Multi-level safety isolation architecture of the measurement and control system of the secondary utilization power lithium battery energy storage system

Abstract

The present invention relates to a multi-level safety isolation architecture of a measurement and control system of a cascade utilization power lithium battery energy storage system, and to the field of safety technology of energy storage systems for cascade utilization of retired power lithium batteries. The control power supply of each BMS board of the present invention is independent and isolated, and the power supply of each BMS board is provided by its corresponding battery group. Optical coupling, optical fiber, magnetic coupling and other isolation methods are adopted between each BMS board and the communication bus. Optical fiber and other isolation methods are also adopted between the communication bus and the host computer. Compared with the existing practice of sharing control power supply and CAN bus for BMS boards corresponding to multiple groups of batteries in the energy storage system, the present invention inserts safety isolation in each level of the measurement and control of the energy storage system to form a multi-level safety isolation architecture, which can prevent the unknown high voltage generated by the explosion from breaking through other BMS boards in the system and causing short circuits of other groups of battery cells when a battery explosion accident occurs, thereby greatly improving the safety of the lithium battery centralized energy storage system.

Description

Technical Field

[0001] The present invention relates to the field of power electronics and the safety technology of energy storage systems for cascade utilization of retired power lithium batteries, and in particular to a multi-level safety isolation architecture of an energy storage system for cascade utilization of retired power lithium batteries. Background Art

[0002] Compared with other forms of energy storage, energy storage based on lithium batteries has advantages such as high energy density, long cycle life, and high efficiency, but its price remains high. As electric vehicles have become increasingly popular in recent years, a large number of retired power lithium batteries will be generated. These retired batteries usually retain 70% to 80% of the initial capacity. Therefore, the cascade utilization of retired power lithium batteries is conducive to reducing the construction cost of large-scale energy storage systems and promoting the popularization of energy storage technology.

[0003] The battery capacity of the energy storage power station is huge, and the safety hazards of the centralized application of lithium batteries are very prominent and have been ignored for a long time. Under the current technical and process levels, the thermal runaway and explosion of lithium battery cells have a high probability. A large number of electric vehicle combustion accidents reflect that traditional firefighting measures are extremely difficult to control the fire. The power batteries placed in the power storage station are equivalent to the batteries of dozens or even hundreds of cars. For example, the battery modules are stacked in an open space like shelves. The above content is added here. If there is only one thermal runaway and explosion among the tens of thousands of single cells, it will ignite the entire site, and the existing firefighting measures cannot extinguish it at all. At present, in South Korea, where centralized energy storage demonstration projects are relatively active, more than 40 sites have spontaneous combustion and the entire site has been burned, accounting for the majority of all its energy storage sites. Therefore, the existing technology proposes to use the method of isolating the warehouses from each other to prevent the explosion of lithium battery packs from spreading to the entire site, and to carry out firefighting in the warehouse at the same time. However, despite the physical separation, the control power supply and CAN bus of the BMS of each battery group are traditionally connected together. When one group explodes, an unknown high voltage will be generated on the CAN bus, thereby affecting other BMS boards and host computers connected to the CAN, thereby causing secondary disasters, as shown in the attached figure. Figure 1 shown.

[0004] Therefore, the electrical and control signal architecture of the control power supply and communication of the BMS board corresponding to each battery pack needs to ensure the safety of other battery packs in the energy storage station and their host computers when a battery pack explodes. Therefore, a new multi-level safety isolation architecture is required in the electrical and control signal architecture. Summary of the invention

[0005] The technical problem to be solved by the present invention is: the present invention provides a multi-level safety isolation architecture for the measurement and control system of the cascade utilization power lithium battery energy storage system, achieving the control electrical isolation of the BMS, the isolation between each BMS board and the communication bus, and the isolation between the communication bus and the host computer, greatly improving the safety of the warehouse and the host computer in terms of electrical and control signal architecture.

