Emergency airplane battery preheating detection method based on non-contact battery rapid preheating system

Abstract

The invention provides an emergency airplane battery preheating detection method based on a non-contact battery rapid preheating system. The emergency airplane battery preheating detection method comprises the steps that the in-pack imaging temperature of a battery pack is acquired; detecting whether the lowest imaging temperature is smaller than a preset first safety temperature threshold value or not; if the lowest imaging temperature is greater than or equal to a preset first safety temperature threshold, detecting whether the highest imaging temperature is greater than a preset second safety temperature threshold; if the highest imaging temperature is smaller than or equal to a preset second safety temperature threshold value, the battery preheating power is calculated according to the in-group forming temperature, the preheating target temperature and the specific product microparameter; and sending a power raising signal to a high-frequency preheater according to the battery preheating power. The imaging temperature in the battery pack is comprehensively detected through the thermal imaging sensor, so that the main controller can control whether the high-frequency preheater is started or not, and the safety of the battery pack is guaranteed. When the battery pack is applied to an emergency aircraft, the battery pack is suitable for extremely cold exploration, emergency rescue and other scenes, so that normal use of the battery pack is ensured.

Description

Technical Field

[0001] This disclosure relates to the field of battery technology, and in particular to an emergency aircraft battery preheating detection method based on a non-contact battery rapid preheating system. Background Technology

[0002] As the core power source, the performance of the battery in low-temperature environments directly affects the reliability and usability of the equipment. In extreme environments such as high-altitude and frigid conditions in the wild, the charging and discharging efficiency of the battery pack,

[0003] Both usable capacity and service life will decrease significantly, or even fail completely, which poses a severe challenge to critical activities such as emergency rescue, scientific research and exploration, and outdoor operations.

[0004] In response to the above situation, some companies have adopted different solutions to raise the battery temperature in order to ensure the usable capacity and lifespan of the battery pack. For example, the battery is heated by a contact resistance wire or a PTC heater, but this method relies on physical contact, which has problems such as inconvenient installation, localized heating, and delayed thermal response. Another example is heating the battery with hot air or liquid circulation, but this method has problems such as slow preheating speed, low energy efficiency, and long time required to reach the required temperature. Yet another example is heating the battery with a pre-embedded thin film as a heating element, followed by current heating, but the internal temperature distribution is uneven, which alters the internal structure of the battery, reduces energy density, and poses a risk of thermal runaway. None of the above solutions are suitable for emergency aircraft.

[0005] In light of the above, how to achieve rapid preheating and ensure uniform preheating of the battery in emergency situations and extremely cold environments remains a problem that technicians need to solve. Summary of the Invention

[0006] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide an emergency aircraft battery preheating detection method based on a non-contact rapid battery preheating system, which can effectively, quickly and uniformly preheat the battery pack and effectively detect the thermal imaging temperature of the battery pack.

[0007] The purpose of this disclosure is achieved through the following technical solution:

[0008] The application discloses an emergency airplane battery preheating detection method based on a non-contact battery quick preheating system.

[0009] The emergency airplane battery preheating detection method comprises the following steps:

[0010] S101, acquiring an imaging temperature in a battery pack, wherein the imaging temperature in the battery pack comprises a lowest imaging temperature and a highest imaging temperature of the battery pack;

[0011] S102, detecting whether the lowest imaging temperature is less than a preset first safety temperature threshold value;

[0012] S103, if the lowest imaging temperature is greater than or equal to the preset first safety temperature threshold value, detecting whether the highest imaging temperature is greater than a preset second safety temperature threshold value, wherein the preset second safety temperature threshold value is greater than the preset first safety temperature threshold value;

[0013] S104, if the highest imaging temperature is less than or equal to the preset second safety temperature threshold value, calculating a battery preheating power according to the imaging temperature in the battery pack, a preheating target temperature and a specific volume parameter;

[0014] S105, sending a power lifting signal to the high-frequency preheater according to the battery preheating power.

[0015] In one embodiment, after S106 is performed, the following steps are included: cyclically performing S101-S104 to adjust the battery preheating power according to a feedback adjustment action.

[0016] In one embodiment, when S104 is performed, the following steps are included:

[0017] S1041, if the highest imaging temperature is less than or equal to the preset second safety temperature threshold value, acquiring an imaging temperature of a measuring point in the battery pack;

[0018] S1042, detecting whether the imaging temperature of the measuring point in the battery pack is less than a preset target temperature threshold value;

[0019] S1043, if the in-group imaging temperature of the measuring point is less than the preset target temperature threshold, calculating the battery preheating power according to the in-group forming temperature, the preheating target temperature and the specific micro parameter.

[0020] In one of the embodiments, S1043 is performed, specifically including the following steps:

[0021] S10431, calculating the battery preheating power according to the in-group imaging temperature of the battery pack and the preheating target temperature;

[0022] S10432, adjusting the battery preheating power according to the specific micro parameter.

