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

Abstract

The invention belongs to the technical field of power electronics, and provides a battery management system power supply circuit of a high-voltage direct-hanging energy storage system, an energy storage valve and an energy storage station. And under the condition that the energy storage sub-module where the battery management system is located is bypassed, the energy storage sub-modules except the energy storage sub-module where the battery management system is located are selected to supply power to the battery management system, so that the problem that the battery modules in the bypassed energy storage sub-modules are over-discharged due to continuous consumption of the battery management system is solved. Furthermore, all the battery management systems in the energy storage sub-modules are controlled to be powered by the electric cabinet batteries where the battery management systems are located, so that the electric quantity uniformity of all the electric cabinets in the same energy storage sub-module is achieved.

Description

Technical Field

[0001] 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

[0002] In conventional high-voltage direct-mounted energy storage systems, the power supply system of the battery management system (BMS) draws power from the battery modules in the electrical cabinet, which brings the following problems: for example, when the energy storage submodule is bypassed due to a fault, its battery module will enter a long-term static state due to a series of reasons such as the maintenance cycle. However, due to the safety and reliability requirements of the high-voltage direct-mounted energy storage system, the monitoring of the battery module is not allowed to be lost, that is, the battery management system that performs the battery monitoring function must always be powered. Therefore, after the energy storage submodule is bypassed, the static battery module will be deeply over-discharged due to the continuous consumption of the battery management system, causing irreversible damage to the battery and waste of battery cells. Summary of the invention

[0003] In view of the above problems, the present application provides a battery management system power supply circuit, energy storage valve and energy storage station of an energy storage system, aiming to solve the problem that static battery modules in related energy storage systems may be deeply over-discharged due to continuous consumption of the battery management system, causing irreversible damage.

[0004] In a first aspect, an embodiment of the present application provides a battery management system power supply circuit of an energy storage system, wherein the energy storage system includes a plurality of energy storage sub-modules and a DC bus connected to each of the energy storage sub-modules, and the battery management system power supply circuit includes:

[0005] A first power supply module, connected to the battery module, for supplying power to the battery management system based on the power of the battery module;

[0006] A 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.

[0007] In the technical solution of the embodiment of the present application, two power supply modes are proposed 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.

[0008] In some embodiments, a power supply selection module is further included, and the power supply selection module is connected to the first power supply module, the second power supply module and the battery management system, wherein the power supply selection module is used to:

[0009] 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;

[0010] 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.

[0011] 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.

[0012] In some embodiments, 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.

[0013] In the technical solution of the embodiment of the present application, the battery management systems of each electric cabinet of the same energy storage submodule are powered by the battery modules of the electric cabinets where they are located, thereby improving the uniformity of the power of the batteries in the electric cabinets of the same energy storage submodule.

[0014] In some embodiments, 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.

[0015] 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.

[0016] In some embodiments, the power supply selection module includes a first input terminal, a second input terminal, an output terminal, and a switching unit;

[0017] 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.

[0018] 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.

[0019] In some embodiments, the switching switch unit includes a first switch element, a first unidirectional conductor, and a second unidirectional conductor, one end of the first switch element serves as the first end of the switching switch unit, the other end of the first switch element is connected to the input end of the first unidirectional conductor, the input end of the second unidirectional conductor serves as the second end of the switching switch unit, and the output end of the first unidirectional conductor is connected to the output end of the second unidirectional conductor and serves as the third end of the switching switch unit;

[0020] 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.

[0021] 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 unidirectional conductor are added together less than the impedance of the second unidirectional conductor, the battery management system is powered by the battery module in the same electrical cabinet when the energy storage submodule is in normal operation; 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 unidirectional conductor and the second unidirectional conductor can also flow back to the current at 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 unidirectional conductor without outputting current when the energy storage submodule where the battery management system is located is in normal operation, and is in a hot standby state.

[0022] In some embodiments, the first unidirectional conductor includes a first diode, and an anode and a cathode of the first diode serve as an input terminal and an output terminal of the first unidirectional conductor, respectively.

[0023] 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.

[0024] In some embodiments, the second unidirectional conductor includes at least one more second diode than the first diodes, and the positive pole and 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 unidirectional conductor.

