Control circuit and control method for preventing battery heating from being out of control and storage medium

Abstract

The invention discloses a control circuit and method for preventing battery heating from being out of control and a storage medium. One end of the control circuit is connected with the positive electrode of a battery, and the other end of the control circuit is sequentially connected with a main relay, a controllable fuse, a heating relay, a digital potentiometer, a heating film and a diverter in series to be connected to the negative electrode of the battery; the battery management system BMS is connected with the temperature sensing array, the main relay, the controllable fuse, the heating relay, the digital potentiometer and the shunt; the temperature sensing array is arranged near the battery; the battery management system BMS is set to control the main relay and the heating relay to be closed and control the circuit to be switched on; when the battery temperature reaches a threshold value, the digital potentiometer is controlled to increase the resistance value, so that the heating film reaches the safe heating power density; or the heating relay and / or the main relay are / is controlled to be switched off; or the controllable fuse is controlled to be fused; according to the invention, through dynamic threshold grading protection, multi-parameter collaborative fusing and distributed temperature sensing technologies, rapid blocking of abnormal temperature rise and active prevention of thermal runaway can be realized.

Description

Technical Field

[0001] The present application relates to the technical field of battery heating, and in particular to a control circuit, a control method and a storage medium for preventing battery heating from getting out of control. Background Art

[0002] As a core component of the modern energy system, battery energy storage devices play an irreplaceable role by enhancing the flexibility of the grid and the ability to absorb renewable energy. At the specific operational level, the performance of the battery is strictly limited to the operating temperature range of 0~65℃, especially under low temperature conditions, it faces multiple technical bottlenecks: its capacity retention rate is significantly reduced, the decay rate increases exponentially, and the cycle rate performance also drops drastically. Heating the battery brings new safety challenges and increases the risk of failure of the thermal management system. When the heating load is out of control due to complex factors such as relay failure and control logic delay, the battery cell will experience a violent heat accumulation process. This uncontrolled temperature rise will trigger a chain exothermic reaction in the electrochemical system, and eventually evolve into a thermal runaway phenomenon, accompanied by characteristic violent combustion and explosion and other catastrophic consequences.

[0003] Current heating control technologies mostly rely on a simple combination of heating film and relays. Their inherent defects further exacerbate the risk of high temperature: on the one hand, traditional temperature control strategies only rely on a single temperature threshold to determine the heating end point; on the other hand, when the relay loses control due to contact adhesion or signal delay, the temperature control logic preset by the software is difficult to cut off the abnormal heating circuit, and the battery temperature may exceed the safety limit within tens of seconds. Summary of the invention

[0004] In response to the above problems, the purpose of this application is to provide a control circuit, a control method and a storage medium for preventing battery heating runaway, which solves the risk of temperature rise runaway and heat spread caused by insufficient coordinated control of the main / heating circuit and slow response speed of the battery system under abnormal heating load conditions.

[0005] According to one aspect of the present application, a control circuit for preventing battery heating runaway is provided.

[0006] One end of the control circuit is connected to the positive electrode of the battery, and the other end is connected in series with the main relay, the controllable fuse, the heating relay, the digital potentiometer, the heating film, the shunt, and finally connected to the negative electrode of the battery;

[0007] The control circuit also includes a battery management system BMS, a first end of which is connected to a temperature sensing array, a second end of which is connected to a main relay, a third end of which is connected to a controllable fuse, a fourth end of which is connected to a heating relay, a fifth end of which is connected to a digital potentiometer, and a sixth end of which is connected to a shunt; the temperature sensing array is arranged near the battery;

[0008] The battery management system BMS is set to: control the main relay and the heating relay to close, and control the circuit to conduct; preset the battery temperature threshold; obtain the temperature of the battery in real time through the temperature sensing array. When the battery temperature threshold is reached: control the digital potentiometer to increase the resistance value until the heating current passing through the shunt makes the heating film reach a safe heating power density; and / or, control the heating relay and / or the main relay to turn off and stop heating; and / or, control the controllable fuse to blow.

[0009] Calculate the heating power density of the heating film based on the following formula:

[0010] ,

[0011] Among them, \(P_L\) represents the heating power density of the heating film, \(U\) represents the heating film voltage, \(I\) represents the heating current, and \(S\) represents the heating film area.

[0012] Preferably, in some embodiments of the present application, the control circuit further includes an inverter, and the inverter is connected in parallel with the battery.

[0013] Preferably, in some embodiments of the present application, the control circuit is powered by the inverter or the battery.

