Battery pack thermal management
By designing a controller that can detect temperature change rates in the battery pack, disconnecting the battery cell array at high temperature positions and enhancing cooling, the problem of uneven temperature change rates in the battery pack is solved, and more effective thermal management and safety improvement is achieved.
Patent Information
- Application Number
- CN202411506736.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-11-01
- Filing Date
- 2024-10-28
- Publication Date
- 2025-05-13
AI Technical Summary
The temperature change rate of the battery pack at different locations is uneven, which makes it difficult for traditional battery management systems to cool effectively, which may cause heat events.
A controller is designed to detect the temperature change rate at different locations of the battery pack. If the temperature increase rate at a certain location is found to be the largest, the controller can disconnect the battery cell array at that location and enhance cooling at that location, while sending temperature data to the remote server to receive cooling adjustment commands.
By disconnecting the high-temperature battery cell array and enhancing local cooling, it effectively reduces heat accumulation in the battery pack, prevents heat events, and improves the response and safety of the battery management system.
Smart Images
Figure CN119994312A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to methods for thermal management of battery packs. Background Art
[0002] Battery systems, particularly lithium-ion battery packs used in vehicles, typically include arrays of multiple cells designed to store and release energy. As these systems operate, they generate heat, with some areas experiencing temperature changes at varying rates due to factors like uneven energy or cooling distribution. Traditional battery management systems can evenly cool the entire battery pack. Summary of the Invention
[0003] In one embodiment, a battery system includes a controller designed and programmed to perform a specific function. When it is detected from measured temperatures at different locations of a battery pack that these locations indicate different rates of temperature increase, the controller is capable of disconnecting a specific cell array of the battery pack that is closest to the location with the greatest rate of temperature increase. This action is taken without disconnecting other cell arrays of the same battery pack.
[0004] Additionally, the controller can be further programmed to increase cooling near the identified location if the measured temperature indicates an increasing rate of change. In scenarios where such a temperature increase is detected, the controller can also generate an alert to notify the driver or system operator. To enhance communication and control, the controller has the ability to send collected temperature data to a remote server. Furthermore, it can receive specific commands regarding disconnection actions from this server.
[0005] In another embodiment, a method is provided that involves increasing cooling near a specific location within a battery pack if that location exhibits a temperature rise rate exceeding a set threshold. This enhanced cooling does not affect other locations within the battery pack, particularly those locations experiencing a temperature rise rate below the predetermined threshold or those locations remote from the location. If a location within the battery pack exhibits a temperature rise rate that violates the threshold, the method further includes the steps of disconnecting the nearest cell array and generating an alert. In addition, the method discloses sending data related to the temperature rise rate to a remote server and receiving related commands regarding cooling adjustments.
[0006] In yet another embodiment, a vehicle is equipped with a battery pack consisting of numerous cell arrays and a programmed controller. If the controller senses that a specific location within the battery pack has reached a temperature exceeding a set threshold, it has the capability to amplify cooling near that location without affecting cooling at other remote locations. The programmed controller can also disconnect the cell array closest to the exceeded location, generate an alert, and send temperature data to a remote server. Furthermore, the controller can receive instructions or commands directly from the server, enhancing its response mechanism. BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Figure 1A is a schematic diagram of a battery cell with sparse sensors.
[0008] Figure 1B is a graph of the temperature at the sensor.
[0009] Figure 2A is a schematic diagram of a battery cell with sparse sensors.
[0010] Figure 2B is a graph of the temperature at the sensor.
[0011] Figure 3A is a schematic diagram of a battery cell with sparse sensors.
[0012] Figure 3B is a graph of the temperature at the sensor.
[0013] Figure 4 is a flow chart of an event detection method according to an embodiment of the present disclosure. DETAILED DESCRIPTION
[0014] Embodiments are described herein. However, it should be understood that the disclosed embodiments are merely examples and that other embodiments may take various and alternative forms. The drawings are not necessarily drawn to scale. Some features may be exaggerated or minimized to illustrate details of particular components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as a representative basis for teaching those skilled in the art.
[0015] The various features shown and described with reference to any one of the accompanying drawings may be combined with features shown in one or more other drawings to produce embodiments not explicitly shown or described. The combinations of features shown provide representative embodiments for typical applications. However, for specific applications or implementations, various combinations and modifications of features may be desired consistent with the teachings of this disclosure.
