Control circuit, control method and storage medium for preventing battery heating runaway

Abstract

The present application discloses a control circuit, a control method and a storage medium for preventing battery heating runaway. One end of the control circuit is connected to the positive electrode of the battery, and the other end is connected in series with a main relay, a controllable fuse, a heating relay, a digital potentiometer, a heating film and a shunt to the negative electrode of the battery. The battery management system BMS is connected to the temperature sensor array, the main relay, the controllable fuse, the heating relay, the digital potentiometer and the shunt; the temperature sensor 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 the control circuit to be turned on; when the battery temperature reaches the threshold: control the digital potentiometer to increase the resistance value so that the heating film reaches a safe heating power density; or control the heating relay and / or the main relay to be turned off; or control the controllable fuse to be blown; the present application can achieve rapid blocking of abnormal temperature rise and active prevention of thermal runaway through dynamic threshold hierarchical protection, multi-parameter coordinated fusing and distributed temperature sensing technology.

Description

Technical Field

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

[0002] As a core component of modern energy systems, battery energy storage devices play an irreplaceable role by enhancing grid flexibility and renewable energy absorption capacity. In terms of specific operation, battery performance is strictly limited to the operating temperature range of 0-65°C. In particular, they face multiple technical bottlenecks under low-temperature conditions: their capacity retention rate is significantly reduced, the decay rate increases exponentially, and the cycle rate performance also drops off a cliff. Heating batteries brings new safety challenges and increases the risk of failure of thermal management systems. When combined factors such as relay failures and control logic delays cause the heating load to run away, the battery cell will experience a severe heat accumulation process. This uncontrolled temperature rise can trigger a chain reaction of exothermic reactions within the electrochemical system, eventually evolving into thermal runaway, accompanied by catastrophic consequences such as characteristic violent combustion and explosion.

[0003] Current heating control technologies mostly rely on a simple combination of heating film and relays, and their inherent defects further exacerbate the risk of high temperature: on the one hand, traditional temperature control strategies rely only 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 software-preset temperature control logic has difficulty cutting 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, control method and 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 under abnormal heating load conditions of the battery system.

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

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

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

[0008] The battery management system BMS is set to: control the main relay and heating relay to close, and control the circuit to be turned on; preset the battery temperature threshold; obtain the battery temperature in real time through the temperature sensor array, and when the battery temperature reaches the first-level temperature threshold, input the battery's ambient temperature, operating temperature, and heating film model; calculate the unit time taken for the heating film with different heating power densities to heat from the ambient temperature to the operating temperature, and obtain the estimated heating time of the heating film; based on the estimated heating time of the heating film, control the digital potentiometer to increase the resistance value, so that the heating current passing through the shunt makes the heating film reach a safe heating power; when the battery temperature reaches the second-level temperature threshold, control the heating relay and / or main relay to turn off and stop heating; when the battery temperature reaches the third-level temperature threshold, control the controllable fuse to melt.

[0009] The heating power density of the heating film is calculated based on the following formula:

[0010] ,

[0011] 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.

[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 an inverter or a battery.

[0014] According to another aspect of the present application, the present application further provides a control method for preventing battery heating runaway, comprising the control circuit of any one of the above embodiments, including:

[0015] Control the main relay and heating relay to close and the control circuit to conduct; preset the battery temperature threshold; obtain the battery temperature in real time through the temperature sensor array, and when the battery temperature reaches the first-level temperature threshold, input the battery's ambient temperature, operating temperature, and heating film model; calculate the unit time taken for heating films with different heating power densities to heat from ambient temperature to operating temperature, and obtain the estimated heating time of the heating film; based on the estimated heating time of the heating film, control the digital potentiometer to increase the resistance value so that the heating current passing through the shunt makes the heating film reach a safe heating power; when the battery temperature reaches the second-level temperature threshold, control the heating relay and / or the main relay to turn off and stop heating; when the battery temperature reaches the third-level temperature threshold, control the controllable fuse to melt.

[0016] The heating power density of the heating film is calculated based on the following formula:

[0017] ,

[0018] 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.

