Lithium battery high temperature monitoring circuit
By designing a high-temperature monitoring circuit for lithium batteries, the risk of thermal runaway from high-temperature lithium batteries is solved by using real-time temperature monitoring and multiple prevention and control measures, the risk of thermal runaway from high-temperature lithium batteries is solved, effective prevention and control of thermal runaway and improved safety.
Patent Information
- Application Number
- CN202421900173.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-07
- Publication Date
- 2025-06-27
- Estimated Expiration
- 2034-08-07
AI Technical Summary
High-temperature lithium batteries have the risk of thermal runaway in high-temperature environments, which may cause the battery to catch fire or explode, and it is difficult for the existing technology to effectively prevent and control such accidents.
A high-temperature monitoring circuit for lithium batteries is designed to monitor the working temperature of lithium batteries in real time, and use temperature warning measures and multiple prevention and control measures (such as temperature fuses and overcurrent protection) to cut off the output of lithium batteries to prevent thermal runaway.
Effective prevention and control of high-temperature lithium batteries is achieved, ensuring that lithium batteries will not cause fire or explosion due to thermal runaway in high-temperature environments, and improving the safety of equipment and personnel.
Smart Images
Figure CN223038136U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of lithium batteries, and particularly relates to a high-temperature monitoring circuit for lithium batteries. Background Art
[0002] With the continuous maturity of oil exploration and development technical means, continuous breakthroughs have been made in the discovery of deep and ultra-deep oil and gas. The burial depth of oil and gas reaches more than 8000 meters, with characteristics such as deep reservoir burial depth, high temperature (bottom hole temperature up to 200 °C), variable wellbore pressure, and complex geological conditions. In order to improve development efficiency, most wells are developed using highly deviated wells or even horizontal wells; affected by factors such as well conditions, drilling technology, wellbore size, well deviation, well depth structure, loss of target layer, and (severe) instability of wellbore wall, the conventional cable logging construction technology can no longer meet the requirements; for the construction of ultra-deep highly deviated / horizontal wells, the logging technology mainly using drill string conveyance storage type instruments is adopted; high-temperature lithium batteries, as core components, have been widely used to provide electrical energy in storage logging.
[0003] According to the temperature grade classification, high-temperature lithium batteries have 4 temperature grades, namely 150 °C, 165 °C, 180 °C, and 200 °C. In a high-temperature environment, lithium batteries have the risk of thermal runaway, which may cause the battery to catch fire or explode, posing a serious threat to the safety of personnel and equipment. At present, the safety control of high-temperature lithium batteries basically adopts detecting voltage, current, and judging the battery power according to the preset discharge duration (maximum discharge duration = battery capacity / current) based on the load current to prevent thermal runaway explosion caused by over-discharge; the battery output is turned off through over-current, but the rated current of acoustic instruments is 0.2 A, and the instantaneous emission current of the transducer is as high as 2 A, and the over-current design margin is relatively large, resulting in that in actual use, the battery output cannot be turned off through over-current control, and the phenomenon of thermal runaway explosion of the battery occurs; because the acoustic instruments do not have a constant current, in a high-temperature environment, the error of measuring the power by the ampere-hour method exceeds 20%, and over-discharge causing thermal runaway explosion of the battery has also occurred many times in actual use.
[0004] Therefore, how to effectively prevent and control the thermal runaway of high-temperature lithium batteries has become an urgent problem to be solved. Summary of the Invention
[0005] In order to overcome the above deficiencies, the utility model provides a high-temperature monitoring circuit for lithium batteries, which can effectively prevent and control the thermal runaway of high-temperature lithium batteries by real-time monitoring the working temperature of the lithium battery and cutting off the battery output through temperature warning measures.
