Whole vehicle low-temperature active heating control method and device after power-off

Abstract

This invention provides a method and device for active heating control at extremely low temperatures after a vehicle is powered off, relating to the field of electric vehicle battery thermal management technology. In the vehicle's power-off sleep state, the Battery Management System (BMS) periodically collects cell temperature and State of Charge (SOC) data and filters for the lowest temperature. After a threshold is set to meet the heating conditions, a wake-up command is generated. The Electron Control Module (ECM) performs high-voltage power-on verification and feeds back the command. The BMS closes the high-voltage circuit to initiate heating, continuously collects temperature data, determines exit conditions, and ultimately controls the cessation of heating and high-voltage power-off, completing a single heating cycle. This invention can automatically initiate extremely low-temperature heating when the vehicle is in a static sleep state, improving the low-temperature activity and range stability of the power battery, avoiding performance degradation, limited charging and discharging, and shortened lifespan caused by low temperatures, and ensuring safe, reliable, and continuous heating control.

Description

Technical Field

[0001] This invention mainly relates to the field of electric vehicle battery thermal management technology, specifically to a method and device for active heating control at extremely low temperatures after the vehicle is powered off. Background Technology

[0002] Currently, the performance degradation of power batteries in new energy vehicles is a significant issue in low-temperature environments. Especially during periods when the vehicle is powered off and parked, battery cells are prone to decreased activity and limited charging / discharging capabilities due to excessively low ambient temperatures. Prolonged exposure to extremely low temperatures also accelerates cell aging, reduces battery charging / discharging efficiency, shortens the overall battery lifespan, and negatively impacts vehicle range and reliability. Protecting batteries from static storage in extremely low-temperature scenarios has become a pressing technical challenge for the use and promotion of new energy vehicles.

[0003] To mitigate battery performance degradation caused by low temperatures, most existing technologies employ battery heating methods that are manually triggered by the driver after vehicle startup or automatically activated by the system after vehicle power is supplied. These solutions rely on the vehicle being powered on to perform heating operations, making it impossible to actively preheat the battery during vehicle shutdown or dormancy, thus hindering the ability to improve battery condition in advance when the vehicle is parked for extended periods. Furthermore, existing heating control methods often use fixed-cycle temperature monitoring strategies without adaptive adjustments based on actual battery temperature and remaining charge, leading to issues such as ineffective monitoring and excessive power consumption during dormancy.

[0004] Furthermore, existing technologies generally lack comprehensive multi-layered safety verification mechanisms in the heating start-up and shutdown phases, failing to comprehensively assess factors such as the number of heating cycles, high-voltage power-on / off conditions, and system fault states. In practical applications, this can easily lead to safety hazards and energy consumption issues such as frequent heating, excessive power consumption, and high-voltage system malfunctions. Because existing heating control schemes cannot achieve fully automatic, intelligent, and highly safe active heating at extremely low temperatures after the vehicle is powered off, they are insufficient to meet the low-temperature protection requirements of batteries during long-term stationary parking. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method and device for active heating control at extremely low temperatures after the vehicle is powered off, in order to address the shortcomings of the prior art.

[0006] The technical solution of this invention to solve the above-mentioned technical problems is as follows: A method for active heating control at extremely low temperatures after a vehicle is powered off, comprising the following steps: When the vehicle is in a power-off sleep state, the BMS battery management system periodically collects raw data of the cell temperature and the SOC state of charge of the power battery, and performs extreme value filtering on the raw cell temperature data to obtain the lowest cell temperature data. The BMS battery management system performs threshold comparison and judgment processing on the cell's lowest temperature data and the original SOC state of charge data to obtain the first judgment result data on whether the ultra-low temperature heating start-up conditions are met. The BMS battery management system performs heating trigger decision processing based on the first judgment result data and generates wake-up control command data. The BMS battery management system transmits the wake-up control command data to the BCM body controller. After receiving the command, the BCM body controller performs hard-wired drive processing, generates wake-up signal data, and transmits it to the ECM vehicle controller. The ECM vehicle controller performs high-voltage power-on condition verification processing based on the wake-up signal data, generates high-voltage power-on request command data, and feeds it back to the BMS battery management system. The BMS battery management system executes high-voltage circuit closure processing according to the high-voltage power-on request command data, enters the heating working state, and collects real-time cell temperature data during the heating process. The BMS battery management system performs a heating exit threshold comparison process on the real-time cell temperature data during the heating process to obtain a second judgment result data on whether the heating exit condition is met. Based on the second judgment result data, the BMS battery management system controls the ECM vehicle controller to execute heating stop and high voltage power-off processing, completing a single extreme low temperature active heating control process.

