Energy storage battery system

Abstract

Provided in the present invention is an energy storage battery system, comprising a battery management system, an energy storage converter, a direct-current contactor, a first protection apparatus and a second protection apparatus, wherein the battery management system is in communication connection with the energy storage converter by means of a dry contact, an input terminal of the first protection apparatus is connected to a dry-contact output interface of the battery management system, and an input terminal and an output terminal of the second protection apparatus are connected to a dry-contact input interface of the energy storage converter in parallel; the first protection apparatus is used for sending a trigger signal to the second protection apparatus when it is detected that the battery management system sends a dry-contact signal; the second protection apparatus is used for starting, upon receiving the trigger signal, to detect whether the input terminal receives the dry-contact signal transmitted from the dry contact, and if the input terminal does not receive the dry-contact signal transmitted from the dry contact, the output terminal of the second protection apparatus outputs a dry-contact signal to the energy storage converter; the energy storage converter is used for disconnecting a connection with a power grid on the basis of the dry-contact signal; and the battery management system is used for controlling the turning-off of the direct-current contactor on the basis of the dry-contact signal.

Description

Energy storage battery system Technical Field

[0001] The present invention mainly relates to the technical field of energy storage systems, and in particular to an energy storage battery system. Background Art

[0002] Figure 1 is a system block diagram of a conventional energy storage battery system. As shown in Figure 1, the energy storage battery system includes a battery stack, a DC contactor, a battery management system (BMS), and a power conversion system (PCS). The BMS and PCS are connected via dry contacts. A dry contact is a passive switch with two states: closed and open. When the BMS detects a battery stack fault, it controls the dry contact to close and immediately outputs a dry contact signal. After detecting this dry contact signal, the PCS disconnects from the grid, and the BMS then controls the DC contactor to open within seconds.

[0003] During site deployment, the BMS and PCS are located some distance apart, and the cables connecting the dry contacts are susceptible to disconnection or interference. If the dry contact signal from the BMS fails to reach the PCS, the PCS will be unable to disconnect from the grid in a timely manner. The BMS will disconnect the DC contactor while it's on load, causing arcing and a fire risk.

[0004] Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an energy storage battery system to solve the problem that the PCS cannot be disconnected from the power grid in time when the dry contact link fails.

[0006] In order to solve the above technical problems, the present invention provides an energy storage battery system, including a battery management system, an energy storage converter, a DC contactor, and also a first protection device and a second protection device; wherein, the battery management system is connected to the energy storage converter via dry contact communication, the DC contactor connects the battery stack and the energy storage converter, the input terminal of the first protection device is connected to the dry contact output interface of the battery management system, the input terminal and the output terminal of the second protection device are connected in parallel with the dry contact input interface of the energy storage converter, and the first protection device is connected to the second protection device in communication; the battery management system The system is used to send a dry contact signal when an abnormality is detected in the battery stack. The first protection device is used to send a trigger signal to the second protection device when it monitors the dry contact signal sent by the battery management system; the second protection device is used to start detecting whether the input terminal receives the dry contact signal transmitted from the dry contact when receiving the trigger signal. If not, the output terminal of the second protection device outputs a dry contact signal to the energy storage inverter. The energy storage inverter is used to disconnect from the power grid according to the dry contact signal, and the battery management system is used to control the disconnection of the DC contactor according to the dry contact signal.

[0007] Optionally, the first protection device and the second protection device both include: an input terminal, an output terminal, a communication module and a control module, and the control module is respectively communicatively connected to the input terminal, the output terminal and the communication module, wherein the control module is used to determine whether the input terminal receives a dry contact signal; if no dry contact signal is received, the output terminal is controlled to output the dry contact signal; if a dry contact signal is received, the control module generates a trigger signal, and the communication module is used to send the trigger signal.

[0008] Optionally, the control module is further configured to generate a dry contact abnormality signal when the input terminal does not receive a dry contact signal, and the communication module is further configured to send the dry contact abnormality signal.