[0025] In the technical solution of the embodiment of the present application, a diode is used to implement the second unidirectional 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, so that when the energy storage sub-module is in normal operation, 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.

[0026] In some embodiments, the energy storage submodule also includes a first controller, which is connected to the first switch element, and 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 operating normally, and to control the first switch element to open when the energy storage submodule where the battery management system is located is bypassed.

[0027] In the technical solution of the embodiment of the present application, it is provided to actively use the first controller to control the conduction and closing of the first switch element in the power supply selection module, so as to realize the switching of the power supply mode of the battery management system, and the control method is simple and reliable.

[0028] 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, without the need for separate settings, thus saving costs.

[0029] 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.

[0030] In the technical solution of the embodiment of the present application, an implementation of a first power supply module is provided.

[0031] 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.

[0032] 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.

[0033] In a second aspect, an embodiment of the present application further provides an energy storage valve, which includes a plurality of energy storage sub-modules and a battery management system power supply circuit of the energy storage system as described above.

[0034] In the technical solution of the embodiment of the present application, when the energy storage submodule of the energy storage valve operates 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 of over-discharge of the battery module in the bypassed energy storage submodule due to continuous consumption of the battery management system.

[0035] 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 energy storage system as described above.

[0036] In the technical solution of the embodiment of the present application, when the energy storage sub-module of the energy storage station operates 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.

[0037] 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

[0038] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0039] Figure 1 A schematic diagram of the structure of an energy storage system provided in one embodiment of the present application;

[0040] Figure 2 A schematic diagram of a power supply circuit of a battery management system of an energy storage system provided in one embodiment of the present application;

[0041] Figure 3 A schematic diagram of the structure of an energy storage system provided in one embodiment of the present application;

[0042] Figure 4A schematic diagram of a power supply circuit of a battery management system of an energy storage system provided in one embodiment of the present application;

[0043] Figure 5 A schematic diagram of a power supply circuit of a battery management system of an energy storage system provided in one embodiment of the present application;

[0044] Figure 6 A schematic diagram of a power supply circuit of a battery management system of an energy storage system provided in one embodiment of the present application;

[0045] Figure 7 A schematic diagram of the structure of an energy storage submodule of an energy storage system provided in one embodiment of the present application. DETAILED DESCRIPTION

[0046] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field 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" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0048] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0049] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0050] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0051] 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).

[0052] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0053] Energy storage systems are mainly divided into several technical routes, including MMC (Modular Multilevel Converter) AC direct-mounted energy storage system, DC direct-mounted energy storage system, AC cascade energy storage system, etc. Compared with traditional energy storage technology, the direct-mounted energy storage system has a higher voltage level, larger capacity, stronger grid regulation ability and grid support function, and has important research significance for the new power system with new energy as the main body.

[0054] However, there are still some problems with the current energy storage system. For example, when the battery module of the energy storage submodule is at rest, the battery management system is redundantly powered by external AC; or the battery management system is put into low-power mode, and the power supply system of the battery management system is equipped with a micro uninterruptible power supply (UPS) to extend the safe rest time of the battery module as much as possible. However, in the field of energy storage, the insulation of external AC cables is too difficult and the cost is too high. When using UPS, due to the uncertainty of the initial power of the battery before resting and the long maintenance cycle of the energy storage system, the low-power battery management system cannot completely solve the problem of battery over-discharge at rest.

[0055] According to some embodiments of the present application, Figure 1 A schematic diagram of the structure of an energy storage system provided in an embodiment of the present application is shown. Figure 2 A schematic diagram of the structure of a battery management system power supply circuit of an energy storage system provided in an embodiment of the present application is shown. For ease of explanation, only the parts related to the present embodiment are shown, which are described in detail as follows:

[0056] See also Figure 1The energy storage system includes a plurality of energy storage submodules 10, and each energy storage submodule 10 is connected in series to the DC power supply bus Vbus+ / Vbus-, and electric energy can be transmitted to each energy storage submodule 10 through the DC power supply bus Vbus+ / Vbus- to realize charging and discharging of the energy storage submodule 10. It can be understood that when the energy storage submodule 10 is working normally, the battery module Bat therein is connected to the DC power supply bus Vbus+ / Vbus-, and charging and discharging can be realized; when the energy storage submodule 10 fails, it will be bypassed, and the battery module Bat therein will be stationary.