[0007] Based on the above technical solution, the present invention can be further improved as follows.

[0008] Furthermore, the threshold comparison and judgment process includes: The lowest temperature data of the battery cell is compared with a preset extremely low temperature threshold, and the original SOC state of charge data is compared with a preset minimum allowable heating power threshold. If and only if the lowest temperature data of the battery cell is less than the preset extremely low temperature threshold, and the original SOC state of charge data is greater than or equal to the preset minimum allowable heating power threshold, the first judgment result data that meets the conditions for starting the extremely low temperature heating is generated.

[0009] Furthermore, the heating trigger decision processing also includes a heating count limitation step: Before generating wake-up control command data, the current cumulative heating count is counted and compared with the preset maximum allowable heating count. The wake-up control command data is only generated when the cumulative heating count is less than the preset maximum allowable heating count. If the cumulative heating count reaches the preset maximum allowable heating count, the wake-up control command data is not generated, the vehicle remains in a dormant state, and the periodic acquisition and extreme value screening process is re-executed.

[0010] Furthermore, the high-voltage power-on condition verification process includes: The system verifies whether the vehicle is currently powered down, whether there are fault codes, and whether there are charging or discharging prohibition signals. When all verification items meet the preset requirements, and the vehicle is determined to be powered down, without fault codes, and without charging or discharging prohibition signals, the system generates the high-voltage power-on request command data.

[0011] Furthermore, the heating exit threshold comparison process includes: The real-time cell temperature data collected during the heating process is compared with a preset heating exit temperature threshold. The preset heating exit temperature threshold is greater than a preset ultra-low temperature threshold. When the real-time cell temperature data is greater than or equal to the preset heating exit temperature threshold, a second judgment result data that meets the heating exit condition is generated; otherwise, a second judgment result data that does not meet the heating exit condition and needs to continue heating is generated.

[0012] Furthermore, the heating cessation and high-voltage power-off process includes: Once the second judgment result data that meets the heating exit condition is generated, the heating operation is stopped first, and then a high-voltage power-off command is sent to perform high-voltage circuit disconnection. After the high-voltage power-off is completed, the vehicle returns to the power-off sleep state and continues to perform periodic data acquisition and status monitoring.

[0013] Furthermore, it also includes: The BMS (Battery Management System) performs adaptive wake-up interval calculation based on the real-time cell temperature data and the original SOC (State of Charge) data during the heating process to obtain the data for the next data acquisition cycle. The lower the cell temperature and the higher the SOC, the shorter the calculated acquisition cycle; the higher the cell temperature and the lower the SOC, the longer the calculated acquisition cycle. The initial acquisition cycle data is then updated with the data from the next data acquisition cycle.

[0014] Another technical solution of the present invention to solve the above-mentioned technical problems is as follows: an active heating control device for extremely low temperature after the vehicle is powered off, including a BMS battery management system, a BCM body controller and an ECM vehicle controller; The BMS battery management system is used to: periodically collect raw data of cell temperature and raw data of SOC of the power battery when the vehicle is in a power-off hibernation state, and perform extreme value filtering processing on the raw data of cell temperature to obtain the lowest cell temperature data. It is also used to perform threshold comparison and judgment processing on the lowest temperature data of the battery cell and the original SOC state of charge data to obtain the first judgment result data on whether the ultra-low temperature heating start-up conditions are met. It is also used to perform heating trigger decision processing based on the first judgment result data to generate wake-up control command data; The BCM body controller is used to receive wake-up control command data sent by the BMS battery management system, perform hard-wired drive processing, generate wake-up signal data, and transmit it to the ECM vehicle controller. The ECM vehicle controller is used to perform high-voltage power-on condition verification processing based on the wake-up signal data, generate high-voltage power-on request command data, and feed it back to the BMS battery management system. The BMS battery management system is also used to: execute high-voltage circuit closure processing according to the high-voltage power-on request command data, enter the heating working state, and collect real-time data of cell temperature during the heating process. It is also used to perform heating exit threshold comparison processing on the real-time cell temperature data during the heating process to obtain a second judgment result data on whether the heating exit condition is met; It is also used to control the ECM vehicle controller to perform heating stop and high voltage power-off processing based on the second judgment result data, and complete a single extreme low temperature active heating control process.