[0006] The utility model realizes the above object through the following technical solutions:
[0007] A high-temperature monitoring circuit for a lithium battery, comprising a lithium battery pack. A temperature fuse is provided in the lithium battery pack. The lithium battery pack is electrically connected to a load through the temperature fuse and a power switch circuit. The lithium battery pack is electrically connected to the power switch circuit through an MCU control module. The lithium battery pack is electrically connected to the MCU control module through an ADC temperature acquisition module;
[0008] The power switch circuit includes a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a triode, a thyristor, and a fifth capacitor. The base of the triode is electrically connected to the signal output terminal of the MCU control module through the fourth resistor. The base of the triode is grounded through the fifth resistor. The emitter of the triode is grounded. The collector of the triode is electrically connected to the gate of the field effect transistor. The gate of the field effect transistor is electrically connected to the positive electrode of the lithium battery pack through the sixth resistor. The source of the field effect transistor is electrically connected to the positive electrode of the lithium battery pack. The drain of the field effect transistor is grounded through a parallel circuit composed of the seventh resistor and the fifth capacitor. The drain of the field effect transistor is the output connected to the load.
[0009] Preferably, the ADC temperature acquisition module includes a temperature sensor. The temperature sensor is attached to the surface of the lithium battery pack. The temperature sensor attached to the surface of the lithium battery monitors the temperature of the high-temperature lithium battery in real time. The MCU control module controls the ADC acquisition chip to collect the temperature sensor data in real time, and controls the power switch circuit to turn on or off according to the temperature sensor data.
[0010] Preferably, the temperature fuse is connected to the output positive electrode of the lithium battery pack. The temperature fuse is connected in series in the output positive electrode of the lithium battery. It judges whether the lithium battery is in a high-temperature state according to the melting temperature point. If the temperature of the lithium battery exceeds the melting point temperature of the temperature fuse, the fuse is triggered to melt, disconnecting the lithium battery output to prevent thermal runaway.
[0011] Preferably, the ADC temperature acquisition module further includes a first integrated circuit, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a first resistor, a second resistor, and a third resistor. The model of the first integrated circuit is AD7792BRUZ. The tenth pin of the first integrated circuit is grounded. The twenty-first pin of the first integrated circuit is grounded through the first capacitor. The twenty-first pin of the first integrated circuit is externally connected to a +5V DC voltage power supply. The eighteenth pin of the first integrated circuit is grounded through the second capacitor. The eighteenth pin of the first integrated circuit is grounded through the first resistor and the second resistor. The second resistor is in parallel with the third resistor. A PT1000 platinum resistor is connected between the third resistor and the third capacitor. The seventeenth pin of the first integrated circuit is grounded through the third capacitor. The fourteenth pin of the first integrated circuit is grounded. The thirteenth pin of the first integrated circuit is grounded through the fourth capacitor, and the thirteenth pin of the first integrated circuit is externally connected to a +5V DC voltage power supply. The PT1000 platinum resistor serves as the temperature sensor.
[0012] Preferably, the model of the field effect transistor is FQD7P20.
[0013] The beneficial effects of the present utility model are as follows: In this lithium battery high-temperature monitoring circuit,
[0014] the temperature sensor monitors the temperature on the surface of the lithium battery core in real time to ensure that the high-temperature state can be detected in time.
[0015] The MCU in the MCU control module accurately judges whether the lithium battery is in a high-temperature state according to the preset temperature threshold.
[0016] Active protection: The temperature sensor monitors the surface temperature of the lithium battery in real time; Passive protection: Overheat protection and overcurrent protection of the temperature fuse, multiple prevention and control measures prevent the occurrence of thermal runaway. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The present utility model will be described by way of examples with reference to the accompanying drawings, where:
[0018] Figure 1 is the electrical schematic diagram of the present utility model;
[0019] Figure 2 is the circuit schematic diagram of the ADC temperature acquisition module of the present utility model;
[0020] Figure 3 is the circuit schematic diagram of the power switch circuit of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0021] Now, the present utility model will be further described in detail with reference to the accompanying drawings. These drawings are all simplified schematic diagrams, which only illustrate the basic structure of the present utility model in a schematic way, so they only show the components related to the present utility model.
