A method and device for determining a junction temperature of a vehicle power module, a vehicle and a medium
By combining the operating status of the motor controller and the status of the cooling system, the junction temperature of the chip in the power module can be accurately calculated, which solves the problem of inaccurate estimation caused by cooling system abnormalities and improves the accuracy of junction temperature estimation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SAIC GM WULING AUTOMOBILE CO LTD
- Filing Date
- 2026-01-27
- Publication Date
- 2026-05-29
AI Technical Summary
Existing technologies cannot accurately estimate the junction temperature of chips within the power module when the motor controller cooling system malfunctions, resulting in inaccurate estimation results.
The power loss is determined based on the operating status information of the motor controller, the thermal resistance parameter is determined in combination with the operating status of the cooling system, and the junction temperature of the chip is calculated using the current sampling temperature of the temperature sensor.
It improves the accuracy of chip junction temperature estimation under abnormal cooling system conditions and reduces the impact of cooling water pump operation on the estimation results.
Smart Images
Figure CN122111137A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of vehicle technology, and more specifically to a method, apparatus, vehicle, and medium for determining the junction temperature of a vehicle power module. Background Technology
[0002] As a core component of electric vehicles, the motor controller converts the direct current (DC) output from the battery into alternating current (AC) through its internal power module to control the motor's operation. During the DC-to-AC conversion process, the switching elements in the power module may undergo high-frequency switching, resulting in power loss and generating a significant amount of heat. Therefore, temperature monitoring of the power module is extremely important.
[0003] In practical applications, temperature sensors can usually be installed inside the power module. However, temperature sensors are typically not installed inside the switching elements. Therefore, it may not be possible to directly detect the junction temperature of the switching elements, and consequently, it may not be possible to directly obtain the junction temperature of the chips related to the switching elements within the power module.
[0004] Currently, temperature and thermal resistance models, measured by temperature sensors inside the power module, are typically used to determine the junction temperature changes of the switching elements within the power module, thereby estimating the junction temperature of the chips within the power module. However, this method is usually limited to the normal operation of the motor controller's cooling system. When the cooling system experiences abnormal conditions such as coolant leakage or the cooling water pump malfunction, the thermal resistance characteristics inside the power module will change. Therefore, if the thermal resistance under normal conditions is still used to estimate the junction temperature of the chips within the power module, the estimated junction temperature may be inaccurate.
[0005] It should be noted that the information disclosed in the background section of this application is intended only to enhance the understanding of the general background of this application, and should not be regarded as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention
[0006] This application provides a method, apparatus, vehicle, and medium for determining the junction temperature of a vehicle power module, in order to solve the problem in the related art that the estimated junction temperature of the chips in the power module may be inaccurate due to abnormalities in the cooling system of the motor controller.
[0007] In a first aspect, embodiments of this application provide a method for determining the junction temperature of a vehicle power module, including: Based on the operating status information of the motor controller, determine the power loss of the power module in the motor controller; The thermal resistance parameters of the power module are determined based on the operating status of the cooling system of the motor controller. The junction temperature of the chip in the power module is determined based on the power loss, the thermal resistance parameter, and the current sampling temperature of the temperature sensor inside the power module.
[0008] In one possible implementation, the operating status information includes bus voltage, output current, switching frequency, output modulation ratio, output frequency, and the current sampling temperature of the temperature sensor inside the power module. Determining the power loss of the power module in the motor controller based on the operating status information of the motor controller includes: Based on the bus voltage, the output current, the switching frequency, the output modulation ratio, the output frequency, and the current sampling temperature, determine the power loss corresponding to the bus voltage, the output current, the switching frequency, the output modulation ratio, and the current sampling temperature, respectively. The power loss of the power module in the motor controller is determined based on the power loss corresponding to the bus voltage, the output current, the switching frequency, the output modulation ratio, the output frequency, and the current sampling temperature.
[0009] In one possible implementation, determining the thermal resistance parameter of the power module based on the operating state of the cooling system of the motor controller includes: When the cooling system of the motor controller is in the state of no water pump running dry, the thermal resistance parameter of the power module is determined as the first thermal resistance parameter. When the cooling system is in a state where the cooling water pump is not running, the thermal resistance parameter of the power module is determined to be the second thermal resistance parameter. When the cooling system is in normal operating condition, the thermal resistance parameter of the power module is determined to be the third thermal resistance parameter. Wherein, the first thermal resistance parameter is greater than the second thermal resistance parameter, and the second thermal resistance parameter is greater than the third thermal resistance parameter.
