A new energy automobile power battery temperature monitoring and early warning and forced power-off device

Abstract

The utility model discloses a new energy automobile power battery temperature monitoring early warning and forced power-off device belongs to new energy automobile power battery temperature monitoring field, through two groups of normally open thermal switch setting different temperature response threshold value, when battery temperature reaches primary early warning threshold value, immediately through four foot normally open relay and three foot flash relay linkage trigger early warning horn ringing and emergency double flash lamp scintillation, provide clear sound and light early warning signal for driver, compared with the single software alarm of traditional BMS, send risk prompt in advance, greatly increase the time window of manual intervention, when temperature further increases to emergency power-off threshold value, high voltage contactor rapidly cuts off power battery main positive loop's high breaking fuse, through physical level power-off forced termination energy output, even in the extreme situation of BMS communication interruption or controller failure, still can ensure power-off reliability.

Description

Technical Field

[0001] This utility model relates to the field of temperature monitoring of power batteries for new energy vehicles, and more specifically, to a device for monitoring, warning and forcibly cutting off the temperature of power batteries for new energy vehicles. Background Technology

[0002] With the popularization of new energy vehicles, the safety performance of power batteries, as the core energy carrier, has become a focus of industry attention. During vehicle operation, charging, or prolonged high-load operation, the electrochemical reactions and energy conversion inside the power battery may cause abnormal temperature rises due to factors such as uneven heat dissipation, differences in cell consistency, or external circuit malfunctions. Most existing temperature monitoring systems rely on the periodic data acquisition mechanism of the battery management system (BMS), with detection frequencies typically on the order of seconds or tens of milliseconds. This makes it difficult to capture abnormal changes within the millisecond-level time window of a sudden rise in battery temperature, resulting in delayed warnings. This "post-event response" mode often causes the system to trigger an alarm only when the temperature has already exceeded the safety threshold, missing the best opportunity for manual intervention.

[0003] More importantly, traditional monitoring solutions heavily rely on the reliability of software algorithms and electronic controllers: temperature signals must pass through multiple stages, including sensor acquisition, analog-to-digital conversion, microprocessor logic judgment, and communication protocol transmission. Delays or malfunctions in any stage (such as CAN bus interference, program deadlock, or chip overheating failure) can prevent the execution of warning or power-off commands. Furthermore, existing systems generally employ a single temperature threshold control strategy, achieving only a simple binary response of "detection-power-off," lacking a tiered warning mechanism. This means they cannot alert drivers to potential risks through early warning signals (such as pre-alarms when temperatures approach critical values), nor can they effectively execute emergency power-off through independent physical mechanisms when the BMS completely fails. This "software-dominated, single-point protection" architectural flaw, under high-temperature conditions where the risk of battery thermal runaway increases exponentially (such as when the local cell temperature exceeds 80°C during fast charging), may lead to protection failure due to an excessively long system response chain or control logic malfunction, ultimately resulting in serious safety accidents such as spontaneous combustion.

[0004] Meanwhile, existing power-off solutions largely rely on software commands from the BMS to control high-voltage contactors, lacking physical-level redundancy protection mechanisms. In extreme situations such as wiring harness short circuits or controller burnout within the battery compartment, the software-controlled contactors may fail to disconnect due to power outages or mechanical jamming, leading to continuous battery discharge and further exacerbating the risk of thermal runaway. Therefore, developing a safety protection device that does not rely on real-time BMS communication, possesses physical-level temperature triggering capabilities, and has an independent power-off path is crucial to solving the problems of "lagging monitoring, single control, and insufficient redundancy" in existing technologies. Utility Model Content

[0005] 1. Technical problems to be solved

[0006] The purpose of this invention is to provide a device that can monitor the temperature of a power battery in real time, issue an audible and visual warning when an abnormally high temperature is detected, and force power off when necessary. This device can effectively prevent spontaneous combustion caused by the heat generated during the charging and discharging of the power battery, which would cause the battery temperature to continue to rise.

[0007] 2. Technical Solution

[0008] To solve the above problems, the present invention adopts the following technical solution.

