Battery thermal management system

Abstract

The utility model discloses a battery thermal management system, and relates to the technical field of battery thermal management. Comprising a temperature sensor unit which is connected with a comparator unit and is used for monitoring an analog signal of the surface temperature of a battery module and inputting the collected temperature analog signal into the comparator unit; the comparator unit is electrically connected with the micro-control unit and is used for comparing the acquired temperature analog signal with a threshold voltage and outputting different level signals; the micro-control unit is electrically connected with the temperature control device and controls the temperature control device to operate according to different level signals output by the comparator unit; and the temperature control device comprises a fan and a heating film and is used for heating and cooling the battery module.

Description

Technical Field

[0001] The utility model relates to the technical field of battery thermal management, in particular to a battery thermal management system. Background Art

[0002] With the diversification of the automotive industry and increasingly severe environmental challenges, the new energy vehicle industry is developing rapidly. Electric vehicles, in particular, are increasingly widely used due to their lower environmental impact compared to traditional vehicles. Electric vehicles are powered by an onboard electrical system, with motors driving the wheels. Battery operating temperature is crucial for safe operation and a significant factor affecting battery life.

[0003] As the core component of electric vehicles, the performance and service life of the power battery system are closely related to temperature. High temperature will reduce the safety performance of the battery and even cause thermal runaway. Low temperature will reduce the battery capacity and affect the endurance. Therefore, a reasonable thermal management system must be designed to ensure that the maximum and minimum temperatures of the power battery are always within the appropriate range and ensure the uniformity of the temperature field, thereby improving the overall performance of the power battery and extending its service life.

[0004] In the prior art, publication number CN112542631A discloses a battery thermal management system, comprising a battery module, a heating mechanism for heating the battery module, an air cooling mechanism for reducing the temperature of the battery module, the battery module comprising a plurality of transversely arranged battery assemblies, and a spacing adjustment mechanism. The battery thermal management system provided by this invention has two modes: heat dissipation and heating and heat preservation. When the battery module temperature is overheated, the heat dissipation mode is activated, the spacing adjustment mechanism increases the spacing between two adjacent battery assemblies, and an air flow channel is formed between the two adjacent battery assemblies. The air cooling mechanism ventilates and dissipates heat for the battery assemblies, effectively suppressing the occurrence and expansion of thermal runaway. This invention uses the temperature sensor directly as the input of the controller. The controller needs to process the data from the temperature sensor, which increases its computational burden. In particular, when multiple sensor data need to be processed in real time, the real-time performance and effectiveness of the system are reduced.

[0005] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art. Utility Model Content

[0006] The purpose of the present invention is to provide a battery thermal management system to solve the problems raised in the above background technology.

[0007] To achieve the above objectives, the present invention provides the following technical solutions:

[0008] A battery thermal management system, the specific structure includes:

[0009] A temperature sensor unit, which is arranged on the surface of the battery module to be monitored and is electrically connected to the positive input terminal of the voltage comparator, is used to measure an analog signal of the surface temperature of the battery module and input the collected temperature analog signal into the voltage comparator;

[0010] A voltage comparator, wherein the negative input terminal of the voltage comparator is electrically connected to an adjustable potentiometer, and is used to compare the collected temperature analog signal with a reference voltage and output a level signal;

[0011] a microcontroller unit, the microcontroller unit being electrically connected to an output end of the voltage comparator and configured to receive a level signal output by the voltage comparator and drive the motor drive unit and the heating film drive unit to operate;

[0012] A drive motor unit, the drive motor unit being electrically connected to the microcontroller unit and configured to drive the cooling fan to operate under the control of the microcontroller unit;

[0013] A heating film driving unit, the heating film driving unit being electrically connected to the microcontroller unit and configured to drive the heating film to operate under the control of the microcontroller unit;

[0014] a cooling fan electrically connected to the drive motor unit and disposed on the surface of the battery module, and configured to operate under the drive of the drive motor unit to dissipate heat from the surface of the battery module;

[0015] The heating film is electrically connected to the heating film driving unit and is arranged between the battery modules. The heating film is driven by the heating film driving unit to heat the battery modules.

[0016] Furthermore, the temperature sensor unit comprises a temperature sensor LM, a positive power supply terminal of the temperature sensor being electrically connected to an external power supply VCC, a negative power supply terminal being electrically connected to a ground terminal via a diode D1, and an output terminal of the temperature sensor LM being electrically connected to an external resistor R1, outputting a voltage signal of the surface temperature of the battery module.

[0017] Furthermore, the negative input terminal of the voltage comparator is electrically connected to the slider terminal of the adjustable potentiometer, the starting terminal of the adjustable potentiometer is electrically connected to the external power supply VCC, and the ending terminal is electrically connected to the ground terminal.

