Junction temperature control method and device

Abstract

The present application discloses a junction temperature control method and device, the method comprising: obtaining the transient junction temperature of the target chip of the target controller at N moments, obtaining N transient junction temperatures; N is an integer greater than 0; at least based on the N transient junction temperatures, using a fuzzy control algorithm to determine the target operating parameters of the target controller; the target operating parameters are parameters that affect the junction temperature of the target chip; controlling the target controller to operate with the target operating parameters to adjust the junction temperature of the target chip. The present application scheme is flexible and comprehensive, and can accurately and effectively adjust the junction temperature of the target chip.

Description

Technical Field

[0001] The present application relates to the field of data processing, and relates to but is not limited to a junction temperature control method and device. Background Art

[0002] Existing vehicle equipment is usually equipped with a motor controller, and the junction temperature of the power chip of the motor controller has a key impact on the reliability and service life of the motor controller. If the junction temperature of the power chip fluctuates too much, it will aggravate the aging of the packaging material of the motor controller and easily cause the adjacent material layers to peel off, thereby reducing the reliability and service life of the motor controller.

[0003] In the related art, in order to solve the above problems, the switching frequency of the motor controller is usually increased, decreased or maintained according to the size relationship between the junction temperature fluctuation value and the junction temperature fluctuation amplitude range, thereby adjusting the junction temperature of the power chip. This solution only adjusts the switching frequency according to the size relationship between the junction temperature fluctuation value and the junction temperature fluctuation amplitude. Its implementation scheme is relatively simple and limited, and it is impossible to accurately and effectively adjust the junction temperature of the target chip. Summary of the invention

[0004] The present application provides a junction temperature control method, device, equipment, storage medium and computer program product, which have flexible and comprehensive implementation schemes and can accurately and effectively adjust the junction temperature of a target chip.

[0005] The technical solution of this application is implemented as follows:

[0006] In a first aspect, the present application provides a junction temperature control method, the method comprising:

[0007] Obtaining transient junction temperatures of a target chip of a target controller at N moments to obtain N transient junction temperatures, wherein N is an integer greater than 0;

[0008] At least based on the N transient junction temperatures, a fuzzy control algorithm is used to determine a target operating parameter of a target controller; the target operating parameter is a parameter that affects the junction temperature of the target chip;

[0009] The target controller is controlled to operate with the target operating parameters to adjust the junction temperature of the target chip.

[0010] In a second aspect, the present application provides a junction temperature control device, characterized in that the device comprises:

[0011] An acquisition unit, used to acquire the transient junction temperatures of the target chip of the target controller at N moments, to obtain N transient junction temperatures; wherein N is an integer greater than 0;

[0012] A determination unit, configured to determine a target operating parameter of a target controller by using a fuzzy control algorithm based at least on the N transient junction temperatures; the target operating parameter is a parameter that affects the junction temperature of the target chip;

[0013] A control unit is used to control the target controller to operate with the target operating parameters to adjust the junction temperature of the target chip.

[0014] In a third aspect, the present application further provides an electronic device, comprising: a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and the processor implements the above-mentioned junction temperature control method when executing the program.

[0015] In a fourth aspect, the present application further provides a storage medium, on which a computer program is stored. When the computer program on the storage medium is executed, the above-mentioned junction temperature control method provided by the present application is implemented.

[0016] In a fifth aspect, the present application also provides a computer program product, including a computer program or instructions, which, when executed by a processor, implements the above-mentioned junction temperature control method.

[0017] The present application provides a junction temperature control method, device, equipment, storage medium and computer program product, the method comprising: obtaining the transient junction temperature of a target chip of a target controller at N moments to obtain N transient junction temperatures; N is an integer greater than 0; at least based on the N transient junction temperatures, using a fuzzy control algorithm to determine the target operating parameters of the target controller; the target operating parameters are parameters that affect the junction temperature of the target chip; and controlling the target controller to operate with the target operating parameters to adjust the junction temperature of the target chip.

[0018] In the scheme of the present application, by obtaining the transient junction temperature of the target chip of the target controller at N moments, it is possible to determine the target operating parameters of the target controller by using a fuzzy control algorithm based on at least N transient junction temperatures, and then the target controller can be controlled to work with the target operating parameters to achieve the adjustment of the junction temperature of the target chip. It can be seen that in the scheme of the present application, considering that multiple operating parameters of the target controller will affect the junction temperature of the target chip, when adjusting the junction temperature of the target chip, by introducing a fuzzy control algorithm, it is possible to determine the target operating parameters of the target controller by using a fuzzy control algorithm based on at least N transient junction temperatures of the target chip. Since the fuzzy control algorithm has the advantages of multivariable control, rapid response and adjustment, and strong anti-interference ability, the scheme of the present application is flexible and comprehensive, and can accurately and effectively adjust the junction temperature of the target chip. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1A schematic diagram of a first optional flow chart of a junction temperature control method provided in an embodiment of the present application;

[0020] Figure 2 A second optional flow chart of the junction temperature control method provided in the embodiment of the present application;

[0021] Figure 3 A third optional flow chart of the junction temperature control method provided in the embodiment of the present application;

[0022] Figure 4 A fourth optional flow chart of the junction temperature control method provided in the embodiment of the present application;

[0023] Figure 5 A fifth optional flow chart of the junction temperature control method provided in the embodiment of the present application;

[0024] Figure 6 A sixth optional flow chart of the junction temperature control method provided in the embodiment of the present application;

[0025] Figure 7 A seventh optional flow chart of the junction temperature control method provided in the embodiment of the present application;

[0026] Figure 8 An eighth optional flow chart of the junction temperature control method provided in the embodiment of the present application;

[0027] Fig. 9 A ninth optional flow chart of the junction temperature control method provided in the embodiment of the present application;

[0028] Fig.10 An optional schematic diagram of a junction temperature estimation process of a junction temperature control method provided in an embodiment of the present application;

[0029] Fig.11 An optional schematic diagram of the working process of the fuzzy controller I and the fuzzy controller II of the junction temperature control method provided in an embodiment of the present application;

[0030] Fig.12 An optional schematic diagram of the fundamental frequency, transient junction temperature fluctuation amplitude, and membership function of the switching frequency of the fuzzy controller I of the junction temperature control method provided in an embodiment of the present application;

[0031] Fig.13 An optional schematic diagram of the average junction temperature, average junction temperature fluctuation amplitude, switching frequency, and membership function of the PWM mode of the fuzzy controller II of the junction temperature control method provided in an embodiment of the present application;

[0032] Fig.14 A schematic diagram of an optional structure of a junction temperature control device provided in an embodiment of the present application;

[0033] Fig.15 An optional structural diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the specific technical solution of the application will be further described in detail below in conjunction with the drawings in the embodiments of the present application. The following embodiments are used to illustrate the present application, but are not used to limit the scope of the present application.

[0035] In the following description, reference is made to “some embodiments”, which describe a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0036] In the following description, the terms "first\second\third" are used only as examples to distinguish different objects, and do not represent a specific order for the objects, nor do they have a limitation on the order of precedence. It is understandable that "first\second\third" can be interchanged with a specific order or order of precedence where permitted, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0038] The embodiments of the present application provide a junction temperature control method, device, equipment, storage medium and computer program product. In practical applications, the junction temperature control method can be implemented by a junction temperature control device, and each functional entity in the junction temperature control device can be collaboratively implemented by hardware resources of the electronic device, such as computing resources such as a processor, and communication resources (such as for supporting various communication methods such as optical cables and cellular).

[0039] Below, various embodiments of the junction temperature control method, device, equipment, storage medium and computer program product provided in the embodiments of the present application are described.

[0040] In the first aspect, the embodiment of the present application provides a junction temperature control method. The function implemented by the method can be implemented by a processor in an electronic device (such as a controller) calling a program code, and of course the program code can be stored in a computer storage medium. It can be seen that the electronic device at least includes a processor and a storage medium.

[0041] Below, taking an electronic device as an execution subject as an example, the junction temperature control method provided in the embodiment of the present application is described.

[0042] Figure 1 FIG. 1 is a flow chart of a junction temperature control method according to an embodiment of the present application. Figure 1 As shown, the process may include but is not limited to the following S101 to S103.

[0043] S101 : The electronic device obtains transient junction temperatures of a target chip of a target controller at N moments to obtain N transient junction temperatures.

[0044] The target controller may be any controller. The embodiment of the present application does not limit the specific type of the target controller, and it can be set according to actual conditions. For example, the target controller may be a motor controller in a vehicle device.

[0045] The target chip may be any chip in the target controller. The specific type of the target chip is not limited in the present embodiment of the application, and it can be set according to the actual situation. For example, when the target controller is a motor controller in a vehicle device, the target chip may be a power chip in the motor controller.

[0046] N is an integer greater than 0. The embodiment of the present application does not limit the specific value of the number of moments N, which can be set according to actual conditions.

[0047] Junction temperature refers to the actual operating temperature of the semiconductor chip in an electronic device, which is usually higher than the package case temperature and the device surface temperature.

[0048] Transient junction temperature refers to the junction temperature of a semiconductor chip in an electronic device at a certain moment, and is usually used to describe the change in junction temperature of a semiconductor chip in a short period of time. The embodiment of the present application does not limit the specific measurement or estimation method of transient junction temperature, and can be set according to actual conditions.

[0049] In practice, since the target chip is located inside the target controller, the junction temperature of the target chip cannot be directly measured by a temperature sensor. The junction temperature of the target chip is usually obtained indirectly by measuring electrical parameters related to the junction temperature of the target chip, or by using the loss model of the power chip and the thermal resistance network model of the motor controller to estimate the junction temperature of the target chip.

[0050] The embodiment of the present application does not limit the specific method of estimating the junction temperature of the power chip using the loss model of the power chip and the thermal resistance network model of the motor controller, which can be determined based on actual conditions.

[0051] Exemplarily, in advance, the transient junction temperature of the target chip of the target controller at N moments can be measured by a measurement circuit, or the transient junction temperature of the target chip of the target controller at N moments can be estimated by a loss model and a thermal resistance network model to obtain N transient junction temperatures and store them locally or in the cloud. Correspondingly, S101 can be implemented as follows: the electronic device obtains N transient junction temperatures from the local or cloud.

[0052] S102 . The electronic device uses a fuzzy control algorithm to determine target operating parameters of a target controller based at least on the N transient junction temperatures.

[0053] Fuzzy control algorithm is a control algorithm based on fuzzy logic, which uses fuzzy sets and fuzzy rules to simulate human thinking and decision-making processes. First, the input and output in the control problem are fuzzified, and the fuzzy relationship between the input and output is established by defining fuzzy sets and fuzzy rules; then the precise value of the input is converted into a fuzzy value through fuzzification processing, and the fuzzy value of the output is calculated based on the fuzzy value of the input and fuzzy rules; finally, the fuzzy value of the output is converted into a precise value through defuzzification processing, thereby realizing a fuzzy control of the output. The advantages of fuzzy control algorithm include: multivariable control, fast response and adjustment, strong anti-interference ability, no need for precise mathematical models, ability to handle uncertainty and nonlinearity, easy implementation, and strong scalability.

[0054] The target operating parameter is a parameter that affects the junction temperature of the target chip.

[0055] The target operating parameters are the operating parameters of the target controller. The specific types and quantities of the target operating parameters are not limited in the present embodiment of the application, and can be set according to actual conditions. For example, the target operating parameters may include switching frequency, drive resistance, coolant flow rate, pulse width modulation (PWM) mode, etc.