[0023] In one of the embodiments, after S101 is performed and before S102 is performed, the following steps are included:

[0024] A deviation correction operation is performed on the obtained in-group imaging temperature of the battery pack to obtain an actual imaging temperature, wherein the actual imaging temperature satisfies the following formula:

[0025] T actual = T measured +△T emission +△T distance +△T angle +△T environment

[0026] T actual is the actual imaging temperature of the battery pack, T measured is the in-group imaging temperature obtained by the infrared thermal imager,△T emission is a material emission temperature difference,△T distance is a distance temperature difference,△T angle is an angle temperature difference,△T environment is an environmental temperature difference;

[0027] Wherein,△T emission =k e *(1-ζ)*T measured

[0028] △T distance =k d *(D-D0)

[0029] △T angle =k a *(1-cosθ)

[0030] △T environment =k env *(T env -T ref )

[0031] k eis an emissivity correction coefficient, ζ is a material emissivity; k d is a distance correction coefficient, D is a distance between the first thermal imaging sensor and / or the second thermal imaging sensor and the battery pack, D0 is a standard reference distance; k a is an angle correction coefficient, θ is an observation angle; k env is an environment correction coefficient, T env is an ambient temperature, T ref is a reference temperature.

[0032] In one of the embodiments, when S10432 is executed, the following formula is satisfied:

[0033]

[0034] wherein u(t) represents a main controller output at time t, used to adjust the battery preheating power of the high-frequency preheater; e(t) represents a temperature deviation at time t; K p , K i , K d are proportional, integral, and differential coefficients respectively, which are obtained through system debugging optimization.

[0035] In one of the embodiments, when S10432 is executed, the following formula is satisfied:

[0036]

[0037] wherein u(t) represents a main controller output at time t, used to adjust the battery preheating power of the high-frequency preheater; e(t) represents a temperature deviation at time t; K p , K i , K d are proportional, integral, and differential coefficients respectively, which are obtained through system debugging optimization; f sep (e) is an integral separation function, T target is a target temperature of the battery pack.

[0038] In one of the embodiments, after S102 is executed, the following step is included: if the lowest imaging temperature is less than a preset first safety temperature threshold, the high-frequency preheater sends an excessively low temperature shutdown signal.

[0039] In one of the embodiments, after S103 is executed, the following step is included: if the highest imaging temperature is greater than a preset second safety temperature threshold, the high-frequency preheater sends an excessively high temperature shutdown signal.

[0040] In one of the embodiments, the number of the infrared thermal imagers is two, and the two infrared thermal imagers are arranged at opposite top corner positions of the box body.

[0041] Compared with the prior art, the present disclosure has at least the following advantages:

[0042] The present scheme will adopt a spiral coil to heat by induction eddy current. There is a gap between each surface of the battery pack and the inner wall of the spiral coil, so that the battery pack can be quickly, uniformly and non-contact preheated. At the same time, the thermal imaging sensor comprehensively detects the imaging temperature of the battery pack, so that the main controller controls the start of the high-frequency preheater according to the temperature, the upper and lower limits of the safety temperature and the target temperature of the battery pack, so as to ensure the safety of the battery pack. When the battery pack is applied to an emergency aircraft, it is suitable for extremely cold exploration, emergency rescue and other scenes, so as to ensure that the battery pack can be used normally. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present disclosure, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0044] Figure 1 Flow chart of the battery preheating detection method for an emergency aircraft based on the non-contact battery fast preheating system in an embodiment;

[0045] Figure 2 Module diagram of the non-contact battery fast preheating system;

[0046] Figure 3 Specific flow chart of the battery preheating detection method for an emergency aircraft based on the non-contact battery fast preheating system in another embodiment;

[0047] Figure 4 Structure diagram of the non-contact battery fast preheating system in another embodiment.

[0048] Reference signs: 100, box body; 200, high-frequency power supply assembly; 210, main controller; 220, high-frequency power supply; 230, spiral coil; 300, infrared thermal imaging assembly; 400, electromagnetic support. DETAILED DESCRIPTION

[0049] In order to facilitate the understanding of the present disclosure, the present disclosure will be described more fully below with reference to the related drawings. The preferred embodiments of the present disclosure are shown in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present disclosure more thorough and comprehensive.

[0050] It should be noted that when an element is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements can also be present. The terms "vertical", "horizontal", "left", "right", and the like as used herein are made only for purposes of illustration and are not intended to be limiting.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used in the description of the disclosure herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0052] In order to better understand the technical solutions and beneficial effects of the disclosure, the disclosure will be further described in detail below in combination with specific embodiments:

[0053] Please refer to Figures 1 to 3 , which is an emergency aircraft battery preheating detection method based on a non-contact battery rapid preheating system according to an embodiment of the present application. The non-contact battery rapid preheating system is used to perform battery preheating, as shown in Figure 2 , the non-contact battery rapid preheating system includes a box body, a main controller, a high-frequency preheater, and an infrared thermal imager. The main controller, the high-frequency preheater, and the infrared thermal imager are all located in the box body. The driving output end of the main controller is electrically connected to the controlled end of the high-frequency preheater. The eddy current output end of the high-frequency preheater is used to place a battery pack. The acquisition end of the infrared thermal imager is used to obtain the imaging temperature of the battery pack. The acquisition feedback end of the infrared thermal imager is electrically connected to the receiving end of the main controller. It can be understood that the eddy current output end of the high-frequency preheater is a spiral coil. The inner cavity of the spiral coil is used to place the battery pack. There is a certain gap between the outer wall of the battery pack and the inner wall of the spiral coil to achieve a non-contact effect. The infrared thermal imager is used to obtain the imaging temperature of the battery pack, i.e., the temperature of each region inside the battery pack, so as to feed back the temperature data to the main controller, and then drive the main controller to start or not start the high-frequency preheater, thereby achieving the effects of rapid preheating, uniform preheating, and temperature safety detection. The high-frequency preheater includes a high-frequency power supply and an electromagnetic induction heating unit. The output end of the high-frequency power supply is electrically connected to the electromagnetic induction heating unit. The eddy current output end of the electromagnetic induction heating unit is used to place the battery pack.