[0009] Optionally, it also includes: an energy storage monitoring system and a communication device, the communication device is communicatively connected to the second protection device and the energy storage monitoring system, the second protection device is also used to send a dry contact abnormality signal to the communication device when its input terminal does not receive a dry contact signal, and the communication device is used to report the dry contact abnormality signal to the energy storage monitoring system.

[0010] Optionally, the energy storage monitoring system is further configured to issue an alarm signal according to the dry contact abnormality signal.

[0011] Optionally, an AC contactor is further included, and the energy storage converter is connected to the power grid via the AC contactor.

[0012] Optionally, the energy storage converter is further configured to control the AC contactor to disconnect according to the dry contact signal.

[0013] Optionally, the energy storage converter is used to shut down according to the dry contact signal.

[0014] Optionally, the communication module is a wireless communication module.

[0015] Optionally, the first protection device is connected to the second protection device via wireless communication.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] The energy storage protection device of the present invention uses input terminals and a control module to determine whether the energy storage system's dry contact link has failed. Upon failure, it promptly outputs a dry contact signal through the output terminals. The energy storage battery system of the present invention establishes a redundant communication circuit for the dry contact signal through the first and second protection devices. This device activates when the energy storage system's dry contact link fails, promptly outputting a dry contact signal to the energy storage converter, ensuring that the converter is promptly disconnected from the grid. This prevents the battery management system from disconnecting the DC contactor while under load, thereby improving system safety.

[0018] Summary of the Figures

[0019] The accompanying drawings are included to provide a further understanding of the present application. They are incorporated into and constitute a part of this application. The accompanying drawings illustrate embodiments of the present application and together with the description serve to explain the principle of the present invention.

[0020] In the attached figure:

[0021] FIG1 is a system block diagram of a conventional energy storage battery system.

[0022] FIG2 is an energy storage protection device according to an embodiment of the present invention.

[0023] FIG3 is a system block diagram of an energy storage battery system according to an embodiment of the present invention.

[0024] FIG4 is a system block diagram of the energy storage battery system of the optimized embodiment of FIG3 .

[0025] Preferred embodiments of the present invention

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the following is a brief introduction to the drawings required for describing the embodiments. Obviously, the drawings described below are merely examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios based on these drawings without inventive effort. Unless otherwise apparent from the context or otherwise noted, the same reference numerals in the figures represent the same structure or operation.

[0027] As used in this application and the claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not intended to refer to the singular but may include the plural. Generally speaking, the terms "comprises" and "include" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0028] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is solely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. Furthermore, while the terms used in this application are selected from commonly known and commonly used terms, some terms mentioned in this specification may have been selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant sections of this description. Furthermore, this application should be understood not only by the actual terms used, but also by the meaning implied by each term.

[0029] As mentioned in the background technology, the dry contact cable between the BMS and the PCS may be disconnected or interfered with. When the dry contact signal output by the BMS cannot be delivered to the PCS, the PCS will not be able to disconnect from the power grid in time. The BMS will cut off the DC contactor under load, causing arcing and posing a risk of fire. To address the above problems, this application proposes an energy storage protection device that operates when the dry contact link of the energy storage system fails, ensuring that the PCS is disconnected from the power grid in time and that the BMS will not cut off the DC contactor under load.