[0010] In one possible implementation, before determining the thermal resistance parameter of the power module based on the operating state of the cooling system of the motor controller, the method further includes: Based on the ratio of power loss to measured temperature rise, a proportionality coefficient is determined. The measured temperature rise is used to characterize the difference between the current sampling temperature and the historical sampling temperature of the temperature sensor in the power module. The historical sampling temperature is the temperature detected by the temperature sensor in the previous sampling cycle corresponding to the current sampling temperature. The operating status of the cooling system of the motor controller is determined based on the comparison between the proportional coefficient and the preset proportional coefficient range.
[0011] In one possible implementation, determining the operating state of the motor controller's cooling system based on a comparison between the proportional coefficient and a preset proportional coefficient range includes: If the proportional coefficient is within the first proportional coefficient range, then the operating state of the cooling system of the motor controller is determined to be the state of the cooling water pump running dry. If the proportional coefficient is within the second proportional coefficient range, then the operating state of the cooling system is determined to be that the cooling water pump is not running. If the proportional coefficient is within the third proportional coefficient range, then the operating state of the cooling system is determined to be normal operation. Wherein, the lower limit of the first proportional coefficient interval is greater than the upper limit of the second proportional coefficient interval, and the lower limit of the second proportional coefficient interval is greater than the upper limit of the third proportional coefficient interval.
[0012] In one possible implementation, determining the junction temperature of the chip in the power module based on the power loss, the thermal resistance parameter, and the current sampling temperature of the temperature sensor inside the power module includes: The actual temperature rise of the chip in the power module is determined based on the power loss and the thermal resistance parameters. The junction temperature of the chip in the power module is determined based on the actual temperature rise and the current sampling temperature of the temperature sensor inside the power module.
[0013] In one possible implementation, determining the junction temperature of the chip in the power module based on the actual temperature rise and the current sampling temperature of the temperature sensor inside the power module includes: The actual temperature rise is corrected based on the historical sampling temperature of the power module, the historical coolant temperature of the cooling system, and the temperature compensation coefficient to determine the corrected actual temperature rise. The historical sampling temperature is the actual temperature of the power module in the previous sampling period corresponding to the current sampling temperature. The junction temperature of the chip in the power module is determined based on the corrected actual temperature rise and the current sampling temperature of the temperature sensor inside the power module.
[0014] Secondly, embodiments of this application provide a junction temperature determination device for a vehicle power module, comprising: The power loss determination module is used to determine the power loss of the power module in the motor controller based on the operating status information of the motor controller. The thermal resistance parameter determination module is used to determine the thermal resistance parameter of the power module based on the operating status of the cooling system of the motor controller. The junction temperature determination module is used to determine the junction temperature of the chip in the power module based on the power loss, the thermal resistance parameter, and the current sampling temperature of the temperature sensor inside the power module.
[0015] Thirdly, embodiments of this application provide a vehicle, including: A controller configured to perform the method described in any one of the first aspects.
[0016] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in any one of the first aspects.
[0017] In this embodiment, the power loss of the power module in the motor controller can first be determined based on the operating status information of the motor controller; then, the thermal resistance parameter of the power module can be determined based on the operating status of the cooling system of the motor controller; finally, the junction temperature of the chip in the power module can be determined based on the power loss, thermal resistance parameter, and the current sampling temperature of the internal temperature sensor of the power module. It can be understood that by determining the thermal resistance parameter in real time, matching the operating status of the cooling system, the impact of the cooling water pump's operation on the estimated junction temperature of the chip within the power module can be reduced, thereby improving the accuracy of the junction temperature estimation to a certain extent. Attached Figure Description
[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0019] Figure 1 This is a schematic diagram illustrating an application scenario provided in an embodiment of this application.
[0020] Figure 2 This is a flowchart illustrating a method for determining the junction temperature of a vehicle power module, as provided in an embodiment of this application.
[0021] Figure 3 This is a flowchart illustrating another method for determining the junction temperature of a vehicle power module provided in an embodiment of this application.