[0009] A device for monitoring and warning the temperature of a power battery in a new energy vehicle and forcibly cutting off power, comprising:

[0010] Temperature detection module: Two sets of normally open thermal switches are installed in parallel on the surface of the power battery cell or module. The temperature closing threshold of the first set of thermal switches is T1, and the temperature closing threshold of the second set of thermal switches is T2.

[0011] Warning control module: One end of the coil of the four-pin normally open relay is connected to the positive terminal (12V+) of the vehicle low-voltage auxiliary power supply, and the other end is connected in parallel with the output terminal of the first set of thermal switches. The normally open contacts of the four-pin normally open relay are respectively connected to the control terminals of the alarm horn and the three-pin flashing relay. The output terminal of the three-pin flashing relay is connected to the vehicle emergency hazard lights.

[0012] Forced power-off module: The low-voltage power supply of the coil end of the high-voltage contactor is connected to the positive terminal of the vehicle's low-voltage auxiliary power supply for constant power supply. The coil output grounding terminal is connected in series with the output terminal of the second set of thermal switches. After the second thermal switch is connected to the ground, it starts to work. The high-voltage contacts of the high-voltage contactor are connected in parallel to the positive and negative terminals of the high-voltage components output by the vehicle's power battery and share the same high-voltage protection fuse with the vehicle's high-voltage components.

[0013] Auxiliary control module: A normally closed one-button stop switch is connected in series in the common control circuit of a four-pin normally open relay and a three-pin flashing relay, and a pre-alarm daily test switch is connected in parallel across the first group of thermal switches.

[0014] Furthermore, the power supply terminal of the alarm horn is directly connected to a low-voltage auxiliary power supply (12V), and the control terminal achieves on / off control through the normally open contacts of a four-pin normally open relay. When the four-pin normally open relay is energized, the alarm horn is powered on and emits an audible warning.

[0015] Furthermore, the power supply terminal of the three-pin flashing relay is connected to a low-voltage auxiliary power supply (12V), the signal input terminal is linked with the normally open contact of the four-pin normally open relay, and the output terminal is connected to the left front, left rear, right front, and right rear turn signals of the car respectively, so as to realize the synchronous flashing control of the emergency hazard lights.

[0016] Furthermore, the coil end of the high-voltage contactor is connected to the second set of thermal switches and the low-voltage auxiliary power supply (12V) through an independent double-wire shielded circuit. The rated current of its high-voltage contacts is greater than the maximum operating current of the power battery. When the high-voltage contactor is engaged, the main positive connection line is connected to the power battery fuse. When the high-voltage contactor is disengaged or the power battery fuse is blown, the main circuit of the power battery is cut off.

[0017] Furthermore, the input terminals of the two sets of thermal switches are connected in parallel to the temperature sampling points of the high-voltage circuit of the power battery, and the output terminals are respectively connected to the early warning control module and the forced power-off module through independent double-wire shielded lines, forming independent temperature signal transmission paths.

[0018] Furthermore, the low-voltage control terminal of the main positive (negative) contactor and the common ground terminal of the normally open relay and the three-pin flashing relay are all connected to the negative terminal (12V-) of the low-voltage auxiliary power supply, forming a complete low-voltage control circuit. This circuit is in an open circuit state when the two sets of normally open thermal switches are not triggered, and does not consume battery power.

[0019] Furthermore, the pre-alarm daily test switch is a normally open automatic reset switch. When the pre-alarm daily test switch is pressed, it simulates the closing signal of the first group of thermal switches, triggering the alarm horn to sound and the left front, left rear, right front, and right rear turn signals to flash, which is used to detect whether the pre-alarm module is functioning normally.

[0020] Furthermore, the power battery fuse is a high breaking capacity fuse, connected in series with the main positive connection line near the power battery. When the high voltage contactor is engaged, the power battery fuse acts as a physical disconnect point to achieve emergency power cut-off.

[0021] Furthermore, the low-voltage auxiliary power supply (12V) is an on-board battery independent of the power battery, providing a stable power supply for the low-voltage control circuits of the temperature detection module, the early warning control module, and the forced power-off module.