[0018] Furthermore, the output terminal of the voltage comparator is electrically connected to the external power supply VCC via a pull-up resistor R3.

[0019] Furthermore, the driving motor unit includes a transistor Q1, an external power supply V1, resistors R4, R9 and a resistor R5. The base of the transistor is electrically connected to the output end of the microcontroller through the resistor R4, and the external power supply V1 is electrically connected to the collector of the transistor Q1 through the resistor R5. The collector is electrically connected to the cooling fan as an output.

[0020] Furthermore, the heating film driving unit includes a photocoupler, a bidirectional thyristor, an inverter integrated circuit, an external AC power supply, a capacitor C1 and resistors R6, R7, R8, and R12. The output end of the microcontroller is electrically connected to the negative input end of the photocoupler through the inverter integrated circuit, the positive input end of the photocoupler is electrically connected to the external power supply VCC through the resistor R6, the output of the photocoupler is electrically connected to the two main terminals of the bidirectional thyristor through resistors R7 and R8 respectively, the gate of the bidirectional thyristor is electrically connected to one of the output ends of the photocoupler, the phase end of the external AC power supply is electrically connected to the capacitor C1, and the capacitor C1 is electrically connected to the neutral end of the external AC power supply through the resistor R12.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] This system is composed of integrated components, takes up little space and is easy to install. At the same time, it converts the temperature of the battery module into a voltage analog quantity, and judges the battery status by comparing the battery module temperature voltage analog quantity with the reference voltage. According to the different level signals output by the comparator, the microcontroller controls the drive unit to complete the high and low temperature thermal management system of the battery. The high and low levels output by the comparator are used as the output of the microcontroller, which reduces the burden of the microcontroller in processing real-time data, improves the real-time performance and effectiveness of the system, and makes the battery always work at an appropriate temperature, effectively improving the battery working efficiency and extending the battery life. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the utility model. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0025] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in this utility model should have the usual meanings understood by people with ordinary skills in the field to which this utility model belongs. The "first", "second" and similar words used in this utility model do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative position relationships. When the absolute position of the object being described changes, the relative position relationship may also change accordingly.

[0026] Example:

[0027] See also Figure 1 , the utility model provides a technical solution:

[0028] A battery thermal management system, specifically comprising:

[0029] A temperature sensor unit, which is arranged on the surface of the battery module to be monitored and is electrically connected to the positive input terminal of the voltage comparator, is used to measure an analog signal of the surface temperature of the battery module and input the collected temperature analog signal into the voltage comparator;

[0030] An integrated circuit temperature sensor (IC temperature sensor) is an electronic device that integrates temperature detection and signal processing on a single chip. They typically have an analog output, provide accurate temperature measurements, and are easily interfaced with microcontrollers or other digital systems. Analog output temperature sensors output an analog voltage signal proportional to temperature that can be directly connected to an analog input port for measurement. They can be used in portable devices and electric vehicles to monitor battery temperature and prevent overheating or overcooling. For example, the LM35, a common analog output temperature sensor, has an output voltage proportional to the Celsius temperature, outputting 10mV per degree Celsius.

[0031] The battery module is composed of at least two electrically connected single cells; the battery type is a lithium-ion battery, and each battery module is composed of 15 single cells connected in series. Side panels are provided on both sides of the battery mounting base assembly, and the side panels are used to fix the battery module. In this embodiment, taking four battery modules as an example, each battery module is composed of 15 single cells connected in series, for a total of 60 single cells.

[0032] A voltage comparator, wherein a negative input point of the voltage comparator is connected to a reference voltage, and is used to compare the collected temperature analog signal with the reference voltage and output a level signal;

[0033] The comparator unit uses the LM393 dual comparator. The LM393 is a dual voltage comparator integrated circuit that contains two independent voltage comparators. Each comparator has two input terminals (positive input terminal and negative input terminal) and one output terminal. When in use, the Vcc terminal of the LM393 dual comparator is connected to the positive terminal of the power supply, and the GND terminal is connected to the power ground.

[0034] The battery module surface temperature voltage signal output by the temperature sensor unit is used as an input of the comparator unit and connected to the positive input of the LM393 dual comparator. The threshold voltage is connected to the negative input of the LM393 dual comparator. The LM393 is an open-drain output (Open-Collector), which means it cannot actively output a high level and must be achieved through an external pull-up resistor. Its low level is achieved by its internal transistor being turned on to ground. The output of the LM393 dual comparator is connected to a 5V power supply through a pull-up resistor.

[0035] The preset threshold voltage is set using an adjustable potentiometer. A potentiometer is a three-terminal resistor commonly used to adjust voltage or current in a circuit. It consists of a sliding contact (called a slider or vernier) that moves along the length of a fixed resistor, changing the resistance value. By changing the position of the potentiometer's slider, the resistor's voltage divider ratio, and thus the output voltage, can be changed. The potentiometer sets a reference voltage, which is then compared with the temperature analog voltage value using the LM393 dual comparator.