[0056] The embodiment of the present application does not limit the specific method of using a fuzzy control algorithm to determine the target operating parameters of the target controller based on at least N transient junction temperatures of the electronic device, and can be set according to actual conditions. For example, the electronic device can calculate the precise value of the input quantity of the fuzzy control algorithm based on at least N transient junction temperatures; convert the precise value of the input quantity into a fuzzy value through fuzzification processing; calculate the fuzzy value of the operating parameter based on the fuzzy value of the input quantity and the pre-established fuzzy rules; finally, convert the fuzzy value of the operating parameter into a precise value through defuzzification processing to obtain the target operating parameter.

[0057] In a possible implementation, S102 may be implemented as follows: the electronic device determines a first input quantity of the fuzzy control algorithm based on N transient junction temperatures, and processes the first input quantity using the first fuzzy control algorithm to obtain a target operating parameter of the target controller.

[0058] In another possible implementation, S102 may be implemented as follows: the electronic device determines a second input quantity of the fuzzy control algorithm based on N transient junction temperatures and load parameters of the target controller, processes the second input quantity using a second fuzzy control algorithm, and obtains target operating parameters of the target controller.

[0059] In another possible implementation, S102 can be implemented as follows: the electronic device determines a first input quantity of the fuzzy control algorithm based on N transient junction temperatures, and processes the first input quantity using a first fuzzy control algorithm to obtain a first operating parameter of the target controller; the electronic device determines a second input quantity of the fuzzy control algorithm based on the N transient junction temperatures and the load parameter of the target controller, and processes the second input quantity using a second fuzzy control algorithm to obtain a second operating parameter of the target controller; and selects the optimal values ​​of the first operating parameter and the second operating parameter as the target operating parameters of the target controller.

[0060] S103: The electronic device controls the target controller to operate with the target operating parameters to adjust the junction temperature of the target chip.

[0061] Exemplarily, S103 can be implemented as follows: the electronic device sends the target operating parameters to the target controller; the target controller adjusts the current operating parameters to the target operating parameters to operate, which will affect the junction temperature of the target chip of the target controller during the operation, thereby adjusting the junction temperature of the target chip.

[0062] For example, when the target operating parameters include a target switching frequency, the electronic device can send the target switching frequency to the target controller; the target controller adjusts the current switching frequency to the target switching frequency for operation. When the target switching frequency is greater than the current switching frequency, a higher switching frequency means a shorter on / off time and more energy loss. When other operating parameters remain unchanged, a shorter on / off time and more energy loss will cause the target chip of the target controller to generate more heat, thereby causing the junction temperature of the target chip to increase; when the target switching frequency is less than the current switching frequency, the above process is the opposite, which will eventually cause the junction temperature of the target chip to decrease.

[0063] The present application provides a junction temperature control method, the method comprising: determining N target impact factors of a target fault occurring on a target device; the N is an integer greater than 0; determining M target measurement points corresponding to the N target impact factors from at least one measurement point on the target device; the M is greater than or equal to the N; constructing a target control map of the target fault based at least on the M target measurement points; the target control map comprises: the M target measurement points, and measurement data of each of the M target measurement points; and displaying the target control map to assist in locating the target fault based on the target control map.

[0064] In the scheme of the present application, by obtaining the transient junction temperature of the target chip of the target controller at N moments, it is possible to determine the target operating parameters of the target controller by using a fuzzy control algorithm based on at least N transient junction temperatures, and then the target controller can be controlled to work with the target operating parameters to achieve the adjustment of the junction temperature of the target chip. It can be seen that in the scheme of the present application, considering that multiple operating parameters of the target controller will affect the junction temperature of the target chip, when adjusting the junction temperature of the target chip, by introducing a fuzzy control algorithm, it is possible to determine the target operating parameters of the target controller by using a fuzzy control algorithm based on at least N transient junction temperatures of the target chip. Since the fuzzy control algorithm has the advantages of multivariable control, rapid response and adjustment, and strong anti-interference ability, the scheme of the present application is flexible and comprehensive, and can accurately and effectively adjust the junction temperature of the target chip.

[0065] The following describes a process in which the electronic device uses a fuzzy control algorithm to determine the target operating parameters of the target controller based on at least the N transient junction temperatures in S102.

[0066] The process may include but is not limited to the following method 1, method 2 and method 3.

[0067] Method 1: Based on N transient junction temperatures and the load parameters of the target controller, a first fuzzy control algorithm is used to determine the target operating parameters of the target controller.

[0068] Method 2: Based on N transient junction temperatures, a second fuzzy control algorithm is used to determine the target operating parameters of the target controller.

[0069] Method three: Based on N transient junction temperatures and the load parameters of the target controller, the first fuzzy control algorithm and the second fuzzy control algorithm are used to determine the target operating parameters of the target controller.

[0070] Next, a process in which the electronic device in the first approach uses the first fuzzy control algorithm to determine the target operating parameters of the target controller based on N transient junction temperatures and the load parameters of the target controller is described.

[0071] refer to Figure 2 As shown in the content, the process may include but is not limited to the following S201 to S202.

[0072] S201. The electronic device determines a transient junction temperature fluctuation amplitude of the target chip based on the N transient junction temperatures.

[0073] The transient junction temperature fluctuation amplitude is used to describe the variation amplitude of the transient junction temperature within a specific time period. The specific calculation method of the transient junction temperature fluctuation amplitude is not limited in the embodiment of the present application, and can be set according to actual conditions.

[0074] Exemplarily, S201 may be implemented as follows: the electronic device calculates the minimum and maximum values ​​of N transient junction temperatures; and takes the absolute value of the difference between the maximum and minimum values ​​to obtain the transient junction temperature fluctuation amplitude of the target chip.

[0075] S202: The electronic device uses a first fuzzy control algorithm to determine a target operating parameter of the target controller based on a load parameter of the target controller at a current moment and the transient junction temperature fluctuation amplitude.

[0076] Load parameters refer to electrical parameters or physical parameters related to the load. The specific content and quantity of the load parameters are not limited in the present embodiment, and can be set according to actual conditions. Load parameters may include voltage, current, power, impedance, fundamental frequency, speed, etc.

[0077] The first fuzzy control algorithm refers to a fuzzy control algorithm whose input is load parameters and transient junction temperature fluctuation amplitude and output is target working parameters. The specific content and processing process of the first fuzzy control algorithm are not limited in the present application embodiment and can be set according to actual conditions.

[0078] Exemplarily, S202 can be implemented as follows: the electronic device obtains the load parameters of the target controller at the current moment; the load parameters and the transient junction temperature fluctuation amplitude are input into the first fuzzy control algorithm; the first fuzzy control algorithm processes the load parameters and the transient junction temperature fluctuation amplitude to obtain and output the target operating parameters.

[0079] Next, the process of the electronic device in the second method determining the target operating parameters of the target controller based on N transient junction temperatures by using the second fuzzy control algorithm is described.

[0080] refer to Figure 2 As shown in the content, the process may include but is not limited to the following S203 to S204.

[0081] S203: The electronic device determines an average junction temperature and an average junction temperature fluctuation amplitude of the target chip based on the N transient junction temperatures.

[0082] The average junction temperature refers to the average junction temperature of the semiconductor chip in the electronic device. The specific measurement or estimation method of the average junction temperature is not limited in the embodiment of the present application, and can be set according to the actual situation.

[0083] In practice, the average junction temperature can be obtained by calculating the definite integral of the transient junction temperature in a specific time period, or by calculating the average value of multiple transient junction temperatures.

[0084] The average junction temperature fluctuation amplitude is used to describe the variation amplitude of the average junction temperature within a specific time period. The specific calculation method of the average junction temperature fluctuation amplitude is not limited in the present application embodiment and can be set according to actual conditions.

[0085] Exemplarily, S203 can be implemented as follows: the electronic device calculates the average value of N transient junction temperatures; determines the average value as the average junction temperature of the target chip; counts the average junction temperature of the target chip in at least one time period to obtain at least one average junction temperature; calculates the minimum and maximum values ​​of at least one average junction temperature; takes the absolute value of the difference between the maximum and minimum values ​​to obtain the average junction temperature fluctuation amplitude of the target chip.

[0086] S204: The electronic device uses a second fuzzy control algorithm to determine target operating parameters of the target controller based on the average junction temperature and the average junction temperature fluctuation amplitude.

[0087] The second fuzzy control algorithm refers to a fuzzy control algorithm whose input is the average junction temperature and the average junction temperature fluctuation amplitude and whose output is the target working parameter. The specific content and processing process of the second fuzzy control algorithm are not limited in the present application embodiment and can be set according to actual conditions.

[0088] Exemplarily, S204 may be implemented as follows: the electronic device inputs the average junction temperature and the average junction temperature fluctuation amplitude into the second fuzzy control algorithm; the second fuzzy control algorithm processes the average junction temperature and the average junction temperature fluctuation amplitude to obtain and output target operating parameters.

[0089] Next, a process of determining the target operating parameters of the target controller by using the first fuzzy control algorithm and the second fuzzy control algorithm based on N transient junction temperatures and the load parameters of the target controller in the electronic device in the third mode is described.

[0090] refer to Figure 2 As shown in the content, the process may include but is not limited to the following S205 to S207.

[0091] S205. The electronic device determines a first operating parameter of the target controller by using the first fuzzy control algorithm based on the load parameter and the N transient junction temperatures.

[0092] For the specific implementation process of S205, reference may be made to the detailed description of S201 to S202 above, which will not be repeated here.

[0093] S206: The electronic device uses the second fuzzy control algorithm to determine a second operating parameter of the target controller based on the N transient junction temperatures.

[0094] For the specific implementation process of S206, reference may be made to the detailed description of S203 to S204 above, which will not be repeated here.

[0095] S207: The electronic device determines the minimum value of the first operating parameter and the second operating parameter as the target operating parameter.

[0096] Exemplarily, S207 can be implemented as follows: the electronic device compares the first operating parameter and the second operating parameter; if the first operating parameter is greater than the second operating parameter, the second operating parameter is determined as the target operating parameter; if the first operating parameter is less than the second operating parameter, the first operating parameter is determined as the target operating parameter; if the first operating parameter is equal to the second operating parameter, any one of the first operating parameter and the second operating parameter is determined as the target operating parameter.

[0097] It should be noted that there is no strict execution order between S201 to S202, S203 to S204, and S205 to S207, and they may be executed simultaneously or one after another.

[0098] The following describes a process in which the electronic device uses the first fuzzy control algorithm to determine the target operating parameters of the target controller based on the load parameters of the target controller at the current moment and the transient junction temperature fluctuation amplitude in S202.

[0099] refer to Figure 3 As shown in the content, the process may include but is not limited to the following S301 to S303.

[0100] S301. The electronic device performs fuzzy processing on the load parameter and the transient junction temperature fluctuation amplitude respectively to obtain a target load parameter level corresponding to the load parameter and a target transient junction temperature fluctuation amplitude level corresponding to the transient junction temperature fluctuation amplitude.

[0101] Fuzzification processing refers to the process of converting an exact value into a fuzzy value. The specific content and process of fuzzification processing are not limited in the present embodiment of the application and can be set according to actual conditions.

[0102] The load parameter level is used to characterize the size range of the load parameter. The specific content and number of the load parameter levels are not limited in the present application embodiment, and can be set according to actual conditions. For example, the load parameter level can include three levels: low, medium, and high, and the corresponding size range increases successively; it can also include the first level, the second level, the third level, the fourth level, and the fifth level, and the corresponding size range increases successively.