[0054] As shown in Figure 1 , the emergency aircraft battery preheating detection method includes the following steps:

[0055] S101, acquire the intra-battery imaging temperature of the battery pack, the intra-battery imaging temperature including the lowest imaging temperature and the highest imaging temperature of the battery pack; that is, the infrared thermal imager collects the temperature of each region inside the battery pack, and then sends the acquired temperature data to the main controller in the form of an electrical signal for subsequent comparison of the temperature data with the threshold value. Specifically, the infrared thermal imager collects imaging data of all the battery cells of the battery pack, forms a thermal image on the system, and then sends the temperature data related to the thermal image to the main controller in the form of an electrical signal and amplification for subsequent comparison of the temperature data with the threshold value. The lowest imaging temperature is the lowest temperature among the temperatures of the regions of the battery pack, that is, the lowest temperature at the measuring points of the battery pack, and the highest imaging temperature is the highest temperature among the temperatures of the regions of the battery pack, that is, the highest temperature at the measuring points of the battery pack.

[0056] S102, detect whether the lowest imaging temperature is less than a preset first safety temperature threshold value; the preset first safety temperature threshold value is the lower limit value of the battery safety temperature, that is, the lower limit value of the safety temperature range, and is used to determine whether to stop the high-frequency preheater from working.

[0057] S103, if the lowest imaging temperature is greater than or equal to the preset first safety temperature threshold value, detect whether the highest imaging temperature is greater than a preset second safety temperature threshold value, wherein the preset second safety temperature threshold value is greater than the preset first safety temperature threshold value; it can be understood that when the lowest imaging temperature is greater than or equal to the preset first safety temperature threshold value, it means that the lower limit value of the battery safety temperature is not exceeded, that is, the lower limit of the safety temperature range is not exceeded, and it means that there is no situation that one or more battery cells of the battery pack are at an excessively low temperature, and the next step is to detect whether the highest imaging temperature is greater than the preset second safety temperature threshold value, so as to determine whether to start the high-frequency preheater to work.

[0058] S104, if the highest imaging temperature is less than or equal to the preset second safety temperature threshold value, calculate the battery preheating power according to the intra-battery imaging temperature, the preheating target temperature and the specific energy micro parameter; in this embodiment, the highest imaging temperature is less than or equal to the preset second safety temperature threshold value, which means that the highest temperature of the battery pack does not exceed the upper limit of the normal temperature range, that is, the upper limit of the safety temperature range is not exceeded, and it means that there is no situation that one or more battery cells of the battery pack are at an excessively high temperature, and at this time, the main controller sends a power-up signal to the high-frequency preheater, that is, the power is raised or directly started, so that the high-frequency preheater works.

[0059] S105, according to the battery preheating power, send a power-up signal to the high-frequency preheater; it can be understood that when the high-frequency preheater works, the electromagnetic induction heating unit generates an alternating magnetic field through the battery pack, the magnetic field passing through the current collector of the battery pack generates an electromotive force, and then forms a closed eddy current loop, the dissipation of eddy current on the current collector resistance is the main source of battery heating, and then the heat is conducted to the surface of the battery pack. The high-frequency power supply of the high-frequency preheater can generate alternating current, and then generate a stronger alternating magnetic field in the electromagnetic induction heating unit, so that the battery pack can be quickly preheated, and at the same time, the system confirms the battery preheating power according to the collected temperature data, target temperature and proportional-integral-derivative (PID) parameters, so that the battery pack in low temperature state (such as 0℃, 2℃, 5℃, etc.) can be quickly and uniformly preheated by the high-frequency preheater, and the normal capacity and service life of the battery pack are guaranteed.

[0060] In the above embodiment, the emergency aircraft battery preheating detection method based on the non-contact battery rapid preheating system will use a spiral coil to heat by induction eddy current. There is a gap between each surface of the battery pack and the inner wall of the spiral coil, which can realize the rapid, uniform and non-contact preheating of the battery pack. At the same time, the thermal imaging sensor comprehensively detects the imaging temperature of the battery pack, so that the main controller controls whether the high-frequency preheater starts or not according to the temperature of the battery pack, the upper and lower limits of the safety temperature and the target temperature, so as to ensure the safety of the battery pack. When the battery pack is applied to the emergency aircraft, it is suitable for extremely cold exploration, emergency rescue and other scenes, so as to ensure that the battery pack can be used normally. When the battery preheating detection method is applied to the emergency aircraft, the battery pack to be used is placed in the non-contact battery rapid preheating system before take-off, specifically in the electromagnetic induction heating unit, so that the battery pack can be quickly preheated, and after completion, the preheated battery pack is taken out, which is carried by the emergency aircraft. For emergency rescue actions or outdoor operations with weight requirements, the efficiency is higher and the carrying convenience is higher.

[0061] In one embodiment, the number of infrared thermal imagers is two, and the two infrared thermal imagers are arranged at opposite top corners of the box. It can be understood that when two infrared thermal imagers are used and arranged at opposite top corners of the box, one of the infrared thermal imagers is used to collect the temperature of the internal partial region of the battery pack, that is, the temperature of part of the measuring points, and the other infrared thermal imager is used to collect the temperature of the internal partial region of the battery pack, that is, the temperature of the remaining measuring points. In this way, the temperatures of the internal regions are obtained by the two infrared thermal imagers to better collect the current temperatures of all regions inside the battery pack in order to determine whether the main controller starts the high-frequency preheater. At the same time, each infrared thermal imager can simultaneously detect the temperature of multiple three-dimensional regions responsible for it, and through the image processing step, the multiple region temperatures collected by the two infrared thermal imagers are data fused to construct the overall three-dimensional temperature field of the battery pack, so as to more accurately evaluate the heating state and temperature uniformity of the battery pack, and then adjust the battery preheating power set by the main controller according to the heating state and temperature uniformity of the battery pack. For example, when a square battery pack for an airplane is used, one infrared thermal imager is used to collect the temperature of three measuring point regions of the battery pack, and the other infrared thermal imager is used to collect the temperature of the remaining three measuring point regions of the battery pack, so that the temperature of each internal region of the battery pack can be fully collected.

