar Vbus+ / Vbus-.

[0099] In the technical solution of the embodiment of the present application, when the energy storage submodule 10 of the energy storage station is operating normally, the battery module Bat of the energy storage submodule 10 is selected to power the battery management system. When the energy storage submodule 10 is bypassed, the energy storage submodule 10' (see Figures 2 and 4) not located in the battery management system is selected to power the battery management system, so as to improve the battery module Bat in the bypassed energy storage submodule 10 from being over-discharged due to continuous consumption of the battery management system.

[0100] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery management system power supply circuit for an energy storage system, wherein: The energy storage system includes a plurality of energy storage submodules, and the battery management system power supply circuit includes: A first power supply module, connected to the battery module, and configured to supply power to the battery management system based on the power of the battery module; A second power supply module is connected to a DC bus and is used to power the battery management system based on the power of the DC bus, wherein the power of the DC bus comes from an energy storage submodule other than the energy storage submodule where the battery management system is located in the energy storage system.

2. The battery management system power supply circuit according to claim 1, wherein: It also includes a power supply selection module, which is connected to the first power supply module, the second power supply module and the battery management system, and is used to: When the energy storage submodule where the battery management system is located works normally, selecting the first power supply module to supply power to the battery management system; When the energy storage submodule where the battery management system is located is bypassed, the second power supply module is selected to supply power to the battery management system.

3. The battery management system power supply circuit according to claim 1 or 2, wherein: The battery module is connected to the battery management system in the same electrical cabinet through the first power supply module, and supplies power to the battery management system.

4. The battery management system power supply circuit according to claim 1, wherein: When the energy storage submodule where the battery management system is located operates normally, the second power supply module is in a hot standby state.

5. The battery management system power supply circuit according to claim 2 or 4, wherein: The power supply selection module includes a first input terminal, a second input terminal, an output terminal and a switching unit; The first input end of the power supply selection module is connected to the output end of the first power supply module and the first end of the switching switch unit, the second input end of the power supply selection module is connected to the output end of the second power supply module and the second end of the switching switch unit, the third end of the switching switch unit is connected to the output end of the power supply selection module, the output end of the power supply selection module is connected to the power supply end of the battery management system, and the switching switch unit is used to select the first input end of the power supply selection module to be connected to the output end or the second input end of the power supply selection module to be connected to the output end.

6. The battery management system power supply circuit as claimed in claim 5, wherein: The switching switch unit comprises a first switch element, a first unidirectional conduction device and a second unidirectional conduction device, one end of the first switch element serves as a first end of the switching switch unit, the other end of the first switch element is connected to an input end of the first unidirectional conduction device, the input end of the second unidirectional conduction device serves as a second end of the switching switch unit, and the output end of the first unidirectional conduction device is connected to an output end of the second unidirectional conduction device and serves as a third end of the switching switch unit; The sum of the impedance of the first switch element and the impedance of the first one-way conductor is smaller than the impedance of the second one-way conductor.

7. The battery management system power supply circuit according to claim 6, wherein: The first one-way conductor includes a first diode, and an anode and a cathode of the first diode serve as an input end and an output end of the first one-way conductor respectively.

8. The battery management system power supply circuit according to claim 7, wherein: The second one-way conductor includes at least one more second diode than the first diodes, and the positive pole and the negative pole of each of the second diodes connected in series in the same direction are respectively connected to the input end and the output end of the second one-way conductor.

9. The battery management system power supply circuit according to claim 6, wherein: The energy storage submodule also includes a first controller, which is connected to the first switch element. The first controller is used to control the first switch element to close when the energy storage submodule where the battery management system is located is working normally, and to control the first switch element to open when the energy storage submodule where the battery management system is located is bypassed.

10. The battery management system power supply circuit according to claim 7, wherein: The first controller includes a submodule controller or a battery management controller.

11. The battery management system power supply circuit according to claim 1, wherein: Each of the energy storage submodules in the energy storage system is connected in parallel to the DC bus.

12. The battery management system power supply circuit according to claim 1, wherein: The first power supply module includes a first DC conversion circuit, an input end of the first DC conversion circuit is connected to the battery module, and an output end of the first DC conversion circuit is connected to the power supply selection module.

13. The battery management system power supply circuit according to claim 1, wherein: The second power supply module includes a second DC conversion circuit, an input end of the second DC conversion circuit is connected to the DC bus, and an output end of the second DC conversion circuit is connected to the power supply selection module.

14. A storage valve, wherein: The energy storage valve includes a plurality of energy storage submodules and a battery management system power supply circuit of a high-voltage direct-mounted energy storage system according to any one of claims 1 to 13.

15. An energy storage station, wherein: The energy storage station includes a plurality of energy storage submodules and a battery management system power supply circuit of a high-voltage direct-mounted energy storage system according to any one of claims 1 to 13.

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