[0014] Preferably, in some embodiments of the present application, the battery management system BMS is set to: preset a three-level battery temperature threshold; when the battery temperature threshold reaches the first level, control the digital potentiometer to increase the resistance value until the heating current passing through the shunt makes the heating film reach a safe heating power; when the battery temperature threshold reaches the second level, control the heating relay and / or the main relay to turn off and stop heating; when the battery temperature threshold reaches the third level, control the controllable fuse to blow.

[0015] Preferably, in some embodiments of the present application, the battery management system BMS is set to: input the ambient temperature, working temperature, and heating film model of the battery; calculate the time taken per unit time for the heating film with different heating power densities to be heated from the ambient temperature to the working temperature, and obtain the predicted heating time of the heating film; based on the predicted heating time of the heating film, flexibly adjust the resistance value of the digital potentiometer.

[0016] According to another aspect of the present application, the present application also provides a control method for preventing the out-of-control heating of the battery, including the control circuit of any one of the above embodiments, including:

[0017] Control the main relay and the heating relay to close, and control the circuit to conduct; preset the battery temperature threshold; obtain the temperature of the battery in real time through the temperature sensing array. When the battery temperature threshold is reached: control the digital potentiometer to increase the resistance value until the heating current passing through the shunt makes the heating film reach a safe heating power density; and / or, control the heating relay and / or the main relay to turn off and stop heating; and / or, control the controllable fuse to blow.

[0018] Calculate the heating power density of the heating film based on the following formula:

[0019] ,

[0020] wherein, PL represents the heating power density of the heating film, U represents the heating film voltage, I represents the heating current, and S represents the heating film area.

[0021] Preferably, in some embodiments of the present application, the control method further includes: presetting a three-level battery temperature threshold;

[0022] When the battery temperature threshold reaches the first level, control the digital potentiometer to increase the resistance value until the heating current passing through the shunt makes the heating film reach a safe heating power; when the battery temperature threshold reaches the second level, control the heating relay and / or the main relay to turn off and stop heating; when the battery temperature threshold reaches the third level, control the controllable fuse to blow.

[0023] Preferably, in some embodiments of the present application, the control method further includes: inputting the ambient temperature, operating temperature, and heating film model of the battery; calculating the time taken per unit time for the heating film with different heating power densities to heat from the ambient temperature to the operating temperature to obtain the expected heating time of the heating film; and flexibly adjusting the resistance value of the digital potentiometer based on the expected heating time of the heating film.

[0024] According to another aspect of the present application, the present application also provides a computer-readable storage medium, on which computer instructions are stored. When the computer instructions are executed by a processor, the control method of any one of the above embodiments can be implemented.

[0025] It should be understood that within the scope of the present application, the above technical features of the present application and the technical features specifically described below (such as in the embodiments) can be combined with each other to form new or preferred technical solutions. Due to space limitations, they will not be elaborated one by one here.

[0026] Compared with the prior art, the present application has the following technical effects:

[0027] When the relay is stuck or the signal fails in the present application, the triggering condition of thermal runaway can be directly blocked; at the same time, through dynamic threshold hierarchical protection, multi-parameter collaborative fusing, and distributed temperature sensing technology, rapid blocking of abnormal temperature rise and active prevention of thermal runaway are achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] By referring to the accompanying drawings and describing its exemplary embodiments in detail, the above and other features and advantages of the present application will become more apparent.

[0029] Figure 1The figure shows a schematic diagram of a control circuit for preventing battery heating out of control according to an embodiment of the present application.

[0030] Figure 2 The figure shows the discharge capacity of the battery of the present application at different temperatures.

[0031] Reference numerals: 1 Battery Management System BMS; 2 Battery; 3 Inverter; 4 Temperature sensing array; 5 Shunt; 6 Digital potentiometer; 7 Controllable fuse; 8 Heating relay; 9 Main relay; 10 Heating film. Specific embodiments

[0032] To make the objectives, technical solutions, beneficial effects and remarkable progress of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the embodiments of the present application. Obviously, all the described embodiments are only partial embodiments of the present application, rather than all the embodiments; based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0033] The present application will be further elaborated below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present application and not to limit the scope of the present application.

[0034] The mention of "embodiments" in this article means that the specific features, structures or characteristics described in conjunction with the embodiments can be included in at least one embodiment of this article. The phrase appears in various positions in the specification and does not necessarily refer to the same embodiment, nor is it limited to mutually exclusive independent or alternative embodiments. Those skilled in the art should be able to understand that the embodiments in this article can be combined with other embodiments without structural conflicts.

[0035] In the description of this article, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection" should be understood in a broad sense. It can be a movable connection, a fixed connection or integrated, or it can be connected through a certain connecting piece. 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 specific circumstances.