[0022] Figure 4 This is a schematic diagram of a junction temperature determination device for a vehicle power module provided in an embodiment of this application.
[0023] Figure 5This is a structural schematic diagram of a vehicle provided in an embodiment of this application. Detailed Implementation
[0024] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.
[0025] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.
[0026] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.
[0027] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.
[0028] See Figure 1 This is a schematic diagram illustrating an application scenario provided by an embodiment of this application. For example... Figure 1 As shown, the vehicle 100 includes a motor controller 110, a cooling system 120, and a motor 130. The motor controller 110 includes an Insulated Gate Bipolar Transistor (IGBT) power module 111. The IGBT power module 111 converts the direct current output from the battery into alternating current to control the operation of the motor 130.
[0029] It is understandable that the IGBT power module 111 controls the switching elements inside it to turn on or off, thereby achieving precise control of the output torque and speed of the motor 130, and thus achieving precise control of vehicle operation.
[0030] Furthermore, during the DC to AC conversion process, the switching elements in the IGBT power module 111 may undergo high-frequency switching, resulting in power loss and generating significant heat. This could lead to overheating of the IGBT power module 111, potentially causing damage to internal components or circuit failure. Therefore, the cooling system 120 can control the operating temperature of the IGBT power module 111 to ensure stable operation within a safe range.
[0031] Specifically, the junction temperature of the chip inside the IGBT power module 111 can be monitored during its operation. When the junction temperature of the chip inside the IGBT power module 111 reaches a certain temperature, the cooling system 120 is activated to cool down the IGBT power module 111.
[0032] It should be pointed out that, Figure 1 The vehicle 100 shown is merely an exemplary description and should not be construed as a limitation on the scope of protection of this application.
[0033] In practical applications, temperature sensors can usually be installed inside the power module. However, temperature sensors are typically not installed inside the switching elements. Therefore, it may not be possible to directly detect the junction temperature of the switching elements, and consequently, it may not be possible to directly obtain the junction temperature of the chips related to the switching elements within the power module.
[0034] Currently, temperature and thermal resistance models, measured by temperature sensors inside the power module, are typically used to determine the junction temperature changes of the switching elements within the power module, thereby estimating the junction temperature of the chips within the power module. However, this method is usually limited to the normal operation of the motor controller's cooling system. When the cooling system experiences abnormal conditions such as coolant leakage or the cooling water pump malfunction, the thermal resistance characteristics inside the power module will change. Therefore, if the thermal resistance under normal conditions is still used to estimate the junction temperature of the chips within the power module, the estimated junction temperature may be inaccurate.
[0035] To address the aforementioned issues, this application provides a method for determining the junction temperature of a vehicle power module. This method first determines the power loss of the power module within the motor controller based on the motor controller's operating status information. Then, it determines the thermal resistance parameter of the power module based on the operating status of the motor controller's cooling system. Finally, it determines the junction temperature of the chip within the power module based on the power loss, thermal resistance parameter, and the current sampling temperature of the internal temperature sensor of the power module. It can be understood that by determining the thermal resistance parameter in real time, matching the operating status of the cooling system, the impact of the cooling water pump's operation on the estimated junction temperature of the chip within the power module can be reduced, thereby improving the accuracy of the junction temperature estimation to a certain extent.
[0036] Specifically, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments.
[0037] See Figure 2 This is a flowchart illustrating a method for determining the junction temperature of a vehicle power module according to an embodiment of this application. This method can be applied to... Figure 1 Among the vehicles shown, such as Figure 2 As shown, it specifically includes steps S201 to S203.
[0038] Step S201: Determine the power loss of the power module in the motor controller based on the operating status information of the motor controller.
[0039] It is understandable that during the operation of a motor controller, the internal IGBT power module (hereinafter referred to as "power module") typically experiences certain conduction losses and switching losses due to the overlap of voltage drop during conduction and voltage and current during switching. These losses are usually dissipated as heat, causing the chip temperature within the power module to rise. These losses are the root cause of the increased chip temperature within the power module; therefore, when determining the chip temperature (i.e., junction temperature) within the power module, the impact of power losses on the chip temperature must usually be considered.