[0062] In another embodiment, as shown in Figure 4 the non-contact battery rapid preheating system includes a box 100, a high-frequency power supply assembly 200, an infrared thermal imaging assembly 300, and an electromagnetic support 400. The main controller 210, the high-frequency power supply assembly 200, the infrared thermal imaging assembly 300, and the electromagnetic support 400 are all located in the box 100. The electromagnetic support 400 is also connected to the box 100. The high-frequency power supply assembly 200 includes a main controller 210, a high-frequency power supply 220, and a spiral coil 230. The inner cavity of the spiral coil 230 is used to place the battery pack, and the battery pack is arranged on the electromagnetic support 400. The collection end of the infrared thermal imaging assembly 300 is used to obtain the in-group imaging temperature of the battery pack, that is, the temperature of each measuring point of the battery pack, and then determine the highest temperature and the lowest temperature. The collection feedback end of the infrared thermal imaging assembly 300 is electrically connected to the receiving end of the main controller 210. The driving output end of the main controller 210 is electrically connected to the controlled end of the high-frequency power supply 220. The output end of the high-frequency power supply 220 is electrically connected to the power supply end of the spiral coil 230. The electromagnetic support 400 is used to place the battery pack, and the battery pack is also arranged in the inner cavity of the spiral coil 230, so that the battery pack can be fixed by the electromagnetic support 400 when preheating, and the position of the battery pack in the spiral coil 230 is stable, ensuring that each surface of the battery pack can be uniformly preheated. The infrared thermal imaging assembly 300 includes two infrared thermal imagers, which jointly collect the temperature of the battery pack to form a thermal imaging image, and then confirm the in-group imaging temperature.

[0063] In one embodiment, S102 is performed, followed by the step of: if the lowest imaging temperature is less than a preset first safety temperature threshold, sending an over-low temperature shutdown signal to the high-frequency preheater. In this embodiment, before or during preheating of the battery pack, temperature detection is performed on the battery pack, and when the lowest temperature in the collected thermal image is lower than the first safety temperature threshold, it indicates that the temperature of one of the battery cells is lower than the lower limit of the safety temperature, i.e., the battery cell temperature is too low, at this time, the flowability of the internal electrolyte of the battery cell is greatly reduced, and the conductivity performance is invalid, and this phenomenon is irreversible. In addition, the lowest temperature of the battery pack is less than the preset first safety temperature threshold, indicating that the temperatures of the battery cells are not balanced, at this time, the main controller sends an over-low temperature shutdown signal to the high-frequency preheater to end the preheating process, so as to prevent the preheating of the battery pack under an extremely low temperature state and prevent further deterioration of the performance of the battery cells of the battery pack.

[0064] In one embodiment, S103 is performed, followed by the step of: if the highest imaging temperature is greater than a preset second safety temperature threshold, sending an over-high temperature shutdown signal to the high-frequency preheater. In this embodiment, before or during preheating of the battery pack, temperature detection is performed on the battery pack, and when the highest temperature in the collected thermal image is higher than the second safety temperature threshold, it indicates that the temperature of one of the battery cells is higher than the upper limit of the safety temperature, i.e., the battery cell temperature is too high, at this time, the internal electrolyte of the battery cell is too high in temperature, and there is a hidden danger of thermal runaway, and this phenomenon is irreversible. In addition, the highest temperature of the battery pack is greater than the preset second safety temperature threshold, indicating that the temperatures of the battery cells are not balanced, and there is a possibility of thermal runaway, and this temperature can spread to the battery cells at normal temperature, further exacerbating the battery pack explosion situation, at this time, the main controller sends an over-high temperature shutdown signal to the high-frequency preheater to end the preheating process, so as to prevent the battery pack from continuing to preheat, and prevent the situation of the over-high temperature battery cell thermal runaway spreading to the battery cells at normal temperature.

[0065] In one of the embodiments, after S106, the following steps are included: cyclically performing S101-S104 to adjust the battery preheating power according to the feedback adjustment action. It can be understood that when the lowest temperature collected in the group imaging temperature collected by the infrared thermal imager is greater than or equal to the preset first safety temperature threshold, and the highest temperature collected is less than or equal to the preset second safety temperature threshold, it indicates that the battery pack is in a safe temperature interval, at this time, the battery preheating power is calculated, and the high-frequency preheater is output according to the battery preheating power to perform the battery preheating step, during which the infrared thermal imager still continues to collect the temperature of each measuring point of the battery pack, that is, the group imaging temperature is collected, and then the current temperature data is fed back to the main controller, so as to stop the high-frequency preheater according to the current feedback data, or adjust the battery preheating power to adjust the preheating speed of the battery pack. Among them, the feedback adjustment action is to feed back the group imaging temperature obtained to the main controller.