[0036] In the description of this article, terms indicating orientation or positional relationships such as "upper", "lower", "left", "right", "horizontal", "vertical", "height", "length", "width", etc. are intended to accurately describe the embodiments and simplify the description, rather than limiting the parts or structures involved to have a specific orientation, be installed or operated in a specific orientation, and should not be construed as a limitation to the embodiments in this article.

[0037] In the description of this article, terms such as "first" and "second" are only used to distinguish different objects, and cannot be understood as indicating relative importance or limiting the quantity, specific order, or primary-secondary relationship of the described technical features. In the description of this article, the meaning of "a plurality" is at least two.

[0038] Embodiments of the present application will now be described in detail with reference to the accompanying drawings. Preferred embodiments of the present application will now be described in detail, and examples thereof are shown in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout all the drawings to represent the same or similar parts.

[0039] Figure 1 A schematic diagram of a control circuit for preventing battery heating runaway according to an embodiment of the present application is shown. As Figure 1 shown, one end of the control circuit for preventing battery heating runaway of the present application is connected to the positive electrode of the battery, and the other end is sequentially connected in series with a main relay, a controllable fuse, a heating relay, a digital potentiometer, a heating film, and a shunt, and finally connected to the negative electrode of the battery to form a heating circuit. The digital potentiometer of the present application adjusts the resistance value in a numerical control manner, and has significant advantages such as flexible use, high adjustment accuracy, no contacts, low noise, not easily soiled, vibration resistance, interference resistance, small volume, and long service life. The controllable fuse of the present application selects a fuse that can manually or automatically control the fusing process according to needs. It combines the protection function of a traditional fuse and the characteristics of a controllable switch, and can manually disconnect the circuit when needed, and keep the circuit connected when not needed.

[0040] The control circuit further includes a battery management system BMS, whose first end is connected to the temperature sensing array, whose second end is connected to the main relay, whose third end is connected to the controllable fuse, whose fourth end is connected to the heating relay, whose fifth end is connected to the digital potentiometer, and whose sixth end is connected to the shunt; the temperature sensing array is arranged near the battery; the temperature sensing array of the present application is a device formed by arranging a plurality of temperature sensors in a certain geometric pattern for collecting and processing battery temperature information.

[0041] The battery management system BMS is set to: control the main relay and the heating relay to close, and the control circuit is turned on; preset a battery temperature threshold; obtain the temperature of the battery in real time through the temperature sensing array, and when the battery temperature threshold is reached: control the digital potentiometer to increase the resistance value until the heating current passing through the shunt makes the heating film reach a safe heating power density; and / or, control the heating relay and / or the main relay to turn off to stop heating; and / or, control the controllable fuse to fuse;

[0042] Calculate the heating power density of the heating film based on the following formula:

[0043] ,

[0044] Among them, PL represents the heating power density of the heating film, U represents the heating film voltage, I represents the heating current, and S represents the heating film area.

[0045] Preferably, in some embodiments of the present application, the control circuit further includes an inverter, and the inverter is connected in parallel with the battery to form the main circuit of the battery system.

[0046] Preferably, in some embodiments of the present application, the control circuit is powered by an inverter or a battery.

[0047] Preferably, in some embodiments of the present application, the battery management system BMS is set as follows: preset three-level battery temperature thresholds; when the battery temperature threshold reaches the first level, control the digital potentiometer to increase the resistance value until the heating current passing through the shunt makes the heating film reach a safe heating power; when the battery temperature threshold reaches the second level, control the heating relay and / or the main relay to turn off and stop heating; when the battery temperature threshold reaches the third level, control the controllable fuse to blow.

[0048] As can be understood by those skilled in the art, the battery management system BMS can control the heating circuit to conduct by closing the main relay and the heating relay. The battery management system BMS monitors the value of the heating current passing through by using a shunt; the battery temperature can be monitored in real time by using a temperature sensing array. When the battery temperature reaches the first-level warning value, increase the resistance value of the digital potentiometer to limit the power flowing through the heating film; if the temperature continues to rise to the second-level warning value, the battery management system BMS cuts off the heating relay and the main relay to stop heating; if the monitored temperature continues to rise to the third-level warning stage, control the controllable fuse to blow. Therefore, the present application can actively block the out-of-control battery heating, respond to different treatment strategies under different out-of-control heating conditions in a hierarchical manner, and effectively prevent the battery temperature from being too high and causing an explosion.

[0049] Preferably, in some embodiments of the present application, the battery management system BMS is set as follows: input the ambient temperature, working temperature, and heating film model of the battery; calculate the time taken per unit time for the heating film with different heating power densities to be heated from the ambient temperature to the working temperature to obtain the estimated heating time of the heating film; based on the estimated heating time of the heating film, flexibly adjust the resistance value of the digital potentiometer.

