A method, device, equipment and medium for analyzing heat accumulation of MOS tube

Abstract

The present invention relates to the field of motor control technology, and in particular, to a MOS tube heat accumulation analysis method, device, equipment and medium, which are used in a vehicle-mounted motor control system, and the analysis method includes: obtaining a minimum test voltage and a maximum test voltage; performing a gradient test, if the motor does not rotate to release pressure, obtaining a first time, a first voltage difference and a first current based on the gradient test; checking whether the first voltage difference is in the safe operation area of ​​the MOS tube, if the first voltage difference is in the safe operation area of ​​the MOS tube, calculating the heat accumulation amount of the MOS tube in the first time based on the first time, the first voltage difference and the first current; using the heat accumulation amount in the first time as the critical value of the heat accumulation amount of the MOS tube. In this way, the problem that it is impossible to clearly identify the reason why the MOS tube in the vehicle-mounted motor control system is damaged even though it is in the working voltage range is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of motor control, and in particular to a method, device, equipment and medium for analyzing heat accumulation of a MOS tube. Background Art

[0002] Power MOS tubes are widely used in electronic circuits due to their advantages of fast response speed and easy control. Power MOS tubes can be found in automotive electronics. Automotive-grade electronic products have more stringent requirements on the circuit design of MOS tubes. The MOS of automotive-grade drive motors will consider the following factors: working current at maximum load at different temperatures, maximum peak current at the moment of load startup; fault diagnosis of drive motor MOS tubes; the on and off states of the MOS tubes during operation; the reverse pressure bearing capacity of the D / S poles of the MOS tube at the moment the motor is shut down; the average conduction loss of the MOS tube during PWM control; and short-term energy accumulation of the MOS tube under extreme working conditions.

[0003] However, the existing technology does not consider the MOS power loss under abnormal power supply conditions of the whole vehicle. At the same time, due to the differences between individual MOS tubes, although the test items for product design verification basically cover the extreme working conditions within the life cycle of the vehicle, the limited test samples fail to fully cover the possibility of failure due to individual differences. Specifically, when MOS is in the vehicle motor control system, all components are within the normal operating voltage range, but the MOS is damaged. However, there is no specific analysis method for this phenomenon in the existing technology. Summary of the invention

[0004] In order to solve the problem that the prior art cannot clearly identify the reason why the MOS tube in the vehicle motor control system is within the operating voltage range but is damaged, the present invention provides a MOS tube heat accumulation analysis method, device, equipment and medium.

[0005] In a first aspect, the present invention provides a MOS tube heat accumulation analysis method, the analysis method is used for a vehicle motor control system, the vehicle motor system includes an execution chip, a MOS tube, a motor and a battery, the analysis method includes:

[0006] Obtaining a minimum test voltage and a maximum test voltage, wherein the minimum test voltage and the maximum test voltage are input voltages of the drain of the MOS tube;

[0007] Performing a gradient test based on the minimum test voltage and the maximum test voltage;

[0008] If the motor does not rotate to release pressure, a first time, a first voltage difference and a first current are obtained based on a gradient test, wherein the first time is the time from when the MOS tube is turned on to when it is damaged, the first voltage difference is the voltage difference between the drain and the source of the MOS tube, and the first current is the current flowing through the drain and the source of the MOS tube;

[0009] Check whether the first voltage difference is within the safe operation area of ​​the MOS tube;

[0010] If the first voltage difference is in the safe operation region of the MOS tube, calculating the heat accumulation amount of the MOS tube in the first time based on the first time, the first voltage difference and the first current;

[0011] The heat accumulation amount within the first time is used as a critical value of the heat accumulation amount of the MOS tube.

[0012] In some embodiments, the method further comprises:

[0013] If the motor is rotating to release pressure, the MOS tube has been fully opened, and the MOS tube is not damaged, the test is stopped.

[0014] In some embodiments, the method further comprises:

[0015] If the motor does not rotate to release pressure, and the first voltage difference exceeds the safe operation area of ​​the MOS tube, the first voltage difference is too large to damage the MOS tube, and the test is stopped.