[0030] FIG2 illustrates an energy storage protection device according to an embodiment of the present invention. As shown in FIG2 , the energy storage protection device 200 includes an input terminal 21, an output terminal 22, a control module 23, and a communication module 24. The control module 23 is communicatively connected to the input terminal 21, the output terminal 22, and the communication module 24, respectively. The input terminal 21 can receive dry contact signals input from an external source, the output terminal 22 can output dry contact signals, and the communication module 24 is responsible for external communication. The dry contact signal can be sent by the battery management system (BMS) when a battery stack anomaly is detected. The input terminal 21 is used to receive dry contact signals input from an external source and send the dry contact signal to the control module 23. The control module 23 is used to determine whether the input terminal 21 has received a dry contact signal. If not, the control module 23 controls the output terminal 22 to output a dry contact signal. If the input terminal 21 has received a dry contact signal, the control module 23 generates a trigger signal, and the communication module 24 sends the trigger signal. The trigger signal is different from the dry contact signal; the trigger signal only serves as a notification. Taking the energy storage protection device 200 located near the battery management system (BMS) as an example, the energy storage protection device 200 sends a trigger signal to the protection device near the energy storage converter (PCS). The trigger signal notifies the protection device near the energy storage converter (PCS) to start detecting whether its input terminal receives a dry contact signal. If no dry contact signal is received, it indicates that the dry contact link between the BMS and the PCS has failed, and the output terminal of the protection device near the PCS immediately outputs a dry contact signal.

[0031] The energy storage protection device of the present invention determines whether the dry contact link of the energy storage system fails through the open input terminal and the control module, and outputs the dry contact signal in time through the open output terminal when it fails.

[0032] In some embodiments, the control module 23 is further configured to generate a dry contact abnormality signal when the input terminal 21 does not receive a dry contact signal. The communication module 24 is further configured to send the dry contact abnormality signal.

[0033] Optionally, the communication module 24 is a wireless communication module, including but not limited to a WiFi module, a ZigBee module, a Bluetooth module, etc.

[0034] Figure 3 is a system block diagram of an energy storage battery system according to one embodiment of the present invention. As shown in Figure 3, the energy storage battery system 300 includes a battery management system (BMS) 31, a power storage converter (PCS) 32, and a DC contactor K1. The BMS 31 and the power storage converter 32 are connected via dry contacts. The DC contactor K1 electrically connects the power storage converter 32 and a battery stack (not shown). The BMS 31 is used to monitor and evaluate the operating status of the battery stack. When a battery stack fault is detected, the BMS 31 immediately outputs a dry contact signal and controls the dry contact state from open to closed. When the cable connecting the dry contact is normal, the power storage converter 32 receives the dry contact signal, shuts down according to the dry contact signal, and disconnects from the external power grid. The BMS 31 then controls the DC contactor K1 to disconnect the electrical connection with the PCS in response to the dry contact signal (in seconds).

[0035] However, the dry contact cable between the battery management system 31 and the energy storage converter 32 may be disconnected or interfered with. If the dry contact signal output by the battery management system 31 cannot reach the energy storage converter 32, the energy storage converter 32 will not be able to disconnect from the grid in time. The battery management system 31 will disconnect the DC contactor K1 under load, causing arcing and posing a fire risk. To address this, the energy storage battery system 300 of the present application also includes a first protection device 33 and a second protection device 34.

[0036] The first protection device 33 includes an input terminal A1, an output terminal A2, a communication module, and a control module (not shown). The first protection device 34 includes an input terminal B1, an output terminal B2, a communication module, and a control module (not shown). A detailed description of the first protection device 33 and the second protection device 34 can be found in the energy storage protection device 200 and will not be repeated here. The first protection device 33 is communicatively connected to the second protection device 34. Optionally, the first protection device 33 and the second protection device 34 communicate via wireless communication methods such as WiFi, ZigBee, and Bluetooth. The battery management system 31 includes a dry contact output interface that outputs dry contact signals. The input terminal A1 of the first protection device 33 is connected to the dry contact output interface of the battery management system 31. The energy storage converter 32 includes a dry contact input interface that receives dry contact signals via the dry contact input interface. The input terminal B1 and output terminal B2 of the second protection device 34 are connected in parallel to the dry contact input interface of the energy storage converter 32. The first protection device 33 monitors the battery management system 31 in real time. Upon detecting a dry contact signal from the battery management system 31 via input terminal A1, the first protection device 33 transmits a trigger signal M to the second protection device 34 via the communication module. For example, input terminal A1 receives the dry contact signal from the battery management system 31 and transmits the dry contact signal to the control module. The control module determines whether the dry contact signal has been received. If so, the control module generates a trigger signal M, which the communication module then transmits to the second protection device 34.