[0057] See also Figure 2 The battery management system power supply circuit of the energy storage system includes a first power supply module 110 and a second power supply module 120 .

[0058] 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.

[0059] The battery module Bat includes one or more batteries. In this solution, the battery management system acts as a load, and the power provided by the first power supply module 110 and the second power supply module 120 can be equal, and 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 power of the DC bus V+ / V- comes from other energy storage submodules 10', so it does not consume the power of the battery module Bat.

[0060] 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 energy storage sub-module 10 outside the energy storage sub-module 10 and other energy storage sub-modules 10' in the energy storage system will be selected to power the battery management system through the DC bus V+ / V-, 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.

[0061] According to some embodiments of the present application, Figure 3 The schematic diagram of the structure of the energy storage system provided by an embodiment of the present application is shown. Figure 2 and Figure 3For the convenience of explanation, only the parts related to this embodiment are shown, which are described in detail as follows:

[0062] Each energy storage submodule 10, 10_1 ... 10_n in the energy storage system is connected in parallel to the DC bus V+ / V-, so that when the energy storage submodule 10 where the battery management system is located is bypassed, the other energy storage submodules 10_1 ... 10_n (i.e. Figure 2 Other energy storage submodules 10') in the battery management system can provide the required power to the second power supply module 120 for the DC bus V+ / V- without consuming the power of the battery module Bat in the energy storage submodule 10 where the battery management system is located, thereby improving the problem of over-discharge caused by continuous consumption of the battery management system.

[0063] It can be understood that each energy storage submodule 10 is connected in parallel to the DC bus V+ / V- to jointly provide the required electrical energy for the DC bus V+ / V-, and can maintain the consistency of the electrical energy for each energy storage submodule 10_1...10_n. Optionally, in the parallel circuit of the DC bus V+ / V-, a controllable switch can be set between each energy storage submodule 10_1...10_n, so that each energy storage submodule 10 is disconnected from the parallel circuit DC bus V+ / V- during the charging and discharging period through the DC power supply bus Vbus+ / Vbus-, so as to prevent the charging and discharging of each energy storage submodule 10 from being affected.

[0064] According to some embodiments of the present application, Figure 4 The 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 is shown. Figure 1 and Figure 4 For the convenience of explanation, only the parts related to this embodiment are shown, which are described in detail as follows:

[0065] 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 working 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.

[0066] The power supply selection module 130 can be controlled manually or automatically. It is understandable that when the energy storage submodule 10 is working normally, the battery module Bat therein is connected to the DC power supply bus Vbus+ / Vbus-, and can realize charging and discharging; when the energy storage submodule 10 fails, it will be bypassed, the battery module Bat therein will be stationary, and the energy storage submodule 10' not located in the battery management system is selected to power the battery management system through the second power supply module 120.

[0067] 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 the energy storage submodule 10' other than the energy storage submodule 10 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 Bat in the bypassed energy storage submodule 10 may be over-discharged due to the continuous consumption of the battery management system.

[0068] According to some embodiments of the present application, Figure 2 and Figure 4 For the convenience of explanation, only the parts related to this embodiment are shown, which are described in detail as follows:

[0069] 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.

[0070] Typically, an energy storage submodule 10 may include multiple electrical cabinets 100, each of which is provided with a battery module Bat and a battery management system, and the battery management system is typically configured to manage the battery module Bat in the electrical cabinet 100 and to communicate and interact with the outside. 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 module Bat in each electrical cabinet 100 through the first power supply module 110, thereby improving the uniformity of the power of the battery module Bat of the electrical cabinet 100 of the same energy storage submodule 10.

[0071] In some embodiments, when the energy storage submodule 10 in which the battery management system is located 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, which means that the second power supply module 120 is in a state of outputting voltage but not outputting current, that is, not outputting power. Therefore, the load power of the DC power supply bus Vbus+ / Vbus- is optimized.