[0040] In practical applications, the power loss of the power module in a motor controller is closely related to its operating status. Therefore, the power loss of the power module can be determined by the operating status information of the motor controller.
[0041] In one possible implementation, the operating status information of the motor controller includes bus voltage, output current, switching frequency, output modulation ratio, output frequency, and the current sampling temperature of the temperature sensor inside the power module.
[0042] As can be understood, the bus voltage of the motor controller refers to the DC input voltage of the motor controller, which is usually provided by the battery or stable power supply in the vehicle; the output current of the motor controller refers to the effective value of the three-phase current output by the motor controller on the AC side; the switching frequency of the motor controller refers to the on and off frequency of the switching elements in the motor controller; the output modulation ratio of the motor controller refers to the ratio of the amplitude of the output fundamental voltage to the amplitude of the maximum output fundamental voltage, which is usually used to measure the voltage utilization of the power module; the output frequency of the motor controller refers to the fundamental frequency of the AC voltage output by the motor controller; the current sampling temperature refers to the junction temperature of the power module in the three-phase circuit with the highest temperature in the three-phase AC circuit, as measured by the temperature sensor inside the power module, or it can be considered as the temperature of the temperature sensor itself inside the power module.
[0043] In this embodiment, the bus voltage, output current, switching frequency, output modulation ratio, and output frequency can be obtained by directly measuring or indirectly calculating using detection components installed in the vehicle (e.g., voltage sensors, current sensors, oscilloscopes, etc.). Of course, those skilled in the art can also obtain the bus voltage, output current, switching frequency, output modulation ratio, and output frequency through other methods, and this embodiment does not impose specific limitations on these methods.
[0044] Furthermore, after obtaining the bus voltage, output current, switching frequency, output modulation ratio, output frequency, and current sampling temperature of the motor controller, the power loss corresponding to the bus voltage, output current, switching frequency, output modulation ratio, output frequency, and current sampling temperature can be determined respectively. Then, the power loss of the power module in the motor controller can be determined based on the power loss corresponding to the bus voltage, output current, switching frequency, modulation ratio, output frequency, and current sampling temperature.
[0045] Specifically, it can be done according to the formula: Determine the power loss of the power module in the motor controller. .
[0046] in, The bus voltage of the motor controller used to represent the current sampling period. The corresponding power loss can be determined by the relationship function between bus voltage and power loss. Used to represent the output current of the motor controller in the current sampling period. The corresponding power loss can be determined by the relationship table between output current and power loss. The switching frequency of the motor controller used to indicate the current sampling period. The corresponding power loss can be determined by the relationship function between switching frequency and power loss; Used to indicate the output modulation ratio of the motor controller in the current sampling period. The corresponding power loss can be determined by the relationship function between the output modulation ratio and the power loss; Used to indicate the output frequency of the motor controller in the current sampling period. The corresponding power loss can be determined by the relationship function between the output frequency and the power loss. The current sampled temperature of the motor controller is used to indicate the current sampling period. The corresponding power loss can be determined by the relationship function between the current sampling temperature and the power loss.
[0047] In this embodiment of the application, by using various parameter information closely related to the working state of the motor controller, the power loss of the power module can be determined more accurately, and then the junction temperature of the chip in the power module can be determined more accurately based on the power loss of the power module.
[0048] Step S202: Determine the thermal resistance parameters of the power module based on the operating status of the motor controller's cooling system.
[0049] It is understandable that the operating state of the cooling system of a motor controller is closely related to the thermal resistance characteristics of the power nodes within the motor controller. In some application scenarios, changes in the operating state of the cooling system may lead to changes in the thermal resistance characteristics of the internal circuit loops of the motor controller.
[0050] For example, when the cooling system leaks coolant, the amount of coolant in the cooling circuit may decrease, resulting in insufficient heat transfer medium. The heat generated by the power module may not be effectively transferred to the radiator of the cooling system, which may increase thermal resistance. When the cooling water pump is not running, the coolant may stagnate, forced convection will disappear, and the heat dissipation efficiency of natural convection and heat conduction alone will be extremely low, which may not be able to meet the high heat load requirements of the power module, resulting in a significant increase in thermal resistance.