[0015] The beneficial effects of this invention are as follows: By having the BMS battery management system complete the entire closed-loop process of cell temperature and state of charge acquisition, extreme value screening, threshold judgment, wake-up triggering, cross-controller collaboration, high-voltage power-on verification, heating execution and exit control in the vehicle's power-off hibernation state, it can automatically start the ultra-low temperature heating strategy when the vehicle is stationary and in hibernation, effectively improving the activity and range stability of the power battery in low-temperature environments, avoiding cell performance degradation, limited charging and discharging, and shortened lifespan due to low temperatures, while ensuring the safety, reliability, and continuity of heating control after the vehicle is powered off. Attached Figure Description

[0016] Figure 1 A flowchart of an active heating control method for extremely low temperatures after power-off of a vehicle, provided in an embodiment of the present invention; Figure 2 This is a module block diagram of the vehicle's low-temperature active heating control device provided in an embodiment of the present invention. Figure 3 This is an overall flowchart of the active heating control for extremely low temperatures after the vehicle is powered off, provided in an embodiment of the present invention. Detailed Implementation

[0017] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0018] Example 1: As Figure 1 As shown, this embodiment of the invention provides a method for active heating control at extremely low temperatures after the vehicle is powered off, including the following steps: S1. In the vehicle's power-off hibernation state, the BMS battery management system periodically collects the original data of the battery cell temperature and the original data of the SOC state of charge, and performs extreme value filtering on the original data of the battery cell temperature to obtain the lowest temperature data of the battery cell. S2, the BMS battery management system performs threshold comparison and judgment processing on the cell's minimum temperature data and the original SOC state of charge data to obtain the first judgment result data on whether the ultra-low temperature heating start-up conditions are met. S3, the BMS battery management system performs heating trigger decision processing based on the first judgment result data and generates wake-up control command data; S4. The BMS battery management system transmits the wake-up control command data to the BCM body controller. After receiving the command, the BCM body controller performs hard-wired drive processing, generates wake-up signal data, and transmits it to the ECM vehicle controller. S5. The ECM vehicle controller performs high-voltage power-on condition verification processing based on the wake-up signal data, generates high-voltage power-on request command data, and feeds it back to the BMS battery management system. S6. The BMS battery management system executes high-voltage circuit closure processing according to the high-voltage power-on request command data, enters the heating working state, and collects real-time cell temperature data during the heating process. S7, the BMS battery management system performs a heating exit threshold comparison on the real-time cell temperature data during the heating process to obtain a second judgment result data on whether the heating exit condition is met; S8, the BMS battery management system controls the ECM vehicle controller to perform heating stop and high voltage power-off processing based on the second judgment result data, completing a single extreme low temperature active heating control process.

[0019] In the above embodiments, by having the BMS battery management system complete the entire closed-loop process of cell temperature and state of charge acquisition, extreme value screening, threshold judgment, wake-up triggering, cross-controller collaboration, high-voltage power-on verification, heating execution and exit control in the vehicle's power-off sleep state, the system can automatically start the ultra-low temperature heating strategy when the vehicle is stationary in sleep mode. This effectively improves the activity and range stability of the power battery in low-temperature environments, avoids cell performance degradation, limited charging and discharging, and shortened lifespan due to low temperatures, and ensures the safety, reliability, and continuity of heating control after the vehicle is powered off.