[0072] According to some embodiments of the present application, Figure 5 The structure diagram of the battery management system power supply circuit of the energy storage system provided by an embodiment of the present application is shown. For the convenience of explanation, only the part related to the present embodiment is shown, which is described in detail as follows:

[0073] 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;

[0074] 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 end 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 end of the switching switch unit 132, the third end 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 end 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.

[0075] The switching unit 132 may be an electronic switch with a single-pole double-throw function, which is used to select a channel between the first input terminal in1 and the output terminal out or a channel between the second input terminal in2 and the output terminal out. A manually or automatically controlled electronic switch may be used, such as a single-pole double-throw switch, a relay, or a contactor. Alternatively, electronic devices may be used to form different channel impedances so that the current automatically selects different channels to output the current to the power supply terminal of the battery management system.

[0076] 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, so as to solve the problem that static battery modules may be deeply over-discharged and cause irreversible damage due to continuous consumption of the battery management system.

[0077] According to some embodiments of the present application, Figure 6 The structure diagram of the battery management system power supply circuit of the energy storage system provided by an embodiment of the present application is shown. For the convenience of explanation, only the part related to the present embodiment is shown, which is described in detail as follows:

[0078] The switch unit 132 includes a first switch element S1 , a first unidirectional conductor D1 , and a second unidirectional conductor D2 .

[0079] One end of the first switch 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 switch 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 switch element S1 and the impedance of the first unidirectional conductor D1 is less than the impedance of the second unidirectional conductor D2.

[0080] Among them, the first switch element S1 can be an electronic switch such as a relay or a contactor that can control the on and off of the circuit by operation. The first one-way conductor D1 and the second one-way conductor D2 can be implemented by semiconductor devices, which can prevent current backflow and protect the power supply module that does not output power. In addition, the impedance of the first switch element S1 and the impedance of the first one-way conductor D1 are set to be less than the impedance of the second one-way conductor D2, so that when the energy storage submodule 10 operates normally, the first power supply voltage output by the first power supply module 110 can be output to the battery management system, and the second power supply voltage output by the second power supply module 120 is only in a hot standby state, but does not consume power.

[0081] In the technical solution of the embodiment of the present application, when the energy storage submodule 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 submodule 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 submodule 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 performing anti-interference protection on the first and second power supply modules, and also improving the power supply stability of the battery management system.

[0082] In some embodiments, the first unidirectional conductor D1 includes a first diode, and the anode and cathode of the first diode serve as the input and output ends of the first unidirectional conductor D1, respectively. The use of a diode to implement the first unidirectional conductor D1 has the function of preventing backflow while having relatively low cost and loss.

[0083] In some embodiments, the second unidirectional conductor D2 includes at least one more second diode than the first diode, and the positive pole and the negative pole of each second diode connected in series in the same direction are respectively connected to the input end and the output end of the second unidirectional conductor D2. The positive pole of each second diode connected in series in the same direction refers to the anode of the first second diode in the current transmission direction, and the negative pole of each second diode connected in series in the same direction refers 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 make the sum of the impedance of the first switch element S1 and the impedance of the first unidirectional conductor D1 smaller than the impedance of the second unidirectional conductor D2.

[0084] 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 the second diode is at least one more than the number of the first diode for the purpose of ensuring that when the energy storage submodule 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.

[0085] According to some embodiments of the present application, Figure 7 The 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 is shown. Figure 6 and Figure 7 For the convenience of explanation, only the parts related to this embodiment are shown, which are described in detail as follows:

[0086] The energy storage submodule 10 further 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 used to output an input signal and a disconnection signal. The power circuit 101 is used to connect the battery module Bat according to the input signal to make the energy storage submodule 10 work normally, and disconnect the electrical connection with the battery module Bat according to the disconnection signal to make the energy storage submodule 10 bypassed. At the same time, the first controller 102 is connected to the first switch element S1. The first controller 102 is used to control the first switch element S1 to close when the energy storage submodule 10 where the battery management system is located works normally, and to control the first switch element S1 to open when the energy storage submodule 10 where the battery management system is located is bypassed.