[0037] The second protection device 34 is used to monitor the trigger signal M sent by the first protection device 33. When the trigger signal M is received, it starts to detect whether the input terminal B1 of the second protection device 34 receives the dry contact signal transmitted from the dry contact cable. If the input terminal B1 does not receive the dry contact signal, the output terminal B2 of the second protection device 34 immediately outputs the dry contact signal to the dry contact input interface of the energy storage inverter 32. The energy storage inverter 32 is also used to disconnect from the power grid according to the dry contact signal. For example, the energy storage inverter 32 is used to shut down according to the dry contact signal and disconnect from the external power grid. The battery management system 31 is then used (in seconds) to control the DC contactor K1 to disconnect according to the dry contact signal.

[0038] It should be noted that, due to the distance between the battery management system (BMS) 31 and the energy storage converter (PCS) 32 during site deployment, it is unreliable to directly establish wireless communication between the BMS and the PCS and transmit the dry contact signal through wireless communication. If there is packet loss, error frame transmission, etc. in the dry contact signal during the wireless communication transmission process, the PCS cannot be disconnected from the power grid based on the received dry contact signal. In this application, the trigger signal M is transmitted through wireless communication. The trigger signal M only serves as a notification, with a small amount of data and fast transmission. The dry contact signal is directly generated by the output terminal B2 of the second protection device 34 near the PCS, and there is no packet loss.

[0039] The energy storage battery system of the present invention constructs a redundant communication line for dry contact signals through the first protection device and the second protection device. When the dry contact link of the energy storage system fails, the first protection device notifies the output terminal of the second protection device to immediately output a dry contact signal. The energy storage converter disconnects from the power grid according to the dry contact signal, ensuring that the energy storage converter is disconnected from the power grid in a timely manner. The battery management system will not cut off the DC contactor under load, thereby improving the safety of the system.

[0040] Figure 4 is a system block diagram of the energy storage battery system according to the optimized embodiment of Figure 3. As shown in Figure 4, energy storage battery system 400 also includes an AC contactor K2. Energy storage converter 32 is connected to the power grid via AC contactor K2. Energy storage converter 32 is also configured to disconnect AC contactor K2 based on a dry contact signal. Disconnecting the energy storage converter from the power grid via the AC contactor eliminates the need to shut down the converter, extending its lifespan and ensuring a more timely disconnection.

[0041] In some embodiments, the energy storage battery system 400 further includes a communication device 35 and an energy storage monitoring system 36. The communication device 35 is communicatively coupled to the second protection device 34 and the energy storage monitoring system 36, respectively. Preferably, the communication device 35 is coupled to the second protection device 34 via wireless communication, including but not limited to WiFi, ZigBee, Bluetooth, and the like. The second protection device 34 is further configured to determine that the dry contact link has failed and transmit a dry contact abnormality signal to the communication device 35 when its input terminal B1 does not receive a dry contact signal. The communication device 35 is configured to report the dry contact abnormality signal to the energy storage monitoring system 36.

[0042] Optionally, the energy storage monitoring system 36 is further configured to issue an alarm signal according to the dry contact abnormality signal.

[0043] The basic concepts have been described above. It will be apparent to those skilled in the art that the above disclosures are merely illustrative and do not constitute limitations on this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and amendments to this application. Such modifications, improvements, and amendments are suggested in this application and remain within the spirit and scope of the exemplary embodiments of this application.

[0044] At the same time, this application uses specific terms to describe the embodiments of this application. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a certain feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that "one embodiment," "an embodiment," or "an alternative embodiment" mentioned twice or multiple times in different locations in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application may be appropriately combined.

[0045] Some aspects of the present application can be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software can be referred to as "data blocks", "modules", "engines", "units", "components" or "systems". The processor can be one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors or combinations thereof. In addition, various aspects of the present application may be expressed as computer products located in one or more computer-readable media, which include computer-readable program code. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, tapes...), optical disks (e.g., compact disks CDs, digital versatile disks DVDs...), smart cards, and flash memory devices (e.g., cards, sticks, key drives...).