[0019] According to another aspect of the present application, the present application further 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.

[0020] It should be understood that within the scope of this application, the above-mentioned technical features of this application and the technical features described in detail 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 listed here one by one.

[0021] Compared with the existing technology, this application has the following technical effects:

[0022] This application can directly block the thermal runaway triggering conditions when the relay is stuck or the signal fails; at the same time, through dynamic threshold hierarchical protection, multi-parameter coordinated fusing and distributed temperature sensing technology, it can achieve rapid blocking of abnormal temperature rise and active prevention of thermal runaway. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and other features and advantages of the present application will become more apparent by describing in detail example embodiments thereof with reference to the accompanying drawings.

[0024] Figure 1 A schematic diagram of a control circuit for preventing battery heating runaway according to an embodiment of the present application is shown.

[0025] Figure 2 The discharge capacity of the battery of the present application at different temperatures is shown.

[0026] Reference numerals: 1 Battery management system BMS; 2 Battery; 3 Inverter; 4 Temperature sensor array; 5 Shunt; 6 Digital potentiometer; 7 Controllable fuse; 8 Heating relay; 9 Main relay; 10 Heating film. DETAILED DESCRIPTION

[0027] To make the purpose, technical solutions, beneficial effects, and significant improvements of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the embodiments of this application. Obviously, all the embodiments described are only some of the embodiments of this application, not all of them; based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0028] The present application will be further described below in conjunction with specific implementations. It should be understood that these embodiments are only used to illustrate the present application and are not intended to limit the scope of the present application.

[0029] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment herein. The appearance of such phrases in various places in the specification does not necessarily refer to the same embodiment, nor does it limit mutually exclusive independent or alternative embodiments. Those skilled in the art will appreciate that an embodiment herein may be combined with other embodiments as long as no structural conflicts arise.

[0030] In the description herein, unless otherwise specified or limited, the technical terms "installed," "connected," and "connected" should be understood broadly, and may refer to a movable connection, a fixed connection or integration, or connection via a connector. Those skilled in the art will understand the specific meanings of these terms in the embodiments of this application based on the specific circumstances.

[0031] In the description of this document, terms indicating orientation or positional relationships, such as "up", "down", "left", "right", "horizontal", "vertical", "height", "length", and "width", are intended to accurately describe the embodiments and simplify the description, but are not intended to limit the parts or structures involved to having a specific orientation, being installed or operated in a specific orientation, and should not be understood as limiting the embodiments in this document.

[0032] In the description herein, terms such as "first" and "second" are used only to distinguish different objects and should not be understood to indicate relative importance or to limit the quantity, specific order, or primary and secondary relationship of the described technical features. In the description herein, "plurality" means at least two.

[0033] Embodiments of the present application will now be described in detail with reference to the accompanying drawings. Reference will now be made in detail to preferred embodiments of the present application, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings to refer to the same or similar parts.

[0034] Figure 1 FIG1 shows a schematic diagram of a control circuit for preventing battery heating out of control according to an embodiment of the present application. Figure 1As shown, the control circuit for preventing battery heating runaway of the present application has one end connected to the positive pole of the battery, and the other end is connected in series with the main relay, controllable fuse, heating relay, digital potentiometer, heating film, shunt in sequence, and finally connected to the negative pole of the battery to form a heating circuit. The digital potentiometer of the present application uses a digital control method to adjust the resistance value, and has significant advantages such as flexible use, high adjustment accuracy, no contact, low noise, not easy to be contaminated, anti-vibration, anti-interference, small size, and long life. The controllable fuse of the present application selects a fuse that can manually or automatically control the melting process as needed. It combines the protection function of a traditional fuse and the characteristics of a controllable switch. The circuit can be manually disconnected when needed, and the circuit can be kept connected when not needed.

[0035] 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; the temperature sensing array of the present application is a device composed of multiple temperature sensors arranged in a certain geometric pattern, which is used to collect and process battery temperature information.