[0036] The output logic of the output end of the LM393 dual comparator is: when the output voltage of the temperature sensor is greater than the threshold voltage, the LM393 outputs a high level; when the output voltage of the temperature sensor is less than the threshold voltage, the LM393 outputs a low level, wherein the low level is a voltage of 0 to 0.5V, and the high level is a voltage of 4.5 to 5V.

[0037] a microcontrol unit, the microcontrol unit being electrically connected to the temperature control device and configured to control the operation of the temperature control device according to different level signals output by the comparator unit;

[0038] The microcontroller unit is based on the ATmega328 chip and is a single-chip microcomputer that integrates a microprocessor core, memory (RAM, ROM, EEPROM or Flash), input / output interface (I / O), timer / counter, analog-to-digital converter (ADC), serial communication interface (such as UART, SPI, I2C), and other components. It is designed to perform specific control tasks and is widely used in various electronic devices and systems. The different level signals output by the comparator unit serve as the input of the microcontroller unit, which is used to control the operation of the drive motor unit and the heating film drive unit according to different signals.

[0039] When the LM393 dual comparator outputs a high level, the pin of the micro control unit connected to the driving motor unit outputs a high level; when the LM393 dual comparator outputs a low level, the pin of the micro control unit connected to the heating film driving unit outputs a high level.

[0040] A drive motor unit, the drive motor unit being electrically connected to the microcontroller unit and configured to drive the cooling fan to operate under the control of the microcontroller unit;

[0041] The drive motor unit includes a transistor Q1, an external power supply V1, resistors R4, R9 and a resistor R5. The base of the transistor is electrically connected to the output end of the microcontroller through the resistor R4. The external power supply V1 is electrically connected to the collector of the transistor Q1 through the resistor R5. The collector is electrically connected to the cooling fan as an output.

[0042] The drive motor unit is controlled to work according to the different level signals output by the voltage comparator. When a high level signal is received, the transistor is turned on, the drive motor unit is started, and the drive motor unit drives the cooling fan to start working.

[0043] a cooling fan electrically connected to the drive motor unit and disposed on the surface of the battery module, and configured to operate under the drive of the drive motor unit to dissipate heat from the surface of the battery module;

[0044] When the temperature is too high, the chemical reaction inside the lithium battery will accelerate as the temperature rises, which can easily cause the normal structure of the positive and negative electrode materials to be destroyed. Therefore, if the lithium battery is operated at too high a temperature for a long time, the battery polarization effect will be obvious, causing the battery to age faster.

[0045] When the voltage analog value of the battery module surface temperature detected by the LM35 temperature sensor exceeds the set reference voltage value, the LM393 dual comparator outputs a high level, and the microcontroller controls the pin connected to the drive motor unit to output a high level. The transistor in the drive motor unit is turned on, and the external power supply V1 supplies power to the cooling fan, which cools the battery module.

[0046] A heating film driving unit, the heating film driving unit being electrically connected to the microcontroller unit and configured to drive the heating film to operate under the control of the microcontroller unit;

[0047] The heating film drive unit includes a photocoupler, a bidirectional thyristor, an inverter integrated circuit, an external AC power supply, a capacitor C1 and resistors R6, R7, R8, and R12. The output end of the microcontroller is electrically connected to the negative input end of the photocoupler through the inverter integrated circuit, the positive input end of the photocoupler is electrically connected to the external power supply VCC through the resistor R6, the output of the photocoupler is electrically connected to the two main terminals of the bidirectional thyristor through resistors R7 and R8 respectively, the gate of the bidirectional thyristor is electrically connected to one of the output ends of the photocoupler, the phase end of the external AC power supply is electrically connected to the capacitor C1, and the capacitor C1 is electrically connected to the neutral end of the external AC power supply through the resistor R12.

[0048] The inverter integrated circuit is a 7406 inverter, and the optocoupler is MOC3602. MOC3062 is a commonly used optocoupler (Optocoupler), which is mainly used to isolate and transmit electrical signals from one circuit to another while maintaining electrical isolation between the two circuits. MOC3062 is usually used to drive the bidirectional thyristor K1 to receive and convert it into an electrical signal, thereby controlling the external main circuit.

[0049] When the voltage analog value of the battery module surface temperature detected by the LM35 temperature sensor is lower than the set reference voltage value, the LM393 dual comparator outputs a low level, and the microcontroller controls the pin connected to the heating film drive unit to output a high level. The output signal passes through the 7406 inverter and is connected to the negative input terminal of the MOC3062 optocoupler to start the heating film drive unit.