[0051] As mentioned above, an malfunction in the motor controller's cooling system can lead to inaccurate estimates of the junction temperature of the chips within the power module. Therefore, by analyzing the operating status of the cooling system, the thermal resistance parameters of the power module can be determined to match the operating status of the cooling system, thus enabling a more accurate determination of the junction temperature of the chips within the power module.
[0052] In one possible implementation, when the cooling system of the motor controller is in a state where the cooling water pump is running dry, the thermal resistance parameter of the power module is determined as the first thermal resistance parameter; when the cooling system is in a state where the cooling water pump is not running, the thermal resistance parameter of the power module is determined as the second thermal resistance parameter; and when the cooling system is in a normal operating state, the thermal resistance parameter of the power module is determined as the third thermal resistance parameter.
[0053] The first thermal resistance parameter is greater than the second thermal resistance parameter, and the second thermal resistance parameter is greater than the third thermal resistance parameter. It can be understood that when the cooling system is operating with the cooling water pump running dry, there is no coolant in the cooling system, and only the cooling water pump is running idle. In this situation, the heat generated by the power module may not be able to be dissipated through coolant circulation, causing the thermal resistance parameter to increase significantly. Therefore, when the cooling water pump is running dry, the thermal resistance parameter of the power module is determined to be the first thermal resistance parameter.
[0054] When the cooling system is in a state where the cooling water pump is not running, the coolant cannot flow, and the heat exchange efficiency of the cooling system decreases. However, the thermal resistance is usually lower than when the cooling water pump is running dry. Therefore, when the cooling water pump is not running, the thermal resistance parameter of the power module is determined as the second thermal resistance parameter.
[0055] When the cooling system is operating normally, the coolant circulates under the drive of the cooling water pump, effectively carrying away heat. The heat transfer path is unobstructed, and the thermal resistance parameter is at its lowest. Therefore, under normal operating conditions, the thermal resistance parameter of the power module is determined to be the third thermal resistance parameter.
[0056] In this embodiment, the cooling water pump is the core power component of the cooling system, which drives the coolant to circulate in the cooling circuit to dissipate heat from the power module. Therefore, by classifying the operating states of the cooling water pump in detail, thermal resistance parameters matching the operating states of the cooling water pump can be determined, thereby determining a more accurate junction temperature of the chips in the power module.
[0057] In practical applications, temperature sensors can be installed on the cooler of the cooling system to sample the coolant temperature in real time, thereby indirectly determining the operating status of the cooling system. However, this method usually increases the cost, and because the temperature sensor is attached to the outside of the cooler, it is easily affected by the external temperature and may not accurately reflect the operating status of the cooling system. This could lead to inaccurate estimations of the junction temperature of the chips within the power module.
[0058] See Figure 3 This is a flowchart illustrating another method for determining the junction temperature of a vehicle power module provided in an embodiment of this application. Figure 3 As shown, the embodiments of this application are in Figure 2Based on the embodiment shown, steps S301 to S302 are included before step S202.
[0059] Step S301: Determine the proportionality coefficient based on the ratio of power loss to measured temperature rise.
[0060] It is understandable that measuring the temperature rise is used to characterize the difference between the current sampling temperature and the historical sampling temperature of the temperature sensor within the power module, i.e. Among them, measuring temperature rise This represents the temperature change value of the temperature sensor from the previous sampling period to the current sampling period; the current sampling temperature. Temperature measured by the temperature sensor in the current sampling period; historical sampling temperatures. This refers to the temperature detected by the temperature sensor in the previous sampling period corresponding to the current sampling temperature. Of course, the historical sampling temperature is typically the junction temperature of the power module in the three-phase circuit of the three-phase AC system, measured by the temperature sensor in the previous sampling period, which was the highest temperature recorded.
[0061] In this embodiment of the application, it can be based on the formula: Determine the proportionality coefficient Among them, the proportionality coefficient This is used to reflect the temperature rise of the internal temperature sensor of the power module caused by unit power loss.
[0062] Step S302: Determine the operating status of the motor controller's cooling system based on the comparison results between the proportional coefficient and the preset proportional coefficient range.
[0063] Understandably, once the proportional coefficient is determined, it can be compared with a preset proportional coefficient range to determine the proportional coefficient range to which the proportional coefficient belongs, thereby determining the operating status of the cooling system.