[0036] The battery management system BMS is set to: control the main relay and heating relay to close, and control the circuit to be turned on; preset the battery temperature threshold; obtain the battery temperature in real time through the temperature sensor array, and when the battery temperature reaches the first-level temperature threshold, input the battery's ambient temperature, operating temperature, and heating film model; calculate the unit time taken for the heating film with different heating power densities to heat from the ambient temperature to the operating temperature, and obtain the estimated heating time of the heating film; based on the estimated heating time of the heating film, control the digital potentiometer to increase the resistance value, so that the heating current passing through the shunt makes the heating film reach a safe heating power; when the battery temperature reaches the second-level temperature threshold, control the heating relay and / or main relay to turn off and stop heating; when the battery temperature reaches the third-level temperature threshold, control the controllable fuse to melt.

[0037] The heating power density of the heating film is calculated based on the following formula:

[0038] ,

[0039] 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.

[0040] 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 a main circuit of the battery system.

[0041] Preferably, in some embodiments of the present application, the control circuit is powered by an inverter or a battery.

[0042] As those skilled in the art can understand, the battery management system BMS closes the main relay and the heating relay to control the conduction of the heating circuit. The battery management system BMS uses a shunt to monitor the value of the heating current passing through; and uses a temperature sensor array to monitor the battery temperature in real time. When the temperature of the battery reaches the first-level alarm value, the resistance of the digital potentiometer is increased to limit the power flowing through the heating film; if the temperature of the battery continues to rise to the second-level alarm value, the battery management system BMS cuts off the heating relay and the main relay to stop heating; if the temperature of the monitored battery continues to rise to the third-level alarm stage, the controllable fuse is controlled to blow. Therefore, the present application can actively block battery heating out of control, respond to different heating out of control processing strategies in a graded manner, and effectively prevent the battery from exploding due to excessive temperature.

[0043] Preferably, in some embodiments of the present application, the battery management system BMS is configured to: input the ambient temperature, operating temperature, and heating film model of the battery; calculate the unit time taken for heating films with different heating power densities to heat from the ambient temperature to the operating temperature, and obtain the estimated heating film heating time; based on the estimated heating film heating time, flexibly adjust the resistance value of the digital potentiometer.

[0044] According to another aspect of the present application, the present application further provides a control method for preventing battery heating runaway, comprising the control circuit of any one of the above embodiments, including:

[0045] Control the main relay and heating relay to close and the control circuit to conduct; preset the battery temperature threshold; obtain the battery temperature in real time through the temperature sensor array, and when the battery temperature reaches the first-level temperature threshold, input the battery's ambient temperature, operating temperature, and heating film model; calculate the unit time taken for heating films with different heating power densities to heat from ambient temperature to operating temperature, and obtain the estimated heating time of the heating film; based on the estimated heating time of the heating film, control the digital potentiometer to increase the resistance value so that the heating current passing through the shunt makes the heating film reach a safe heating power; when the battery temperature reaches the second-level temperature threshold, control the heating relay and / or main relay to turn off and stop heating; when the battery temperature reaches the third-level temperature threshold, control the controllable fuse to melt.

[0046] The heating power density of the heating film is calculated based on the following formula:

[0047] ,

[0048] 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.

[0049] As those skilled in the art can understand, the battery management system BMS closes the main relay and the heating relay to control the conduction of the heating circuit. The battery management system BMS uses a shunt to monitor the value of the heating current passing through; and uses a temperature sensor array to monitor the battery temperature in real time. When the temperature of the battery reaches the first-level alarm value, the resistance of the digital potentiometer is increased to limit the power flowing through the heating film; if the temperature of the battery continues to rise to the second-level alarm value, the battery management system BMS cuts off the heating relay and the main relay to stop heating; if the battery temperature is monitored to continue to rise to the third-level alarm stage, the controllable fuse is controlled to blow. Therefore, the present application can actively block battery heating out of control, respond to different heating out of control processing strategies in a graded manner, and effectively prevent the battery from exploding due to excessive temperature.

[0050] Preferably, in some embodiments of the present application, the control method also includes: inputting the ambient temperature, operating temperature, and heating film model of the battery; calculating the unit time taken for heating films with different heating power densities to heat from the ambient temperature to the operating temperature, and obtaining the estimated heating time of the heating film; based on the estimated heating time of the heating film, flexibly adjusting the resistance value of the digital potentiometer.

