Battery pack active thermal control method and system for electric vehicles

Abstract

The application provides a battery pack active insulation control method and system for an electric vehicle, which is based on the ambient temperature of the battery pack during charging to determine whether the battery pack is in an effective charging state, so as to adjust the active insulation state of the first insulation device and the heat storage working mode of the second insulation device, actively insulate the battery pack during charging and pre-store heat energy for subsequent active insulation of the battery pack for external power supply; based on the electric energy storage state data of the battery pack when the charging is completed and the battery pack is not supplying power externally, it is determined whether the battery pack has an electric energy storage relaxation event, so as to adjust the active insulation wake-up state of the second insulation device for the battery pack, and reduce the electric energy storage loss rate of the battery pack; and based on the electric energy output state data of the battery pack during external power supply, it is determined whether the battery pack has an unstable electric energy output event, so as to adjust the active heating state of the second insulation device for the battery pack, ensure that the battery pack can stably and continuously supply power externally, and improve the charge-discharge performance stability and reliability of the battery pack.

Description

Technical Field

[0001] This invention relates to the field of battery packs, and more particularly to an active thermal insulation control method and system for battery packs of electric vehicles. Background Technology

[0002] As the power source of an electric vehicle, the battery pack provides electrical energy for the operation of all its components. The battery pack contains multiple independent lithium-ion battery cells, each capable of independent charging and discharging. Due to the inherent operating characteristics of lithium-ion batteries, when the ambient temperature is low, such as below their optimal operating temperature, the battery capacity decreases. In this situation, the battery cannot charge properly, and the stored energy leaks rapidly. This compromises the battery's ability to continuously and stably charge, store, and supply power, thus reducing the battery pack's charging and discharging performance and hindering its reliable power source for the electric vehicle. To mitigate the impact of ambient temperature on battery pack performance, heating devices have been installed inside the battery pack for active insulation. However, existing heating devices operate in a single, fixed mode, unable to flexibly adjust heating operations to suit different operating conditions, reducing the efficiency of heat utilization and limiting the long-term effectiveness of active insulation. Summary of the Invention

[0003] The purpose of this invention is to provide an active heat preservation control method and system for electric vehicle battery packs. Based on the ambient temperature of the battery pack during charging, the method determines whether the battery pack is in an effective charging state, thereby adjusting the active heat preservation state of the first heat preservation device and the heat storage working mode of the second heat preservation device. This provides active heat preservation of the battery pack during charging and pre-stores thermal energy for subsequent power supply from the battery pack. Based on the energy storage state data of the battery pack when charging is complete and no power is being supplied, the method determines whether an energy storage relaxation event has occurred, thereby adjusting the active heat preservation wake-up state of the second heat preservation device to reduce the energy storage loss rate of the battery pack. Furthermore, based on the energy output state data of the battery pack during power supply, the method determines whether an unstable energy output event has occurred, thereby adjusting the active heating state of the second heat preservation device to ensure that the battery pack can stably and continuously supply power. By flexibly selecting appropriate active heat preservation methods according to the working characteristics of the battery pack at different stages of charging and discharging, the method improves the stability and reliability of the battery pack's charging and discharging performance.

[0004] This invention is achieved through the following technical solution:

[0005] Active thermal insulation control methods for electric vehicle battery packs include:

[0006] Based on the ambient temperature data of the electric vehicle's battery pack during the charging process, it is determined whether the battery pack is in an effective charging state; based on the determination result of the effective charging state, the active heat preservation state of the first heat preservation device adjacent to the battery pack is adjusted, and the second heat preservation device adjacent to the battery pack is triggered to enter the heat storage working mode.

[0007] The system acquires energy storage status data of the battery pack when it is fully charged and not supplying power to the outside world, analyzes the energy storage status data, and determines whether the battery pack has experienced an energy storage relaxation event. Based on the determination result of whether the energy storage relaxation event has occurred, the system adjusts the active wake-up state of the second heat preservation device for the battery pack.

[0008] The system acquires power output status data of the battery pack during external power supply, analyzes the power output status data, and determines whether the battery pack has experienced a power output instability event. Based on the determination result of whether the power output instability event has occurred, the system adjusts the active heating state of the second heat preservation device for the battery pack.

[0009] Optionally, based on the ambient temperature data of the electric vehicle's battery pack during charging, it is determined whether the battery pack is in an effective charging state; based on the determination result of the effective charging state, the active heat preservation state of the first heat preservation device adjacent to the battery pack is adjusted, and the second heat preservation device adjacent to the battery pack is triggered to enter the heat storage working mode, including:

[0010] The ambient temperature of the external environment during the charging process of the electric vehicle's battery pack at the charging station is periodically collected to obtain ambient temperature data; the ambient temperature data is analyzed to obtain the duration during which the ambient temperature is lower than the preset optimal operating temperature of the battery pack; if the duration exceeds a preset time threshold, it is determined that the battery pack is not in an effective charging state; otherwise, it is determined that the battery pack is in an effective charging state.

[0011] When the battery pack is in an effective charging state, the first insulation device adjacent to the battery pack is instructed not to actively heat and insulate the battery pack, and the second insulation device adjacent to the battery pack is instructed to obtain electrical energy from the charging pile at a first power for phase change heat storage.

[0012] When the battery pack is not in an effective charging state, the first heat preservation device adjacent to the battery pack is instructed to actively heat and preserve the battery pack at a heating temperature higher than the preset optimal operating temperature, and the second heat preservation device adjacent to the battery pack is instructed to obtain electrical energy from the charging pile at a second power for phase change heat storage; wherein, the first power is greater than the second power.

[0013] Optionally, based on the determination result of the effective charging state, the active heat preservation state of the first heat preservation device adjacent to the battery pack is adjusted, including:

[0014] Step S1: Using the following formula (1), determine whether the ambient temperature of the electric vehicle's battery pack during the charging process is lower than the preset optimal operating temperature of the battery pack, and control whether to enter the start-up preheating stage of the first heat preservation device.

[0015] Y1=[Q(t) <Q0]||[|Q(t)-Q0|≤1℃] (1)

[0016] In the above formula (1), Y1 represents the control value of the first heat preservation device entering the start-up preheating stage; Q(t) represents the ambient temperature of the electric vehicle's battery pack during the charging process at the current moment; Q0 represents the preset optimal operating temperature of the battery pack; || represents the absolute value; || represents a logical OR operation. When neither side of the expression is true, the corresponding output value is 0. When one or more of the expressions on both sides of the expression are true, the corresponding output value is 1; 1℃ represents 1 degree Celsius.

[0017] If Y1 = 1, it means that the first insulation device is controlled to enter the preheating stage;

[0018] If Y1 = 0, it means that the first insulation device is not controlled to enter the preheating stage;

[0019] Step S2: If the first insulation device enters the preheating stage, the preheating setting temperature of the first insulation device is controlled using the following formula (2) based on the ambient temperature of the electric vehicle's battery pack during charging and the preset optimal operating temperature of the battery pack.