[0050] The heating film is electrically connected to the heating film driving unit and is arranged between the battery modules. The heating film is driven by the heating film driving unit to heat the battery modules.

[0051] If lithium-ion batteries are exposed to high or low temperatures for a long time, their service life will be shortened and may even cause safety accidents. When the temperature is too low, lithium batteries are prone to "lithium deposition", which affects driving safety.

[0052] The heating film is located between each battery module and is used to make the temperature of each battery module uniform. The main function of the heating device is to quickly increase the temperature of all single batteries inside the battery pack to the optimal range, while ensuring the temperature uniformity inside the battery pack during heating. The heating performance of the heating film meets the requirements. At the same time, it has low cost and low energy consumption, so the heating component adopts the heating film heating method.

[0053] The above formulas are all dimensionless and numerical calculations. The formulas are obtained by collecting a large amount of data and performing software simulation to obtain the most recent real situation. The preset parameters in the formulas are set by technicians in this field according to actual conditions.

[0054] The above embodiments can be implemented in whole or in part by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented in whole or in part in the form of a computer program product. Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed by hardware or software depends on the specific application and design constraints of the technical solution.

[0055] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, and may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment as needed.

[0056] The above is only a specific implementation method of the present application, but the scope of protection of the present application is not limited thereto. Any technician familiar with this technical field can easily think of changes or replacements within the technical scope disclosed in this application, which should be covered by the scope of protection of the present application.

Claims

1. A battery thermal management system, characterized in that: Specifically include: A temperature sensor unit, which is arranged on the surface of the battery module to be monitored and is electrically connected to the positive input terminal of the voltage comparator, is used to measure an analog signal of the surface temperature of the battery module and input the collected temperature analog signal into the voltage comparator; A voltage comparator, wherein the negative input terminal of the voltage comparator is electrically connected to an adjustable potentiometer, and is used to compare the collected temperature analog signal with a reference voltage and output a level signal; a microcontroller unit, the microcontroller unit being electrically connected to an output end of the voltage comparator and configured to receive a level signal output by the voltage comparator and drive the motor drive unit and the heating film drive unit to operate; A drive motor unit, the drive motor unit being electrically connected to the microcontroller unit and configured to drive the cooling fan to operate under the control of the microcontroller unit; A heating film driving unit, the heating film driving unit being electrically connected to the microcontroller unit and configured to drive the heating film to operate under the control of the microcontroller unit; a cooling fan electrically connected to the drive motor unit and disposed on the surface of the battery module, and configured to operate under the drive of the drive motor unit to dissipate heat from the surface of the battery module; The heating film is electrically connected to the heating film driving unit and is arranged between the battery modules. The heating film is driven by the heating film driving unit to heat the battery modules.

2. A battery thermal management system according to claim 1, characterized in that: The temperature sensor unit includes a temperature sensor LM, a positive power supply terminal of the temperature sensor is electrically connected to an external power supply VCC, a negative power supply terminal is electrically connected to a ground terminal through a diode D1, and an output terminal of the temperature sensor LM is electrically connected to an external resistor R1 to output a voltage signal of the surface temperature of the battery module.

3. A battery thermal management system according to claim 1, characterized in that: The negative input terminal of the voltage comparator is electrically connected to the slider terminal of the adjustable potentiometer. The starting terminal of the adjustable potentiometer is electrically connected to the external power supply VCC, and the ending terminal is electrically connected to the ground terminal.

4. A battery thermal management system according to claim 3, characterized in that: The output terminal of the voltage comparator is electrically connected to the external power supply VCC via a pull-up resistor R3.

5. The battery thermal management system according to claim 1, characterized in that: The drive motor unit includes a transistor Q1, an external power supply V1, resistors R4, R9 and a resistor R5. The base of the transistor is electrically connected to the output end of the microcontroller through the resistor R4. The external power supply V1 is electrically connected to the collector of the transistor Q1 through the resistor R5. The collector is electrically connected to the cooling fan as an output.

6. A battery thermal management system according to claim 1, characterized in that: The heating film drive unit includes a photocoupler, a bidirectional thyristor, an inverter integrated circuit, an external AC power supply, a capacitor C1 and resistors R6, R7, R8, and R12. The output end of the microcontroller is electrically connected to the negative input end of the photocoupler through the inverter integrated circuit, the positive input end of the photocoupler is electrically connected to the external power supply VCC through the resistor R6, the output of the photocoupler is electrically connected to the two main terminals of the bidirectional thyristor through resistors R7 and R8 respectively, the gate of the bidirectional thyristor is electrically connected to one of the output ends of the photocoupler, the phase end of the external AC power supply is electrically connected to the capacitor C1, and the capacitor C1 is electrically connected to the neutral end of the external AC power supply through the resistor R12.

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