[0016] The present disclosure relates to the field of battery pack thermal management, specifically as it relates to heat reduction and efficiency. Battery packs can benefit from continuous monitoring and control of their temperature. Within a battery pack, there can be multiple different sets of arrays. In an example configuration of two arrays, the first set includes arrays one through five, while the second set includes arrays six through ten. In this example configuration, the thermal sensors, which are means for measuring temperature changes, are not evenly distributed throughout all arrays. Instead, they are selectively positioned in arrays three, four, five, six, nine, and ten. This sparse distribution can make it challenging to detect thermal events in arrays that lack thermal sensors. Such gaps in monitoring can sometimes make thermal events more difficult to detect based on cell voltage data when the voltage drop is a small amount (e.g., 0.2V) and is complicated by factors like voltage rebound and infrequent data sampling (e.g., every 30 seconds).
[0017] This disclosure describes systems and methods for thermal event detection and management thereof. In one scenario, if a thermal event is detected by one thermal sensor within its own array and subsequently confirmed by another thermal sensor in an adjacent array using a specific temperature difference (e.g., TD1 = 15°C) within a specific time frame (e.g., TDT1 = 400 seconds), the location of the original problem can be narrowed down and verified.
[0018] In another example scenario, when a single thermal sensor reading exhibits rapid fluctuations beyond a set temperature difference (e.g., TD2 = 20°C) within a determined duration (e.g., TDT2 = 60 seconds), this indicates the proximity of a thermal event within the same array, but farther away from the thermal sensor.
[0019] In a third example scenario, if multiple thermal sensors show an increase in temperature but none meet a set temperature threshold (e.g., TT1 = 65°C), the sequence in which these thermal sensors reach a specific temperature difference (e.g., TD3 = 10°C) within a specified time frame (e.g., TDT3 = 800 seconds) can reveal the distance of each thermal sensor from incipient failure.
[0020] Now refer to Figure 1A , shows a battery pack 10. Inside the pack are two different sets of arrays. The first set 12 consists of individual arrays 16, 18, 20, 22, and 24. Specifically, arrays 20, 22, and 24 are equipped with temperature sensors 26, 28, and 30, respectively. The second set 14 encompasses arrays 32, 34, 36, 38, and 40. Notably, arrays 32, 34, and 40 include temperature sensors 42, 44, and 46, respectively.
[0021] The sets of arrays can be placed in separate cooling zones or wired in parallel. In the case where they are wired in parallel, one set of arrays (perhaps set 12) can be disconnected, thereby making another set (e.g., set 14) fully functional.
[0022] The controller 48 is operably configured with the battery pack 10. The controller 48 receives temperature data from the sensors and, when in the scenario described above, if an array (like array 22) shows a significant temperature increase compared to other arrays, the controller 48 can disconnect the array set 12. In other configurations, the controller can be programmed to increase cooling around the array or designated area experiencing the thermal event to offset the temperature increase.
[0023] The controller 48 may also be further programmed to communicate operationally with the driver by sending an alert to the driver if certain temperature thresholds are violated. The controller 48 may also be further programmed to communicate operationally with a remote data server by sending temperature data to the remote server for off-site monitoring. This data may be further analyzed by the remote team, wherein the controller 48 may be further programmed to receive commands from the remote server and act accordingly, thereby allowing remote adjustments to be made. It should be understood that when the controller 48 is described as being configured or programmed to do something, this is functionally equivalent to the controller 48 causing or commanding it to be done.
[0024] Now refer to Figure 1B , the graph reveals a significant temperature increase near array 22 as detected by temperature sensor 28 (or T2). At the same time, temperature sensor 26 (or T1) on the adjacent array 20 also recorded a rise in temperature. This corroborative data from both sensors indicates that a thermal event has occurred in array 22. Specific metrics can be set to measure these thermal events: a temperature difference threshold (TD1) of 15°C and a duration threshold (TDT1) of 400 seconds. Based on these readings, the following is inferred under the example rules. If a sensor (like sensor 28 (or T2)) detects a thermal irregularity in its local array and a nearby sensor (such as sensor 26 (or T1)) confirms this within the parameters of TD1 and TDT1, the location of the fault is determined. In this case, the outage is traced to array 22, signaling it as the origin of the thermal event.
[0025] Now refer to Figure 2A Now let's look at battery pack 50. Inside it are two distinct sets of arrays. Set 52 contains arrays 56, 58, 60, 62, and 64. Arrays 60, 62, and 64 are equipped with temperature sensors 76, 78, and 80, respectively. The corresponding set 54 houses arrays 66, 68, 70, 72, and 74. Arrays 66, 68, and 74 are equipped with temperature sensors 82, 84, and 86, in that order.