[0066] In one of the embodiments, when S104 is performed, the following steps are specifically included:

[0067] S1041, if the highest imaging temperature is less than or equal to the preset second safety temperature threshold, the group imaging temperature of the battery pack is obtained;

[0068] S1042, detecting whether the group imaging temperature is less than the preset target temperature threshold;

[0069] S1043, if the group imaging temperature is less than the preset target temperature threshold, the battery preheating power is calculated according to the group imaging temperature, the preheating target temperature and the specific volume micro parameter.

[0070] The imaging temperature of the measuring points in the group is the temperature of each measuring point of the battery group projected on the thermal imaging diagram, and the preset target temperature threshold is the target temperature set by the system. In this embodiment, when the highest imaging temperature is less than or equal to the preset second safety temperature threshold, that is, the temperature of all battery cells of the battery group does not exceed the upper limit of the safety temperature and is not lower than the lower limit of the safety temperature, the battery group is in a safe state, but it is necessary to determine whether the battery group reaches the set target temperature. At this time, the imaging temperature of the measuring points in the group, that is, the temperature of each measuring point in the battery group is obtained by the infrared thermal imager, and then it is detected whether the imaging temperature of the measuring points in the group is less than the preset target temperature threshold, so as to determine whether to stop the heating of the high-frequency preheater or start the high-frequency preheater. When the imaging temperature of the measuring points in the group is less than the preset target temperature threshold, it indicates that the temperature of each measuring point of the battery group is less than the target temperature, and at this time, the battery preheating power is confirmed, and the final battery preheating power is confirmed according to the group forming temperature, the preheating target temperature and the proportional integral derivative (PID) parameter, so that the system adjusts the battery preheating power according to the PID control correction parameter, and then the battery group preheating speed is determined, so as to ensure that the battery group can be normally preheated, and then S105 is executed to start the preheating step. That is, the higher the battery preheating power is, the faster the battery preheating speed is.

[0071] Further, after S1042 is executed, the following steps are further included:

[0072] If the imaging temperature of the measuring points in the group is less than the preset target temperature threshold, it is detected whether the imaging temperature of the measuring points in the group is less than a preset power reduction temperature threshold; wherein the preset power reduction temperature threshold is a critical value for the temperature of each measuring point in the battery group to reach the condition of reducing the battery preheating power.

[0073] If the imaging temperature of the measuring points in the group is less than the preset power reduction temperature threshold, the battery preheating power is calculated according to the group forming temperature, the preheating target temperature and the PID parameter.

[0074] In this embodiment, in the case that the lowest imaging temperature and the highest imaging temperature of the battery group are located in the safety temperature interval, when the imaging temperature of the measuring points in the group is less than the preset target temperature threshold, the requirement of the battery group preheating is met, and at this time, it is further needed to confirm whether the temperature of each measuring point of the battery group is close to the target temperature, so as to ensure that the battery group is not easily over-preheated and is always in a usable state. When the imaging temperature of the measuring points in the group is less than the preset power reduction temperature threshold, the battery preheating power is calculated according to the group forming temperature, the preheating target temperature and the PID parameter, and the battery group is preheated according to the current battery preheating power, so as to ensure the preheating efficiency of the battery group.

[0075] In another embodiment, if the imaging temperature of the measuring point in the group is greater than or equal to the preset power reduction temperature threshold, a power reduction signal is sent to the high-frequency preheater. It can be understood that when the imaging temperature of the measuring point in the group is greater than or equal to the preset power reduction temperature threshold, it indicates that the temperature of each measuring point in the battery pack reaches the preset power reduction temperature threshold, at which time the main controller sends a power reduction signal to the high-frequency preheater to reduce the output power of the high-frequency preheater, that is, to reduce the battery preheating power, so as to slow down the preheating speed of the battery pack, and at the same time, the power is fine-tuned according to the temperature condition of each measuring point of the battery pack, so as to realize the temperature uniformization of each measuring point of the battery pack and prevent the battery pack from being over-preheated.

[0076] In another embodiment, if the imaging temperature of the measuring point in the group is greater than or equal to the preset target temperature threshold, a preheating shutdown signal is sent to the high-frequency preheater, thereby ending the preheating process of the battery pack.

[0077] In one embodiment, the preset target temperature threshold is set to 15°C, the preset power reduction temperature threshold is set to 13°C, the upper limit threshold of the safety temperature is set to 25°C, and the lower limit threshold is set to -20°C, so that the safety temperature interval is -20°C-25°C. Before preheating, the infrared thermal imager obtains the imaging temperature of the battery pack in the group, and then performs data analysis, for example, the lowest imaging temperature obtained is -2°C and the highest imaging temperature is 1°C, which is lower than the preset second safety temperature threshold, satisfying the preheating condition of the battery pack, so that the preheating step of the battery pack is started, and the battery preheating power is calculated according to the imaging temperature in the group, the preheating target temperature and the specific product micro parameter; when the imaging temperature of the measuring point in the battery pack reaches the preset power reduction temperature threshold, the high-frequency preheater reduces the battery preheating power to slow down the preheating speed of the battery pack and reduce the temperature difference of each measuring point; when the imaging temperature of the measuring point in the battery pack reaches the preset target temperature threshold, the high-frequency preheater stops outputting, thereby stopping the preheating of the battery pack, at which time the battery pack is in the safety temperature interval; if the highest temperature of the battery pack is greater than or equal to the upper limit threshold of the safety temperature, it indicates that the temperature of the battery cell in the battery pack is too high, so the main controller sends an over-high temperature shutdown signal to the high-frequency preheater to prevent the battery pack from being over-preheated. In addition, when it is detected that the lowest temperature of the battery is less than the lower limit threshold of the safety temperature, it indicates that the temperature of the battery cell in the battery pack is too low, so that the overall temperature of the battery pack is not balanced, which has a safety hazard, and the main controller sends an over-low temperature shutdown signal to the high-frequency preheater to prevent the battery pack from being preheated under the condition that the temperature of each measuring point is not balanced. It should be noted that the above-mentioned thresholds and intervals can be adjusted according to actual needs, and are not limited to the thresholds and intervals mentioned above.