[0020] Q1=F[Q(t)≥Q0]×1.5×Q0+F[Q(t) <Q0]×[3×Q0-Q(t)] (2)

[0021] In the above formula (2), Q1 represents the preheating control setting temperature of the first heat preservation equipment; F[] represents the formula validity function. If the formula in the parentheses is valid, the output value of the formula validity function is 1. If the formula in the parentheses is invalid, the output value of the formula validity function is 0.

[0022] Step S3: If the first insulation device has entered the preheating stage, the time for the first insulation device to preheat to the set temperature is controlled using the following formula (3) based on the ambient temperature of the electric vehicle's battery pack during charging and the preset optimal operating temperature of the battery pack.

[0023]

[0024] In the above formula (3), T1 represents the control time for the first heat preservation device to preheat to the set temperature; T0 represents the preset time threshold corresponding to the duration for which the external ambient temperature is lower than the preset optimal working temperature of the battery pack.

[0025] Optionally, the energy storage state data of the battery pack when it has completed charging and is not supplying power to the outside is obtained; the energy storage state data is analyzed to determine whether an energy storage relaxation event has occurred in the battery pack; based on the determination result of whether the energy storage relaxation event has occurred, the active wake-up state of the second heat preservation device for the battery pack is adjusted, including:

[0026] Dark current detection is performed on the battery pack when it is fully charged and not supplying power to the outside to obtain dark current change data of the battery pack. Based on the dark current change data, the energy loss rate stored in the battery pack is determined. The energy loss rate is compared with a preset energy reduction rate threshold. If the energy loss rate is greater than the preset energy reduction rate threshold, it is determined that the battery pack has experienced an energy storage relaxation event; otherwise, it is determined that the battery pack has not experienced an energy storage relaxation event.

[0027] When the battery pack experiences an energy storage relaxation event, the second insulation device is instructed to perform intermittent phase change heat release operations at a corresponding frequency, thereby periodically and actively heating and waking up the battery pack; when the battery pack does not experience an energy storage relaxation event, the second insulation device is instructed not to perform phase change heat release operations, thereby not actively heating and waking up the battery pack.

[0028] Optionally, the power output status data of the battery pack during external power supply is acquired, the power output status data is analyzed, and it is determined whether the battery pack has experienced a power output instability event; based on the determination result of whether the power output instability event has occurred, the active heating state of the second heat preservation device for the battery pack is adjusted, including:

[0029] The current output status of the battery pack is detected during the external power supply process to obtain the power supply current change data of the battery pack; the power supply current change data is analyzed to obtain the average drift rate of the actual power supply current of the battery pack relative to the reference power supply current during the external power supply process; if the average drift rate is greater than a preset drift rate threshold, it is determined that the battery pack has experienced a power output instability event; otherwise, it is determined that the battery pack has not experienced a power output instability event.

[0030] When the battery pack experiences an unstable power output event, based on the remaining thermal energy storage value of the second insulation device, the second insulation device is instructed to perform a continuous phase change heat release operation on the battery pack at a corresponding heat release rate, thereby actively heating the battery pack.

[0031] If the battery pack does not experience an unstable power output event, the second insulation device is instructed not to perform a phase change heat release operation, thereby not actively heating the battery pack.

[0032] The active thermal insulation control system for the battery pack of electric vehicles includes:

[0033] The temperature detection and analysis module is used to determine whether the battery pack is in an effective charging state based on the ambient temperature data of the electric vehicle's battery pack during the charging process.

[0034] The first insulation device control module is used to adjust the active insulation state of the first insulation device adjacent to the battery pack based on the judgment result of the effective charging state.

[0035] The second insulation device control module is used to trigger the second insulation device adjacent to the battery pack to enter the heat storage working mode based on the judgment result of the effective charging state.

[0036] The energy storage detection and analysis module is used to acquire energy storage status data of the battery pack when it is fully charged and not supplying power to the outside, analyze the energy storage status data, and determine whether the battery pack has experienced an energy storage relaxation event.

[0037] The second insulation device control module is also used to adjust the active wake-up state of the second insulation device for the battery pack based on the judgment result of whether the energy storage relaxation event has occurred.

[0038] The power output detection and analysis module is used to acquire power output status data of the battery pack during the external power supply process, analyze the power output status data, and determine whether the battery pack has experienced a power output instability event.

[0039] The second heat preservation device control module is also used to adjust the active heating state of the second heat preservation device for the battery pack based on the judgment result of whether the power output instability event has occurred.

[0040] Optionally, the temperature detection and analysis module is used to determine whether the battery pack is in an effective charging state based on the ambient temperature data of the electric vehicle's battery pack during the charging process, including:

[0041] The ambient temperature of the external environment during the charging process of the electric vehicle's battery pack at the charging station is periodically collected to obtain ambient temperature data; the ambient temperature data is analyzed to obtain the duration during which the ambient temperature is lower than the preset optimal operating temperature of the battery pack; if the duration exceeds a preset time threshold, it is determined that the battery pack is not in an effective charging state; otherwise, it is determined that the battery pack is in an effective charging state.

[0042] The first insulation device control module is used to adjust the active insulation state of the first insulation device adjacent to the battery pack based on the determination result of the effective charging state, including:

[0043] When the battery pack is in an effective charging state, the first insulation device adjacent to the battery pack is instructed not to actively heat and insulate the battery pack; when the battery pack is not in an effective charging state, the first insulation device adjacent to the battery pack is instructed to actively heat and insulate the battery pack at a heating temperature higher than the preset optimal operating temperature.

[0044] The second insulation device control module is used to trigger the second insulation device adjacent to the battery pack to enter the heat storage working mode based on the determination result of the effective charging state, including:

[0045] When the battery pack is in an effective charging state, the second insulation device adjacent to the battery pack is instructed to obtain electrical energy from the charging pile at a first power for phase change heat storage; when the battery pack is not in an effective charging state, the second insulation device adjacent to the battery pack is instructed to obtain electrical energy from the charging pile at a second power for phase change heat storage; wherein, the first power is greater than the second power.

[0046] Optionally, the energy storage detection and analysis module is used to acquire energy storage status data of the battery pack when it has completed charging and is not supplying power to the outside world, analyze the energy storage status data, and determine whether the battery pack has experienced an energy storage relaxation event, including:

[0047] Dark current detection is performed on the battery pack when it is fully charged and not supplying power to the outside to obtain dark current change data of the battery pack. Based on the dark current change data, the energy loss rate stored in the battery pack is determined. The energy loss rate is compared with a preset energy reduction rate threshold. If the energy loss rate is greater than the preset energy reduction rate threshold, it is determined that the battery pack has experienced an energy storage relaxation event; otherwise, it is determined that the battery pack has not experienced an energy storage relaxation event.