[0016] In some embodiments, obtaining the minimum test voltage and the maximum test voltage includes:

[0017] Obtaining a voltage safety strategy for the vehicle-mounted motor control system;

[0018] Determining the maximum operating voltage of the vehicle-mounted motor control system based on the voltage safety strategy;

[0019] determining the maximum test voltage based on the maximum operating voltage;

[0020] The voltage required for auxiliary starting of the whole vehicle is determined based on the voltage safety strategy, and the voltage required for auxiliary starting of the whole vehicle is used as the minimum test voltage.

[0021] In some embodiments, the gradient test comprises:

[0022] The test is started from the minimum test voltage, and the fixed voltage values ​​are increased in sequence until the voltage value reaches the maximum test voltage;

[0023] During the gradient test, the first time, the first voltage difference and the first current during the test at each voltage are collected at a fixed frequency;

[0024] The first time, the first voltage difference and the first current when the MOS tube is damaged are collected.

[0025] In some embodiments, the heat accumulation amount of the MOS tube in the first time is calculated based on the first time, the first voltage difference and the first current, and the calculation formula is:

[0026] ;

[0027] Wherein, J is the heat accumulation amount, t1 is the test start time, t2 is the test end time, For the first time, U DS is the first voltage difference, and I is the first current.

[0028] In some embodiments, it is characterized in that the minimum test voltage is preferably 24V;

[0029] The maximum test voltage is preferably 31V.

[0030] In a second aspect, the present invention provides a MOS tube heat accumulation analysis device, comprising:

[0031] Data acquisition module: used to obtain the minimum test voltage and the maximum test voltage, and obtain the first time, the first voltage difference and the first current;

[0032] A state judgment module: used to monitor whether the motor is rotating to release pressure, and to monitor whether the first voltage difference is in the safe operation area of ​​the MOS tube;

[0033] Comprehensive calculation module: used to calculate the heat accumulation amount of the MOS tube within the first time based on the first time, the first voltage difference and the first current.

[0034] In a third aspect, the present invention proposes an electronic device, comprising a processor and a memory, wherein the memory stores a program that can be run on the processor, and when the program is executed by the processor, the MOS tube thermal aggregation analysis method described in the first aspect is implemented.

[0035] In a fourth aspect, the present invention proposes a storage medium having a computer program stored thereon, and when the computer program is executed by at least one processor, the MOS tube thermal aggregation analysis method described in the first aspect is implemented.

[0036] In order to solve the problem that the prior art cannot clearly identify the reason why the MOS tube in the vehicle motor control system is damaged even though it is within the working voltage range, the present invention has the following advantages:

[0037] Through the technical solution of the present invention, it is possible to analyze the cause of the phenomenon that MOS is damaged even though all components in the vehicle-mounted motor control system are within the normal operating voltage range. Based on the analysis results, the damage range of MOS under actual working conditions is obtained, and protection measures are formulated to effectively control the damage situation. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The circuit structure diagram of the vehicle motor control system is shown;

[0039] Figure 2 A flow chart of a method for analyzing heat accumulation of a MOS tube is shown;

[0040] Figure 3 A structural block diagram of a MOS tube heat accumulation analysis device is shown;

[0041] Figure 4 Schematic diagrams of three operating conditions for the gradient test of the vehicle motor control system are shown. DETAILED DESCRIPTION

[0042] The present disclosure will now be discussed with reference to several exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and thus implement the present disclosure, rather than implying any limitation on the scope of the present disclosure.

[0043] As used herein, the term "including" and its variants are to be interpreted as open-ended terms meaning "including but not limited to". The term "based on" is to be interpreted as "based at least in part on". The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment". The term "another embodiment" is to be interpreted as "at least one other embodiment". The orientation or position relationship indicated by the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "vertical", "horizontal", "lateral", "longitudinal" and the like is based on the orientation or position relationship shown in the accompanying drawings. These terms are mainly for better describing the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation. In addition, in addition to being used to indicate an orientation or position relationship, some of the above terms may also be used to indicate other meanings, such as the term "upper" may also be used to indicate a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to the specific circumstances. In addition, the terms "install", "set", "provided with", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be an internal connection between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances. In addition, the terms "first", "second", etc. are mainly used to distinguish different devices, elements or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, elements or components. Unless otherwise specified, "plurality" means two or more.