[0050] According to another aspect of the present application, the present application further provides a control method for preventing out-of-control battery heating, including the control circuit of any one of the above embodiments, including:

[0051] Control the main relay and the heating relay to close, and the control circuit is turned on; preset the battery temperature threshold; obtain the temperature of the battery in real time through the temperature sensing array. When the battery temperature threshold is reached: control the digital potentiometer to increase the resistance until the heating current passing through the shunt makes the heating film reach a safe heating power density; and / or, control the heating relay and / or the main relay to turn off and stop heating; and / or, control the controllable fuse to blow.

[0052] Calculate the heating power density of the heating film based on the following formula:

[0053] ,

[0054] wherein, \(P_L\) represents the heating power density of the heating film, \(U\) represents the heating film voltage, \(I\) represents the heating current, and \(S\) represents the heating film area.

[0055] Preferably, in some embodiments of the present application, the control method further includes: presetting a three-level battery temperature threshold;

[0056] When the battery temperature threshold reaches the first level, control the digital potentiometer to increase the resistance until the heating current passing through the shunt makes the heating film reach a safe heating power; when the battery temperature threshold reaches the second level, control the heating relay and / or the main relay to turn off and stop heating; when the battery temperature threshold reaches the third level, control the controllable fuse to blow.

[0057] As can be understood by those skilled in the art, the battery management system BMS closes the main relay and the heating relay, and can control the heating circuit to be turned on. The battery management system BMS uses a shunt to monitor the value of the heating current passing through; the temperature sensing array can be used to monitor the battery temperature in real time. When the battery temperature reaches the first-level warning value, increase the resistance of the digital potentiometer to limit the power flowing through the heating film; if the temperature continues to rise to the second-level warning value, the battery management system BMS cuts off the heating relay and the main relay to stop heating; if the monitored temperature continues to rise to the third-level warning stage, control the controllable fuse to blow. Therefore, the present application can actively block the out-of-control battery heating, respond to different processing strategies under different heating out-of-control situations in a hierarchical manner, and effectively prevent the battery temperature from being too high and causing an explosion.

[0058] Preferably, in some embodiments of the present application, the control method further includes: inputting the ambient temperature, working temperature, and heating film model of the battery; calculating the time-consuming per unit time for the heating film with different heating power densities to be heated from the ambient temperature to the working temperature, and obtaining the expected heating time of the heating film; based on the expected heating time of the heating film, flexibly adjust the resistance value of the digital potentiometer.

[0059] As can be understood by those skilled in the art, Figure 2 shows the discharge capacity of the battery of the present application at different temperatures in some embodiments. From Figure 2It can be seen that when the ambient temperature is too low, the discharge capacity of the battery will be impaired. Heating it to an appropriate temperature will greatly improve the battery's discharge capacity.

[0060] Specifically, in some embodiments of the present application, the ambient temperature of the input battery is -20°C, the operating temperature is 5°C, and the heating film model is selected as a polyimide heating film here; Table 1 shows the experimental data of heating films with different powers of a 4V battery from -20°C to 5°C. It can be seen from Table 1 that the greater the heating power density, the less time it takes for the heating film to heat from the ambient temperature of -20°C to the operating temperature of 5°C per unit time. The expected heating time of the heating film is obtained through experiments; based on the expected heating time of the heating film, the resistance value of the digital potentiometer can be flexibly adjusted. After the power of the heating film is increased, the battery temperature rise time is greatly reduced, and the out-of-control risk is greatly increased. By predicting the heating time of the heating film in advance, restricting the power of the heating film in a timely manner, controlling the heating time, and monitoring the battery temperature in real time, the present application can effectively prevent heating out-of-control.

[0061] Table 1 Experimental data of heating films with different powers of a 4V battery from -20°C to 5°C

[0062]

[0063] According to another aspect of the present application, the present application also provides a computer-readable storage medium, on which computer instructions are stored. When the computer instructions are executed by a processor, the control method of any of the above embodiments can be implemented.

[0064] A control circuit, control method, and storage medium for preventing battery heating out-of-control according to the present application. Aiming at the problems of response hysteresis and relay out-of-control risk existing in the existing heating control technology, the present application takes "active blocking and hierarchical response" as the core. Through the coordinated control of the main circuit and the heating circuit and the dynamic threshold response mechanism, when the relay adheres or the signal fails, the thermal runaway trigger condition is directly blocked; at the same time, a hierarchical fuse protection strategy is designed to actively cut off the energy transmission path under extreme working conditions such as heating film short circuit and local overheating, and adjust the heating current threshold in real time, so as to suppress the risk of thermal spread from the source and ensure the precise balance between the low-temperature heating demand and the high-temperature safety protection of the battery system.