[0022] Furthermore, the temperature closure threshold T1 is 5-10°C higher than the original vehicle BMS power-off threshold, and the temperature closure threshold T2 is 20-30°C higher than the original vehicle BMS power-off threshold.

[0023] 3. Beneficial Effects

[0024] Compared with existing technologies, the advantages of this utility model are:

[0025] (1) This solution sets differentiated temperature response thresholds through two sets of normally open thermal switches. When the battery temperature reaches the primary warning threshold (5-10℃ higher than the original vehicle BMS power-off threshold), the warning horn and emergency hazard lights are immediately triggered by the linkage of the four-pin normally open relay and the three-pin flashing relay, providing the driver with a clear audible and visual warning signal. Compared with the single software alarm of the traditional BMS, the risk warning is issued 3-5 minutes in advance, which greatly increases the time window for manual intervention. When the temperature rises further to the emergency power-off threshold (20-30℃ higher than the original vehicle BMS power-off threshold), the high-voltage contactor quickly cuts off the high-breaking capacity fuse of the main positive circuit of the power battery, and the energy output is forcibly terminated through physical power-off. Even in extreme cases of BMS communication interruption or controller failure, the reliability of power-off can still be ensured.

[0026] (2) The low-voltage circuit components of the temperature detection device, pre-alarm device, and forced power-off device in this solution are all connected to the low-voltage auxiliary battery in the new energy vehicle. This allows for early detection of thermal runaway events without significantly increasing the number of temperature sampling lines, thereby triggering an alarm. Attached Figure Description

[0027] Figure 1 The present invention includes a sound alarm block diagram and a light alarm principle diagram.

[0028] Figure 2 This is a schematic diagram of the fuse principle of the power battery of this utility model. Detailed Implementation

[0029] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0030] Example:

[0031] Please see Figure 1-2 A device for monitoring and warning the temperature of a power battery in a new energy vehicle and forcibly cutting off power, comprising:

[0032] Temperature detection module: Two sets of normally open thermal switches are installed in parallel on the surface of the power battery cell or module. The temperature closing threshold of the first set of thermal switches is T1, and the temperature closing threshold of the second set of thermal switches is T2. The temperature closing threshold T1 is 5-10℃ higher than the original vehicle BMS power-down threshold, and the temperature closing threshold T2 is 20-30℃ higher than the original vehicle BMS power-down threshold.

[0033] Two types of normally open thermal switches are installed on individual battery cells or battery modules, one for each square solid or square pouch cell. For battery module units composed of cylindrical cells, normally open thermal switches can be selected in appropriate quantities as needed. For battery modules similar to multilayer batteries, an appropriate number of normally open thermal switches can be placed in the gaps between every two layers or on the outside of the multilayer, depending on the requirements. Installation methods include physical methods such as bonding, screw fixing, welding, and riveting.

[0034] Warning control module: One end of the coil of the four-pin normally open relay is connected to the positive terminal (12V+) of the vehicle low-voltage auxiliary power supply, and the other end is connected in parallel with the output terminal of the first set of thermal switches. The normally open contacts of the four-pin normally open relay are respectively connected to the control terminals of the alarm horn and the three-pin flashing relay. The output terminal of the three-pin flashing relay is electrically connected to the vehicle's emergency hazard lights.

[0035] The low-voltage auxiliary power supply (12V) is an on-board battery independent of the power battery, providing a stable power supply for the low-voltage control circuits of the temperature detection module, the early warning control module, and the forced power-off module.

[0036] The power supply terminal of the alarm horn is directly connected to a low-voltage auxiliary power supply (12V). The control terminal achieves on / off control through the normally open contacts of a four-pin normally open relay. When the four-pin normally open relay is energized, the alarm horn is powered on and emits an audible warning.

[0037] The power supply terminal of the three-pin hazard light relay is connected to a low-voltage auxiliary power supply (12V). The signal input terminal is linked with the normally open contact of the four-pin normally open relay. The output terminal is connected to the left front, left rear, right front, and right rear turn signals of the car respectively to realize the synchronous flashing control of the emergency hazard lights.