[0078] Further, S1043 is executed, specifically including the following steps:

[0079] S10431, calculating the battery preheating power according to the imaging temperature in the group of the battery pack and the preheating target temperature, so that the preheating power is calculated and confirmed by the imaging temperature distribution in the group of the battery pack;

[0080] S10432, adjusting the battery preheating power according to the specific product parameter, that is, adjusting the battery preheating by the PID control correction parameter to eliminate the data error caused by the distance, time, angle, etc., that is, the deviation between the actual temperature of each measuring point of the battery pack and the collected temperature of each measuring point.

[0081] Further, after S101 is executed and before S102 is executed, the following steps are included:

[0082] The deviation correction operation is performed on the acquired imaging temperature in the group of the battery pack to obtain the actual imaging temperature, wherein the actual imaging temperature satisfies the following formula:

[0083] T actual = T measured +△T emission +△T distance +△T angle +△T environment

[0084] T actual is the actual imaging temperature of the battery pack, that is, the actual temperature of each region inside the battery pack, T measured is the imaging temperature in the group of the battery pack acquired by the infrared thermal imager, that is, the measured temperature,△T emission is the material emission temperature difference,△T distance is the distance temperature difference,△T angle is the angle temperature difference,△T environment is the environmental temperature difference;

[0085] Wherein,△T emission =k e *(1-ζ)*T measured

[0086] △T distance =k d *(D-D0)

[0087] △T angle =k a *(1-cosθ)

[0088] △T environment =k env *(T env -T ref )

[0089] k e is the emissivity correction coefficient, ζ is the material emissivity; kd is a distance correction coefficient, D is a distance between the first thermal imaging sensor and / or the second thermal imaging sensor and the battery pack, D0 is a standard reference distance; k a is an angle correction coefficient, θ is an observation angle; k env is an environment correction coefficient, T env is an ambient temperature, T ref is a reference temperature.

[0090] It can be understood that when the preheating step of the battery pack is performed, the temperature of each measuring point of the battery pack will be collected by the infrared thermal imager, but the collected temperature deviates from the internal area temperature of the battery pack itself, and the influencing factors include but are not limited to the shape of the battery pack, the collection distance, the collection angle, the environment, the material of the battery pack shell, etc. Therefore, in order to eliminate the error between the actual temperature and the test temperature, the material emissivity, the collection distance, the collection angle, and the ambient temperature are corrected and compensated, wherein the observation angle θ represents the angle between the collection direction of the infrared thermal imager and the side surface of the battery pack. By confirming the material emissivity, the collection distance parameter, the collection angle, and the ambient temperature, the corresponding temperature difference value is calculated, and then the collected temperature is compensated by the difference value, so as to eliminate the error between the actual temperature of the battery pack at each internal area and the collected temperature at each measuring point, and then facilitate the subsequent judgment condition, so as to prevent the error between the collected temperature and the actual temperature from affecting the normal work or normal shutdown of the high-frequency preheater.

[0091] Further, when S10432 is executed, the following formula is satisfied:

[0092]

[0093] wherein u(t) represents the output parameter of the main controller at time t, which is used to adjust the battery preheating power of the high-frequency preheater; e(t) represents the temperature deviation at time t; K p , K i , K d are proportional, integral, and differential coefficients respectively, which are obtained by system debugging and optimization. In this way, the battery preheating power of the high-frequency preheater can be confirmed by the deviation state of the in-pack imaging temperature of the battery pack, so that the battery preheating step is performed according to the battery preheating power, thereby ensuring the control of the temperature of the battery pack.

[0094] Further, when S10432 is executed, the following formula is satisfied:

[0095]

[0096] wherein u(t) represents the output of the main controller at time t, which is used to adjust the battery preheating power of the high-frequency preheater; e(t) represents the temperature deviation at time t; K p , Ki , K d are proportional, integral, and derivative coefficients, respectively, which are obtained by system debugging and optimization; sep (e) is an integral separation function, T target is the target temperature of the battery pack. It can be understood that the power-related parameters output by the main controller can be determined by the temperature deviation e(t) and the integral separation function f sep (e). When the temperature deviation e(t) is large, the integral action is weakened, thereby avoiding the situation of power overshoot. When the temperature deviation e(t) is small, the integral action is enhanced to eliminate the steady-state error. The derivative term directly acts on the rate of change of the target temperature, which helps to improve the response speed of the system to the change of the target temperature, and can dynamically adjust the battery preheating power of the high-frequency preheater, that is, adjust the temperature change of the battery pack during preheating.

[0097] The step of preheating the emergency aircraft battery is carried out in a closed-loop control environment, that is, it needs to be carried out in the box space. Specifically, when the high-frequency alternating current passes through the induction coil, a high-frequency alternating magnetic field is generated. The current collector, pole piece and the like in the battery pack are located in the magnetic field, forming eddy current, and then heating the current collector, pole piece and the like, so that the temperature rises. The heat is transmitted to the surface of the battery pack to achieve the effect of preheating the battery pack. Because the box space is relatively closed, and the battery pack is preheated by the high-frequency method in this scheme, it is limited by the box space. When the heat in the box accumulates to a certain extent, the battery temperature will continue to rise, which has the risk of thermal runaway, that is, the temperature of the battery cell in the battery pack rises sharply, the heat generation increases, which causes the temperature difference of each surface of the battery pack to increase, aggravating the occurrence of thermal runaway. Serious, will cause the battery pack to explode and cause a fire.