[0064] In one possible implementation, if the proportional coefficient is within the first proportional coefficient range, the operating state of the cooling system of the motor controller is determined to be the state of no water pump running dry; if the proportional coefficient is within the second proportional coefficient range, the operating state of the cooling system is determined to be the state of no water pump running; if the proportional coefficient is within the third proportional coefficient range, the operating state of the cooling system is determined to be the state of normal operation.
[0065] The lower limit of the first proportional coefficient interval is greater than the upper limit of the second proportional coefficient interval, and the lower limit of the second proportional coefficient interval is greater than the upper limit of the third proportional coefficient interval. It can be understood that a larger proportional coefficient indicates a greater temperature rise in the internal temperature sensor of the power module caused by a unit power loss.
[0066] In this embodiment, when the proportional coefficient is within the first proportional coefficient range, it can be assumed that there is no coolant in the cooling system and only the cooling water pump is running idle. In this case, the heat generated by the power module may not be dissipated through coolant circulation. Therefore, the temperature rise of the internal temperature sensor of the power module caused by unit power loss is relatively large. Based on this, when the proportional coefficient is within the first proportional coefficient range, it can be determined that the operating state of the cooling system is that the cooling water pump is running idle without water.
[0067] When the proportional coefficient is in the second proportional coefficient range, it can be assumed that the coolant cannot flow, and the heat exchange efficiency of the cooling system decreases. However, compared to the state where the cooling water pump runs dry, the temperature rise of the internal temperature sensor of the power module caused by unit power loss is relatively low. Therefore, when the proportional coefficient is in the second proportional coefficient range, the operating state of the cooling system can be determined as the state where the cooling water pump is not running.
[0068] When the proportional coefficient is in the third proportional coefficient range, it can be assumed that the coolant circulates under the drive of the cooling water pump, effectively removing heat and ensuring a smooth heat transfer path. At this point, the temperature rise of the internal temperature sensor of the power module caused by unit power loss is relatively small. Therefore, when the proportional coefficient is in the third proportional coefficient range, the cooling system can be determined to be operating normally.
[0069] In this embodiment, the operating status of the motor controller's cooling system is determined by the proportional relationship between the temperature change of the internal temperature sensor of the power module and the power module's losses. This involves fewer external environmental variables and requires less computation, thus improving the system's data processing efficiency. Furthermore, the operating status of the cooling system can be obtained without installing a corresponding temperature sensor, reducing hardware costs to some extent.
[0070] In addition, after obtaining the operating status of the cooling system, if the cooling system is in an abnormal state, the system can output an error message to alert the user that the cooling system is malfunctioning. This allows the user to perform timely maintenance on the cooling system.
[0071] Step S203: Determine the junction temperature of the chip in the power module based on the power loss, thermal resistance parameters, and the current sampling temperature of the temperature sensor inside the power module.
[0072] In this embodiment, the actual temperature rise of the chip in the power module can be determined based on the power loss and thermal resistance parameters; then, the junction temperature of the chip in the power module can be determined based on the actual temperature rise and the current sampling temperature of the temperature sensor inside the power module.
[0073] Specifically, it can be done according to the formula: Determine the actual temperature rise .in, Used to characterize the temperature change of the chip caused by power module losses. These are the thermal resistance parameters determined based on the operating status of the cooling system.
[0074] As can be understood, the actual temperature rise is the difference between the chip's junction temperature and the current sampling temperature of the temperature sensor inside the power module; that is, the amount of temperature change of the chip relative to the temperature of the temperature sensor inside the power module. Therefore, once the actual temperature rise is determined, the actual temperature rise and the current sampling temperature can be added together to calculate the junction temperature of the chip in the power module.
[0075] However, the temperature variation of the chips inside the power module may also be affected by factors such as historical sampling temperatures and fluctuations in the coolant in the cooling system. To reduce the influence of other factors and improve the accuracy of the estimated junction temperature of the chips inside the power module, one possible implementation is to correct the actual temperature rise based on the historical sampling temperature of the power module, the historical coolant temperature of the cooling system, and the temperature compensation coefficient, thus determining the corrected actual temperature rise. Then, based on the corrected actual temperature rise and the current sampling temperature of the temperature sensor inside the power module, the junction temperature of the chips in the power module can be determined.