[0026] These collections can be managed within separate cooling zones, or they can be wired in parallel. In the scenario where they are connected in parallel, a particular collection (such as collection 52) can be disconnected independently, allowing its counterpart (i.e., collection 54) to remain operational. Another controller 88 is integrated with the battery pack 50. This controller 88 processes the temperature data relayed from the sensors. If a particular array (such as array 64) records a temperature spike, the controller 88 can disconnect its associated collection (i.e., collection 52). The controller 88 can also regulate cooling within a specific nearby area if the array indicates a thermal event.
[0027] The controller 88 can be further programmed to alert the driver if a temperature threshold is exceeded. The controller 88 can also communicate with an external remote server. The controller 88 can also send temperature measurements to this server, enabling remote diagnostics. This off-site data allows an external team to interpret the data, and the controller 88 can be programmed to execute commands dispatched from this remote server. It should be understood that when the controller 88 is described as being configured or programmed to do something, this is functionally equivalent to the controller 88 causing or commanding it to be done.
[0028] Move to Figure 2B , the graphical representation provides clarity. As indicated by sensor 80 (or T3), there is a clear temperature rise around array 64. Sensor 78 (or T2) from adjacent array 62 also records a rise, further confirming T3's observation. Using parameters such as a temperature difference threshold (TD3) of 20°C and a duration threshold (TDT) of 60 seconds, the data from the two sensors is analyzed by controller 88. When T3 resonates within the parameters of TD3 and TDT3, it helps to identify the area of the thermal event. Another thermistor T2 in the adjacent array shows a gentle temperature rise. In this case, array 64 appears as a segment experiencing the event, marking it for increased cooling.
[0029] refer to Figure 3A , we look at a battery pack 90 for an electric vehicle. Inside, there are two different sets of arrays. Set 92 includes arrays 94, 96, 98, 100, and 102. Within these, arrays 98, 100, and 102 are placed with temperature sensors 104, 106, and 108, respectively. Set 110 houses arrays 112, 114, 116, 118, and 120. From this set, arrays 112, 114, and 120 are placed with temperature sensors 122, 124, and 126, in that order. Both sets 92 and 110 can be managed in separate cooling zones or wired separately in parallel. When wired separately, sets like set 92 can be disconnected, leaving set 110 to function.
[0030] Within the battery pack 90, there is a controller 128. This controller processes the temperature data from the sensors. In the absence of direct monitoring readings for the array 94, adjacent sensors, such as sensors 122 (T6), 124 (T5), and 104 (T1), provide inferred temperatures for the array 94. Using these readings, the controller 128 can make decisions regarding the operation of the associated set or array. It should be understood that when the controller 128 is described as being configured or programmed to do something, this is functionally equivalent to the controller 128 causing or commanding it to be done.
[0031] When several sensors indicate rising temperatures, but none cross the set mark of TT1 = 65°C, the sequence of sensors reaching a difference of TD3 = 10°C within TDT = 800 seconds provides insight into the origin of the event. Here, the focus is on the inner cells of array 94. Controller 128 can also adjust cooling near the indicated location without affecting other areas. Controller 128 can also disconnect specific arrays, generate an alarm, and maintain communication with a remote server for data transmission and adjustments.
[0032] exist Figure 3B , the graphical representation provides a clearer perspective on the temperature dynamics within battery pack 90. Even in the absence of direct monitoring, significant temperature increases around array 94 are evident. Coordinated data from adjacent sensors, particularly sensors 122 (T6), 124 (T5), and 104 (T1), provides the information needed by controller 128.
[0033] The graph plots temperature changes over time, and the three lines corresponding to sensors 122 (T6), 124 (T5), and 104 (T1) show synchronized spikes. This synchronized rise indicates that the event originated near or within array 94. The sequence in which the lines rise indicates proximity to the source of the event. Even though none of the lines crosses the specified threshold of TT1 = 65°C, their simultaneous and sequential rise within the parameters of TD3 = 10°C within TDT = 800 seconds indicates a thermal event. This pattern indicates that the source of the temperature increase is closest to the inner cells of array 94.
[0034] refer to Figure 4 The method begins at decision block 130 where the controller, receiving temperature data from the thermal sensors, records if any of the thermal sensors has detected a temperature change (specifically, a 20° C. rise within 60 seconds).
[0035] If the result at block 130 is yes, the process proceeds to block 132, indicating that the source of the thermal event is within the same array but not immediately adjacent to the detecting thermal sensor. If the controller does not identify a rapid temperature rise at block 130, the controller moves to decision block 134, where it inquires whether any of the thermal sensors have already registered a thermal event. If the result is yes, the process proceeds to decision block 136, which checks whether another thermal sensor located in a different array has also observed the same event.