[0048] The second insulation device control module is used to adjust the active wake-up state of the second insulation device for the battery pack based on the determination result of whether the energy storage relaxation event has occurred, including:

[0049] When the battery pack experiences an energy storage relaxation event, the second insulation device is instructed to perform intermittent phase change heat release operations at a corresponding frequency, thereby periodically and actively heating and waking up the battery pack; when the battery pack does not experience an energy storage relaxation event, the second insulation device is instructed not to perform phase change heat release operations, thereby not actively heating and waking up the battery pack.

[0050] Optionally, the power output detection and analysis module is used to acquire power output status data of the battery pack during the external power supply process, analyze the power output status data, and determine whether the battery pack has experienced a power output instability event, including:

[0051] The current output status of the battery pack is detected during the external power supply process to obtain the power supply current change data of the battery pack; the power supply current change data is analyzed to obtain the average drift rate of the actual power supply current of the battery pack relative to the reference power supply current during the external power supply process; if the average drift rate is greater than a preset drift rate threshold, it is determined that the battery pack has experienced a power output instability event; otherwise, it is determined that the battery pack has not experienced a power output instability event.

[0052] The second heat preservation equipment control module is used to adjust the active heating state of the second heat preservation equipment for the battery pack based on the judgment result of whether the power output instability event has occurred, including:

[0053] When the battery pack experiences an unstable power output event, based on the remaining thermal energy storage value of the second insulation device, the second insulation device is instructed to perform a continuous phase change heat release operation on the battery pack at a corresponding heat release rate, thereby actively heating the battery pack.

[0054] If the battery pack does not experience an unstable power output event, the second insulation device is instructed not to perform a phase change heat release operation, thereby not actively heating the battery pack.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] The active heat preservation control method and system for electric vehicle battery packs provided in this application determine whether the battery pack is in an effective charging state based on the ambient temperature during the charging process. This adjusts the active heat preservation state of the first heat preservation device and the heat storage working mode of the second heat preservation device accordingly. During charging, the system actively preserves the battery pack and stores heat energy in advance for subsequent power supply. Based on the energy storage state data of the battery pack when charging is complete and no power is supplied, it determines whether an energy storage relaxation event has occurred, adjusting the active heat preservation wake-up state of the second heat preservation device to reduce the energy storage loss rate of the battery pack. Furthermore, based on the energy output state data of the battery pack during power supply, it determines whether an unstable energy output event has occurred, adjusting the active heating state of the second heat preservation device to ensure stable and continuous power supply. By flexibly selecting appropriate active heat preservation methods according to the working characteristics of the battery pack at different stages of charging and discharging, the system improves the stability and reliability of the battery pack's charging and discharging performance. Attached Figure Description

[0057] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0058] Figure 1 This is a flowchart illustrating the active heat preservation control method for the battery pack of an electric vehicle provided by the present invention.

[0059] Figure 2 This is a schematic diagram of the active thermal insulation control system for the battery pack of an electric vehicle provided by the present invention. Detailed Implementation

[0060] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, it should be noted that, for ease of description, only the parts relevant to this application are shown in the accompanying drawings, not the entire structure. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0061] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0062] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0063] Please see Figure 1 As shown, an embodiment of this application provides an active heat preservation control method for an electric vehicle's battery pack. This active heat preservation control method for an electric vehicle's battery pack includes:

[0064] Based on the ambient temperature data of the electric vehicle's battery pack during the charging process, it is determined whether the battery pack is in an effective charging state; based on the determination result of the effective charging state, the active heat preservation state of the first heat preservation device adjacent to the battery pack is adjusted, and the second heat preservation device adjacent to the battery pack is triggered to enter the heat storage working mode.

[0065] Acquire the energy storage status data of the battery pack when it is fully charged and not supplying power to the outside, analyze the energy storage status data, and determine whether the battery pack has experienced an energy storage relaxation event; based on the determination result of whether the energy storage relaxation event has occurred, adjust the active wake-up state of the second heat preservation device for the battery pack.

[0066] The system acquires power output status data of the battery pack during external power supply, analyzes the power output status data, and determines whether the battery pack has experienced a power output instability event. Based on the determination of whether the power output instability event has occurred, the system adjusts the active heating state of the second insulation device for the battery pack.

[0067] The beneficial effects of the above embodiments are as follows: the active heat preservation control method for the battery pack of the electric vehicle determines whether the battery pack is in an effective charging state based on the ambient temperature of the battery pack during the charging process, and adjusts the active heat preservation state of the first heat preservation device and the heat storage working mode of the second heat preservation device accordingly. During the charging process, the method actively preserves the battery pack and stores heat energy in advance for subsequent power supply from the battery pack. Based on the energy storage state data of the battery pack when it has completed charging and is not supplying power to the outside, the method determines whether an energy storage relaxation event has occurred, and adjusts the active heat preservation wake-up state of the second heat preservation device to reduce the energy storage loss rate of the battery pack. Furthermore, based on the energy output state data of the battery pack during the power supply process, the method determines whether an unstable energy output event has occurred, and adjusts the active heating state of the second heat preservation device to ensure that the battery pack can stably and continuously supply power to the outside. By flexibly selecting appropriate active heat preservation methods according to the working characteristics of the battery pack at different stages of charging and discharging, the method improves the stability and reliability of the battery pack's charging and discharging performance.

[0068] In another embodiment, based on the ambient temperature data of the electric vehicle's battery pack during charging, it is determined whether the battery pack is in an effective charging state; based on the determination result of the effective charging state, the active heat preservation state of the first heat preservation device adjacent to the battery pack is adjusted, and the second heat preservation device adjacent to the battery pack is triggered to enter the heat storage working mode, including:

[0069] The system periodically collects ambient temperature data of the external environment during the charging process of the electric vehicle's battery pack at the charging station. It then analyzes this ambient temperature data to determine the duration during which the ambient temperature is below the preset optimal operating temperature of the battery pack. If this duration exceeds a preset time threshold, the system determines that the battery pack is not in an effective charging state; otherwise, it determines that the battery pack is in an effective charging state.

[0070] When the battery pack is in an effective charging state, the first insulation device adjacent to the battery pack is instructed not to actively heat and insulate the battery pack, and the second insulation device adjacent to the battery pack is instructed to obtain electrical energy from the charging pile at the first power for phase change heat storage.

[0071] When the battery pack is not in an effective charging state, the first heat preservation device adjacent to the battery pack is instructed to actively heat and preserve the battery pack at a heating temperature higher than the preset optimal operating temperature, and the second heat preservation device adjacent to the battery pack is instructed to obtain electrical energy from the charging pile at a second power for phase change heat storage; wherein, the first power is greater than the second power.