[0020] Specifically, the extreme value screening process is as follows: the BMS battery management system acquires the raw temperature data of all cells in the power battery within one acquisition cycle, and by traversing and comparing all the raw temperature data of the cells, it selects the temperature data with the smallest value and determines the minimum temperature data of the cell, which is used to determine the subsequent ultra-low temperature heating start-up conditions.

[0021] Preferably, it also includes a GW gateway unit, with the BMS battery management system as the core logic judgment unit, the ECM as the high-voltage control and heating execution unit, the BCM as the hard-wired wake-up unit, and the GW as the gateway unit, which is responsible for routing the control signals between the controllers and coordinating the hibernation and wake-up of each component. Through the coordinated work of multiple controllers, it prevents the minimum temperature of the battery cell from falling below the preset ultra-low temperature threshold (-30℃), thus avoiding the situation where the power battery discharges with zero power and the vehicle cannot start normally due to excessively low temperature.

[0022] Preferably, in step S2, the threshold comparison and judgment process includes: The lowest temperature data of the battery cell is compared with a preset extremely low temperature threshold, and the original SOC state of charge data is compared with a preset minimum allowable heating power threshold. If and only if the lowest temperature data of the battery cell is less than the preset extremely low temperature threshold, and the original SOC state of charge data is greater than or equal to the preset minimum allowable heating power threshold, the first judgment result data that meets the conditions for starting the extremely low temperature heating is generated.

[0023] Specifically, the preset extreme low temperature threshold is set to -30℃. When the cell temperature is below this threshold, the power battery discharge power drops to 0, and the vehicle will not be able to start smoothly. This dual-condition judgment ensures that heating is only triggered when the temperature is extremely low and the battery is fully charged. In the above embodiments, by performing dual condition judgments on the minimum cell temperature and the preset extremely low temperature threshold, and the state of charge and the minimum allowable heating power threshold, the extreme low temperature heating triggering scenario can be accurately identified, ineffective heating and power waste can be avoided, and the heating operation can be performed within the safe power range, thereby improving the rationality of heating control and the power safety of the power battery.

[0024] Preferably, in step S3, the heating trigger decision processing further includes a heating number limitation step: Before generating wake-up control command data, the current cumulative heating count is counted and compared with the preset maximum allowable heating count. The wake-up control command data is only generated when the cumulative heating count is less than the preset maximum allowable heating count. If the cumulative heating count reaches the preset maximum allowable heating count, the wake-up control command data is not generated, the vehicle remains in sleep mode, and the process returns to step S1.

[0025] Specifically, by setting a heating cycle limit mechanism, the repeated activation of the heating function during long-term parking can be avoided, which would cause serious power loss to the power battery, thus achieving a balance between precise temperature control and power protection.

[0026] In the above embodiments, adding a cumulative heating count limit in the heating trigger decision-making process can prevent the frequent start-up of heating after the vehicle is powered off, which would lead to excessive power consumption of the power battery and component wear. While ensuring the low-temperature heating effect, it can also reduce dormant power consumption, extend the vehicle's stationary parking time, and improve the stability and service life of the system control.

[0027] Preferably, in step S5, the high-voltage power-on condition verification process includes: The system verifies whether the vehicle is currently powered down, whether there are fault codes, and whether there are charging or discharging prohibition signals. When all verification items meet the preset requirements, and the vehicle is determined to be powered down, without fault codes, and without charging or discharging prohibition signals, the system generates the high-voltage power-on request command data.

[0028] Specifically, the ECM vehicle controller maintains power-on priority judgment when performing high-voltage power-on verification, strictly follows the vehicle safety control logic, and only allows high-voltage power-on when all safety conditions are met, thereby improving the stability of system operation.

[0029] In the above embodiments, by verifying multiple conditions such as the vehicle's power-off status, fault codes, and charging / discharging prohibition signals before power-on, abnormal operating conditions and safety risks can be eliminated, ensuring that high-voltage power-on is only performed under safe and compliant conditions, avoiding potential hazards such as accidental power-on and malfunctions, and improving the safety and reliability of high-voltage system control.