[0087] Among them, the first controller 102 is, for example, a submodule controller (SubModuleController, SMC). Specifically, the SMC is used to monitor the working state of the energy storage submodule 10, receive the energy storage submodule 10 control information issued by the valve base control device (Valve BaseController, VBC) of the energy storage valve, manage the power circuit 101 of the energy storage submodule 10, control the input and removal of each energy storage submodule 10, and transmit the state of the energy storage submodule 10 to the VBC. When the SMC detects that the energy storage submodule 10 has a fault, the SMC bypasses the faulty energy storage submodule 10 and transmits the fault information to the VBC, which can ensure that other energy storage submodules 10 continue to operate normally.

[0088] The first controller 102 is, for example, a battery management controller (BMC). The BMC communicates with the SMC and receives a signal transmitted by 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 supply power to the battery management system. The BMC receives a signal transmitted by 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 supply power to the battery management system. The control method is simple and reliable.

[0089] Please continue reading Figure 7 In some embodiments, the power circuit 101 includes second switch elements T1 , T2 and an energy storage element C1 connected in parallel to the second switch elements T1 , T2 , and the second switch elements T1 , T2 are connected to the first controller 102 .

[0090] The second switch elements T1, T2 may be multiple, and the multiple second switch elements T1, T2 are connected in series and / or in parallel, and the energy storage element C1 is connected in parallel with the multiple second switch elements T1, T2 connected in series and / or in parallel. In a specific implementation, the multiple second switch elements T1, 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 the large current on the second switch elements T1, T2 and improving the reliability of the energy storage submodule 10.

[0091] In the technical solution of the embodiment of the present application, the power circuit 101 includes a half-bridge circuit or a full-bridge circuit. It should be noted that the half-bridge circuit is a power circuit 101 including two switch tubes, and the full-bridge circuit is a power circuit 101 including four switch tubes. The half-bridge circuit has low cost and simple circuit; the full-bridge circuit has high cost and relatively complex circuit. However, the full-bridge circuit has less interference than the half-bridge circuit and has higher reliability. Flexible configuration of the power circuit 101 is achieved, and the flexibility of the design of the energy storage submodule 10 is improved.

[0092] In some embodiments, the first power supply module 110 includes a first DC conversion circuit, the input end of the first DC conversion circuit is connected to the battery module Bat, and the 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.

[0093] In some embodiments, the second power supply module 120 includes a second DC conversion circuit, the input end of the second DC conversion circuit is connected to the DC bus V+ / V-, and the output end out of the second DC conversion circuit is connected to the power supply selection module 130. A simple and reliable implementation of the second power supply module 120 is provided, which uses different DC conversion circuits from the first power supply module 110 to improve reliability.

[0094] In a second aspect, the present application also provides an energy storage valve, which includes a plurality of energy storage submodules 10 and a battery management system power supply circuit of the energy storage system as described above. Figure 1 , multiple energy storage sub-modules 10 can be connected in series to the DC power supply bus Vbus+ / Vbus-.

[0095] In the technical solution of the embodiment of the present application, when the energy storage submodule 10 of the energy storage valve is working 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 Figure 2 , Figure 4 ) supplies power to the battery management system 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.

[0096] In a third aspect, the present application also provides an energy storage station, which includes a plurality of energy storage submodules 10 and a battery management system power supply circuit of the energy storage system as described above. Figure 1 , multiple energy storage sub-modules 10 can be connected in series to the DC power supply bus Vbus+ / Vbus-.

[0097] In the technical solution of the embodiment of the present application, when the energy storage submodule 10 of the energy storage station is working 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 Figure 2 , Figure 4 ) supplies power to the battery management system to improve the over-discharge of the battery module Bat in the bypassed energy storage submodule 10 due to the continuous consumption of the battery management system.

[0098] 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 replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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 according to claim 5, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: 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, characterized in that: The first controller includes a submodule controller or a battery management controller.

11. The battery management system power supply circuit according to claim 1, characterized in that: 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, characterized in that: 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, characterized in that: 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. An energy storage valve, characterized in that: 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, characterized in that: 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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