[0103] The target load parameter level refers to the load parameter level corresponding to the load parameter.

[0104] For example, when the load parameter levels include three levels: low, medium, and high, and the low level ranges from 0 to 4, the medium level ranges from 4 to 7, and the high level ranges from 7 to 10, assuming that the value of the load parameter is 5, then the target load parameter level is the medium level.

[0105] The transient junction temperature fluctuation amplitude level is used to characterize the magnitude range of the transient junction temperature fluctuation amplitude. The specific content and quantity of the transient junction temperature fluctuation amplitude level are not limited in the embodiment of the present application and can be set according to actual conditions.

[0106] The target transient junction temperature fluctuation amplitude level refers to the transient junction temperature fluctuation amplitude level corresponding to the transient junction temperature fluctuation amplitude.

[0107] Exemplarily, the electronic device pre-stores a first correspondence between the load parameter level and the load parameter size range, and a second correspondence between the transient junction temperature fluctuation amplitude level and the transient junction temperature fluctuation amplitude size range. Correspondingly, S301 can be implemented as follows: the electronic device determines the size range of the load parameter according to the value of the load parameter; searches for the size range of the load parameter in the first correspondence; determines the load parameter level corresponding to the size range of the load parameter as the target load parameter level; and determines the size range of the transient junction temperature fluctuation amplitude according to the transient junction temperature fluctuation amplitude; searches for the size range of the transient junction temperature fluctuation amplitude in the second correspondence; determines the transient junction temperature fluctuation amplitude level corresponding to the size range of the transient junction temperature fluctuation amplitude as the target transient junction temperature fluctuation amplitude level.

[0108] S302: The electronic device determines a target operating parameter level based on the target load parameter level, the target transient junction temperature fluctuation amplitude, and at least one first fuzzy rule.

[0109] Fuzzy rules are used to describe the relationship between input and output quantities, usually conditional statements.

[0110] Exemplarily, assuming that the input quantities include A and B, the output quantity is C, and the conditions corresponding to A include A1 and A2, the conditions corresponding to B include B1 and B2, and the conditions corresponding to C include C1, C2, C3, and C4, then the fuzzy rules may include: if A satisfies A1 and B satisfies B1, then C satisfies C1; if A satisfies A1 and B satisfies B2, then C satisfies C2; if A satisfies A2 and B satisfies B1, then C satisfies C3; if A satisfies A2 and B satisfies B2, then C satisfies C4.

[0111] The first fuzzy rule is a fuzzy rule corresponding to the first fuzzy algorithm. The embodiment of the present application does not limit the specific content and quantity of the first fuzzy rule, which can be set according to actual conditions.

[0112] In practice, at least one first fuzzy rule may be determined through subjective experience or simulation analysis or a specific algorithm.

[0113] The working parameter level is used to characterize the size range of the working parameter. The specific content and number of the working parameter level are not limited in the present embodiment of the application and can be set according to actual conditions.

[0114] The target operating parameter level refers to the operating parameter level corresponding to the load parameter and the transient junction temperature fluctuation amplitude.

[0115] Exemplarily, S302 can be implemented as follows: the electronic device searches for the target load parameter level and the target transient junction temperature fluctuation amplitude level in at least one first fuzzy rule; determines the first fuzzy rule including the target load parameter level and the target transient junction temperature fluctuation amplitude level as the target first fuzzy rule; and determines the working parameter level included in the target first fuzzy rule as the target working parameter level.

[0116] S303: The electronic device performs a defuzzification process on the target operating parameter level to obtain the target operating parameter.

[0117] Defuzzification refers to the process of converting a fuzzy value into an accurate value. The specific content and process of the defuzzification process are not limited in the present embodiment, and can be set according to actual conditions.

[0118] Exemplarily, S303 may be implemented as follows: the electronic device determines a size range of the operating parameter corresponding to the target operating parameter level; and rounds or averages the size range to obtain the target operating parameter.

[0119] Next, the process of the electronic device in S301 performing fuzzy processing on the load parameter and the transient junction temperature fluctuation amplitude to obtain a target load parameter level corresponding to the load parameter and a target transient junction temperature fluctuation amplitude level corresponding to the transient junction temperature fluctuation amplitude is described.

[0120] refer to Figure 4 As shown in the content, the process may include but is not limited to the following S401 to S403.

[0121] S401 : The electronic device obtains a first fuzzy set of load parameters and a second fuzzy set of transient junction temperature fluctuation amplitudes.

[0122] The first fuzzy set includes at least one load parameter level; the second fuzzy set includes at least one transient junction temperature fluctuation amplitude level.

[0123] A fuzzy set is a set used to describe the size range of fuzzy variables.

[0124] The first fuzzy set refers to a fuzzy set of load parameters. The embodiment of the present application does not limit the specific content and form of the first fuzzy set, and can be set according to actual conditions. For example, the first fuzzy set can be {low, medium, high}.

[0125] The second fuzzy set refers to a fuzzy set of transient junction temperature fluctuation amplitudes. The embodiment of the present application does not limit the specific content and form of expression of the second fuzzy set, and can be set according to actual conditions. Exemplarily, the second fuzzy set can be {low, low-medium, medium, high-medium, high}.

[0126] In practice, the first fuzzy set of load parameters can be obtained by dividing the theoretical range of load parameters through subjective experience or simulation analysis, and the same is true for the second fuzzy set of transient junction temperature fluctuation amplitude.

[0127] Exemplarily, the first fuzzy set of load parameters and the second fuzzy set of transient junction temperature fluctuation amplitude are pre-constructed and stored locally or in the cloud. Correspondingly, S401 can be implemented as follows: the electronic device obtains the first fuzzy set of load parameters and the second fuzzy set of transient junction temperature fluctuation amplitude from the local or cloud.

[0128] S402: The electronic device determines a first membership function of a load parameter based on the first fuzzy set, and determines a second membership function of a transient junction temperature fluctuation amplitude based on the second fuzzy set.

[0129] Membership is used to characterize the degree to which an element in a fuzzy set belongs to the fuzzy set. The value of membership is usually between 0 and 1. The closer the membership is to 1, the higher the degree to which the element belongs to the fuzzy set. The closer the membership is to 0, the lower the degree to which the element belongs to the fuzzy set.

[0130] For example, in the case of a fuzzy set of high temperature, assuming the temperature is 60°C, then its membership can be 0.6, indicating that 60°C is a high temperature to a greater extent; assuming the temperature is 20°C, then its membership can be 0.2, indicating that 20°C is a high temperature to a lesser extent.

[0131] Membership function is used to describe the relationship between elements and membership. Common types include trapezoidal function, triangular function, Gaussian function, S-shaped function, etc.

[0132] The first membership function refers to the membership function of the load parameter. The embodiment of the present application does not limit the specific content and expression form of the first membership function, and can be set according to actual conditions. Exemplarily, the first membership function can be a combination of a trapezoidal function and a triangular function.

[0133] The second membership function refers to the membership function of the transient junction temperature fluctuation amplitude. The specific content and expression form of the second membership function are not limited in the present embodiment of the application and can be set according to actual conditions.

[0134] In practice, the type of the first membership function can be selected by the changing characteristics of the load parameters (such as response time, sensitivity) or subjective experience, and the type of the second membership function can be selected by the changing characteristics of the transient junction temperature fluctuation amplitude (such as response time, sensitivity) or subjective experience.

[0135] Exemplarily, S402 can be implemented as follows: the electronic device takes at least one load parameter level included in the first fuzzy set and the size range of the load parameter corresponding to the at least one load parameter level as independent variables; takes the membership of the load parameter belonging to at least one load parameter level as a dependent variable; based on the correspondence between the three, a first membership function is obtained; and, takes at least one transient junction temperature fluctuation amplitude level included in the second fuzzy set and the size range of the transient junction temperature fluctuation amplitude corresponding to the at least one transient junction temperature fluctuation amplitude level as independent variables; takes the membership of the transient junction temperature fluctuation amplitude belonging to at least one transient junction temperature fluctuation amplitude level as a dependent variable; based on the correspondence between the three, a second membership function is obtained.

[0136] S403: The electronic device determines a target load parameter level corresponding to the load parameter based on the first membership function, and determines a target transient junction temperature fluctuation amplitude level corresponding to the transient junction temperature fluctuation amplitude based on the second membership function.

[0137] Exemplarily, S403 can be implemented as follows: the electronic device searches for the load parameter in a first membership function to determine the size range of the load parameter; determines the load parameter level corresponding to the size range of the load parameter as the target load parameter level; and searches for the transient junction temperature fluctuation amplitude in a second membership function to determine the size range of the transient junction temperature fluctuation amplitude; determines the transient junction temperature fluctuation amplitude level corresponding to the size range of the transient junction temperature fluctuation amplitude as the target load parameter level.

[0138] The junction temperature control method provided in the embodiment of the present application may also include a process of constructing a first fuzzy set and a second fuzzy set.

[0139] refer to Figure 5 As shown in the content, before obtaining the first fuzzy set of load parameters and the second fuzzy set of transient junction temperature fluctuation amplitude, the process may include but is not limited to the following S501 to S502.

[0140] S501. The electronic device enlarges or reduces the first basic domain of the load parameter based on the first quantization factor of the load parameter; grades the enlarged or reduced first basic domain to obtain at least one load parameter level; and determines the at least one load parameter level as the first fuzzy set.

[0141] The basic domain is used to describe the actual value range of the variable.

[0142] The first basic domain refers to the basic domain of the load parameter. The embodiment of the present application does not limit the specific content of the first basic domain, and can be set according to actual conditions. For example, when the load parameter is the fundamental frequency, the first basic domain can be [0, 1000].

[0143] The quantization factor is used to enlarge or reduce the basic domain to match the basic domain of the related parameters. For example, when the basic domain of the load parameter is [0, 1000] and the basic domain of the transient junction temperature fluctuation amplitude is [0, 60], in order to make the basic domain of the load parameter match the basic domain of the transient junction temperature fluctuation amplitude, the quantization factor of the load parameter can be set to a logarithmic function (lg) with a base of 10, and the quantization factor of the transient junction temperature fluctuation amplitude can be set to 10. Then, the basic domain of the load parameter after enlargement or reduction is [0, 3], and the basic domain of the transient junction temperature fluctuation amplitude after enlargement or reduction is [0, 6]. It can be seen that the two match each other.

[0144] The first quantization factor refers to the quantization factor of the load parameter. The embodiment of the present application does not limit the specific value of the first quantization factor, and it can be set according to actual conditions.

[0145] Exemplarily, S501 can be implemented as follows: the electronic device multiplies the first quantization factor of the load parameter by the first basic domain of the load parameter to obtain the enlarged or reduced first basic domain; based on a specific algorithm, the enlarged or reduced first basic domain is graded to obtain at least one load parameter level; and at least one load parameter level is determined as a first fuzzy set.

[0146] S502. The electronic device enlarges or reduces the second basic domain of the transient junction temperature fluctuation amplitude based on the second quantization factor of the transient junction temperature fluctuation amplitude; grades the enlarged or reduced second basic domain to obtain at least one transient junction temperature fluctuation amplitude grade; and determines the at least one transient junction temperature fluctuation amplitude grade as the second fuzzy set.

[0147] The second basic domain refers to the basic domain of transient junction temperature fluctuation amplitude. The specific content of the second basic domain is not limited in the present application embodiment, and can be set according to actual conditions. For example, the second basic domain can be [0, 60].