[0030] Preferably, in step S7, the heating exit threshold comparison process includes: The real-time cell temperature data collected during the heating process is compared with a preset heating exit temperature threshold. The preset heating exit temperature threshold is greater than a preset ultra-low temperature threshold. When the real-time cell temperature data is greater than or equal to the preset heating exit temperature threshold, a second judgment result data that meets the heating exit condition is generated; otherwise, a second judgment result data that does not meet the heating exit condition and needs to continue heating is generated.

[0031] Specifically, if an abnormal temperature rise rate or other malfunction occurs during the heating process, the system will immediately stop heating and enter a dormant state to avoid safety hazards caused by heating failure and ensure reliable operation of the low-temperature heating process.

[0032] In the above embodiments, the real-time temperature of the battery cell is judged based on the preset heating exit temperature threshold. Heating can be stopped in time when the battery cell reaches the appropriate temperature, which not only ensures that the low-temperature heating effect is fully realized, but also prevents excessive heating from increasing energy consumption and the risk of battery cell overheating, thus achieving precise start and stop of the heating process and energy consumption optimization.

[0033] Preferably, in step S8, the heating stop and high-voltage power-off process includes: After generating the second judgment result data that meets the heating exit condition, the heating operation is stopped first, and then a high-voltage power-off command is sent to perform high-voltage circuit disconnection. After the high-voltage power-off is completed, the vehicle returns to the power-off sleep state and returns to step S1 to continue periodically collecting data.

[0034] Specifically, the ECM vehicle controller requests a high-voltage power-off based on the low-temperature heating request signal and the actual vehicle status, and disconnects the high-voltage circuit according to a preset timing sequence, so that the vehicle can safely return to the power-off sleep state.

[0035] In the above embodiments, the power-off process is executed in the order of stopping heating first and then disconnecting the high-voltage circuit. This can standardize the power-off operation of the high-voltage system, reduce the electrical shock and safety risks caused by high-voltage switching, ensure that the vehicle smoothly returns to the dormant state after heating is completed, and support cyclic data collection and periodic monitoring to improve the system's continuous operation capability.

[0036] Preferably, the method further includes step S9: The BMS battery management system performs adaptive calculation of the wake-up interval based on the real-time cell temperature data and the original SOC state of charge data during the heating process to obtain the data for the next round of data acquisition cycle. The lower the cell temperature and the higher the SOC state of charge, the shorter the calculated acquisition cycle; the higher the cell temperature and the lower the SOC state of charge, the longer the calculated acquisition cycle. Then, the data in the acquisition cycle update step S1 is updated with the data for the next round of data acquisition cycle.

[0037] Specifically, the method of dynamically adjusting the wake-up frequency based on cell temperature and SOC is a pioneering technology in the disclosed materials. This can avoid excessive wake-up leading to battery depletion, and at the same time prevent untimely wake-up from causing the cell temperature to drop too low and the vehicle to fail to start.

[0038] In the above embodiments, the data acquisition cycle is adaptively adjusted according to the real-time temperature and state of charge of the battery cell. The monitoring interval is shortened in the low temperature and high charge state to improve the response speed, and the monitoring interval is extended in the high temperature and low charge state to reduce power consumption. This achieves a dynamic balance between energy consumption and control sensitivity in the sleep state, and optimizes the overall control strategy and energy-saving effect.

[0039] The following is through Figure 3 The overall flowchart of the active heating control at extremely low temperatures after the vehicle is powered off introduces the control method of this invention.