[0072] The beneficial effects of the above embodiments are that active heat preservation of the battery pack requires the consumption of corresponding energy (such as electrical energy and / or thermal energy). If only a single heat preservation device is used for the battery pack, the active heating and heat preservation endurance of the device will be subject to high requirements. Therefore, a first heat preservation device and a second heat preservation device are set up for the battery pack, so that the corresponding heat preservation device can be used to achieve active heating of the battery pack in different operating stages such as charging, external power supply, and charging completed and not external power supply. In actual operation, active heat preservation of the battery pack is only required when the temperature of the external environment is low. For this purpose, the temperature of the external environment of the electric vehicle battery pack during the charging process at the charging pile is periodically collected to obtain the external environmental temperature data. The external environmental temperature data is then analyzed to determine the duration for which the external environmental temperature is lower than the preset optimal operating temperature of the battery pack, where the preset optimal operating temperature is determined by the electrical characteristics of the battery pack itself. Then, a threshold comparison is made on the duration. When the duration exceeds the preset time threshold, it indicates that the temperature of the external environment where the battery pack is located is too low, which causes the battery pack capacity to decrease. At this time, the battery pack will not be able to charge effectively, that is, the battery pack is not in an effective charging state. Therefore, it is necessary to actively heat and keep the battery pack warm to provide a suitable temperature environment for the battery pack. When the battery pack is in an effective charging state, active heating and insulation are not required. This indicates that the first insulation device adjacent to the battery pack (such as a semiconductor heating element) does not need to draw power from the charging pile for heating. Simultaneously, it instructs the second insulation device adjacent to the battery pack (such as a phase-change energy storage device) to draw power from the charging pile at a first power level, convert the power into heat energy through phase change, and store it. This provides a heat source for active insulation of the battery pack during subsequent power supply phases. When the battery pack is not in an effective charging state, active heating and insulation are required. This instructs the first insulation device to draw power from the charging pile and actively heat the battery pack at a temperature higher than the preset optimal operating temperature. Simultaneously, it instructs the second insulation device adjacent to the battery pack to draw power from the charging pile at a second power level, convert the power into heat energy through phase change, and store it. This provides a heat source for active insulation of the battery pack during subsequent power supply phases, ensuring normal and efficient charging of the battery pack and pre-storing heat energy for active heating and insulation after disconnection from the charging pile.

[0073] In another embodiment, based on the determination result of the effective charging state, adjusting the active heat preservation state of the first heat preservation device adjacent to the battery pack includes:

[0074] Step S1: Using the following formula (1), determine whether the ambient temperature of the electric vehicle's battery pack during the charging process is lower than the preset optimal operating temperature of the battery pack, and control whether to enter the start-up preheating stage of the first heat preservation device.

[0075] Y1=[Q(t) <Q0]||[|Q(t)-Q0|≤1℃](1)

[0076] In the above formula (1), Y1 represents the control value of the first heat preservation device entering the start-up preheating stage; Q(t) represents the ambient temperature of the electric vehicle's battery pack during the charging process at the current moment; Q0 represents the preset optimal operating temperature of the battery pack; || represents the absolute value; || represents the logical OR operation. When neither of the equations on both sides of the symbol is true, the corresponding output value is 0. When one or more of the equations on both sides of the symbol are true, the corresponding output value is 1; 1℃ represents 1 degree Celsius.

[0077] If Y1 = 1, it means that the first insulation device is controlled to enter the preheating stage;

[0078] If Y1 = 0, it means that the first insulation device is not controlled to enter the preheating stage;

[0079] Step S2: If the first insulation device enters the preheating stage, the preheating setting temperature of the first insulation device is controlled using the following formula (2) based on the ambient temperature of the electric vehicle's battery pack during charging and the preset optimal operating temperature of the battery pack.

[0080] Q1=F[Q(t)≥Q0]×1.5×Q0+F[Q(t) <Q0]×[3×Q0-Q(t)](2)

[0081] In the above formula (2), Q1 represents the preheating control setting temperature of the first heat preservation equipment; F[] represents the formula validity function. If the formula in the parentheses is valid, the output value of the formula validity function is 1. If the formula in the parentheses is invalid, the output value of the formula validity function is 0.

[0082] Step S3: If the first insulation device has entered the preheating stage, the time for the first insulation device to preheat to the set temperature is controlled using the following formula (3) based on the ambient temperature of the electric vehicle's battery pack during charging and the preset optimal operating temperature of the battery pack.

[0083]

[0084] In the above formula (3), T1 represents the control time for the first heat preservation device to preheat to the set temperature; T0 represents the preset time threshold corresponding to the duration for which the external ambient temperature is lower than the preset optimal operating temperature of the battery pack.

[0085] The beneficial effects of the above embodiments are as follows: using the above formula (1), it is determined whether the ambient temperature of the electric vehicle's battery pack during the charging process is lower than the preset optimal operating temperature of the battery pack, and whether to enter the start-up preheating stage of the first heat preservation device, so as to perform preheating in advance and ensure the timeliness of heat preservation; then using the above formula (2), according to the ambient temperature of the electric vehicle's battery pack during the charging process and the preset optimal operating temperature of the battery pack, the preheating setting temperature of the first heat preservation device is controlled, so as to ensure that the preheating temperature can raise the ambient temperature to the optimal operating temperature and ensure the stability of the system; then using the above formula (3), according to the ambient temperature of the electric vehicle's battery pack during the charging process and the preset optimal operating temperature of the battery pack, the time for the first heat preservation device to preheat to the set temperature is controlled, so as to raise the ambient temperature to the optimal operating temperature in a timely manner and ensure the reliability of the heat preservation of the first heat preservation device.

[0086] In another embodiment, the energy storage state data of the battery pack when it is fully charged and not supplying power to the outside is obtained; the energy storage state data is analyzed to determine whether an energy storage relaxation event has occurred in the battery pack; based on the determination result of whether the energy storage relaxation event has occurred, the active wake-up state of the second heat preservation device for the battery pack is adjusted, including:

[0087] Dark current detection is performed on the battery pack when it is fully charged and not supplying power to the outside world to obtain dark current change data. Based on the dark current change data, the energy loss rate stored in the battery pack is determined. The energy loss rate is compared with a preset energy reduction rate threshold. If the energy loss rate is greater than the preset energy reduction rate threshold, it is determined that the battery pack has experienced an energy storage relaxation event; otherwise, it is determined that the battery pack has not experienced an energy storage relaxation event.

[0088] When the battery pack experiences an energy storage relaxation event, the second insulation device is instructed to perform intermittent phase change heat release operations at a corresponding frequency, thereby periodically and actively heating and waking up the battery pack; when the battery pack does not experience an energy storage relaxation event, the second insulation device is instructed not to perform phase change heat release operations, thereby not actively heating and waking up the battery pack.