[0148] The second quantization factor refers to the quantization factor of the transient junction temperature fluctuation amplitude. The embodiment of the present application does not limit the specific value of the second quantization factor, and it can be set according to actual conditions.

[0149] In practice, the first quantization factor, the first basic domain, the second quantization factor, and the second basic domain may be determined based on subjective experience or simulation analysis.

[0150] Exemplarily, S502 can be implemented as follows: the electronic device multiplies the second quantization factor of the transient junction temperature fluctuation amplitude by the second basic domain of the transient junction temperature fluctuation amplitude to obtain an enlarged or reduced second basic domain; based on a specific algorithm, the enlarged or reduced second basic domain is graded to obtain at least one transient junction temperature fluctuation amplitude level; and at least one transient junction temperature fluctuation amplitude level is determined as a second fuzzy set.

[0151] Next, the process of the electronic device performing defuzzification processing on the target operating parameter level to obtain the target operating parameter in S303 is described.

[0152] refer to Figure 6 As shown in the content, the process may include but is not limited to the following S601 to S604.

[0153] S601. The electronic device determines a third membership function of the operating parameters based on a third fuzzy set of the operating parameters.

[0154] Wherein, the third fuzzy set includes at least one working parameter level.

[0155] The third fuzzy set refers to the fuzzy set of working parameters. The specific content and form of the third fuzzy set are not limited in the present embodiment, and can be set according to actual conditions. For example, the third fuzzy set can be {low, low medium,

[0156] middle, high school, high}.

[0157] For the construction process of the third fuzzy set, reference may be made to the detailed descriptions of the first fuzzy set and the second fuzzy set in S501 and S502, which will not be repeated here.

[0158] The third membership function refers to the membership function of the working parameter. The specific content and expression form of the third membership function are not limited in the embodiment of the present application, and can be set according to actual conditions. Exemplarily, the third membership function can be the expression form of a combination of a trapezoidal function and a triangular function.

[0159] In practice, the type of the third membership function may be selected based on the variation characteristics of the operating parameters (such as response time, sensitivity) or subjective experience.

[0160] Exemplarily, S601 can be implemented as follows: the electronic device takes at least one working parameter level included in the third fuzzy set and the size range of the working parameter corresponding to at least one working parameter level as independent variables; takes the membership of the working parameter belonging to at least one working parameter level as the dependent variable; and obtains the third membership function based on the correspondence between the three.

[0161] S602: The electronic device determines a target operating parameter range corresponding to the target operating parameter level based on the third membership function.

[0162] The working parameter range refers to the actual value range of the working parameters.

[0163] The target operating parameter range refers to the operating parameter range corresponding to the target operating parameter level after being enlarged or reduced. For example, assuming that the target operating parameter range is [1, 2], it means that the actual operating parameter range corresponding to the target operating parameter level is [10, 20].

[0164] Exemplarily, S602 may be implemented as follows: the electronic device searches for the target operating parameter level in the third membership function; and determines the operating parameter range corresponding to the target operating parameter level as the target operating parameter range.

[0165] It should be noted that the operating parameter ranges in the third membership function are all enlarged or reduced operating parameter ranges.

[0166] S603: The electronic device performs a first process on the target operating parameter range to obtain a first operating parameter.

[0167] The embodiment of the present application does not limit the specific content of the first processing, and can be set according to actual conditions. For example, the first processing can be rounding or averaging.

[0168] The first operating parameter is a target operating parameter range after the first processing.

[0169] Exemplarily, S603 may be implemented as follows: the electronic device performs rounding processing on the target operating parameter range to obtain the first operating parameter.

[0170] For example, assuming that the target operating parameter range is [2.4, 3.5], then the first operating parameter is 3.

[0171] S604: Based on the scale factor of the working parameter, enlarge or reduce the first working parameter to obtain the target working parameter.

[0172] The scale factor is used to restore the enlarged or reduced variable or basic domain to its actual variable value or actual basic domain. For example, if the enlarged or reduced variable is 1.5 and the scale factor is 100, then the actual variable value is 150; if the enlarged or reduced basic domain is [1, 5] and the scale factor is 10000, then the actual basic domain is [10000, 50000].

[0173] In practice, the scaling factors of the operating parameters can be determined based on subjective experience or simulation analysis.

[0174] Exemplarily, S604 may be implemented as follows: the electronic device multiplies the proportional factor of the operating parameter by the first operating parameter to obtain the target operating parameter.

[0175] The following describes a process in which the electronic device uses a second fuzzy control algorithm to determine the target operating parameters of the target controller based on the average junction temperature and the average junction temperature fluctuation amplitude in S204.

[0176] refer to Figure 7 As shown in the content, the process may include but is not limited to the following S701 to S704.

[0177] S701. The electronic device performs the fuzzy processing on the average junction temperature and the average junction temperature fluctuation amplitude respectively to obtain a target average junction temperature level corresponding to the average junction temperature and a target average junction temperature fluctuation amplitude level corresponding to the average junction temperature fluctuation amplitude.

[0178] The average junction temperature level is used to characterize the size range of the average junction temperature. The specific content and number of the average junction temperature level are not limited in the present embodiment of the application and can be set according to actual conditions.

[0179] The target average junction temperature level refers to the average junction temperature level corresponding to the average junction temperature.

[0180] The average junction temperature fluctuation amplitude level is used to characterize the size range of the average junction temperature fluctuation amplitude. The specific content and number of the average junction temperature fluctuation amplitude level are not limited in the present embodiment of the application and can be set according to actual conditions.

[0181] The target average junction temperature fluctuation amplitude level refers to the average junction temperature fluctuation amplitude level corresponding to the average junction temperature fluctuation amplitude.

[0182] Exemplarily, the fourth fuzzy set of the average junction temperature and the fifth fuzzy set of the average junction temperature fluctuation amplitude are pre-constructed and stored locally or in the cloud. Correspondingly, S701 can be implemented as follows: the electronic device obtains the fourth fuzzy set of the average junction temperature and the fifth fuzzy set of the average junction temperature fluctuation amplitude from the local or cloud; wherein the fourth fuzzy set includes at least one average junction temperature level; the fifth fuzzy set includes at least one average junction temperature fluctuation amplitude level; the fourth membership function of the average junction temperature is determined based on the fourth fuzzy set, and the fifth membership function of the average junction temperature fluctuation amplitude is determined based on the fifth fuzzy set; the target average junction temperature level corresponding to the average junction temperature is determined based on the fourth membership function, and the target average junction temperature fluctuation amplitude level corresponding to the average junction temperature fluctuation amplitude is determined based on the fifth membership function.

[0183] For the specific implementation process of S701, reference may be made to the detailed description of S401 to S403 above, which will not be repeated here.

[0184] S702: The electronic device determines a target operating parameter increment level based on the target average junction temperature level, the target average junction temperature fluctuation amplitude level, and at least one second fuzzy rule.

[0185] The second fuzzy rule is a fuzzy rule corresponding to the second fuzzy algorithm. The embodiment of the present application does not limit the specific content and quantity of the second fuzzy rule, which can be set according to actual conditions.

[0186] In practice, the at least one second fuzzy rule can be determined through subjective experience or simulation analysis or a specific algorithm.

[0187] The working parameter increment refers to the increase in the working parameter value.

[0188] The working parameter increment level is used to characterize the size range of the working parameter increment. The specific content and number of the working parameter increment level are not limited in the present embodiment of the application and can be set according to actual conditions.

[0189] The target operating parameter increment level refers to the operating parameter increment level corresponding to the average junction temperature and the average junction temperature fluctuation amplitude.

[0190] Exemplarily, S702 can be implemented as follows: the electronic device searches for the target average junction temperature level and the target average junction temperature fluctuation amplitude level in at least one second fuzzy rule; determines the second fuzzy rule including the target average junction temperature level and the target average junction temperature fluctuation amplitude level as the target second fuzzy rule; and determines the operating parameter increment level included in the target second fuzzy rule as the target operating parameter increment level.

[0191] S703: The electronic device performs the defuzzification process on the target operating parameter increment level to obtain a target operating parameter increment.

[0192] For the specific implementation process of S703, reference may be made to the detailed description of S303 above, which will not be repeated here.

[0193] S704: The electronic device determines the sum of the target operating parameter increment and the reference operating parameter as the target operating parameter.

[0194] Benchmark working parameters refer to the benchmark values ​​or standard values ​​of working parameters.

[0195] Exemplarily, S704 may be implemented as follows: the electronic device adds the target operating parameter increment to the reference operating parameter to obtain the sum of the target operating parameter increment and the reference operating parameter, and determines the sum of the target operating parameter increment and the reference operating parameter as the target operating parameter.

[0196] The junction temperature control method provided in the embodiment of the present application may also include a process of adjusting the junction temperature of the target chip based on a PWM method.

[0197] refer to Figure 8 As shown in the content, the process may include but is not limited to the following S801 to S803.

[0198] S801. The electronic device determines an average junction temperature and an average junction temperature fluctuation amplitude of the target chip based on the N transient junction temperatures.

[0199] For the specific implementation process of S801, reference may be made to the detailed description of S203 above, which will not be repeated here.

[0200] S802: The electronic device determines a target pulse width modulation (PWM) mode of the target controller by using a third fuzzy control algorithm based on the average junction temperature and the average junction temperature fluctuation amplitude.

[0201] The third fuzzy control algorithm refers to a fuzzy control algorithm whose input is the average junction temperature and the average junction temperature fluctuation amplitude and whose output is the target PWM mode. The specific content and processing process of the third fuzzy control algorithm are not limited in the present application embodiment and can be set according to actual conditions.

[0202] The target PWM mode is the PWM mode of the target controller. The embodiment of the present application does not limit the specific content of the target PWM mode, and it can be set according to actual conditions.

[0203] Exemplarily, S802 may be implemented as follows: the electronic device inputs the average junction temperature and the average junction temperature fluctuation amplitude into a third fuzzy control algorithm; the third fuzzy control algorithm processes the load parameters and the transient junction temperature fluctuation amplitude to obtain and output a target PWM mode.

[0204] S803: The electronic device controls the target controller to operate in the target PWM mode to adjust the junction temperature of the target chip.

[0205] For the specific implementation process of S803, reference may be made to the detailed description of S103 above, which will not be repeated here.

[0206] Next, the process of the electronic device in S802 determining the target pulse width modulation (PWM) mode of the target controller based on the average junction temperature and the average junction temperature fluctuation amplitude by using the third fuzzy control algorithm is described.

[0207] refer to Fig. 9 As shown in the content, the process may include but is not limited to the following S901 to S903.

[0208] S901. The electronic device performs the fuzzy processing on the average junction temperature and the average junction temperature fluctuation amplitude respectively to obtain a target average junction temperature level corresponding to the average junction temperature and a target average junction temperature fluctuation amplitude level corresponding to the average junction temperature fluctuation amplitude.

[0209] For the specific implementation process of S901, please refer to the detailed description of S701 above, which will not be repeated here.

[0210] S902: The electronic device determines a target PWM level based on the target average junction temperature level, the target average junction temperature fluctuation amplitude level, and at least one third fuzzy rule.

[0211] The third fuzzy rule is a fuzzy rule corresponding to the third fuzzy algorithm. The embodiment of the present application does not limit the specific content and quantity of the third fuzzy rule, which can be set according to actual conditions.

[0212] In practice, the at least one third fuzzy rule can be determined through subjective experience or simulation analysis or a specific algorithm.

[0213] PWM level is used to characterize the type of PWM mode. The specific content and number of PWM levels are not limited in the present application embodiment and can be set according to actual conditions.