[0040] The control method of this invention assumes the vehicle is in a power-off sleep state. The BMS (Battery Management System) acts as the main control unit. Through a full-process logic encompassing self-wake-up detection, multi-dimensional condition verification, cross-controller collaborative wake-up, closed-loop monitoring of the heating process, and safe exit and sleep recovery, it achieves fully automatic active heating control of the power battery in extremely low-temperature environments. The specific process is as follows: First, after system startup, the BMS performs self-wake-up temperature detection while the vehicle is in a power-down sleep state, periodically collecting status data such as battery cell temperature and displayed SOC, and completing initial state monitoring. Then, it enters a dual pre-condition verification process: the first verification checks the number of heating cycles and battery capacity limits, determining if the total number of active heating cycles at extremely low temperatures is less than 4 and if the displayed SOC is greater than or equal to 40%. If these conditions are not met, the BMS directly requests vehicle sleep mode, maintaining the power-down state and waiting for the next self-wake-up detection. If the conditions are met, it enters the second temperature range verification, determining if the lowest cell temperature Tmin is within the extremely low temperature range of -30℃ to -28℃. If the cell temperature does not fall within this range, it is determined that heating is not required during this power-down cycle, and the extremely low temperature heating function for this cycle is directly shut down. Simultaneously, the BMS is triggered to exit the heating state and request high-voltage sleep mode, and the vehicle completely enters sleep mode, with no further heating operations performed during this power-down cycle. If the cell temperature meets the extremely low temperature range requirements, the heating trigger condition is confirmed, and the vehicle wake-up and heating start-up process begins.

[0041] Next, the BMS sends a wake-up command to the vehicle, waking up controllers such as the BCM and ECM to activate the entire vehicle system. Then, it performs a high-voltage power-on operation, with the ECM performing high-voltage power-on verification and circuit closure to provide high-voltage power to the battery heating system. The BMS then enters an extremely low-temperature heating state, activating the power battery heating system and monitoring the cell temperature and temperature rise in real time. During the heating process, the system performs dual closed-loop monitoring: the first is a heating effectiveness verification, checking if the average battery temperature rise rate is greater than or equal to 1℃ / 10min. If the temperature rise rate is below the standard, the heating system is deemed abnormal, immediately triggering the BMS to exit the heating state, request high-voltage hibernation, shut down heating, and disconnect the high voltage to ensure system safety. If the temperature rise rate is normal, the system enters the second heating exit condition verification, checking if the lowest cell temperature Tmin is greater than or equal to -25℃. If the cell temperature does not reach the exit threshold, it jumps back to the heating state, continuing heating and cyclic monitoring; if the cell temperature reaches -25℃ or above, the heating exit condition is met, and the heating termination process begins.

[0042] Finally, the BMS exits the cryogenic heating state and stops the heating system; it increments the total number of cryogenic active heating cycles by 1 to complete this heating count, providing data support for limiting the number of heating cycles in the future; then the BMS sends a request to the ECM to disconnect the high-voltage circuit, completing the high-voltage power-off and eliminating high-voltage safety risks; finally, the BMS requests the vehicle to return to the power-off sleep state, ending the closed loop of this cryogenic active heating process, and waits for the next BMS self-wake-up temperature detection to repeat the above full process control.

[0043] Example 2: Figure 2As shown, this embodiment of the invention also provides an active heating control device for extremely low temperatures after the vehicle is powered off, including a BMS battery management system, a BCM body controller, and an ECM vehicle controller; The BMS battery management system is used to: periodically collect raw data of cell temperature and raw data of SOC of the power battery when the vehicle is in a power-off hibernation state, and perform extreme value filtering processing on the raw data of cell temperature to obtain the lowest cell temperature data. It is also used to perform threshold comparison and judgment processing on the lowest temperature data of the battery cell and the original SOC state of charge data to obtain the first judgment result data on whether the ultra-low temperature heating start-up conditions are met. It is also used to perform heating trigger decision processing based on the first judgment result data to generate wake-up control command data; The BCM body controller is used to receive wake-up control command data sent by the BMS battery management system, perform hard-wired drive processing, generate wake-up signal data, and transmit it to the ECM vehicle controller. The ECM vehicle controller is used to perform high-voltage power-on condition verification processing based on the wake-up signal data, generate high-voltage power-on request command data, and feed it back to the BMS battery management system. The BMS battery management system is also used to: execute high-voltage circuit closure processing according to the high-voltage power-on request command data, enter the heating working state, and collect real-time data of cell temperature during the heating process. It is also used to perform heating exit threshold comparison processing on the real-time cell temperature data during the heating process to obtain a second judgment result data on whether the heating exit condition is met; It is also used to control the ECM vehicle controller to perform heating stop and high voltage power-off processing based on the second judgment result data, and complete a single extreme low temperature active heating control process.