[0044] This embodiment discloses a MOS tube heat accumulation analysis method, which is used in a vehicle motor control system, such as Figure 1 As shown in the figure, the vehicle motor system includes the main chip, the execution chip, the MOS tube, the motor and the battery. The G pole of the MOS is turned on by the execution chip raising the GPR voltage after receiving the instruction from the main chip. The DPR monitors the D pole voltage of the MOS tube, and its value is consistent with the output voltage of the battery. The SPR is a passive receiving voltage at the chip end and cannot be actively controlled by the chip.

[0045] In a first aspect, the present invention provides a method for analyzing heat accumulation of a MOS tube, the method comprising the following steps:

[0046] Obtaining a minimum test voltage and a maximum test voltage, wherein the minimum test voltage and the maximum test voltage are input voltages of the drain of the MOS tube;

[0047] Performing a gradient test based on the minimum test voltage and the maximum test voltage;

[0048] If the motor does not rotate to release pressure, a first time, a first voltage difference and a first current are obtained based on a gradient test, wherein the first time is the time from when the MOS tube is turned on to when it is damaged, the first voltage difference is the voltage difference between the drain and the source of the MOS tube, and the first current is the current flowing through the drain and the source of the MOS tube;

[0049] Check whether the first voltage difference is within the safe operation area of ​​the MOS tube;

[0050] If the first voltage difference is in the safe operation region of the MOS tube, calculating the heat accumulation amount of the MOS tube in the first time based on the first time, the first voltage difference and the first current;

[0051] The heat accumulation amount within the first time is used as a critical value of the heat accumulation amount of the MOS tube.

[0052] In this embodiment, a method for analyzing heat accumulation of a MOS tube is proposed. First, a minimum test voltage and a maximum test voltage are obtained. The test voltage refers to the input voltage output by the battery and entering the drain of the MOS tube. Secondly, a gradient test is performed from the minimum test voltage to the maximum test voltage. When the motor does not rotate to release pressure, and the first voltage difference is in the safe operation area, that is, the MOS tube is not fully turned on, and the voltage difference between the drain and source of the MOS tube is in the safe operation area, the first time, the first voltage difference and the first current are obtained. Finally, the heat accumulation amount is calculated based on the first time, the first voltage difference and the first current, and the calculated heat accumulation amount is used as the critical value of the heat accumulation amount of the MOS tube. Specifically, if the heat accumulation amount exceeds the critical value when the motor does not rotate to release pressure and the first voltage difference is in the safe operation area, the MOS will be damaged.

[0053] Specifically, the process from turning on the MOS tube to fully turning on is a complex physical process involving gate voltage changes, parasitic capacitance charging and discharging, and drain current changes, which takes a certain amount of time.

[0054] Specifically, the method proposed in the present invention is applied to a vehicle-mounted motor control system. In the vehicle-mounted motor control system to which the method is applied, Figure 1 As shown, the vehicle motor system includes a main chip, an execution chip, a MOS tube, a motor and a battery. The main chip is used to issue instructions to control the execution chip to issue control signals; the execution chip controls the on and off of the MOS tube and monitors the drain voltage of the MOS tube; the battery is used to provide a reference voltage, that is, the voltage flowing into the drain of the MOS tube.

[0055] Specifically, when performing a gradient test, the test voltage refers to the input voltage of the drain. Since the input voltage of the drain is provided by a battery and is monitored by the chip, it is easier to control the voltage there as a reference voltage for the test.