[0036] If the controller positively detects an incident from a thermal sensor of another array at box 136, box 138 is reached, which infers that the source of the event is the array associated with the first responding thermal sensor. However, if the result of box 136 is no, the flowchart advances to decision box 140, which evaluates whether a group of thermal sensors achieves a specific temperature difference (such as a 10°C increase in 800 seconds). If this condition is met, the method advances to operation box 142, indicating the point closest to the first responding thermal sensor as the possible location of the thermal event. For vehicles with integrated connectivity, the event location can be transmitted to a central data center or cloud system. Specialized engineering units can then use this data to assess the scope of the event, enabling remote teams to determine and implement appropriate measures. Although temperature sensors are specified, their equivalent voltage sensors or any such sensors can be used with any of the embodiments.
[0037] The algorithms, methods or processes disclosed herein may be delivered to or implemented by a computer, controller or processing device, which may include any dedicated electronic control unit or programmable electronic control unit. Similarly, the algorithms, methods or processes may be stored in a variety of forms as data and instructions that can be executed by a computer or controller, including but not limited to information permanently stored on a non-writable storage medium such as a read-only memory device and information that can be modified and stored on a writable storage medium such as an optical disc, a random access memory device or other magnetic and optical media. The algorithms, methods or processes may also be implemented as software executable objects. Alternatively, the algorithms, methods or processes may be embodied in whole or in part using suitable hardware components (such as application specific integrated circuits, field programmable gate arrays, state machines or other hardware components or devices) or a combination of firmware, hardware and software components.
[0038] While exemplary embodiments have been described above, these embodiments are not intended to describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it should be understood that various changes can be made without departing from the spirit and scope of these disclosures. For example, the terms "controller" and "controllers" may be used interchangeably herein.
[0039] As previously described, features of the various embodiments may be combined to form additional embodiments of the present disclosure that may not be explicitly described or shown. Although various embodiments may have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, it will be appreciated by those skilled in the art that one or more features or characteristics may be compromised to achieve desired overall system properties, depending on the specific application and implementation. These properties may include, but are not limited to, strength, durability, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, and the like. Therefore, embodiments that are described as being less desirable than other embodiments or prior art implementations with respect to one or more characteristics are within the scope of the present disclosure and may be desirable for a particular application.
Claims
1. A battery system comprising: A controller programmed to disconnect an array of cells of the battery pack that is closest to one of the locations having a maximum of the rates, without disconnecting other arrays of cells of the battery pack, because the measured temperatures at different locations of the battery pack indicate different rates of increase at the locations. 2 . The battery system of claim 1 , wherein the controller is further programmed to increase cooling proximate the one of the locations due to the measured temperatures indicating different rates of increase at the locations. 3 . The battery system of claim 1 , wherein the controller is further programmed to generate a driver alert due to the measured temperatures indicating different rates of increase at the locations.
4. The battery system of claim 1, wherein the controller is further programmed to send the measured temperature to a remote server.
5. The battery system of claim 4, wherein the controller is further programmed to receive a command regarding the disconnection from the remote server.
6. A method comprising: Cooling is increased near a location within the battery pack that experiences a rate of temperature increase exceeding a predetermined threshold rate, while cooling is not increased at a location within the battery pack that experiences a rate of temperature increase less than the predetermined threshold rate and is distant from the location.
7. The method of claim 6, further comprising: Because the location experiences the rate of temperature increase exceeding the predetermined threshold rate, one of a plurality of cell arrays in the battery pack that is closest to the location is disconnected.
8. The method of claim 6, further comprising: As a result of the location experiencing the rate of temperature increase exceeding the predetermined threshold rate, an alarm is generated.
9. The method of claim 6, further comprising: Data related to the temperature increase rate is sent to a remote server.
10. The method of claim 9, further comprising: A command associated with the increasing is received.
11. A vehicle comprising: A battery pack, the battery pack comprising a plurality of battery cell arrays; as well as A controller is programmed to, in response to an indication that one of a plurality of locations within the battery pack has a temperature exceeding a threshold temperature, increase cooling proximate the one location without increasing cooling proximate other of the locations distal to the one location.
12. The vehicle of claim 11, wherein the controller is further programmed to disconnect one of the battery cell arrays that is closest to the one location in response to the indication.
13. The vehicle of claim 11, wherein the controller is further programmed to generate an alarm in response to the indication.
14. The vehicle of claim 11, wherein the controller is further programmed to transmit data related to the temperature to a remote server.
15. The vehicle of claim 14, wherein the controller is further programmed to receive the indication from the remote server.