[0038] Forced power-off module: The low-voltage power supply of the coil end of the high-voltage contactor is connected to the positive terminal of the vehicle's low-voltage auxiliary power supply for constant power supply. The coil output grounding terminal is connected in series with the output terminal of the second set of thermal switches. After the second thermal switch is connected to the ground, it starts to work. The high-voltage contacts of the high-voltage contactor are connected in parallel to the positive and negative terminals of the high-voltage components output by the vehicle's power battery and share the same high-voltage protection fuse with the vehicle's high-voltage components.

[0039] The power battery fuse is a high breaking capacity fuse connected in series with the main positive connection line near the power battery. When the high voltage contactor is engaged, the power battery fuse acts as a physical disconnect point to achieve emergency power cut-off.

[0040] Auxiliary control module: A normally closed one-button stop switch is connected in series in the common control circuit of a four-pin normally open relay and a three-pin flashing relay, and a pre-alarm daily test switch is connected in parallel across the first group of thermal switches.

[0041] The coil end of the high-voltage contactor is connected to the second set of thermal switches and the low-voltage auxiliary power supply (12V) through an independent double-wire shielded circuit. Its high-voltage contact rated current is greater than the maximum operating current of the power battery. When the high-voltage contactor is energized, the main positive connection line is connected to the power battery fuse. When the high-voltage contactor is de-energized or the power battery fuse is blown, the main circuit of the power battery is cut off.

[0042] The input terminals of both sets of thermal switches are connected in parallel to the temperature sampling points of the high-voltage circuit of the power battery, and the output terminals are connected to the early warning control module and the forced power-off module through independent double-wire shielded lines, forming independent temperature signal transmission paths.

[0043] The low-voltage control terminal of the main positive (negative) contactor and the common ground terminal of the normally open relay and the three-pin flashing relay are all connected to the negative terminal of the low-voltage auxiliary power supply (12V-), forming a complete low-voltage control circuit. This circuit is in an open circuit state when the two sets of normally open thermal switches are not triggered, and does not consume battery power.

[0044] The pre-alarm daily test switch is a normally open automatic reset switch. When the pre-alarm daily test switch is pressed, it simulates the closing signal of the first group of thermal switches, triggering the alarm horn to sound and the left front, left rear, right front, and right rear turn signals to flash, which is used to check whether the pre-alarm module is functioning properly.

[0045] Working principle:

[0046] When the vehicle is driving, parked, or charging while parked, the normally open thermal switch will issue an audible and visual alarm if the temperature exceeds the factory-set BMS management control unit's temperature threshold by 5 to 10 degrees Celsius. If the battery temperature reaches 80 degrees Celsius or exceeds the factory-set BMS management control unit's temperature threshold by 20 to 30 degrees Celsius, the battery fuse will be forcibly blown to prevent the battery from continuing to heat up due to charging and discharging energy conversion.

[0047] The above description is merely a preferred embodiment of this utility model; however, the protection scope of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in this utility model, based on the technical solution and its improved concept, should be included within the protection scope of this utility model.

Claims

1. A device for monitoring, warning, and forcibly cutting off the temperature of a power battery in a new energy vehicle, characterized in that: include: Temperature detection module: Two sets of normally open thermal switches are installed in parallel on the surface of the power battery cell or module. The temperature closing threshold of the first set of thermal switches is T1, and the temperature closing threshold of the second set of thermal switches is T2. Warning control module: One end of the coil of the four-pin normally open relay is connected to the positive terminal of the vehicle's low-voltage auxiliary power supply, and the other end is connected in parallel with the output terminal of the first set of thermal switches. The normally open contacts of the four-pin normally open relay are respectively connected to the control terminals of the alarm horn and the three-pin flashing relay. The output terminal of the three-pin flashing relay is electrically connected to the vehicle's emergency hazard lights. Forced power-off module: The low-voltage power supply of the coil end of the high-voltage contactor is connected to the positive terminal of the vehicle's low-voltage auxiliary power supply for constant power supply. The coil output grounding terminal is connected in series with the output terminal of the second set of thermal switches. After the second thermal switch is connected to the ground, it starts to work. The high-voltage contacts of the high-voltage contactor are connected in parallel to the positive and negative terminals of the high-voltage components output by the vehicle's power battery and share the same high-voltage protection fuse with the vehicle's high-voltage components. Auxiliary control module: A normally closed one-button stop switch is connected in series in the common control circuit of a four-pin normally open relay and a three-pin flashing relay, and a pre-alarm daily test switch is connected in parallel across the first group of thermal switches.