[0214] The target PWM level refers to the PWM level corresponding to the average junction temperature and the average junction temperature fluctuation amplitude.

[0215] Exemplarily, S902 can be implemented as follows: the electronic device searches for the target average junction temperature level and the target average junction temperature fluctuation amplitude level in at least one third fuzzy rule; determines the third fuzzy rule including the target average junction temperature level and the target average junction temperature fluctuation amplitude level as the target third fuzzy rule; and determines the PWM level included in the target third fuzzy rule as the target PWM level.

[0216] S903: The electronic device performs the defuzzification process on the target PWM level to obtain the target PWM mode.

[0217] For the specific implementation process of S903, reference may be made to the detailed description of S303 above, which will not be repeated here.

[0218] Below, the junction temperature control method provided by the present application is described through a complete embodiment.

[0219] When the car is running under the conditions of starting, accelerating, climbing and emergency braking, the motor controller (equivalent to the above-mentioned target controller) works under low speed and high torque conditions. At this time, the power chip in the motor controller (equivalent to the above-mentioned target chip) will generate a lot of heat. Due to the heat accumulation effect, the junction temperature of the power chip rises sharply. When the junction temperature is too high, the power chip will burn. In addition, the motor controller is composed of multiple physical material layers with different thermal expansion coefficients. Excessive load changes will cause the junction temperature of the power chip to fluctuate. If the amplitude of the fluctuation is too large, it will aggravate the aging of the packaging materials in the motor controller and easily cause the adjacent material layers to peel off, thereby reducing the reliability and service life of the motor controller. The average junction temperature and the amplitude of the junction temperature fluctuation of the power chip are two important parameters that affect the reliability and service life of the power chip. According to the analysis of a large amount of test data, it is found that with the increase of the amplitude of the junction temperature fluctuation of the power chip, the number of thermal cycles at failure gradually decreases. At the same time, the average junction temperature has a similar effect on the number of thermal cycles at failure. In addition, the influence of the junction temperature fluctuation amplitude on the number of thermal cycles at failure is greater than that of the average junction temperature.

[0220] Active thermal control technology is a technology that analyzes the distribution of thermal stress of heating devices and their generation mechanism, and redistributes the temperature field of heating devices by improving hardware design and using some control strategies, so as to achieve uniform temperature distribution of heating devices and reduce the fluctuation amplitude of chip junction temperature. Active thermal control technology is widely used in fields such as photovoltaic power generation and wind power generation. Generally, it controls the junction temperature of power chips by adjusting the switching frequency, PWM modulation mode, DC bus voltage and cooling conditions, thereby improving the reliability and service life of heating devices. However, compared with the field of energy generation, the driving conditions of electric vehicles are complex and changeable, which increases the fluctuation frequency of the junction temperature of power chips. The existing active thermal control methods of power chips in the field of energy generation cannot accurately and effectively control the junction temperature of power chips of automotive motor controllers.

[0221] This embodiment of the present application aims at the problem that the junction temperature fluctuation amplitude of the power chip of the motor controller of the automobile is large under low-speed, high-torque and variable-load conditions. Taking into account the load current, fundamental frequency, switching frequency, PWM modulation mode and other factors of the motor controller, an active thermal control strategy based on dual fuzzy control is proposed to reduce the junction temperature fluctuation amplitude and average temperature of the power chip, which provides an important theoretical basis and technical support for the research on thermal design, reliability and service life of the motor controller. Among them, one fuzzy controller adjusts the switching frequency according to the fundamental frequency of the load and the transient junction temperature fluctuation amplitude of the power chip to control the junction temperature of the power chip; the other fuzzy controller adjusts the switching frequency and PWM modulation mode according to the average junction temperature and average fluctuation amplitude of the power chip to control the junction temperature of the power chip. This scheme can effectively reduce the junction temperature fluctuation amplitude of the power chip and improve the reliability and service life of the motor controller.

[0222] Next, the process of measuring or estimating the junction temperature of the power chip is described.

[0223] In order to use the active thermal control (ATC) strategy to adjust the junction temperature of the power chip, it is necessary to first measure or estimate the junction temperature of the power chip in real time. Since the power chip is sealed inside the motor controller, the junction temperature of the power chip cannot be directly measured by the temperature sensor. Generally, the junction temperature of the power chip is indirectly obtained by measuring the electrical parameters related to the junction temperature of the power chip, or the junction temperature of the power chip is estimated by using a thermal resistance network model. Considering that measuring the electrical parameters related to the junction temperature of the power chip requires an external measurement circuit, which increases the cost of the motor controller and also reduces the reliability of the motor controller, the loss model of the power chip and the thermal resistance network model of the motor controller can be used to estimate the junction temperature of the power chip. The loss model of the power chip and the thermal resistance network model are analyzed and introduced below.

[0224] 1. Loss model of power chip

[0225] This embodiment of the present application estimates the transient junction temperature, transient junction temperature fluctuation amplitude, average junction temperature, and average junction temperature fluctuation amplitude of the power chip according to the transient loss and average loss models of the power chip. Silicon carbide power chips are the main loss components of motor controllers, accounting for more than 90% of the total loss of motor controllers. There are mainly two types of power semiconductor chips in the motor controller: Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) and freewheeling diode. The losses of these two power chips are analyzed separately below.

[0226] (1) Loss of MOSFET chip.

[0227] The loss of MOSFET chip mainly includes switching loss and conduction loss. Switching loss mainly refers to turn-on loss and turn-off loss. The switching energy loss of power chip is mainly related to the turn-on time, turn-off time, junction temperature, voltage and current of the power chip. When the driving resistance, chip junction temperature and DC bus voltage are constant, the switching energy loss of power chip is a function related to the current and junction temperature flowing through MOSFET. Therefore, the transient turn-on and turn-off power loss of MOSFET can be calculated by the following formula (1):

[0228] p sw_on(t) (t) = f sw ·E on [i ds (t),T j (t)] Formula (1);

[0229] p sw_off(t) (t) = f sw ·E off [i ds (t),T j (t)] Formula (2);

[0230] In formula (1) and formula (2), p sw_on(t) and p sw_off(t) are the transient turn-on and turn-off power losses of MOSFET respectively; f sw is the switching frequency; E on and E off are the turn-on and turn-off energy losses of MOSFET respectively; i ds (t) is the transient current flowing through the MOSFET; T j (t) is the transient junction temperature of the MOSFET.

[0231] By integrating the transient turn-on and turn-off power losses of the MOSFET, we can obtain its average turn-on power loss and turn-off power loss in one cycle, which can be expressed as:

[0232]

[0233]

[0234] In formula (3) and formula (4), P sw_on and P sw_off They are the average turn-on and turn-off power losses of the MOSFET in one fundamental cycle respectively; T0 is the fundamental cycle of the phase current.

[0235] Substituting formula (1) and formula (2) into formula (3) and formula (4) respectively and adding them together, the total switching loss of MOSFET can be obtained as:

[0236]

[0237] In formula (5), P ms is the total switching loss of the MOSFET.

[0238] The transient on-state voltage of MOSFET is a temperature-dependent function, so its transient on-state loss can be expressed as:

[0239] p con_M (t) = f sw ·u ds [i ds (t),T j (t)]·i ds (t)·D M (t) Formula (6);

[0240] In formula (6), p con_M (t) is the transient conduction power loss of MOSFET; u ds is the transient on-state voltage of MOSFET; D M (t) is the duty cycle of MOSFET.

[0241] By integrating the transient conduction loss of the MOSFET, its average conduction loss in one cycle can be obtained, which can be expressed as:

[0242]

[0243] In formula (7), P mc is the average conduction power loss of the MOSFET.

[0244] Finally, adding the total switching loss and conduction loss of the MOSFET gives its loss:

[0245] P mos =P ms +P mc Formula (8);

[0246] In formula (8), P mos It is the average power loss of MOSFET in one fundamental cycle.

[0247] (2) Loss of freewheeling diode.

[0248] The freewheeling diode plays a role of freewheeling during the dead time. Here, the silicon carbide power module is taken as an example. The freewheeling diode inside is a Schottky diode based on silicon carbide material. Its reverse recovery characteristics are almost unaffected by factors such as forward current, chip junction temperature, and stray inductance, but mainly depend on the internal structure of the Schottky diode (such as carrier concentration and life, junction capacitance, etc.). Since the silicon carbide Schottky diode is mainly conducted by majority carriers and there are no minority carriers, the reverse recovery time is very short. In addition, due to the performance of the Schottky diode and the material properties of silicon carbide, the peak value of the reverse recovery current of the silicon carbide Schottky diode is smaller than that of the silicon-based diode, which will cause the silicon carbide Schottky diode to have very small reverse recovery loss. Therefore, when calculating the loss of the freewheeling diode, only its conduction loss is considered, and the reverse recovery loss will not be considered.

[0249] Similar to the conduction loss of MOSFET, the transient conduction loss of the freewheeling diode can be expressed as:

[0250] p con_D (t) = f sw ·u F [i F (t),T j (t)]·i F (t)·D D (t) Formula (9);

[0251] In formula (9), p con_D (t) is the transient conduction power loss of the freewheeling diode; u F and i F (t) are the transient conduction voltage and current of the freewheeling diode respectively; D D (t) is the duty cycle of the freewheeling diode.

[0252] Then, the average loss of the freewheeling diode in one fundamental cycle can be obtained as:

[0253]

[0254] In formula (10), P d io is the average power loss of the freewheeling diode.

[0255] 2. Thermal model of power chip.

[0256] A thermal resistance network model that can accurately estimate the key positions of the motor controller is proposed in the related art. In order to improve the estimation speed of the power chip junction temperature, this scheme will further improve the thermal resistance network model. Considering that this scheme mainly controls the junction temperature of the motor controller power chip, the temperature of other key positions can be ignored. The improved motor controller thermal resistance network model is as follows: Fig.10 As shown. Fig.10 In the figure, P is the power chip loss; ΔT is the temperature increment of the power chip, Z th is the thermal impedance of the power chip; is the junction temperature of the MOSFET chip, It is the self-thermal impedance of the MOSFET chip between the chip layer and the substrate. is the temperature of the target area on the substrate corresponding to the MOSFET chip, is the transient case temperature increment caused by the thermal coupling effect of the freewheeling diode, is the composite thermal impedance of the MOSFET chip between the substrate and the cooling plate (including self-thermal impedance and coupled thermal impedance), is the heat sink surface temperature corresponding to the MOSFET chip, is the transient cooling plate temperature increment caused by the thermal coupling effect of the diode, It is the equivalent thermal impedance of the MOSFET chip between the cooling plate and the coolant (including self-thermal impedance and coupled thermal impedance); is the junction temperature of the freewheeling diode, is the self-heating impedance of the freewheeling diode chip between the chip layer and the substrate, is the temperature of the target area on the substrate corresponding to the freewheeling diode, is the transient case temperature increment caused by the thermal coupling effect of the MOSFET chip, It is the composite thermal impedance of the freewheeling diode chip between the substrate and the cooling plate (including self-thermal impedance and coupled thermal impedance). is the heat sink surface temperature corresponding to the freewheeling diode, is the transient cooling plate temperature increment caused by the thermal coupling effect of the MOSFET chip, is the equivalent thermal impedance of the freewheeling diode chip between the cooling plate and the coolant (including self-thermal impedance and coupled thermal impedance); T cl is the coolant temperature.