[0006] The technical solution of the present invention is: a multi-level safety isolation architecture of the measurement and control system of the cascade utilization power lithium battery energy storage system, wherein the multi-level safety isolation architecture includes the isolation link of the control power supply of the BMS board, the isolation link between the BMS board and the communication bus of the battery pack in each compartment, and the isolation link between the communication bus and the host computer;

[0007] The isolation link of the control power supply of the BMS board is that the BMS board is powered by the corresponding battery pack and uses control power supply isolation. The BMS board collects the status data of the corresponding battery pack and summarizes it to the host computer through the communication bus;

[0008] The isolation link between the BMS board and the communication bus of the battery pack in each compartment is that each BMS board is connected to the communication bus through the isolation link, and the communication bus is the only electrical signal connection between the BMS board and the host computer;

[0009] The isolation link between the communication bus and the host computer is that the communication bus and the host computer are connected through the isolation link, so as to ensure that when a battery pack explosion accident occurs in a certain compartment of the host computer, and when the isolation link between the BMS board and the communication bus is broken down by this accident, the whole station control can still operate reliably.

[0010] As a further solution of the present invention, the battery groups connected and monitored by the BMS board are independently floated or further connected in series and parallel to form groups.

[0011] As a further solution of the present invention, the control power supply of the BMS board is powered by the battery pack connected and monitored by it through a voltage conversion isolation circuit, rather than a unified power supply or an external power supply.

[0012] As a further solution of the present invention, the communication bus adopts a CAN bus.

[0013] As a further solution of the present invention, optical fiber or optical coupling is used as the isolation link between the host computer and each BMS board and the communication bus.

[0014] The beneficial effects of the present invention are:

[0015] 1. The multi-level safety isolation architecture of the measurement and control system of the cascade utilization of retired power lithium battery energy storage system proposed in the present invention is different from the traditional unified power supply in that the power supply of the BMS board is powered by the battery pack that the BMS board needs to collect information. The control power supply isolation of the BMS board is achieved by disconnecting the negative poles of the battery packs.

[0016] 2. On the basis of the physical isolation of placing battery components in different positions, the present invention designs electrical and control signal isolation at multiple positions in the energy storage system. Each BMS board is connected to the communication bus only through an isolation link, that is, the BMS in each position is isolated, and the communication bus is the only electrical signal connection between the BMS board and the host computer. The isolation link between the communication bus and the host computer is that the communication bus and the host computer are connected through the isolation link, so as to ensure that when the host computer is in a battery pack explosion accident in a certain position, and when the isolation link between the BMS board and the communication bus is broken down by this accident, the whole station control can still operate reliably. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of secondary disasters caused by the explosion of a battery pack in a certain warehouse under the traditional control and communication bus architecture;

[0018] Figure 2 This is a schematic diagram of the control power isolation of the BMS;

[0019] Figure 3 Isolation between each BMS board and the communication bus;

[0020] Figure 4 It is a schematic diagram of the isolation between the communication bus and the host computer;

[0021] Figure 5 This is a schematic diagram showing a disaster being confined to a single storage compartment when the multi-level safety isolation architecture of the present invention is adopted. DETAILED DESCRIPTION

[0022] In order to make the objectives, technical solutions and beneficial effects of the present invention clearer and more understandable, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings to facilitate understanding by technicians.

[0023] Example 1, a multi-level safety isolation architecture of the measurement and control system of the cascade utilization power lithium battery energy storage system, the multi-level safety isolation architecture includes the isolation link of the control power supply of the BMS board, the isolation link between the BMS board and the communication bus of the battery pack in each compartment, and the isolation link between the communication bus and the host computer;

[0024] The isolation link of the control power supply of the BMS board is that the BMS board is powered by the corresponding battery pack and uses control power supply isolation. The BMS board collects the status data of the corresponding battery pack and summarizes it to the host computer through the communication bus;

[0025] The isolation link between the BMS board and the communication bus of the battery pack in each compartment is that each BMS board is connected to the communication bus through the isolation link, and the communication bus is the only electrical signal connection between the BMS board and the host computer;

[0026] The isolation link between the communication bus and the host computer is that the communication bus and the host computer are connected through the isolation link, so as to ensure that when a battery pack explosion accident occurs in a certain compartment of the host computer, and when the isolation link between the BMS board and the communication bus is broken down by this accident, the whole station control can still operate reliably.