[0022] As Figures 1 - 3 shown, a lithium battery high-temperature monitoring circuit includes a lithium battery pack 1, in which a temperature fuse 2 is provided. The temperature fuse 2 has overcurrent protection. When the output current exceeds the rated current of the temperature fuse, the temperature fuse 2 is triggered to blow, preventing thermal runaway caused by overcurrent discharge. The lithium battery pack 1 is electrically connected to a load 6 through a power switch circuit 5, the lithium battery pack 1 is electrically connected to the power switch circuit 5 through an MCU control module 4, and the lithium battery pack 1 is electrically connected to the MCU control module 4 through an ADC temperature acquisition module 3;
[0023] The power switch circuit 5 includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a triode Q1, a thyristor Q2, and a fifth capacitor C5. The base of the triode Q1 is electrically connected to the signal output terminal of the MCU control module 4 through the fourth resistor R4. The base of the triode Q1 is grounded through the fifth resistor R5. The emitter of the triode Q1 is grounded. The collector of the triode Q1 is electrically connected to the gate of the field effect transistor. The gate of the field effect transistor is electrically connected to the positive electrode of the lithium battery pack 1 through the sixth resistor R6. The source of the field effect transistor is electrically connected to the positive electrode of the lithium battery pack 1. The drain of the field effect transistor is grounded through a parallel circuit composed of the seventh resistor R7 and the fifth capacitor C5. The drain of the field effect transistor is the output connected to the load.
[0024] The working principle of the high-temperature monitoring circuit for lithium batteries is as follows:
[0025] Real-time monitoring: The MCU control module 4 controls the ADC acquisition chip, i.e., the first integrated circuit U1, to collect temperature sensor data in real time, and controls the power switch circuit 5 to turn on or off according to the temperature sensor data.
[0026] Temperature judgment: The MCU in the MCU control module 4 judges whether the lithium battery is in a high-temperature state according to a preset temperature threshold (the temperature threshold is 6°C higher than the high-temperature lithium battery temperature index). If the temperature does not exceed the threshold, the MCU controls the power switch circuit 5 to be in the on state and continues to monitor the temperature; if the temperature exceeds the threshold, the MCU controls the power switch circuit 5 to turn off the output.
[0027] Temperature fuse 2: When the temperature of the lithium battery exceeds the melting temperature of the temperature fuse 2, the fuse is triggered to melt, disconnecting the output of the lithium battery. The melting point of the temperature fuse 2 is selected to be 10°C higher than the rated temperature of the lithium battery.
[0028] Overcurrent protection: When the output current of the lithium battery exceeds the rated current of the temperature fuse 2, the temperature fuse is triggered to melt. The rated current of the temperature fuse 2 is selected to be twice the maximum output current of the lithium battery.
[0029] Specifically, the ADC temperature acquisition module 3 includes a temperature sensor. The temperature sensor is attached to the surface of the lithium battery pack 1. The temperature sensor attached to the surface of the lithium battery monitors the temperature of the high-temperature lithium battery in real time. The MCU control module 4 controls the ADC acquisition chip to collect temperature sensor data in real time, and controls the power switch circuit 5 to turn on or off according to the temperature sensor data.
[0030] Specifically, the temperature fuse 2 is connected to the output positive electrode of the lithium battery pack 1. The temperature fuse 2 is connected in series to the output positive electrode of the lithium battery. Whether the lithium battery is in a high-temperature state is judged according to the melting temperature point. If the temperature of the lithium battery exceeds the melting temperature of the temperature fuse 2, the fuse is triggered to melt, disconnecting the output of the lithium battery to prevent thermal runaway.
[0031] Specifically, the ADC temperature acquisition module 3 further includes a first integrated circuit U1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a first resistor R1, a second resistor R2, and a third resistor R3. The model of the first integrated circuit U1 is AD7792BRUZ. The tenth pin of the first integrated circuit U1 is grounded. The twenty-first pin of the first integrated circuit U1 is grounded through the first capacitor C1. The twenty-first pin of the first integrated circuit U1 is externally connected to a +5V DC voltage power supply. The eighteenth pin of the first integrated circuit is grounded through the first resistor and the second resistor. The second resistor is connected in parallel with the third resistor. The third resistor and the third capacitor are connected through a PT1000 platinum resistor. The seventeenth pin of the first integrated circuit is grounded through the third capacitor. The fourteenth pin of the first integrated circuit is grounded. The thirteenth pin of the first integrated circuit is grounded through the fourth capacitor, and the thirteenth pin of the first integrated circuit is externally connected to a +5V DC voltage power supply. The PT1000 platinum resistor serves as a temperature sensor.