[0257] It should be pointed out that the thermal impedance of the MOSFET chip from the shell temperature to the heat sink layer is the equivalent thermal impedance of all MOSFET chips in the same module, and the coupled thermal impedance of the diode is the equivalent thermal coupling impedance of all diodes in the same module; the thermal impedance from the heat sink to the coolant layer is the equivalent thermal impedance of the MOSFET chips in the three modules (the motor controller uses three power modules), and the coupled thermal impedance of the diode is the equivalent thermal impedance of all diodes in the three modules. The same is true for the thermal model of the diode. The parameters of the thermal resistance network model of the motor controller can be extracted by 3D finite element model simulation to extract the transient curve of the power chip junction temperature, and the transient thermal impedance curve of the chip can be obtained according to the power chip loss. Then it is obtained by fitting the transient thermal impedance curve. Generally, the transient thermal impedance curve between the chip and the shell can be obtained by fitting the fourth-order model, and the transient thermal impedance curve between other layers can be obtained by fitting the second-order model.

[0258] 3. Estimation of junction temperature of power chip.

[0259] The following will take the MOSFET chip as an example to estimate the junction temperature of the power chip. The thermal coupling effect between the chips will produce a corresponding temperature increment. For MOSFET, the transient shell temperature increment caused by the thermal coupling effect of the diode can be expressed as:

[0260]

[0261] In formula (11), is the transient shell temperature increment caused by the thermal coupling effect of the diode; It refers to the total transient power loss of the diodes on the upper and lower bridge arms in the same module; It is the coupled thermal impedance of the chip MOSFET chip from the freewheeling diode chip between the substrate and the cooling plate.

[0262] Similarly, the transient cold plate temperature increment due to the thermal coupling effect of the diode can be expressed as:

[0263]

[0264] In formula (12), is the transient cooling plate temperature increment caused by the thermal coupling effect of the diode; It refers to the total instantaneous power loss of the diodes in the three modules; It is the coupled thermal impedance of the chip MOSFET chip from the freewheeling diode chip between the cooling plate and the coolant.

[0265] Then the transient junction temperature of the MOSFET chip can be expressed as:

[0266]

[0267] In formula (13), is the transient junction temperature of the MOSFET chip; p M (t) is the transient loss of the MOSFET chip; It is the self-thermal impedance of the MOSFET chip between the chip layer and the substrate; Refers to the total transient power loss of the MOSFET chips on the upper and lower bridge arms in the same module; It is the composite thermal impedance of the MOSFET chip between the substrate and the cooling plate (including self-thermal impedance and coupled thermal impedance); Refers to the total transient power loss of the MOSFET chips on the upper and lower bridge arms in the same three modules; is the equivalent thermal impedance of the MOSFET chip between the cooling plate and the coolant (including self-thermal impedance and coupled thermal impedance); T cl is the coolant temperature.

[0268] Then, the average junction temperature of the MOSFET chip can be expressed as:

[0269]

[0270] In formula (14), is the transient junction temperature of the MOSFET chip.

[0271] Similarly, the transient junction temperature and average junction temperature of the diode can also be obtained, which are:

[0272]

[0273]

[0274] In formula (15) and formula (16), is the transient junction temperature of the freewheeling diode chip; p D (t) is the transient loss of the freewheeling diode; It is the self-heating impedance of the freewheeling diode chip between the chip layer and the substrate; It is the composite thermal impedance of the freewheeling diode chip between the substrate and the cooling plate (including self-thermal impedance and coupled thermal impedance); It is the equivalent thermal impedance of the freewheeling diode chip between the cooling plate and the coolant (including self-thermal impedance and coupled thermal impedance); is the transient shell temperature increment caused by the thermal coupling effect of the MOSFET chip; It is the coupled thermal impedance of the freewheeling diode chip from the MOSFET chip between the substrate and the cooling plate; is the transient cooling plate temperature increment caused by the thermal coupling effect of the MOSFET chip; It is the coupled thermal impedance of the freewheeling diode chip from the MOSFET chip between the cooling plate and the coolant.

[0275] The above formula can be used to estimate the transient junction temperature and average junction temperature of the power chip, and then the transient junction temperature fluctuation amplitude and average junction temperature fluctuation amplitude of the power chip can be obtained. It should be pointed out here that since the loss of the MOSFET chip is higher than the loss of the freewheeling diode, the junction temperature of the MOSFET chip is much higher than the freewheeling diode, and the MOSFET chip is more likely to fail. Therefore, this scheme will propose an active thermal control strategy for the MOSFET chip to control its junction temperature.

[0276] The active thermal control strategy proposed in this embodiment of the present application can be used to control the junction temperature of the MOSFET chip. The active thermal control method proposed in this embodiment of the present application is described in detail below.

[0277] Research shows that, first, the transient junction temperature fluctuation amplitude of the power chip increases linearly with the increase of switching frequency, and increases nonlinearly with the increase of load current. The switching frequency also has a similar effect on the average junction temperature of the power chip. Considering that silicon carbide MOSFET chips have the advantages of higher switching frequency and low loss compared with insulated-gate bipolar transistors (IGBT), the control method of changing the switching frequency can more easily adjust the junction temperature of silicon carbide MOSFET chips. Second, in the continuous PWM modulation method, the space vector pulse width modulation (Space Vector Pulse Width Modulation, SVPWM) method is a modulation method widely used in motor controllers. However, at high switching frequencies, the power chip loss is high when the SVPWM modulation method is used, resulting in high junction temperature of the power chip. The Adaptive Discontinuous Pulse Width Modulation (ADPWM) method proposed in the related art can effectively reduce the power loss of the power chip at a high switching frequency, and then effectively reduce the transient junction temperature fluctuation amplitude and average junction temperature of the power chip. This is mainly because the use of the ADPWM modulation method can reduce the switching loss of the power chip, and then reduce the junction temperature of the power chip. Third, the heat generated by the power chip is mainly transferred out by the coolant in the form of thermal convection to reduce its junction temperature. Generally, the higher the flow rate of the coolant and the faster the heat exchange rate, the lower the junction temperature of the power chip. At the same time, the lower the temperature of the coolant, the lower the junction temperature of the chip. Considering that the thermal time constant of the radiator is relatively large, generally about tens of seconds or even hundreds of seconds, and the junction temperature of the power chip fluctuates faster, about milliseconds. Fourth, at low fundamental frequency, reducing the switching frequency can effectively reduce the junction temperature fluctuation amplitude of the power chip. The transient junction temperature fluctuation amplitude of the power chip using SVPWM modulation is larger than that using ADPWM modulation. This is mainly because the current contains more harmonics when using ADPWM modulation than when using SVPWM modulation. This will cause the transient loss of the power chip to fluctuate violently, thereby increasing the junction temperature fluctuation amplitude of the chip.

[0278] Based on the above four points, since reducing the switching frequency and using ADPWM modulation can reduce the average junction temperature of the power chip, when the load motor works at low speed and high torque, you can consider using a low switching frequency to reduce the junction temperature fluctuation of the chip. When the operating conditions of the motor change, you can change the switching frequency and PWM modulation to adjust the junction temperature of the power chip, thereby reducing the junction temperature fluctuation of the power chip caused by the load power change. This solution uses PWM modulation and switching frequency as adjustment quantities to adjust the junction temperature of the power chip.

[0279] The active thermal control method proposed in this embodiment of the present application first obtains the junction temperature of the power chip at the current moment based on the DC bus voltage, phase current, duty cycle, coolant temperature and the junction temperature of the power chip at the previous moment by using the loss model and thermal resistance network model of the power chip. Then, in combination with the fundamental frequency of the current load motor, the switching frequency and PWM modulation method are adjusted through a fuzzy control strategy to control the junction temperature of the power chip.

[0280] Since the junction temperature fluctuation amplitude of the power chip includes the transient junction temperature fluctuation amplitude and the average junction temperature fluctuation amplitude, this scheme designs two fuzzy controllers to respectively control the transient junction temperature fluctuation amplitude △T of the power chip. j and the average junction temperature fluctuation amplitude △T jm Fuzzy controller I is used to control the transient junction temperature fluctuation amplitude of the power chip. Research has found that the fundamental frequency f0 and the switching frequency have a greater impact on the transient junction temperature fluctuation amplitude of the power chip. In order to reduce the transient junction temperature fluctuation amplitude of the power chip, the fuzzy controller I is used to control the switching frequency f0 according to the transient junction temperature fluctuation amplitude and the fundamental frequency. sw The study found that the average junction temperature fluctuation amplitude is mainly caused by the change of load current. According to the average junction temperature T jm And the average junction temperature fluctuation amplitude △T jm , the switching frequency increment △f is adjusted by fuzzy controller II sw The average junction temperature fluctuation amplitude of the power chip is controlled by PWM modulation, wherein the switching frequency can be determined by the switching frequency increment and the reference switching frequency. Finally, by comparing the switching frequencies of the two fuzzy controllers, the minimum value is selected as the switching frequency of the motor controller.

[0281] like Fig.11 As shown, the input of the fuzzy controller I is the fundamental frequency f0 (equivalent to the above load parameters), the transient junction temperature fluctuation amplitude △T j (equivalent to the above transient junction temperature fluctuation amplitude), through fuzzy processing ( represents fuzzification or defuzzification), rounding, limiting (if the threshold is exceeded, the upper or lower limit is retained), defuzzification and a series of operations (equivalent to the first fuzzy control algorithm mentioned above), the output switching frequency f sw1 (equivalent to the first working parameter above); the input of fuzzy controller II is the average junction temperature T jm (equivalent to the above average junction temperature), average junction temperature fluctuation amplitude △T jm (equivalent to the above average junction temperature fluctuation amplitude), through fuzzy processing, rounding, limiting, summing (reference switching frequency and the switching frequency increment △f sw summation), defuzzification processing (equivalent to the second fuzzy control algorithm mentioned above), output switching frequency f sw2 (equivalent to the second working parameter above); finally, by adjusting f sw1 and f sw2 Perform minimum value and defuzzification processing to obtain the final switching frequency f sw (equivalent to the above target operating parameters).

[0282] Considering the efficiency of the motor controller, the switching frequency is set to a maximum of 50 kilohertz (kHz). In order to prevent the switching frequency from changing too much, the reference switching frequency is set to (equivalent to the above-mentioned benchmark operating parameters) is set to 30kHz. Figure 3 In, K f0 (equivalent to the first quantization factor mentioned above), K △Tj (equivalent to the second quantization factor mentioned above), K fsw0 , K Tjm , K △Tjm and are the quantization factors of fundamental frequency, transient junction temperature fluctuation amplitude, switching frequency, average junction temperature, and average junction temperature fluctuation amplitude, respectively. K fsw is the proportional factor of the switching frequency. The values ​​of these parameters depend on the robustness and dynamic response of the fuzzy control system. For example, the values ​​of these parameters are shown in Table 1.

[0283] Table 1 Quantization factors and scaling factors

[0284] Parameter name Numeric Parameter name Numeric <![CDATA[Quantization factor K f0 > lg <![CDATA[Quantization factor K Tjm > 0.1 <![CDATA[Quantization factor K △Tj > 0.1 <![CDATA[Quantization factor K △Tjm > 0.1 <![CDATA[Quantization factor K fsw0 > <![CDATA[1e-4=1×10 -4 ]]> <![CDATA[Scale factor K fsw > <![CDATA[1e4=1×10 4 ]]>

[0285] Next, the fuzzy logic controller I and the fuzzy controller II are described respectively.