[0076] Specifically, it can be done according to the formula: Determine the corrected actual temperature rise .in, The calculation results are the historical sampling temperature measured by the temperature sensor inside the power module in the previous sampling cycle and the coolant temperature of the cooling system; C is the compensation coefficient, which can usually be adjusted according to the operating status of the cooling system.
[0077] Furthermore, once the corrected actual temperature rise is determined, the corrected actual temperature rise and the current sampling temperature can be added together to calculate the junction temperature of the chip in the power module.
[0078] In this embodiment, the power loss of the power module in the motor controller can be determined based on the operating status information of the motor controller; then, the thermal resistance parameter of the power module can be determined based on the operating status of the cooling system of the motor controller; finally, the junction temperature of the chip in the power module can be determined based on the power loss, thermal resistance parameter, and the current sampling temperature of the internal temperature sensor of the power module. It can be understood that by determining the thermal resistance parameter in real time, matching the operating status of the cooling system of the power module, the influence of the cooling water pump operation on the estimated junction temperature of the chip within the power module can be reduced, thereby improving the accuracy of the junction temperature estimation to a certain extent.
[0079] Corresponding to the above embodiments, this application also provides a device for determining the junction temperature of a vehicle power module.
[0080] See Figure 4 This is a schematic diagram of a junction temperature determination device for a vehicle power module provided in an embodiment of this application. Figure 4 As shown, the junction temperature determination device 400 for the vehicle power module includes: a power loss determination module 401, a thermal resistance parameter determination module 402, and a junction temperature determination module 403.
[0081] The power loss determination module 401 is used to determine the power loss of the power module in the motor controller based on the operating status information of the motor controller; the thermal resistance parameter determination module 402 is used to determine the thermal resistance parameter of the power module based on the operating status of the cooling system of the motor controller; and the junction temperature determination module 403 is used to determine the junction temperature of the chip in the power module based on the power loss, thermal resistance parameter and the current sampling temperature of the temperature sensor inside the power module.
[0082] For details regarding the specific content involved in the embodiments of this application, please refer to the description of the above method embodiments. For the sake of brevity, these details will not be repeated here.
[0083] Corresponding to the above embodiments, this application also provides a vehicle.
[0084] See Figure 5 This is a structural schematic diagram of a vehicle provided in an embodiment of this application. Figure 5 As shown, vehicle 500 includes: controller 501, which is configured to perform some or all of the steps in the above method embodiments.
[0085] For details regarding the specific content involved in the embodiments of this application, please refer to the description of the above method embodiments. For the sake of brevity, these details will not be repeated here.
[0086] Corresponding to the above embodiments, this application also provides a computer-readable storage medium, wherein the computer-readable storage medium may store a program, wherein when the program runs, it can control the device where the computer-readable storage medium is located to execute some or all of the steps in the above method embodiments. In specific implementation, the computer-readable storage medium may be a magnetic disk, an optical disk, read-only memory (ROM), or random access memory (RAM), etc.
[0087] Corresponding to the above embodiments, this application also provides a computer program product containing executable instructions that, when executed on a computer, cause the computer to perform some or all of the steps in the above method embodiments.
[0088] In this application embodiment, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, the simultaneous existence of A and B, or the existence of B alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, and c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.
[0089] Those skilled in the art will recognize that the units and algorithm steps described in the embodiments disclosed herein can be implemented using electronic hardware, computer software, or a combination of electronic hardware and software. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.
[0090] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.
[0091] In the several embodiments provided in this application, any function, if implemented as a software functional unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.
[0092] The above description is merely a specific embodiment of this application. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application. The protection scope of this application should be determined by the protection scope of the claims.
Claims
1. A method for determining the junction temperature of a vehicle power module, characterized in that, include: Based on the operating status information of the motor controller, determine the power loss of the power module in the motor controller; The thermal resistance parameters of the power module are determined based on the operating status of the cooling system of the motor controller. The junction temperature of the chip in the power module is determined based on the power loss, the thermal resistance parameter, and the current sampling temperature of the temperature sensor inside the power module.