2. The device for monitoring, warning, and forced power-off of power battery temperature in new energy vehicles according to claim 1, characterized in that: The power supply terminal of the alarm horn is directly connected to a low-voltage auxiliary power supply. The control terminal achieves on / off control through the normally open contacts of a four-pin normally open relay. When the four-pin normally open relay is energized, the alarm horn is powered on and emits an audible warning.

3. The new energy vehicle power battery temperature monitoring, early warning, and forced power-off device according to claim 2, characterized in that: The power supply terminal of the three-pin flashing relay is connected to a low-voltage auxiliary power supply, the signal input terminal is linked with the normally open contact of the four-pin normally open relay, and the output terminal is connected to the left front, left rear, right front, and right rear turn signals of the car respectively, so as to realize the synchronous flashing control of the emergency hazard lights.

4. The new energy vehicle power battery temperature monitoring, early warning and forced power-off device according to claim 3, characterized in that: The coil end of the high-voltage contactor is connected to the second set of thermal switches and the low-voltage auxiliary power supply through an independent double-wire shielded circuit. The rated current of its high-voltage contact is greater than the maximum operating current of the power battery. When the high-voltage contactor is energized, the main positive connection line is connected to the power battery fuse. When the high-voltage contactor is de-energized or the power battery fuse is blown, the main circuit of the power battery is cut off.

5. The new energy vehicle power battery temperature monitoring, early warning, and forced power-off device according to claim 4, characterized in that: The input terminals of the two sets of thermal switches are connected in parallel to the temperature sampling points of the high-voltage circuit of the power battery, and the output terminals are connected to the early warning control module and the forced power-off module through independent double-wire shielded lines, forming independent temperature signal transmission paths.

6. The device for monitoring, warning, and forced power-off of a new energy vehicle power battery temperature according to claim 5, characterized in that: The low-voltage control terminal of the main positive contactor and the common ground terminal of the normally open relay and the three-pin flashing relay are all connected to the negative terminal of the low-voltage auxiliary power supply, forming a complete low-voltage control circuit. This circuit is in an open circuit state when the two sets of normally open thermal switches are not triggered, and does not consume battery power.

7. The new energy vehicle power battery temperature monitoring, early warning, and forced power-off device according to claim 6, characterized in that: The pre-alarm daily test switch is a normally open automatic reset switch. When the pre-alarm daily test switch is pressed, it simulates the closing signal of the first group of thermal switches, triggering the alarm horn to sound and the left front, left rear, right front, and right rear turn signals to flash, which is used to detect whether the pre-alarm module is functioning normally.

8. The new energy vehicle power battery temperature monitoring, early warning, and forced power-off device according to claim 7, characterized in that: The power battery fuse is a high breaking capacity fuse, connected in series with the main positive connection line near the power battery. When the high voltage contactor is engaged, the power battery fuse acts as a physical disconnect point to achieve emergency power cut-off.

9. A new energy vehicle power battery temperature monitoring, early warning, and forced power-off device according to claim 8, characterized in that: The low-voltage auxiliary power supply is an on-board battery independent of the power battery, providing a stable power supply for the low-voltage control circuits of the temperature detection module, the early warning control module, and the forced power-off module.

10. A new energy vehicle power battery temperature monitoring, early warning, and forced power-off device according to claim 9, characterized in that: The temperature closure threshold T1 is 5-10°C higher than the original vehicle BMS power-off threshold, and the temperature closure threshold T2 is 20-30°C higher than the original vehicle BMS power-off threshold.

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