[0056] Specifically, in the vehicle motor control system, MOS can be turned on, and the operation of each component can be divided into three situations, such as Figure 4 As shown: First, the MOS tube has been fully opened, and the motor has started to rotate, that is, the motor has rotated to release pressure, and the MOS tube will not be damaged; second, the MOS tube is not fully opened, and the voltage difference between the drain and source of the MOS tube is too large, exceeding the safe operation area of ​​the MOS tube, resulting in damage to the MOS tube; third, the MOS tube is not fully opened, and the voltage difference between the drain and source of the MOS tube is also within the safe operation area, but the MOS tube is still damaged. The first case is a normal operation case, and the MOS tube is not damaged, so there is no need to explore. The reason for the damage of the second MOS tube is relatively clear and clear at a glance. The third case cannot directly deduce the reason for the damage of the MOS. Therefore, the present invention proposes a MOS tube thermal accumulation analysis method to explore the specific cause of the third case, and calculates the thermal accumulation performance of the MOS in the comprehensive electrical performance and software protection strategy of the vehicle under the high voltage environment as a specification for subsequent product design. Figure 4 This also includes the case where MOS is not turned on.

[0057] Specifically, in the situation studied in the present invention, the MOS is damaged mainly because the gate and source of the MOS tube are not fully opened. At this time, the source voltage quickly drops to a negative value, the voltage difference between the drain and the source increases sharply, and the current fails to return to zero quickly. Therefore, a considerable amount of energy is accumulated inside the MOS tube. Before the current returns to zero process is completed, the MOS tube breaks down due to the short-term large power consumption.

[0058] Specifically, the safe operation area of ​​the MOS tube is obtained according to the operation manual of the MOS tube.

[0059] Specifically, the first time is the time from when the MOS tube is turned on to when it is damaged, the first voltage difference is the voltage difference between the drain and source of the MOS tube, and the first current is the current flowing through the drain and source of the MOS tube. Based on these three quantities, the amount of heat accumulation in the first time can be obtained.

[0060] Specifically, the above method can be used to analyze the cause of damage to the MOS tube during normal operation, and obtain a critical value of heat accumulation. Based on the analysis results, specific protection measures can be formulated to effectively control the damage of the MOS.

[0061] In some embodiments, the method further comprises:

[0062] If the motor is rotating to release pressure, the MOS tube has been fully opened, and the MOS tube is not damaged, the test is stopped.

[0063] In this embodiment, if the motor rotates to release pressure, it means that the MOS tube is fully turned on and is not damaged. This is the normal operation of the vehicle motor control system, which is not within the analysis scope of the present invention and needs to be excluded. Therefore, the test is stopped to avoid affecting the analysis of other situations.

[0064] In some embodiments, the method further comprises:

[0065] If the motor does not rotate to release pressure, and the first voltage difference exceeds the safe operation area of ​​the MOS tube, the first voltage difference is too large to damage the MOS tube, and the test is stopped.

[0066] In this embodiment, if the motor does not rotate to release pressure, but the collected first voltage difference data exceeds the safe operating area obtained according to the MOS tube operation manual, it is very likely that the MOS tube is damaged because the voltage difference between the drain and source of the MOS tube exceeds the safe operating area. This is contrary to the premise that all components in the vehicle-mounted motor control system to be studied by the present invention are in normal operating conditions, and is not within the scope of analysis of the present invention and needs to be excluded. Therefore, the test is stopped when this situation is encountered.

[0067] In some embodiments, obtaining the minimum test voltage and the maximum test voltage includes:

[0068] Obtaining a voltage safety strategy for the vehicle-mounted motor control system;

[0069] Determining the maximum operating voltage of the vehicle-mounted motor control system based on the voltage safety strategy;

[0070] The maximum test voltage is determined based on the maximum operating voltage; the voltage required for vehicle auxiliary starting is determined based on the voltage safety strategy, and the voltage required for vehicle auxiliary starting is used as the minimum test voltage.

[0071] In this embodiment, the specific method for determining the minimum test voltage and the maximum test voltage is to first obtain the voltage safety strategy of the vehicle motor control system, obtain the maximum operating voltage according to the voltage safety strategy, and then determine the maximum test voltage according to the maximum operating voltage. For example, the maximum operating voltage of the whole vehicle is 30V, and the motor will rotate to release the pressure if it exceeds 30V. Since the motor pressure release needs to be tested during the test to see if the MOS will be damaged, the maximum test voltage needs to be greater than 30V, preferably 31V.