[0044] Preferably, the threshold comparison and judgment process includes: The lowest temperature data of the battery cell is compared with a preset extremely low temperature threshold, and the original SOC state of charge data is compared with a preset minimum allowable heating power threshold. If and only if the lowest temperature data of the battery cell is less than the preset extremely low temperature threshold, and the original SOC state of charge data is greater than or equal to the preset minimum allowable heating power threshold, the first judgment result data that meets the conditions for starting the extremely low temperature heating is generated.

[0045] Preferably, the heating trigger decision processing further includes a heating number limitation step: Before generating wake-up control command data, the current cumulative heating count is counted and compared with the preset maximum allowable heating count. The wake-up control command data is only generated when the cumulative heating count is less than the preset maximum allowable heating count. If the cumulative heating count reaches the preset maximum allowable heating count, the wake-up control command data is not generated, the vehicle remains in a dormant state, and the periodic acquisition and extreme value screening process is re-executed.

[0046] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0047] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the device described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for active heating control at extremely low temperatures after a vehicle is powered off, characterized in that, Includes the following steps: When the vehicle is in a power-off sleep state, the BMS battery management system periodically collects raw data of the cell temperature and the SOC state of charge of the power battery, and performs extreme value filtering on the raw cell temperature data to obtain the lowest cell temperature data. The BMS battery management system performs threshold comparison and judgment processing on the cell's lowest temperature data and the original SOC state of charge data to obtain the first judgment result data on whether the ultra-low temperature heating start-up conditions are met. The BMS battery management system performs heating trigger decision processing based on the first judgment result data and generates wake-up control command data. The BMS battery management system transmits the wake-up control command data to the BCM body controller. After receiving the command, the BCM body controller performs hard-wired drive processing, generates wake-up signal data, and transmits it to the ECM vehicle controller. The ECM vehicle controller performs high-voltage power-on condition verification processing based on the wake-up signal data, generates high-voltage power-on request command data, and feeds it back to the BMS battery management system. The BMS battery management system executes high-voltage circuit closure processing according to the high-voltage power-on request command data, enters the heating working state, and collects real-time cell temperature data during the heating process. The BMS battery management system performs a heating exit threshold comparison process on the real-time cell temperature data during the heating process to obtain a second judgment result data on whether the heating exit condition is met. Based on the second judgment result data, the BMS battery management system controls the ECM vehicle controller to execute heating stop and high voltage power-off processing, completing a single extreme low temperature active heating control process.

2. The method for active heating control at extremely low temperatures after the vehicle is powered off, as described in claim 1, is characterized in that... The threshold comparison and judgment process includes: The lowest temperature data of the battery cell is compared with a preset extremely low temperature threshold, and the original SOC state of charge data is compared with a preset minimum allowable heating power threshold. If and only if the lowest temperature data of the battery cell is less than the preset extremely low temperature threshold, and the original SOC state of charge data is greater than or equal to the preset minimum allowable heating power threshold, the first judgment result data that meets the conditions for starting the extremely low temperature heating is generated.

3. The method for active heating control at extremely low temperatures after the vehicle is powered off, as described in claim 1, is characterized in that... The heating trigger decision processing also includes a heating number limitation step: Before generating wake-up control command data, the current cumulative heating count is counted, and the cumulative heating count is compared with the preset maximum allowed heating count. The wake-up control command data is only generated when the cumulative heating count is less than the preset maximum allowed heating count. If the cumulative number of heating cycles reaches the preset maximum allowable number of heating cycles, no wake-up control command data will be generated, the vehicle will remain in a dormant state, and the periodic data acquisition and extreme value screening process will be re-executed.

4. The method for active heating control at extremely low temperatures after the vehicle is powered off, as described in claim 1, is characterized in that... The high-voltage power-on condition verification process includes: The system verifies whether the vehicle is currently powered down, whether there are fault codes, and whether there are charging or discharging prohibition signals. When all verification items meet the preset requirements, and the vehicle is determined to be powered down, without fault codes, and without charging or discharging prohibition signals, the system generates the high-voltage power-on request command data.