[0089] The beneficial effects of the above embodiments are as follows: Generally speaking, when the battery pack is fully charged and not supplying power to the outside world, the battery pack should be able to fully store the electrical energy obtained from charging. However, in low-temperature environments, the battery pack will experience energy loss, that is, the electrical energy stored inside the battery pack will continuously leak out in the form of dark current. The lower the ambient temperature, the greater the dark current of the battery pack, and the greater its energy loss rate. Therefore, dark current detection is performed on the battery pack when it is fully charged and not supplying power to the outside world to obtain the dark current change data of the battery pack. The dark current change data is then analyzed to obtain the energy loss rate of the battery pack itself (i.e., the amount of energy lost per unit time). Then, the energy loss rate is compared with a threshold to determine whether the battery pack has experienced an energy storage relaxation event, thereby providing an accurate basis for whether the battery pack needs to be actively heated and kept warm. Furthermore, when the battery pack experiences an energy storage relaxation event, the second insulation device is instructed to perform intermittent phase change heat release operations at a corresponding frequency, thereby periodically and actively heating and waking up the battery pack. That is, the second insulation device is instructed to perform phase change heat release operations at corresponding time intervals. Whenever the second insulation device generates heat during phase change, the heat is transferred to the battery pack. At this time, the battery pack is triggered by the heat to switch from a dormant state to an awakened state, thereby effectively suppressing the dark current of the battery pack. When the battery pack does not experience an energy storage relaxation event, the second insulation device is instructed not to perform phase change heat release operations, thereby not actively heating and waking up the battery pack. This allows the second insulation device to retain its own heat energy for active heating and insulation in subsequent stages when needed.

[0090] In another embodiment, the power output status data of the battery pack during the external power supply process is acquired, the power output status data is analyzed, and it is determined whether the battery pack has experienced a power output instability event; based on the determination result of whether the power output instability event has occurred, the active heating state of the second heat preservation device for the battery pack is adjusted, including:

[0091] The current output status of the battery pack is detected during the external power supply process to obtain the power supply current change data of the battery pack; the power supply current change data is analyzed to obtain the average drift rate of the actual power supply current of the battery pack relative to the reference power supply current during the external power supply process; if the average drift rate is greater than the preset drift rate threshold, it is determined that the battery pack has experienced a power output instability event; otherwise, it is determined that the battery pack has not experienced a power output instability event.

[0092] When the battery pack experiences an unstable power output event, based on the remaining thermal energy storage value of the second insulation device, the second insulation device is instructed to perform a continuous phase change heat release operation on the battery pack at a corresponding heat release rate, thereby actively heating the battery pack.

[0093] If the battery pack does not experience an unstable power output event, the second insulation device is instructed not to perform a phase change heat release operation, thereby not actively heating the battery pack.

[0094] The beneficial effects of the above embodiments are that when the ambient temperature is low, the capacity of the battery pack will continuously decrease during the external power supply process, making the current output to the external load unstable. Therefore, the current output status of the battery pack during external power supply is detected to obtain the power supply current change data. This data is used to obtain the average drift rate of the actual power supply current relative to the reference power supply current during external power supply. A threshold comparison is then performed on this average drift rate to accurately determine whether the battery pack has experienced an unstable power output event, providing an accurate basis for subsequent active heating and insulation of the battery pack. When the battery pack experiences an unstable power output event, based on the remaining thermal energy storage value of the second insulation device, the second insulation device is instructed to perform a continuous phase change heat release operation at a corresponding heat release rate, thereby actively heating the battery pack. Generally, the larger the remaining thermal energy storage value of the second insulation device, the greater its heat release rate (heat released per unit time) during the continuous phase change heat release operation, thus fully utilizing the thermal energy stored in the second insulation device to actively insulate the battery pack. If the battery pack does not experience an unstable power output event, the second insulation device is instructed not to perform a phase change heat release operation, thereby not actively heating the battery pack. This allows the second insulation device to retain its own heat energy for active heating and insulation in subsequent stages when needed.

[0095] Please see Figure 2 As shown in one embodiment of this application, an active thermal insulation control system for an electric vehicle's battery pack is provided. This active thermal insulation control system for an electric vehicle's battery pack includes:

[0096] The temperature detection and analysis module is used to determine whether the battery pack is in an effective charging state based on the ambient temperature data of the electric vehicle's battery pack during the charging process.

[0097] The first insulation device control module is used to adjust the active insulation state of the first insulation device adjacent to the battery pack based on the judgment result of the effective charging state.

[0098] The second insulation device control module is used to trigger the second insulation device adjacent to the battery pack to enter the heat storage working mode based on the judgment result of the effective charging state.

[0099] The energy storage detection and analysis module is used to acquire energy storage status data of the battery pack when it has completed charging and is not supplying power to the outside world, analyze the energy storage status data, and determine whether the battery pack has experienced an energy storage relaxation event.

[0100] The second insulation device control module is also used to adjust the active wake-up state of the second insulation device for the battery pack based on the judgment result of whether the energy storage relaxation event has occurred.

[0101] The power output detection and analysis module is used to acquire power output status data of the battery pack during the external power supply process, analyze the power output status data, and determine whether the battery pack has experienced a power output instability event.

[0102] The second insulation device control module is also used to adjust the active heating state of the second insulation device on the battery pack based on the judgment result of whether the power output instability event has occurred.

[0103] The beneficial effects of the above embodiments are as follows: the battery pack active heat preservation control system of the electric vehicle determines whether the battery pack is in an effective charging state based on the ambient temperature of the battery pack during the charging process, and adjusts the active heat preservation state of the first heat preservation device and the heat storage working mode of the second heat preservation device accordingly. During the charging process, it actively preserves the battery pack and stores heat energy in advance for subsequent power supply from the battery pack. Based on the energy storage state data of the battery pack when it has completed charging and is not supplying power, it determines whether an energy storage relaxation event has occurred, and adjusts the active heat preservation wake-up state of the second heat preservation device to reduce the energy storage loss rate of the battery pack. Furthermore, based on the energy output state data of the battery pack during power supply, it determines whether an unstable energy output event has occurred, and adjusts the active heating state of the second heat preservation device to ensure that the battery pack can stably and continuously supply power. It flexibly selects appropriate active heat preservation methods according to the working characteristics of the battery pack at different stages of charging and discharging, improving the stability and reliability of the battery pack's charging and discharging performance.

[0104] In another embodiment, the temperature detection and analysis module is used to determine whether the battery pack is in a valid charging state based on the ambient temperature data of the electric vehicle's battery pack during the charging process, including:

[0105] The system periodically collects ambient temperature data of the external environment during the charging process of the electric vehicle's battery pack at the charging station. It then analyzes this ambient temperature data to determine the duration during which the ambient temperature is below the preset optimal operating temperature of the battery pack. If this duration exceeds a preset time threshold, the system determines that the battery pack is not in an effective charging state; otherwise, it determines that the battery pack is in an effective charging state.

[0106] The first insulation device control module is used to adjust the active insulation state of the first insulation device adjacent to the battery pack based on the determination result of the effective charging state, including:

[0107] When the battery pack is in an effective charging state, the first insulation device adjacent to the battery pack is instructed not to actively heat and insulate the battery pack; when the battery pack is not in an effective charging state, the first insulation device adjacent to the battery pack is instructed to actively heat and insulate the battery pack at a heating temperature higher than the preset optimal operating temperature.