[0065] The above describes the preferred embodiments of the present application. It should be understood that the present application is not limited to the above specific implementation manners, and the devices and structures not described in detail should be understood to be implemented in a common manner in the art; any person skilled in the art, without departing from the scope of the technical solution of the present application, can make many possible changes and modifications to the technical solution of the present application by using the methods and technical contents disclosed above, or modify it into an equivalent embodiment with equivalent changes, which does not affect the essence of the present application. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application still fall within the scope of protection of the technical solution of the present application.

Claims

1. A control circuit for preventing battery heating runaway, characterized in that one end of the control circuit is connected to the positive electrode of the battery, and the other end is sequentially connected in series with a main relay, a controllable fuse, a heating relay, a digital potentiometer, a heating film, and a shunt, and finally connected to the negative electrode of the battery; the control circuit further includes a battery management system, its first end is connected to a temperature sensing array, its second end is connected to the main relay, its third end is connected to the controllable fuse, its fourth end is connected to the heating relay, its fifth end is connected to the digital potentiometer, and its sixth end is connected to the shunt; the temperature sensing array is arranged near the battery; the battery management system is configured to: control the main relay and the heating relay to close, and the control circuit is turned on; preset a battery temperature threshold; obtain the temperature of the battery in real time through the temperature sensing array, and when the battery temperature threshold is reached: control the digital potentiometer to increase the resistance value until the heating current passing through the shunt makes the heating film reach a safe heating power density; and / or, control the heating relay and / or the main relay to turn off to stop heating; and / or, control the controllable fuse to blow; calculate the heating power density of the heating film based on the following formula: ， wherein, PL represents the heating power density of the heating film, U represents the heating film voltage, I represents the heating current, and S represents the heating film area.

2. The control circuit according to claim 1, wherein the control circuit further includes an inverter, and the inverter is connected in parallel with the battery.

3. The control circuit according to claim 2, wherein the control circuit is powered by the inverter or the battery.

4. The control circuit according to claim 1, characterized in that the battery management system is configured to: preset a three-level battery temperature threshold; when the battery temperature threshold reaches the first level, control the digital potentiometer to increase the resistance value until the heating current passing through the shunt makes the heating film reach a safe heating power; when the battery temperature threshold reaches the second level, control the heating relay and / or the main relay to turn off to stop heating; when the battery temperature threshold reaches the third level, control the controllable fuse to blow.

5. The control circuit according to claim 1, wherein the battery management system is configured to: input the ambient temperature, working temperature, and heating film model of the battery; calculate the time taken per unit time for the heating film with different heating power densities to be heated from the ambient temperature to the working temperature to obtain the predicted heating time of the heating film; flexibly adjust the resistance value of the digital potentiometer based on the predicted heating time of the heating film.

6. Control method for preventing battery heating out of control, characterized in that, including the control circuit according to any one of claims 1-5: control the main relay and the heating relay to close, and the control circuit is turned on; preset the battery temperature threshold; obtain the temperature of the battery in real time through the temperature sensing array, and when the battery temperature threshold is reached: control the digital potentiometer to increase the resistance value until the heating current passing through the shunt makes the heating film reach a safe heating power density; and / or, control the heating relay and / or the main relay to turn off to stop heating; and / or, control the controllable fuse to blow; calculate the heating power density of the heating film based on the following formula: ， Among them, PL represents the heating power density of the heating film, U represents the heating film voltage, I represents the heating current, and S represents the heating film area.

7. The control method according to claim 6, characterized in that The control method further includes: Presetting three levels of battery temperature thresholds; When the battery temperature threshold reaches the first level, controlling the digital potentiometer to increase the resistance value until the heating current passing through the shunt makes the heating film reach a safe heating power; When the battery temperature threshold reaches the second level, controlling the heating relay and / or the main relay to turn off and stop heating; When the battery temperature threshold reaches the third level, controlling the controllable fuse to blow.

8. The control method according to claim 6, characterized in that The control method further includes: Inputting the ambient temperature, working temperature, and heating film model of the battery; Calculating the time consumption per unit time for the heating film with different heating power densities to be heated from the ambient temperature to the working temperature to obtain the predicted heating time of the heating film; Based on the predicted heating time of the heating film, flexibly adjusting the resistance value of the digital potentiometer.

9. A computer-readable storage medium having computer instructions stored thereon, characterized in that, When the computer instruction is executed by the processor, the control method described in any one of claims 6-8 is implemented.

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