[0051] As can be understood by those skilled in the art, Figure 2 The figure shows the discharge capacity of the battery of the present application at different temperatures in some embodiments. Figure 2 It can be seen that when the ambient temperature is too low, the discharge capacity of the battery will be damaged. Heating it to a suitable temperature will greatly improve the discharge capacity of the battery.

[0052] Specifically, in some embodiments of the present application, the input battery ambient temperature is -20°C, the operating temperature is 5°C, and the heating film model, in which a polyimide heating film is selected, is used. Table 1 shows the experimental data of heating films of different powers of a 4V battery heating from -20°C to 5°C. As can be seen from Table 1, 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. The experiment obtained the estimated heating time of the heating film at different heating power densities; based on the estimated 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 shortened, and the risk of loss of control is greatly increased. The present application can effectively prevent heating runaway by predicting the heating time of the heating film in advance, timely limiting the power of the heating film, controlling the heating time, and monitoring the battery temperature in real time.

[0053] Table 1 Experimental data of heating film from -20℃ to 5℃ with different powers of 4V battery

[0054]

[0055] According to another aspect of the present application, the present application further 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.

[0056] The present application discloses a control circuit, control method and storage medium for preventing battery heating runaway. Aiming at the problems of response hysteresis, relay out-of-control risk and so on in the existing heating control technology, the present application takes "active blocking and graded response" as the core. Through the coordinated control of the main circuit and the heating circuit and the dynamic threshold response mechanism, the thermal runaway triggering conditions are directly blocked when the relay is stuck or the signal fails. At the same time, a graded 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 to suppress the risk of heat spread from the root, and ensure the precise balance between low-temperature heating requirements and high-temperature safety protection of the battery system.

[0057] The above describes the preferred embodiments of the present application. It should be understood that the present application is not limited to the above-mentioned specific embodiments, and the devices and structures that are not described in detail should be understood to be implemented in a common manner in the art; any technician familiar with the art can use the above-mentioned disclosed methods and technical contents to make many possible changes and modifications to the technical solutions of the present application without departing from the scope of the technical solutions of the present application, or modify them into equivalent embodiments with equivalent changes, which does not affect the substantive content of the present application. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application that do not depart from the content of the technical solutions of the present application are still within the scope of protection of the technical solutions of the present application.

Claims

1. A control method for preventing battery heating out of control, characterized in that: A control circuit for preventing battery heating out of control is included, wherein one end of the control circuit is connected to the positive electrode of the battery, and the other end is connected in series with a main relay, a controllable fuse, a heating relay, a digital potentiometer, a heating film, a shunt, and finally connected to the negative electrode of the battery; The control circuit further includes a battery management system, 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 disposed near the battery; The control method further includes: Controlling the main relay and the heating relay to close and the control circuit to conduct; Preset three-level battery temperature threshold; The temperature of the battery is acquired in real time through the temperature sensor array. When the battery temperature reaches a first-level temperature threshold, the ambient temperature, operating temperature, and model of the heating film of the battery are input; the unit time required for heating the heating films of different heating power densities from the ambient temperature to the operating temperature is calculated to obtain an estimated heating time of the heating film; based on the estimated heating time of the heating film, the digital potentiometer is controlled to increase the resistance value until the heating current passing through the shunt reaches a safe heating power for the heating film; When the temperature of the battery reaches the secondary temperature threshold, the heating relay and / or the main relay are controlled to be turned off to stop heating; When the temperature of the battery reaches a third-level temperature threshold, controlling the controllable fuse to melt; The heating power density of the heating film is calculated 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 method according to claim 1, characterized in that: The control circuit further includes an inverter, which is connected in parallel with the battery.

3. The control method according to claim 2, characterized in that: The control circuit is powered by the inverter or the battery.

4. A computer-readable storage medium having computer instructions stored thereon, characterized in that: When the computer instructions are executed by a processor, the control method according to any one of claims 1 to 3 is implemented.

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