[0027] As a further solution of the present invention, the battery groups connected and monitored by the BMS board are independently floated or further connected in series and parallel to form groups.

[0028] As a further solution of the present invention, the control power supply of the BMS board is powered by the battery pack connected and monitored by it through a voltage conversion isolation circuit, rather than a unified power supply or an external power supply.

[0029] As a further solution of the present invention, the communication bus adopts a CAN bus.

[0030] As a further solution of the present invention, optical fiber or optical coupling is used as the isolation link between the host computer and each BMS board and the communication bus.

[0031] Embodiment 2: The battery pack of the present invention may be multiple. This embodiment takes four battery packs as an example to describe the present invention in detail.

[0032] like Figure 1 As shown, it shows the process in which the unknown high voltage caused by the explosion of battery pack 1 in the measurement and control system of the power lithium battery energy storage system without a multi-layer safety isolation architecture causes damage to the host computer and other BMS boards along the communication bus;

[0033] like Figure 2 As shown, the BMS boards BMS1, BMS2, BMS3, and BMS4 are powered by the voltage of battery pack 1, battery pack 2, battery pack 3, and battery pack 4 in their respective positions, which are converted into 5V through step-down isolation. The isolation of the BMS board control circuit is achieved.

[0034] like Figure 3 As shown, after each BMS board has a control power supply, the collected battery pack status data is transmitted to the communication bus through the isolation link, thereby realizing isolation between each BMS board and the communication bus.

[0035] like Figure 4 As shown in the figure, the information collected by each BMS board is summarized in the communication bus and then must be transmitted to the host computer connected to the communication bus through optical fiber (optical coupler) isolation.

[0036] Figure 5 The beneficial effects of the present invention are illustrated. When the battery pack 1 in the embodiment explodes, the disaster is confined to the compartment 1 by the isolation link between the BMS1 and the CAN bus, and no unknown high voltage can be generated on the communication bus. Even if the isolation link between the BMS1 and the communication bus is broken down, there is another layer of isolation link between the communication bus and the host computer and other BMS boards for protection.

[0037] The present invention inserts safety isolation into each level of the energy storage system measurement and control to form a multi-level safety isolation architecture, which can prevent the unknown high voltage generated by the explosion from breaking through other BMS boards in the system and causing short circuits in other battery cells when a battery explosion accident occurs, thereby greatly improving the safety of the lithium battery centralized energy storage system.

[0038] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solution of the invention rather than to limit it. Among them, the isolation between the BMS board and the communication bus can be optical coupling isolation, optical fiber isolation, magnetic coupling isolation, etc. The interaction between the BMS board and the host computer can use the CAN bus or other communication methods, as long as an isolation link is added in the middle. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. The multi-level safety isolation architecture of the measurement and control system of the secondary utilization power lithium battery energy storage system is characterized by: The multi-level safety isolation architecture includes the isolation link of the control power supply of the BMS board, the isolation link between the BMS board and the communication bus of the battery pack in each compartment, and the isolation link between the communication bus and the host computer; The isolation link of the control power supply of the BMS board is that the BMS board is powered by the corresponding battery pack and uses control power supply isolation. The BMS board collects the status data of the corresponding battery pack and summarizes it to the host computer through the communication bus; The isolation link between the BMS board and the communication bus of the battery pack in each compartment is that each BMS board is connected to the communication bus through the isolation link, and the communication bus is the only electrical signal connection between the BMS board and the host computer; The isolation link between the communication bus and the host computer is that the communication bus and the host computer are connected through the isolation link; The battery packs connected and monitored by the BMS board are each independently floated or further connected in series and parallel to form a group; The control power supply of the BMS board is supplied by the battery pack connected and monitored by it through a voltage conversion isolation circuit, rather than a unified power supply or an external power supply.

2. The multi-level safety isolation architecture of the measurement and control system of the secondary utilization power lithium battery energy storage system according to claim 1 is characterized in that: The communication bus adopts CAN bus.

3. The multi-level safety isolation architecture of the measurement and control system of the secondary utilization power lithium battery energy storage system according to claim 1 is characterized in that: Optical fiber or optical coupling is used as the isolation link between the host computer and each BMS board and the communication bus.

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