[0108] The second insulation device control module is used to trigger the second insulation device adjacent to the battery pack to enter the heat storage working mode based on the determination result of the effective charging state, including:

[0109] When the battery pack is in an effective charging state, the second insulation device adjacent to the battery pack is instructed to obtain electrical energy from the charging pile at a first power for phase change heat storage; when the battery pack is not in an effective charging state, the second insulation device adjacent to the battery pack is instructed to obtain electrical energy from the charging pile at a second power for phase change heat storage; wherein, the first power is greater than the second power.

[0110] The beneficial effects of the above embodiments are that active heat preservation of the battery pack requires the consumption of corresponding energy (such as electrical energy and / or thermal energy). If only a single heat preservation device is used for the battery pack, the active heating and heat preservation endurance of the device will be subject to high requirements. Therefore, a first heat preservation device and a second heat preservation device are set up for the battery pack, so that the corresponding heat preservation device can be used to achieve active heating of the battery pack in different operating stages such as charging, external power supply, and charging completed and not external power supply. In actual operation, active heat preservation of the battery pack is only required when the temperature of the external environment is low. For this purpose, the temperature of the external environment of the electric vehicle battery pack during the charging process at the charging pile is periodically collected to obtain the external environmental temperature data. The external environmental temperature data is then analyzed to determine the duration for which the external environmental temperature is lower than the preset optimal operating temperature of the battery pack, where the preset optimal operating temperature is determined by the electrical characteristics of the battery pack itself. Then, a threshold comparison is made on the duration. When the duration exceeds the preset time threshold, it indicates that the temperature of the external environment where the battery pack is located is too low, which causes the battery pack capacity to decrease. At this time, the battery pack will not be able to charge effectively, that is, the battery pack is not in an effective charging state. Therefore, it is necessary to actively heat and keep the battery pack warm to provide a suitable temperature environment for the battery pack. When the battery pack is in an effective charging state, active heating and insulation are not required. This indicates that the first insulation device adjacent to the battery pack (such as a semiconductor heating element) does not need to draw power from the charging pile for heating. Simultaneously, it instructs the second insulation device adjacent to the battery pack (such as a phase-change energy storage device) to draw power from the charging pile at a first power level, convert the power into heat energy through phase change, and store it. This provides a heat source for active insulation of the battery pack during subsequent power supply phases. When the battery pack is not in an effective charging state, active heating and insulation are required. This instructs the first insulation device to draw power from the charging pile and actively heat the battery pack at a temperature higher than the preset optimal operating temperature. Simultaneously, it instructs the second insulation device adjacent to the battery pack to draw power from the charging pile at a second power level, convert the power into heat energy through phase change, and store it. This provides a heat source for active insulation of the battery pack during subsequent power supply phases, ensuring normal and efficient charging of the battery pack and pre-storing heat energy for active heating and insulation after disconnection from the charging pile.

[0111] In another embodiment, the energy storage detection and analysis module is used to acquire energy storage state data of the battery pack when it has completed charging and is not supplying power to the outside world, analyze the energy storage state data, and determine whether the battery pack has experienced an energy storage relaxation event, including:

[0112] Dark current detection is performed on the battery pack when it is fully charged and not supplying power to the outside world to obtain dark current change data. Based on the dark current change data, the energy loss rate stored in the battery pack is determined. The energy loss rate is compared with a preset energy reduction rate threshold. If the energy loss rate is greater than the preset energy reduction rate threshold, it is determined that the battery pack has experienced an energy storage relaxation event; otherwise, it is determined that the battery pack has not experienced an energy storage relaxation event.

[0113] The second insulation device control module is used to adjust the active wake-up state of the second insulation device for the battery pack based on the judgment result of whether the energy storage relaxation event has occurred, including:

[0114] When the battery pack experiences an energy storage relaxation event, the second insulation device is instructed to perform intermittent phase change heat release operations at a corresponding frequency, thereby periodically and actively heating and waking up the battery pack; when the battery pack does not experience an energy storage relaxation event, the second insulation device is instructed not to perform phase change heat release operations, thereby not actively heating and waking up the battery pack.

[0115] The beneficial effects of the above embodiments are as follows: Generally speaking, when the battery pack is fully charged and not supplying power to the outside world, the battery pack should be able to fully store the electrical energy obtained from charging. However, in low-temperature environments, the battery pack will experience energy loss, that is, the electrical energy stored inside the battery pack will continuously leak out in the form of dark current. The lower the ambient temperature, the greater the dark current of the battery pack, and the greater its energy loss rate. Therefore, dark current detection is performed on the battery pack when it is fully charged and not supplying power to the outside world to obtain the dark current change data of the battery pack. The dark current change data is then analyzed to obtain the energy loss rate of the battery pack itself (i.e., the amount of energy lost per unit time). Then, the energy loss rate is compared with a threshold to determine whether the battery pack has experienced an energy storage relaxation event, thereby providing an accurate basis for whether the battery pack needs to be actively heated and kept warm. Furthermore, when the battery pack experiences an energy storage relaxation event, the second insulation device is instructed to perform intermittent phase change heat release operations at a corresponding frequency, thereby periodically and actively heating and waking up the battery pack. That is, the second insulation device is instructed to perform phase change heat release operations at corresponding time intervals. Whenever the second insulation device generates heat during phase change, the heat is transferred to the battery pack. At this time, the battery pack is triggered by the heat to switch from a dormant state to an awakened state, thereby effectively suppressing the dark current of the battery pack. When the battery pack does not experience an energy storage relaxation event, the second insulation device is instructed not to perform phase change heat release operations, thereby not actively heating and waking up the battery pack. This allows the second insulation device to retain its own heat energy for active heating and insulation in subsequent stages when needed.

[0116] In another embodiment, the power output detection and analysis module is used to acquire power output status data of the battery pack during the external power supply process, analyze the power output status data, and determine whether the battery pack has experienced a power output instability event, including:

[0117] The current output status of the battery pack is detected during the external power supply process to obtain the power supply current change data of the battery pack; the power supply current change data is analyzed to obtain the average drift rate of the actual power supply current of the battery pack relative to the reference power supply current during the external power supply process; if the average drift rate is greater than the preset drift rate threshold, it is determined that the battery pack has experienced a power output instability event; otherwise, it is determined that the battery pack has not experienced a power output instability event.

[0118] The second insulation device control module is used to adjust the active heating state of the second insulation device for the battery pack based on the judgment result of whether the power output instability event has occurred, including:

[0119] When the battery pack experiences an unstable power output event, based on the remaining thermal energy storage value of the second insulation device, the second insulation device is instructed to perform a continuous phase change heat release operation on the battery pack at a corresponding heat release rate, thereby actively heating the battery pack.

[0120] If the battery pack does not experience an unstable power output event, the second insulation device is instructed not to perform a phase change heat release operation, thereby not actively heating the battery pack.