[0098] In order to ensure that the battery pack can be preheated normally and prevent the battery pack from appearing thermal runaway, S106 is executed, and the following steps are further included:

[0099] Obtain the temperature change rate of each measuring point of the battery pack;

[0100] Detect whether there is at least one measuring point temperature change rate of the battery pack greater than or equal to the preset temperature change rate;

[0101] If there is at least one measuring point temperature change rate of the battery pack greater than or equal to the preset temperature change rate, send a power reduction and time increase signal to the high-frequency preheater.

[0102] In the embodiment, the temperature change rate of each measuring point of the battery pack is confirmed by the main control board according to the temperature of each measuring point of the battery pack in the previous acquisition cycle and the temperature of each measuring point of the battery pack in the next acquisition cycle. After the temperature change rate of each measuring point of the battery pack is obtained, it is detected whether at least one temperature change rate of the measuring points of the battery pack is greater than or equal to the preset temperature change rate, to determine whether the battery pack has the risk of thermal runaway. When at least one temperature change rate of the measuring points of the battery pack is greater than or equal to the preset temperature change rate, it indicates that the temperature of at least one measuring point of the battery pack rises too fast, and the battery pack has the risk of thermal runaway. At this time, the main control board sends a power reduction and time increase signal to the high-frequency preheater, to reduce the output power of the high-frequency preheater, slow down the preheating speed of the battery pack, and reduce the probability of thermal runaway of the battery pack. At the same time, by increasing the preheating time, the temperature of each measuring point of the battery pack can reach the target temperature value, so that the battery pack is in a usable state, the service life of the battery pack is ensured, and the battery pack can be used in high-cold environment or exploration.

[0103] It can be understood that the in-group imaging temperature also includes the temperature of each measuring point of the battery pack, that is, the temperature of all internal regions in the battery pack.

[0104] In another embodiment, after it is detected whether at least one temperature change rate of the measuring points of the battery pack is greater than or equal to the preset temperature change rate, the following steps are further included:

[0105] If the temperature change rate of each measuring point of the battery pack is less than the preset temperature change rate, the in-group imaging average temperature of the battery pack is obtained.

[0106] It is detected whether the in-group imaging average temperature of the battery pack is less than the preset average temperature threshold.

[0107] If the in-group imaging average temperature of the battery pack is less than the preset average temperature threshold, a power increase and time reduction signal is sent to the high-frequency preheater.

[0108] It can be understood that the in-group imaging temperature also includes the in-group imaging average temperature, which is used to confirm whether to maintain the limitation or send the power increase and time reduction signal.

[0109] In the embodiment, if the temperature change rate of at least one measuring point of the battery pack is greater than or equal to the preset temperature change rate, that is, the temperature change rate of each measuring point of the battery pack is less than the preset temperature change rate, it indicates that there is no temperature change of one or more battery cells of the battery pack, and the probability of thermal runaway is less. At this time, the temperatures of all measuring points of the battery pack are calculated, and the average value is obtained, that is, the in-group imaging average temperature of the battery pack is obtained. Whether the in-group imaging average temperature of the battery pack is less than the preset average temperature threshold is detected to confirm whether to adjust the battery preheating power and the preheating time. When the in-group imaging average temperature of the battery pack is less than the preset average temperature threshold, it indicates that the average value of the sum of the temperatures of all measuring points of the battery pack is less than the preset average temperature threshold. At this time, an increase power and decrease time signal is sent to the high-frequency preheater, that is, the main controller increases the battery preheating power according to the average temperature, and drives the high-frequency preheater to output the battery preheating power adjusted, while reducing the preheating time, so as to prevent the battery cell temperature from rising too much due to too long preheating time, and prevent the battery pack from overheating or even thermal runaway caused by excessive rise, so as to ensure the service life of the battery pack, and facilitate the use of the battery pack in high-cold environment or exploration. The preset average temperature threshold can be set to 10 DEG C.

[0110] In one of the embodiments, if the in-group imaging average temperature of the battery pack is greater than or equal to the preset average temperature threshold, the current battery preheating power output is maintained.

[0111] Compared with the prior art, the present disclosure has at least the following advantages:

[0112] The present scheme adopts a spiral coil to heat by induction eddy current. There is a gap between each surface of the battery pack and the inner wall of the spiral coil, so that the battery pack can be preheated quickly, uniformly and non-contact. At the same time, the in-group imaging temperature of the battery pack is detected by the thermal imaging sensor, so that the main controller controls the start of the high-frequency preheater according to the temperature, the upper and lower limits of the safety temperature and the target temperature of the battery pack, so as to ensure the safety of the battery pack. When the battery pack is applied to an emergency aircraft, it is suitable for extremely cold exploration, emergency rescue and other scenes, so as to ensure that the battery pack can be used normally.

[0113] The above-described embodiments only express several embodiments of the present disclosure, and the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the disclosed patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present disclosure, a number of modifications and improvements can be made, which belong to the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure patent should be subject to the appended claims.