[0286] Fuzzy controller I controls the transient junction temperature fluctuation of the power chip by adjusting the switching frequency according to the fundamental frequency of the load and the transient junction temperature fluctuation amplitude of the power chip. The input of fuzzy controller I is the fundamental frequency and the transient junction temperature fluctuation amplitude, and the output is the switching frequency. According to the speed operating range of the load motor and the transient junction temperature fluctuation amplitude range of the power chip, the basic domain of the fundamental frequency f0 is [0, 1000] (equivalent to the first basic domain mentioned above), and the transient junction temperature fluctuation amplitude of the power chip △T j The basic domain is [0, 60] (equivalent to the second basic domain mentioned above), and the switching frequency f sw The basic domain is [1e4, 5e4]. Taking into account the influence of switching frequency and PWM modulation mode on the junction temperature of the power chip, as well as the maximum operating temperature allowed by the power chip, according to the domain range of the fundamental frequency, the fuzzy set E1 of the fundamental frequency (equivalent to the first fuzzy set mentioned above) can be divided into 3 levels, namely {L: low, M: medium, H: high} (equivalent to at least one load parameter level mentioned above). Similarly, according to the domain range of the transient junction temperature fluctuation amplitude and the switching frequency, the fuzzy set E2 of the transient junction temperature fluctuation amplitude (equivalent to the second fuzzy set mentioned above) and the fuzzy set U1 of the switching frequency (equivalent to the third fuzzy set mentioned above) can both be expressed as: {L: low, LM: low-medium, M: medium, HM: high-medium, H: high} (equivalent to at least one transient junction temperature fluctuation amplitude level mentioned above). In addition, triangle and trapezoid are selected as the membership function types of the input and output signals. Finally, according to the constructed fuzzy set, the membership function of the input and output signals in the fuzzy logic controller I can be obtained. As shown Fig.12 As shown, (a), (b), and (c) are the membership functions of the fundamental frequency, transient junction temperature fluctuation amplitude, and switching frequency in the fuzzy controller I, respectively.

[0287] The fuzzy rules of fuzzy controller I are: IF E1=A1 and E2=B1, Then U1=C1. Considering the influence of switching frequency on the transient junction temperature fluctuation amplitude of the power chip under different fundamental frequencies, the fuzzy rules formulated for fuzzy controller I are shown in Table 2.

[0288] Table 2 Fuzzy rules of fuzzy controller I

[0289]

[0290] Fuzzy controller II controls the average junction temperature fluctuation of the power chip by adjusting the switching frequency and PWM modulation mode according to the average junction temperature of the power chip and its fluctuation amplitude. The input of fuzzy controller II is the average junction temperature and the average junction temperature fluctuation amplitude, and the output is the switching frequency increment and PWM modulation mode. Considering the maximum operating junction temperature allowed by the power chip and the temperature range of the coolant, the average junction temperature T jmThe basic domain is [65, 175], and the average junction temperature fluctuation amplitude △T jm The basic domain is [-100, 100], considering the switching frequency range is 10kHz to 50kHz, the switching frequency increment △f sw The basic domain of is [-2e4, 2e4], and the basic domain of PWM modulation mode is [1, 2]. According to the domain range of average junction temperature, the fuzzy set E3 of average junction temperature is similar to the fuzzy set E2 of transient junction temperature fluctuation amplitude. According to the domain range of average junction temperature fluctuation amplitude, the fuzzy set E4 of average junction temperature fluctuation amplitude can be expressed as {NH: negative high, NM: negative middle, L: low, PM: positive middle, PH: positive high}. According to the basic domain of switching frequency increment, the fuzzy set U2 of switching frequency increment is similar to the fuzzy set E4 of average junction temperature fluctuation amplitude, except that {ZE: zero} is used instead of {L: low}. The fuzzy set U3 of PWM modulation mode can be expressed as {AD: ADPWM, SV: SVPWM}. The types of membership functions of the input and output signals of fuzzy controller II are the same as those of fuzzy controller I. Finally, based on the constructed fuzzy sets, the membership functions of the input and output signals in fuzzy logic controller II can be obtained. As shown in Fig.13 As shown, (d), (e), (f), and (g) are the membership functions of the average junction temperature, average junction temperature fluctuation amplitude, switching frequency, and PWM mode in the fuzzy controller II, respectively.

[0291] The fuzzy rules of fuzzy controller II are: IF E3=A1 and E4=B1, Then U2=C1 and U3=D1. Considering the influence of switching frequency and PWM modulation mode on the average junction temperature and average junction temperature fluctuation amplitude of the power chip under different fundamental frequencies, the fuzzy rules formulated for fuzzy controller II are shown in Table 3.

[0292] Table 3 Fuzzy rules of fuzzy controller II

[0293]

[0294] The beneficial effects of the active thermal control method provided in this embodiment of the present application include: the active thermal control strategy based on the dual fuzzy logic controller can be used to solve the problem of large junction temperature fluctuation amplitude of the power chip of the motor controller of electric vehicles under low-speed, high-torque and variable load conditions. Among them, one fuzzy controller adjusts the switching frequency according to the fundamental frequency of the load and the transient junction temperature fluctuation amplitude of the power chip to control the transient junction temperature fluctuation of the power chip; the other fuzzy controller adjusts the switching frequency and PWM modulation method according to the average junction temperature and average junction temperature fluctuation amplitude of the power chip to control the average junction temperature fluctuation of the power chip. Compared with the traditional junction temperature control method, this scheme can effectively reduce the transient junction temperature fluctuation amplitude of the power chip under low-speed and high-torque conditions, and can also reduce the average junction temperature fluctuation amplitude of the power chip under variable load conditions, thereby effectively improving the reliability and service life of the motor controller.

[0295] The active thermal control method provided in this embodiment of the present application may also include the following contents:

[0296] First, fuzzy controller I adjusts the switching frequency according to the load speed and the transient junction temperature fluctuation amplitude of the power chip to control the transient junction temperature fluctuation of the power chip. Fuzzy controller II adjusts the switching frequency and PWM modulation method according to the average junction temperature of the power chip and the average junction temperature fluctuation amplitude to control the average junction temperature fluctuation of the power chip.

[0297] Second, fuzzy controller I adjusts the driving resistance of the driving circuit according to the fundamental frequency of the load and the transient junction temperature fluctuation amplitude of the power chip to control the transient junction temperature fluctuation of the power chip. Fuzzy controller II adjusts the driving resistance of the driving circuit and the PWM modulation method according to the average junction temperature of the power chip and the average junction temperature fluctuation amplitude to control the average junction temperature fluctuation of the power chip.

[0298] Third, fuzzy controller I adjusts the coolant flow rate according to the load speed and the transient junction temperature fluctuation amplitude of the power chip to control the transient junction temperature fluctuation of the power chip. Fuzzy controller II adjusts the coolant flow rate and PWM modulation method according to the average junction temperature of the power chip and the average junction temperature fluctuation amplitude to control the average junction temperature fluctuation of the power chip.

[0299] Fourth, in the active thermal control method, the PWM modulation mode adopts the discontinuous pulse width modulation 0 (Discontinuous Pulse Width Modulation 0, DPWM0) modulation technology.

[0300] Fifth, in the active thermal control method, the PWM modulation method adopts the discontinuous pulse width modulation 1 (DPWM1) modulation technology.

[0301] Sixth, in the active thermal control method, the PWM modulation method adopts the discontinuous pulse width modulation 2 (DPWM2) modulation technology.

[0302] Seventh, in the active thermal control method, the PWM modulation method adopts the discontinuous pulse width modulation 3 (DPWM3) modulation technology.

[0303] Eighth, in the active thermal control method, the PWM modulation method adopts the discontinuous pulse width modulation maximum (Discontinuous Pulse Width Modulation MAX, DPWMMAX) modulation technology.

[0304] Ninth, in the active thermal control method, the PWM modulation method adopts the discontinuous pulse width modulation minimum (Discontinuous Pulse Width Modulation MAX, DPWMMIN) modulation technology.

[0305] In a second aspect, the present application provides a junction temperature control device, such as Fig.14 As shown, the junction temperature control device 140 includes: an acquisition unit 1401, a determination unit 1402, and a control unit 1403. Among them:

[0306] The acquisition unit 1401 is used to acquire the transient junction temperatures of the target chip of the target controller at N moments to obtain N transient junction temperatures; wherein N is an integer greater than 0;

[0307] A determination unit 1402 is configured to determine a target operating parameter of a target controller by using a fuzzy control algorithm based at least on the N transient junction temperatures; the target operating parameter is a parameter that affects the junction temperature of the target chip;

[0308] The control unit 1403 is used to control the target controller to operate with the target operating parameters to adjust the junction temperature of the target chip.

[0309] In some embodiments, the determination unit 1402 is specifically used to: determine the transient junction temperature fluctuation amplitude of the target chip based on the N transient junction temperatures; determine the target operating parameters of the target controller based on the load parameters of the target controller at the current moment and the transient junction temperature fluctuation amplitude using a first fuzzy control algorithm; or, determine the average junction temperature and the average junction temperature fluctuation amplitude of the target chip based on the N transient junction temperatures; determine the target operating parameters of the target controller based on the average junction temperature and the average junction temperature fluctuation amplitude using a second fuzzy control algorithm; or, determine the first operating parameters of the target controller based on the load parameters and the N transient junction temperatures using the first fuzzy control algorithm; determine the second operating parameters of the target controller based on the N transient junction temperatures using the second fuzzy control algorithm; and determine the minimum value of the first operating parameter and the second operating parameter as the target operating parameter.

[0310] In some embodiments, the determination unit 1402 is also used to: perform fuzzy processing on the load parameter and the transient junction temperature fluctuation amplitude respectively to obtain a target load parameter level corresponding to the load parameter and a target transient junction temperature fluctuation amplitude level corresponding to the transient junction temperature fluctuation amplitude; determine a target operating parameter level based on the target load parameter level, the target transient junction temperature fluctuation amplitude and at least one first fuzzy rule; and defuzzify the target operating parameter level to obtain the target operating parameter.

[0311] In some embodiments, the determination unit 1402 is also used to: obtain a first fuzzy set of load parameters, and a second fuzzy set of transient junction temperature fluctuation amplitude; wherein the first fuzzy set includes at least one load parameter level; the second fuzzy set includes at least one transient junction temperature fluctuation amplitude level; determine a first membership function of the load parameter based on the first fuzzy set, and determine a second membership function of the transient junction temperature fluctuation amplitude based on the second fuzzy set; determine a target load parameter level corresponding to the load parameter based on the first membership function, and determine a target transient junction temperature fluctuation amplitude level corresponding to the transient junction temperature fluctuation amplitude based on the second membership function.

[0312] In some embodiments, before obtaining the first fuzzy set of load parameters and the second fuzzy set of transient junction temperature fluctuation amplitude, the determination unit 1402 is also used to: based on the first quantization factor of the load parameter, enlarge or reduce the first basic domain of the load parameter; classify the enlarged or reduced first basic domain to obtain the at least one load parameter level; determine the at least one load parameter level as the first fuzzy set; based on the second quantization factor of the transient junction temperature fluctuation amplitude, enlarge or reduce the second basic domain of the transient junction temperature fluctuation amplitude; classify the enlarged or reduced second basic domain to obtain the at least one transient junction temperature fluctuation amplitude level; determine the at least one transient junction temperature fluctuation amplitude level as the second fuzzy set.