[0121] The beneficial effects of the above embodiments are that when the ambient temperature is low, the capacity of the battery pack will continuously decrease during the external power supply process, making the current output to the external load unstable. Therefore, the current output status of the battery pack during external power supply is detected to obtain the power supply current change data. This data is used to obtain the average drift rate of the actual power supply current relative to the reference power supply current during external power supply. A threshold comparison is then performed on this average drift rate to accurately determine whether the battery pack has experienced an unstable power output event, providing an accurate basis for subsequent active heating and insulation of the battery pack. When the battery pack experiences an unstable power output event, based on the remaining thermal energy storage value of the second insulation device, the second insulation device is instructed to perform a continuous phase change heat release operation at a corresponding heat release rate, thereby actively heating the battery pack. Generally, the larger the remaining thermal energy storage value of the second insulation device, the greater its heat release rate (heat released per unit time) during the continuous phase change heat release operation, thus fully utilizing the thermal energy stored in the second insulation device to actively insulate the battery pack. If the battery pack does not experience an unstable power output event, the second insulation device is instructed not to perform a phase change heat release operation, thereby not actively heating the battery pack. This allows the second insulation device to retain its own heat energy for active heating and insulation in subsequent stages when needed.

[0122] In summary, the active heat preservation control method and system for the electric vehicle's battery pack determines whether the battery pack is in an effective charging state based on the ambient temperature during charging. This adjusts the active heat preservation state of the first heat preservation device and the heat storage mode of the second heat preservation device accordingly. During charging, the system actively preserves the battery pack and stores heat energy in advance for subsequent power supply. Based on the energy storage status data of the battery pack when charging is complete and not supplying power, it determines whether an energy storage relaxation event has occurred, adjusting the active heat preservation wake-up state of the second heat preservation device to reduce the energy storage loss rate. Furthermore, based on the energy output status data of the battery pack during power supply, it determines whether an unstable energy output event has occurred, adjusting the active heating state of the second heat preservation device to ensure stable and continuous power supply. By flexibly selecting appropriate active heat preservation methods based on the operating characteristics of the battery pack at different stages of charging and discharging, the system improves the stability and reliability of the battery pack's charging and discharging performance.

[0123] The above is only one specific embodiment of the present invention, and any improvements made based on the concept of the present invention shall be considered within the scope of protection of the present invention.

Claims

1. An active thermal insulation control method for the battery pack of an electric vehicle, characterized in that, include: Based on the ambient temperature data of the electric vehicle's battery pack during the charging process, it is determined whether the battery pack is in an effective charging state. Based on the determination result of the effective charging state, the active heat preservation state of the first heat preservation device adjacent to the battery pack is adjusted, and the second heat preservation device adjacent to the battery pack is triggered to enter the heat storage working mode. The energy storage status data of the battery pack when it is fully charged and not supplying power to the outside is obtained, and the energy storage status data is analyzed to determine whether the battery pack has experienced an energy storage relaxation event. Based on the determination result of whether the energy storage relaxation event has occurred, the active wake-up state of the second heat preservation device for the battery pack is adjusted. The system acquires power output status data of the battery pack during external power supply, analyzes the power output status data, and determines whether the battery pack has experienced a power output instability event. Based on the determination result of whether the power output instability event has occurred, the system adjusts the active heating state of the second heat preservation device for the battery pack. Specifically, based on the ambient temperature data of the electric vehicle's battery pack during charging, it is determined whether the battery pack is in an effective charging state; based on the determination result of the effective charging state, the active heat preservation state of the first heat preservation device adjacent to the battery pack is adjusted, and the second heat preservation device adjacent to the battery pack is triggered to enter the heat storage working mode, including: The ambient temperature of the external environment during the charging process of the electric vehicle's battery pack at the charging station is periodically collected to obtain ambient temperature data; the ambient temperature data is analyzed to obtain the duration during which the ambient temperature is lower than the preset optimal operating temperature of the battery pack; if the duration exceeds a preset time threshold, it is determined that the battery pack is not in an effective charging state; otherwise, it is determined that the battery pack is in an effective charging state. When the battery pack is in an effective charging state, the first insulation device adjacent to the battery pack is instructed not to actively heat and insulate the battery pack, and the second insulation device adjacent to the battery pack is instructed to obtain electrical energy from the charging pile at a first power for phase change heat storage. When the battery pack is not in an effective charging state, the first heat preservation device adjacent to the battery pack is instructed to actively heat and preserve the battery pack at a heating temperature higher than the preset optimal operating temperature, and the second heat preservation device adjacent to the battery pack is instructed to obtain electrical energy from the charging pile at a second power for phase change heat storage; wherein, the first power is greater than the second power.

2. The active thermal insulation control method for the battery pack of an electric vehicle as described in claim 1, characterized in that: Based on the determination result of the effective charging state, the active heat preservation state of the first heat preservation device adjacent to the battery pack is adjusted, including: Step S1: Using the following formula (1), determine whether the ambient temperature of the electric vehicle's battery pack during the charging process is lower than the preset optimal operating temperature of the battery pack, and control whether to enter the start-up preheating stage of the first heat preservation device. （1） In the above formula (1), This indicates the control value for the first insulation equipment to enter the start-up preheating stage; This indicates the ambient temperature of the electric vehicle's battery pack during the charging process at the current moment; This indicates the preset optimal operating temperature of the battery pack; This indicates taking the absolute value; This represents a logical OR operation. When neither of the expressions on either side of the symbol is true, the corresponding output value is 0. When one or more of the expressions on either side of the symbol are true, the corresponding output value is 1. Indicates 1 degree Celsius; like This indicates that the first insulation device is controlled to enter the preheating stage; like This indicates that the first insulation device is not controlled to enter the preheating stage; Step S2: If the first insulation device enters the preheating stage, the preheating setting temperature of the first insulation device is controlled using the following formula (2) based on the ambient temperature of the electric vehicle's battery pack during charging and the preset optimal operating temperature of the battery pack. （2） In the above formula (2), This indicates the preheating control setting temperature of the first insulation equipment; This function represents the expression's validity. If the expression within the parentheses is true, the function outputs 1; if the expression within the parentheses is false, the function outputs 0. Step S3: If the first insulation device has entered the preheating stage, the time for the first insulation device to preheat to the set temperature is controlled using the following formula (3) based on the ambient temperature of the electric vehicle's battery pack during charging and the preset optimal operating temperature of the battery pack. （3） In the above formula (3), This indicates the control time for the first insulation equipment to preheat to the set temperature; This indicates the preset time threshold corresponding to the duration during which the ambient temperature is lower than the preset optimal operating temperature of the battery pack.