5. The method for active heating control at extremely low temperatures after the vehicle is powered off according to claim 1, characterized in that, The heating exit threshold comparison process includes: The real-time cell temperature data collected during the heating process is compared with a preset heating exit temperature threshold. The preset heating exit temperature threshold is greater than a preset ultra-low temperature threshold. When the real-time cell temperature data is greater than or equal to the preset heating exit temperature threshold, a second judgment result data that meets the heating exit condition is generated; otherwise, a second judgment result data that does not meet the heating exit condition and needs to continue heating is generated.

6. The method for active heating control at extremely low temperatures after the vehicle is powered off, as described in claim 1, is characterized in that... The heating cessation and high-voltage power-off process includes: Once the second judgment result data that meets the heating exit condition is generated, the heating operation is stopped first, and then a high-voltage power-off command is sent to perform high-voltage circuit disconnection. After the high-voltage power-off is completed, the vehicle returns to the power-off sleep state and continues to perform periodic data acquisition and status monitoring.

7. The method for active heating control of extremely low temperature after vehicle power-off according to any one of claims 1 to 6, characterized in that, Also includes: The BMS (Battery Management System) performs adaptive calculation of the wake-up interval based on real-time cell temperature data and raw SOC (State of Charge) data during the heating process to obtain the data for the next data acquisition cycle. The lower the cell temperature and the higher the SOC, the shorter the calculated acquisition cycle; the higher the cell temperature and the lower the SOC, the longer the calculated acquisition cycle. The initial acquisition cycle data is then updated with the data from the next data acquisition cycle.

8. A vehicle-to-vehicle low-temperature active heating control device after power-off, characterized in that, This includes the BMS (Battery Management System), BCM (Body Controller System), and ECM (Vehicle Controller System). The BMS battery management system is used to: periodically collect raw data of cell temperature and raw data of SOC of the power battery when the vehicle is in a power-off hibernation state, and perform extreme value filtering processing on the raw data of cell temperature to obtain the lowest cell temperature data. It is also used to perform threshold comparison and judgment processing on the lowest temperature data of the battery cell and the original SOC state of charge data to obtain the first judgment result data on whether the ultra-low temperature heating start-up conditions are met. It is also used to perform heating trigger decision processing based on the first judgment result data to generate wake-up control command data; The BCM body controller is used to receive wake-up control command data sent by the BMS battery management system, perform hard-wired drive processing, generate wake-up signal data, and transmit it to the ECM vehicle controller. The ECM vehicle controller is used to perform high-voltage power-on condition verification processing based on the wake-up signal data, generate high-voltage power-on request command data, and feed it back to the BMS battery management system. The BMS battery management system is also used to: execute high-voltage circuit closure processing according to the high-voltage power-on request command data, enter the heating working state, and collect real-time data of cell temperature during the heating process. It is also used to perform heating exit threshold comparison processing on the real-time cell temperature data during the heating process to obtain a second judgment result data on whether the heating exit condition is met; It is also used to control the ECM vehicle controller to perform heating stop and high voltage power-off processing based on the second judgment result data, and complete a single extreme low temperature active heating control process.

9. The vehicle power-off low-temperature active heating control device according to claim 8, characterized in that, The threshold comparison and judgment process includes: The lowest temperature data of the battery cell is compared with a preset extremely low temperature threshold, and the original SOC state of charge data is compared with a preset minimum allowable heating power threshold. If and only if the lowest temperature data of the battery cell is less than the preset extremely low temperature threshold, and the original SOC state of charge data is greater than or equal to the preset minimum allowable heating power threshold, the first judgment result data that meets the conditions for starting the extremely low temperature heating is generated.

10. The vehicle power-off low-temperature active heating control device according to claim 1, characterized in that, The heating trigger decision processing also includes a heating number limitation step: Before generating wake-up control command data, the current cumulative heating count is counted, and the cumulative heating count is compared with the preset maximum allowed heating count. The wake-up control command data is only generated when the cumulative heating count is less than the preset maximum allowed heating count. If the cumulative number of heating cycles reaches the preset maximum allowable number of heating cycles, no wake-up control command data will be generated, the vehicle will remain in a dormant state, and the periodic data acquisition and extreme value screening process will be re-executed.

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