[0032] Specifically, the model of the field effect transistor is FQD7P20.
[0033] In this circuit, for the prevention and control steps of the high-temperature lithium battery thermal runaway prevention and control system (taking a 150°C battery as an example):
[0034] The MCU control module 4 controls the ADC acquisition chip to collect the temperature sensor (platinum resistor). When the collected temperature < 156°C (threshold temperature), the MCU controls the power switch to turn on and supply power to the load.
[0035] When the collected temperature ≥ 156°C, the MCU controls the power switch to turn off and disconnect the load. The internal temperature of the lithium battery core dissipates heat through the instrument shell to prevent thermal runaway.
[0036] If the main control prevention and control system fails and does not start prevention and control, when the temperature of the lithium battery exceeds the melting temperature of the temperature fuse, which is 160°C, the temperature fuse melts, disconnecting the load. The internal temperature of the lithium battery core dissipates heat through the instrument shell to prevent thermal runaway.
[0037] Inspired by the present invention, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.
Claims
1. A lithium battery high temperature monitoring circuit, comprising a lithium battery pack, characterized in that: The lithium battery pack is provided with a temperature fuse, the lithium battery pack is electrically connected to the load through the temperature fuse and the power switch circuit, the lithium battery pack is electrically connected to the power switch circuit through the MCU control module, and the lithium battery pack and the MCU control module are electrically connected through the ADC temperature acquisition module; The power switch circuit includes a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a triode, a thyristor and a fifth capacitor. The base of the triode is electrically connected to the signal output end of the MCU control module through the fourth resistor, the base of the triode is grounded through the fifth resistor, the emitter of the triode is grounded, the collector of the triode is electrically connected to the gate of the field effect tube, the gate of the field effect tube is electrically connected to the positive electrode of the lithium battery pack through the sixth resistor, the source of the field effect tube is electrically connected to the positive electrode of the lithium battery pack, the drain of the field effect tube is grounded through a parallel circuit composed of the seventh resistor and the fifth capacitor, and the drain of the field effect tube is connected to the load.
2. The lithium battery high temperature monitoring circuit according to claim 1, characterized in that: The ADC temperature acquisition module includes a temperature sensor, and the temperature sensor is attached to the surface of the lithium battery pack.
3. The lithium battery high temperature monitoring circuit according to claim 1, characterized in that: The temperature fuse is connected to the output positive electrode of the lithium battery pack.
4. The lithium battery high temperature monitoring circuit according to claim 2, characterized in that: The ADC temperature acquisition module also includes a first integrated circuit, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a first resistor, a second resistor and a third resistor. The model of the first integrated circuit is AD7792BRUZ. The tenth pin of the first integrated circuit is grounded, the twenty-first pin of the first integrated circuit is grounded through the first capacitor, the twenty-first pin of the first integrated circuit is externally connected to a +5V DC voltage power supply, the eighteenth pin of the first integrated circuit is grounded through the second capacitor, the eighteenth pin of the first integrated circuit is grounded through the first resistor and the second resistor, the second resistor is connected in parallel with the third resistor, the third resistor and the third capacitor are connected through a PT1000 platinum resistor, the seventeenth pin of the first integrated circuit is grounded through the third capacitor, the fourteenth pin of the first integrated circuit is grounded, the thirteenth pin of the first integrated circuit is grounded through the fourth capacitor, and the thirteenth pin of the first integrated circuit is externally connected to a +5V DC voltage power supply.
5. The lithium battery high temperature monitoring circuit according to claim 1, characterized in that: The model of the field effect tube is FQD7P20.