Claims

1. An emergency aircraft battery preheating detection method based on a non-contact battery rapid preheating system, characterized in that, a battery preheating is performed by using a non-contact battery rapid preheating system, the non-contact battery rapid preheating system comprising: a box body; a main controller and a high-frequency preheater, both located in the box body, the driving output end of the main controller being electrically connected with the controlled end of the high-frequency preheater, and the eddy current output end of the high-frequency preheater being used for placing a battery pack; an infrared thermal imager located in the box body, the collection end of the infrared thermal imager being used for acquiring an imaging temperature in the battery pack, and the collection feedback end of the infrared thermal imager being electrically connected with the receiving end of the main controller; the emergency aircraft battery preheating detection method comprising the following steps: S101, acquiring an imaging temperature in the battery pack, the imaging temperature in the battery pack comprising a lowest imaging temperature and a highest imaging temperature in the battery pack; S102, detecting whether the lowest imaging temperature is less than a preset first safety temperature threshold; S103, if the lowest imaging temperature is greater than or equal to the preset first safety temperature threshold, detecting whether the highest imaging temperature is greater than a preset second safety temperature threshold, wherein the preset second safety temperature threshold is greater than the preset first safety temperature threshold; S104, if the highest imaging temperature is less than or equal to the preset second safety temperature threshold, calculating a battery preheating power according to the imaging temperature in the battery pack, a preheating target temperature and a specific energy parameter; S105, sending a power-up signal to the high-frequency preheater according to the battery preheating power.

2. The emergency aircraft battery preheating detection method based on the non-contact battery quick preheating system according to claim 1, characterized in that, After S106 is executed, the following steps are included: S101-S104 are cyclically executed to adjust the battery preheating power according to a feedback adjustment action.

3. The emergency aircraft battery preheating detection method based on the non-contact battery quick preheating system according to claim 1, characterized in that, When S104 is executed, the following steps are specifically included: S1041, if the highest imaging temperature is less than or equal to the preset second safety temperature threshold, acquiring an imaging temperature at a measuring point in the battery pack; S1042, detecting whether the imaging temperature at the measuring point in the battery pack is less than a preset target temperature threshold; S1043, if the imaging temperature at the measuring point in the battery pack is less than the preset target temperature threshold, calculating the battery preheating power according to the imaging temperature in the battery pack, the preheating target temperature and the specific energy parameter.

4. The emergency aircraft battery preheating detection method based on the non-contact battery quick preheating system according to claim 3, characterized in that, When S1043 is executed, the following steps are specifically included: S10431, calculating the battery preheating power according to the imaging temperature in the battery pack and the preheating target temperature; S10432, adjusting the battery preheating power according to the specific energy parameter.

5. The emergency aircraft battery preheating detection method based on the non-contact battery quick preheating system according to claim 4, characterized in that, After S101 is executed and before S102 is executed, the following steps are included: deviation correction operation is performed on the acquired imaging temperature in the battery pack to obtain an actual imaging temperature, wherein the actual imaging temperature satisfies the following formula: T actual = T measured + ΔT emission + ΔT distance + ΔT angle + ΔT environment T actual is the actual imaging temperature of the battery pack, T measured is the imaging temperature within the pack acquired by the infrared thermal imager, ΔT emission is the material emission temperature difference, ΔT distance is the distance temperature difference, ΔT angle is the angle temperature difference, ΔT environment is the ambient temperature difference; wherein ΔT emission = k e *(1-ζ)*T measured ΔT distance = k d *(D - D0) ΔT angle = k a *(1 - cos θ) △T environment = k env *(T env -T ref ) k e is an emissivity correction factor, ζ is a material emissivity;k d is a distance correction factor, D is a distance between the first thermal imaging sensor and / or the second thermal imaging sensor and a battery pack, D0 is a standard reference distance;k a is an angle correction factor, θ is an observation angle;k env is an environmental correction factor, T env is an environmental temperature, T ref is a reference temperature.

6. The emergency aircraft battery preheating detection method based on the non-contact battery quick preheating system according to claim 5, characterized in that, When S10432 is executed, the following formula is satisfied: Wherein, u(t) represents the main controller output at time t, used to adjust the battery preheating power of the high-frequency preheater; e(t) represents the temperature deviation at time t; K p , K i , K d The proportional, integral, and differential coefficients are obtained by system debugging and optimization, respectively.

7. The emergency aircraft battery preheating detection method based on the non-contact battery quick preheating system according to claim 6, characterized in that, When S10432 is executed, the following formula is satisfied: Wherein, u(t) represents the main controller output at time t, used to adjust the battery preheating power of the high-frequency preheater; e(t) represents the temperature deviation at time t; K p , K i , K d The proportional, integral and differential coefficients are obtained by system debugging and optimization; f sep (e) is the integral separation function, T target is the target temperature of the battery pack.

8. The emergency aircraft battery preheating detection method based on the non-contact battery quick preheating system according to claim 1, characterized in that, After S102 is executed, the following steps are included: if the lowest imaging temperature is less than the preset first safety temperature threshold, a low-temperature shutdown signal is sent to the high-frequency preheater.

9. The emergency aircraft battery preheating detection method based on the non-contact battery quick preheating system according to claim 1, characterized in that, After S103 is executed, the following steps are included: If the highest imaging temperature is greater than a preset second safety temperature threshold, a high temperature shutdown signal is sent to the high-frequency preheater.

10. The emergency aircraft battery preheating detection method based on the non-contact battery quick preheating system according to claim 1, characterized in that, The number of the infrared thermal imagers is two, and the two infrared thermal imagers are arranged at opposite top corner positions of the box body.

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