[0313] In some embodiments, the determination unit 1402 is also used to: determine a third membership function of the working parameters based on a third fuzzy set of the working parameters; wherein the third fuzzy set includes at least one working parameter level; determine a target working parameter range corresponding to the target working parameter level based on the third membership function; perform a first processing on the target working parameter range to obtain a first working parameter; and based on a scaling factor of the working parameter, enlarge or reduce the first working parameter to obtain the target working parameter.

[0314] In some embodiments, the determination unit 1402 is also used to: perform the fuzzy processing on the average junction temperature and the average junction temperature fluctuation amplitude respectively to obtain the target average junction temperature level corresponding to the average junction temperature and the target average junction temperature fluctuation amplitude level corresponding to the average junction temperature fluctuation amplitude; determine the target operating parameter increment level based on the target average junction temperature level, the target average junction temperature fluctuation amplitude level and at least one second fuzzy rule; perform the defuzzification processing on the target operating parameter increment level to obtain the target operating parameter increment; determine the sum of the target operating parameter increment and the benchmark operating parameter as the target operating parameter.

[0315] In some embodiments, the determination unit 1402 is also used to: determine the average junction temperature and the average junction temperature fluctuation amplitude of the target chip based on the N transient junction temperatures; and determine the target pulse width modulation (PWM) mode of the target controller using a third fuzzy control algorithm based on the average junction temperature and the average junction temperature fluctuation amplitude.

[0316] The control unit 1403 is further configured to control the target controller to operate in the target PWM mode to adjust the junction temperature of the target chip.

[0317] In some embodiments, the determination unit 1402 is also used to: perform the fuzzy processing on the average junction temperature and the average junction temperature fluctuation amplitude respectively to obtain the target average junction temperature level corresponding to the average junction temperature and the target average junction temperature fluctuation amplitude level corresponding to the average junction temperature fluctuation amplitude; determine the target PWM level based on the target average junction temperature level, the target average junction temperature fluctuation amplitude level and at least one third fuzzy rule; perform the defuzzification processing on the target PWM level to obtain the target PWM mode.

[0318] It should be noted that the various units included in the junction temperature control device provided in the embodiment of the present application can be implemented by a processor in an electronic device; of course, it can also be implemented by a specific logic circuit; in the implementation process, the processor can be a central processing unit (CPU, Central Processing Unit), a microprocessor (MPU, Micro Processor Unit), a digital signal processor (DSP, Digital Signal Processor) or a field programmable gate array (FPGA, Field-Programmable Gate Array), etc.

[0319] The description of the above device embodiment is similar to the description of the above method embodiment, and has similar beneficial effects as the method embodiment. For technical details not disclosed in the device embodiment of the present application, please refer to the description of the method embodiment of the present application for understanding.

[0320] It should be noted that in the embodiment of the present application, if the above-mentioned junction temperature control method is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the relevant technology can be embodied in the form of a software product, which is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a U disk, a mobile hard disk, a read-only memory (ROM), a disk or an optical disk. In this way, the embodiment of the present application is not limited to any specific combination of hardware and software.

[0321] In a third aspect, an embodiment of the present application provides an electronic device, comprising at least a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and when the processor executes the program, the steps in the junction temperature control method provided in the above embodiment are implemented.

[0322] Combine the following Fig.15 The electronic device 150 shown is a block diagram of the electronic device.

[0323] In one example, if Fig.15 As shown, the electronic device 150 includes: a processor 1501, at least one communication bus 1502, at least one external communication interface 1503 and a memory 1504. The communication bus 1502 is configured to realize connection and communication between these components. The external communication interface 1503 may include a standard wired interface and a wireless interface.

[0324] The memory 1504 is configured to store instructions and applications executable by the processor 1501, and can also cache data to be processed or processed by the processor 1501 and various modules in the electronic device (for example, image data, audio data, voice communication data, and video communication data), which can be implemented through flash memory (FLASH) or random access memory (Random Access Memory, RAM).

[0325] In another example, the electronic device may be a vehicle device or a controller. The vehicle device or the controller is used to execute the steps in the junction temperature control method provided in the above embodiment.

[0326] In a fourth aspect, the present application further provides a storage medium, on which a computer program is stored. When the computer program on the storage medium is executed, the steps in the junction temperature control method provided in the embodiment of the present application are implemented.

[0327] In a fifth aspect, the present application also provides a computer program product, including a computer program or instructions, which, when executed by a processor, implement the steps in the above-mentioned junction temperature control method.

[0328] It should be noted here that the description of the above storage medium and device embodiments is similar to the description of the above method embodiments, and has similar beneficial effects as the method embodiments. For technical details not disclosed in the storage medium and device embodiments of this application, please refer to the description of the method embodiments of this application for understanding.

[0329] It should be understood that "one embodiment" or "an embodiment" mentioned throughout the specification means that specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in some embodiments" appearing throughout the specification may not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in various embodiments of the present application, the size of the sequence number of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application. The above-mentioned sequence numbers of the embodiments of the present application are for description only and do not represent the advantages and disadvantages of the embodiments.

[0330] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0331] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0332] The units described above as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units; they may be located in one place or distributed on multiple network units; some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0333] In addition, all functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may be a separate unit, or two or more units may be integrated into one unit; the above-mentioned integrated units may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0334] A person skilled in the art can understand that all or part of the steps of implementing the above method embodiment can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above method embodiment; and the aforementioned storage medium includes: mobile storage devices, read-only memories (ROM), magnetic disks or optical disks, etc., various media that can store program codes.

[0335] Alternatively, if the above-mentioned integrated unit of the present application is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application can be essentially or partly embodied in the form of a software product that contributes to the relevant technology. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROMs, magnetic disks, or optical disks.

[0336] The above is only an implementation method of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A junction temperature control method, characterized in that: The method comprises: Obtaining transient junction temperatures of a target chip of a target controller at N moments to obtain N transient junction temperatures, wherein N is an integer greater than 0; Based on the load parameter and transient junction temperature fluctuation amplitude of the target controller at the current moment, a first fuzzy control algorithm is used to determine the first operating parameter of the target controller; the transient junction temperature fluctuation amplitude is determined based on the N transient junction temperatures; Based on the average junction temperature and the average junction temperature fluctuation amplitude, a second fuzzy control algorithm is used to determine the second operating parameter of the target controller; the average junction temperature and the average junction temperature fluctuation amplitude are determined based on the N transient junction temperatures; Determine the minimum value of the first operating parameter and the second operating parameter as a target operating parameter; the target operating parameter is a parameter that affects the junction temperature of the target chip; The target controller is controlled to operate with the target operating parameters to adjust the junction temperature of the target chip.

2. The method according to claim 1, characterized in that The method of determining the first operating parameter of the target controller by using a first fuzzy control algorithm based on the load parameter of the target controller and the transient junction temperature fluctuation amplitude at the current moment includes: Performing fuzzy processing on the load parameter and the transient junction temperature fluctuation amplitude respectively to obtain a target load parameter level corresponding to the load parameter and a target transient junction temperature fluctuation amplitude level corresponding to the transient junction temperature fluctuation amplitude; Determining a target operating parameter level based on the target load parameter level, the target transient junction temperature fluctuation amplitude level, and at least one first fuzzy rule; The target operating parameter level is defuzzified to obtain the first operating parameter.

3. The method according to claim 2, characterized in that The fuzzy processing is performed on the load parameter and the transient junction temperature fluctuation amplitude respectively to obtain a target load parameter level corresponding to the load parameter and a target transient junction temperature fluctuation amplitude level corresponding to the transient junction temperature fluctuation amplitude, including: Acquire a first fuzzy set of load parameters and a second fuzzy set of transient junction temperature fluctuation amplitude; wherein the first fuzzy set includes at least one load parameter level; and the second fuzzy set includes at least one transient junction temperature fluctuation amplitude level; Determine a first membership function of a load parameter based on the first fuzzy set, and determine a second membership function of a transient junction temperature fluctuation amplitude based on the second fuzzy set; A target load parameter level corresponding to the load parameter is determined based on the first membership function, and a target transient junction temperature fluctuation amplitude level corresponding to the transient junction temperature fluctuation amplitude is determined based on the second membership function.

4. The method according to claim 3, characterized in that Before obtaining the first fuzzy set of load parameters and the second fuzzy set of transient junction temperature fluctuation amplitude, the method further includes: Based on the first quantization factor of the load parameter, the first basic domain of the load parameter is enlarged or reduced; the enlarged or reduced first basic domain is graded to obtain the at least one load parameter grade; the at least one load parameter grade is determined as the first fuzzy set; Based on the second quantization factor of the transient junction temperature fluctuation amplitude, the second basic domain of the transient junction temperature fluctuation amplitude is enlarged or reduced; the enlarged or reduced second basic domain is graded to obtain at least one transient junction temperature fluctuation amplitude level; and the at least one transient junction temperature fluctuation amplitude level is determined as the second fuzzy set.

5. The method according to claim 2, characterized in that: The defuzzifying the target operating parameter level to obtain the first operating parameter includes: Determining a third membership function of the operating parameter based on a third fuzzy set of the operating parameter; wherein the third fuzzy set includes at least one operating parameter level; Based on the third membership function, determining a target operating parameter range corresponding to the target operating parameter level; Performing a first processing on the target operating parameter range to obtain the target operating parameter range after the first processing; Based on the scale factor of the working parameter, the target working parameter range after the first processing is enlarged or reduced to obtain the first working parameter.

6. The method according to claim 1, characterized in that The method further comprises: Based on the N transient junction temperatures, determining an average junction temperature and an average junction temperature fluctuation amplitude of the target chip; Based on the average junction temperature and the average junction temperature fluctuation amplitude, a third fuzzy control algorithm is used to determine a target pulse width modulation (PWM) mode of the target controller; The target controller is controlled to operate in the target pulse width modulation (PWM) mode to adjust the junction temperature of the target chip.

7. The method according to claim 6, characterized in that The method of determining a target pulse width modulation (PWM) mode of the target controller based on the average junction temperature and the average junction temperature fluctuation amplitude by using a third fuzzy control algorithm includes: Performing fuzzy processing on the average junction temperature and the average junction temperature fluctuation amplitude respectively to obtain a target average junction temperature level corresponding to the average junction temperature and a target average junction temperature fluctuation amplitude level corresponding to the average junction temperature fluctuation amplitude; determining a target PWM level based on the target average junction temperature level, the target average junction temperature fluctuation amplitude level, and at least one third fuzzy rule; The target PWM level is defuzzified to obtain the target pulse width modulation PWM mode.

8. A junction temperature control device, characterized in that: The device comprises: An acquisition unit, used to acquire the transient junction temperatures of the target chip of the target controller at N moments, to obtain N transient junction temperatures; wherein N is an integer greater than 0; A determination unit, configured to determine a target operating parameter of a target controller by using a fuzzy control algorithm based at least on the N transient junction temperatures; the target operating parameter is a parameter that affects the junction temperature of the target chip; A control unit, used for controlling the target controller to operate with the target operating parameters to adjust the junction temperature of the target chip; The determination unit is also used to determine the first operating parameter of the target controller using a first fuzzy control algorithm based on the load parameter and transient junction temperature fluctuation amplitude of the target controller at the current moment; the transient junction temperature fluctuation amplitude is determined based on the N transient junction temperatures; based on the average junction temperature and the average junction temperature fluctuation amplitude, the second operating parameter of the target controller is determined using a second fuzzy control algorithm; the average junction temperature and the average junction temperature fluctuation amplitude are determined based on the N transient junction temperatures; and the minimum value of the first operating parameter and the second operating parameter is determined as the target operating parameter.

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