3. The active thermal insulation control method for the battery pack of an electric vehicle as described in claim 1, characterized in that: The energy storage status data of the battery pack when it is fully charged and not supplying power to the outside is obtained, and the energy storage status data is analyzed to determine whether the battery pack has experienced an energy storage relaxation event. Based on the determination result of whether the energy storage relaxation event has occurred, the active wake-up state of the second insulation device for the battery pack is adjusted, including: Dark current detection is performed on the battery pack when it is fully charged and not supplying power to the outside to obtain dark current change data of the battery pack. Based on the dark current change data, the energy loss rate stored in the battery pack is determined. The energy loss rate is compared with a preset energy reduction rate threshold. If the energy loss rate is greater than the preset energy reduction rate threshold, it is determined that the battery pack has experienced an energy storage relaxation event; otherwise, it is determined that the battery pack has not experienced an energy storage relaxation event. When the battery pack experiences an energy storage relaxation event, the second insulation device is instructed to perform intermittent phase change heat release operations at a corresponding frequency, thereby periodically and actively heating and waking up the battery pack; when the battery pack does not experience an energy storage relaxation event, the second insulation device is instructed not to perform phase change heat release operations, thereby not actively heating and waking up the battery pack.

4. The active thermal insulation control method for the battery pack of an electric vehicle as described in claim 1, characterized in that: The power output status data of the battery pack during the external power supply process is obtained, and the power output status data is analyzed to determine whether the battery pack has experienced a power output instability event. Based on the determination result of whether the power output instability event has occurred, the active heating state of the second heat preservation device for the battery pack is adjusted, including: The current output status of the battery pack is detected during the external power supply process to obtain the power supply current change data of the battery pack; the power supply current change data is analyzed to obtain the average drift rate of the actual power supply current of the battery pack relative to the reference power supply current during the external power supply process; if the average drift rate is greater than a preset drift rate threshold, it is determined that the battery pack has experienced a power output instability event; otherwise, it is determined that the battery pack has not experienced a power output instability event. When the battery pack experiences an unstable power output event, based on the remaining thermal energy storage value of the second insulation device, the second insulation device is instructed to perform a continuous phase change heat release operation on the battery pack at a corresponding heat release rate, thereby actively heating the battery pack. If the battery pack does not experience an unstable power output event, the second insulation device is instructed not to perform a phase change heat release operation, thereby not actively heating the battery pack.

5. An active thermal insulation control system for the battery pack of an electric vehicle, characterized in that, include: The temperature detection and analysis module is used to determine whether the battery pack is in an effective charging state based on the ambient temperature data of the electric vehicle's battery pack during the charging process. The first insulation device control module is used to adjust the active insulation state of the first insulation device adjacent to the battery pack based on the judgment result of the effective charging state. The second insulation device control module is used to trigger the second insulation device adjacent to the battery pack to enter the heat storage working mode based on the judgment result of the effective charging state. The energy storage detection and analysis module is used to acquire energy storage status data of the battery pack when it is fully charged and not supplying power to the outside, analyze the energy storage status data, and determine whether the battery pack has experienced an energy storage relaxation event. The second insulation device control module is also used to adjust the active wake-up state of the second insulation device for the battery pack based on the judgment result of whether the energy storage relaxation event has occurred. The power output detection and analysis module is used to acquire power output status data of the battery pack during the external power supply process, analyze the power output status data, and determine whether the battery pack has experienced a power output instability event. The second heat preservation equipment control module is also used to adjust the active heating state of the second heat preservation equipment for the battery pack based on the judgment result of whether the power output instability event has occurred; The temperature detection and analysis module is used to determine whether the battery pack is in an effective charging state based on the ambient temperature data of the electric vehicle's battery pack during the charging process, including: The ambient temperature of the external environment during the charging process of the electric vehicle's battery pack at the charging station is periodically collected to obtain ambient temperature data; the ambient temperature data is analyzed to obtain the duration during which the ambient temperature is lower than the preset optimal operating temperature of the battery pack; if the duration exceeds a preset time threshold, it is determined that the battery pack is not in an effective charging state; otherwise, it is determined that the battery pack is in an effective charging state. The first insulation device control module is used to adjust the active insulation state of the first insulation device adjacent to the battery pack based on the determination result of the effective charging state, including: When the battery pack is in an effective charging state, the first insulation device adjacent to the battery pack is instructed not to actively heat and insulate the battery pack; when the battery pack is not in an effective charging state, the first insulation device adjacent to the battery pack is instructed to actively heat and insulate the battery pack at a heating temperature higher than the preset optimal operating temperature. The second insulation device control module is used to trigger the second insulation device adjacent to the battery pack to enter the heat storage working mode based on the determination result of the effective charging state, including: When the battery pack is in an effective charging state, the second insulation device adjacent to the battery pack is instructed to obtain electrical energy from the charging pile at a first power for phase change heat storage; when the battery pack is not in an effective charging state, the second insulation device adjacent to the battery pack is instructed to obtain electrical energy from the charging pile at a second power for phase change heat storage; wherein, the first power is greater than the second power.

6. The active thermal insulation control system for the battery pack of an electric vehicle as described in claim 5, characterized in that: The energy storage detection and analysis module is used to acquire energy storage status data of the battery pack when it has completed charging and is not supplying power to the outside world, analyze the energy storage status data, and determine whether the battery pack has experienced an energy storage relaxation event, including: Dark current detection is performed on the battery pack when it is fully charged and not supplying power to the outside to obtain dark current change data of the battery pack. Based on the dark current change data, the energy loss rate stored in the battery pack is determined. The energy loss rate is compared with a preset energy reduction rate threshold. If the energy loss rate is greater than the preset energy reduction rate threshold, it is determined that the battery pack has experienced an energy storage relaxation event; otherwise, it is determined that the battery pack has not experienced an energy storage relaxation event. The second insulation device control module is used to adjust the active wake-up state of the second insulation device for the battery pack based on the determination result of whether the energy storage relaxation event has occurred, including: When the battery pack experiences an energy storage relaxation event, the second insulation device is instructed to perform intermittent phase change heat release operations at a corresponding frequency, thereby periodically and actively heating and waking up the battery pack; when the battery pack does not experience an energy storage relaxation event, the second insulation device is instructed not to perform phase change heat release operations, thereby not actively heating and waking up the battery pack.

7. The active thermal insulation control system for the battery pack of an electric vehicle as described in claim 5, characterized in that: The power output detection and analysis module is used to acquire power output status data of the battery pack during external power supply, analyze the power output status data, and determine whether the battery pack has experienced a power output instability event, including: The current output status of the battery pack is detected during the external power supply process to obtain the power supply current change data of the battery pack; the power supply current change data is analyzed to obtain the average drift rate of the actual power supply current of the battery pack relative to the reference power supply current during the external power supply process; if the average drift rate is greater than a preset drift rate threshold, it is determined that the battery pack has experienced a power output instability event; otherwise, it is determined that the battery pack has not experienced a power output instability event. The second heat preservation equipment control module is used to adjust the active heating state of the second heat preservation equipment for the battery pack based on the judgment result of whether the power output instability event has occurred, including: When the battery pack experiences an unstable power output event, based on the remaining thermal energy storage value of the second insulation device, the second insulation device is instructed to perform a continuous phase change heat release operation on the battery pack at a corresponding heat release rate, thereby actively heating the battery pack. If the battery pack does not experience an unstable power output event, the second insulation device is instructed not to perform a phase change heat release operation, thereby not actively heating the battery pack.

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