[0046] A computer-readable medium may include a propagated data signal embodying computer program code, for example, in baseband or as part of a carrier wave. The propagated signal may be in a variety of forms, including electromagnetic, optical, etc., or a suitable combination thereof. A computer-readable medium may be any computer-readable medium other than a computer-readable storage medium that can be connected to an instruction execution system, apparatus, or device to communicate, propagate, or transmit the program for use. The program code on the computer-readable medium may be transmitted via any suitable medium, including radio, cable, fiber optic cable, radio frequency signal, or similar medium, or any combination of the above.

[0047] Similarly, it should be noted that, in order to simplify the presentation of this application and thus facilitate understanding of one or more embodiments of the invention, the foregoing descriptions of the embodiments of this application sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not mean that the subject matter of this application requires more features than those recited in the claims. In fact, an embodiment may have fewer features than all of the features of a single embodiment disclosed above.

[0048] Although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions can be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the scope of the essential spirit of the present application, they will fall within the scope of the claims of the present application.

Claims

1. An energy storage battery system, characterized in that: It includes a battery management system, an energy storage converter, a DC contactor, and also includes a first protection device and a second protection device, wherein the first protection device and the second protection device both include an open input terminal and an open output terminal; The battery management system is connected to the energy storage converter via dry contact communication, the DC contactor connects the battery stack and the energy storage converter, the input terminal of the first protection device is connected to the dry contact output interface of the battery management system, the input terminal and the output terminal of the second protection device are connected in parallel to the dry contact input interface of the energy storage converter, and the first protection device is connected to the second protection device via communication; The battery management system is used to send a dry contact signal when an abnormality is detected in the battery stack. The first protection device is used to send a trigger signal to the second protection device when it monitors the dry contact signal sent by the battery management system. The second protection device is used to start detecting whether the input terminal receives the dry contact signal transmitted from the dry contact when receiving the trigger signal. If not, the output terminal of the second protection device outputs a dry contact signal to the energy storage inverter. The energy storage inverter is used to disconnect from the power grid according to the dry contact signal, and the battery management system is used to control the disconnection of the DC contactor according to the dry contact signal.

2. The system according to claim 1, characterized in that The first protection device and the second protection device also include a communication module and a control module, wherein the control module is respectively connected to the input terminal, the output terminal and the communication module for communication, wherein the control module is used to determine whether the input terminal receives a dry contact signal, and if no dry contact signal is received, the output terminal is controlled to output the dry contact signal, and if a dry contact signal is received, the control module generates a trigger signal, and the communication module is used to send the trigger signal.

3. The system according to claim 2, characterized in that The control module is further used for generating a dry contact abnormality signal when the input terminal does not receive a dry contact signal, and the communication module is further used for sending the dry contact abnormality signal.

4. The system according to claim 3, characterized in that Also includes: An energy storage monitoring system and a communication device, wherein the communication device is communicatively connected with the second protection device and the energy storage monitoring system, and the second protection device is further used to send a dry contact abnormality signal to the communication device when its input terminal does not receive a dry contact signal, and the communication device is used to report the dry contact abnormality signal to the energy storage monitoring system.

5. The system according to claim 4, characterized in that The energy storage monitoring system is also used to send out an alarm signal according to the abnormal signal of the dry contact.

6. The system according to claim 1, wherein: It also includes an AC contactor, and the energy storage converter is connected to the power grid via the AC contactor.

7. The system according to claim 6, characterized in that The energy storage converter is also used to control the AC contactor to disconnect according to the dry contact signal.

8. The system according to any one of claims 1 to 7, characterized in that: The energy storage converter is used to shut down according to the dry contact signal.

9. The system according to claim 2, characterized in that The communication module is a wireless communication module.

10. The system according to claim 9, characterized in that The first protection device is connected to the second protection device via wireless communication.

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