2. The method according to claim 1, characterized in that, The operating status information includes bus voltage, output current, switching frequency, output modulation ratio, output frequency, and the current sampling temperature of the temperature sensor inside the power module. Determining the power loss of the power module in the motor controller based on the operating status information includes: Based on the bus voltage, the output current, the switching frequency, the output modulation ratio, the output frequency, and the current sampling temperature, determine the power loss corresponding to the bus voltage, the output current, the switching frequency, the output modulation ratio, and the current sampling temperature, respectively. The power loss of the power module in the motor controller is determined based on the power loss corresponding to the bus voltage, the output current, the switching frequency, the output modulation ratio, the output frequency, and the current sampling temperature.
3. The method according to claim 1, characterized in that, Determining the thermal resistance parameter of the power module based on the operating status of the cooling system of the motor controller includes: When the cooling system of the motor controller is in the state of no water pump running dry, the thermal resistance parameter of the power module is determined as the first thermal resistance parameter. When the cooling system is in a state where the cooling water pump is not running, the thermal resistance parameter of the power module is determined to be the second thermal resistance parameter. When the cooling system is in normal operating condition, the thermal resistance parameter of the power module is determined to be the third thermal resistance parameter. Wherein, the first thermal resistance parameter is greater than the second thermal resistance parameter, and the second thermal resistance parameter is greater than the third thermal resistance parameter.
4. The method according to claim 1, characterized in that, Before determining the thermal resistance parameter of the power module based on the operating status of the cooling system of the motor controller, the method further includes: Based on the ratio of power loss to measured temperature rise, a proportionality coefficient is determined. The measured temperature rise is used to characterize the difference between the current sampling temperature and the historical sampling temperature of the temperature sensor in the power module. The historical sampling temperature is the temperature detected by the temperature sensor in the previous sampling cycle corresponding to the current sampling temperature. The operating status of the cooling system of the motor controller is determined based on the comparison between the proportional coefficient and the preset proportional coefficient range.
5. The method according to claim 4, characterized in that, Determining the operating status of the motor controller's cooling system based on a comparison between the proportional coefficient and a preset proportional coefficient range includes: If the proportional coefficient is within the first proportional coefficient range, then the operating state of the cooling system of the motor controller is determined to be the state of the cooling water pump running dry. If the proportional coefficient is within the second proportional coefficient range, then the operating state of the cooling system is determined to be that the cooling water pump is not running. If the proportional coefficient is within the third proportional coefficient range, then the operating state of the cooling system is determined to be normal operation. Wherein, the lower limit of the first proportional coefficient interval is greater than the upper limit of the second proportional coefficient interval, and the lower limit of the second proportional coefficient interval is greater than the upper limit of the third proportional coefficient interval.
6. The method according to claim 1, characterized in that, Determining the junction temperature of the chip in the power module based on the power loss, the thermal resistance parameter, and the current sampling temperature of the temperature sensor inside the power module includes: The actual temperature rise of the chip in the power module is determined based on the power loss and the thermal resistance parameters. The junction temperature of the chip in the power module is determined based on the actual temperature rise and the current sampling temperature of the temperature sensor inside the power module.
7. The method according to claim 6, characterized in that, Determining the junction temperature of the chip in the power module based on the actual temperature rise and the current sampling temperature of the temperature sensor inside the power module includes: The actual temperature rise is corrected based on the historical sampling temperature of the power module, the historical coolant temperature of the cooling system, and the temperature compensation coefficient to determine the corrected actual temperature rise. The historical sampling temperature is the actual temperature of the power module in the previous sampling period corresponding to the current sampling temperature. The junction temperature of the chip in the power module is determined based on the corrected actual temperature rise and the current sampling temperature of the temperature sensor inside the power module.
8. A device for determining the junction temperature of a vehicle power module, characterized in that, include: The power loss determination module is used to determine the power loss of the power module in the motor controller based on the operating status information of the motor controller. The thermal resistance parameter determination module is used to determine the thermal resistance parameter of the power module based on the operating status of the cooling system of the motor controller. The junction temperature determination module is used to determine the junction temperature of the chip in the power module based on the power loss, the thermal resistance parameter, and the current sampling temperature of the temperature sensor inside the power module.
9. A vehicle, characterized in that, include: A controller configured to perform the method according to any one of claims 1 to 6.
10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method described in any one of claims 1 to 6.