[0072] Specifically, the minimum test voltage is the voltage required for vehicle auxiliary starting. The voltage required for vehicle auxiliary starting is determined by the voltage safety strategy of the entire vehicle. In the vehicle motor control system, auxiliary starting helps to enrich the actual scenarios that the vehicle can cope with. For example, when the main battery is low, the emergency power supply is used for auxiliary starting. The emergency power supply is usually low voltage to maintain basic power consumption. Therefore, the vehicle motor control system needs to be able to start normally at low voltage, so the voltage required for auxiliary starting is used as the minimum test voltage.

[0073] Specifically, when performing a gradient test, the test voltage refers to the input voltage of the drain. This is because the drain input voltage is provided by a battery, and chip monitoring is performed, which is easy to control.

[0074] Specifically, the voltage safety strategy of the vehicle motor control system is a systematic and holistic safety strategy, which needs to consider many factors, such as MOS opening / closing time, execution chip G pole lifting / closing time, motor current rise and fall time, software control frequency, etc. Based on these related factors, the system will give a maximum operating voltage value to ensure that all components in the system can operate normally.

[0075] Specifically, the test voltage is controlled within the safe operating area of ​​the system in the above manner, which meets the object to be studied in the present invention and facilitates the exploration of the causes of MOS damage when all components in the vehicle motor control system are in normal operation.

[0076] In some embodiments, the gradient test comprises:

[0077] The test is started from the minimum test voltage, and the fixed voltage values ​​are increased in sequence until the voltage value reaches the maximum test voltage;

[0078] During the gradient test, the first time, the first voltage difference and the first current during the test at each voltage are collected at a fixed frequency;

[0079] The first time, the first voltage difference and the first current when the MOS tube is damaged are collected.

[0080] In this embodiment, a gradient test method is shown - starting the test from the minimum test voltage, completing the test analysis of the minimum test voltage, and then successively increasing the fixed voltage values ​​for testing and analysis until the final test voltage value reaches the maximum test voltage.

[0081] Specifically, the fixed voltage value can be selected according to the system environment in which the MOS tube is located, and is preferably 1V in the present invention.

[0082] Specifically, during the test, the first time, the first voltage difference and the first current are collected at a fixed frequency. They can be analyzed and compared with the first time, the first voltage difference and the first current at the time of damage, which is helpful for analyzing the cause of MOS tube damage and eliminating related error options. For example: by comparing the time from MOS opening to damage or full opening in each test situation, it can be deduced that the damage of MOS occurs when the MOS tube is not fully turned on; by comparing the voltage and current at the time of MOS damage and before damage, it can be deduced whether the MOS tube is in a safe operating area, whether other abnormalities such as short circuits occur, etc.

[0083] Specifically, as shown in Table 1, by collecting relevant data, the MOS opening time and V GS From the data in Table 1, we can know that the MOS tube used in this test takes 240us to turn on and 800us to fully turn on. It can be seen that due to the fact that the MOS in the system is connected to the motor at the back end and the influence of the motor's own inductance, there is a certain delay in the current rise.

[0084] Table 1 MOS turn-on time and V GS Data

[0085]

[0086] Specifically, as shown in Table 2, by collecting relevant data, the performance comparison of MOS tubes of different brands and models in the same system is shown. GS Switching time, by comparing the MOS turn-on time in Table 1, it can be concluded that the gate and source of the damaged MOS tube in the test are not fully turned on, that is, the MOS tube is not fully turned on.

[0087] Table 2 Performance data of MOS tubes of various brands and models in the same system

[0088]

[0089] In some embodiments, the heat accumulation amount of the MOS tube in the first time is calculated based on the first time, the first voltage difference and the first current, and the calculation formula is:

[0090] ;

[0091] Wherein, J is the heat accumulation amount, t1 is the test start time, t2 is the test end time, For the first time, U DS is the first voltage difference, and I is the first current.

[0092] In this embodiment, a calculation formula for calculating the heat accumulation amount in the first time is proposed:

[0093] .

[0094] Specifically, the formula represents the heat accumulated by the MOS tube in the first time period from the beginning to the end of the test. If the heat exceeds this threshold, the MOS tube will be damaged.

[0095] Specifically, based on the calculation results, a corresponding control method can be formulated to avoid MOS damage.

[0096] In some embodiments, it is characterized in that the minimum test voltage is preferably 24V;

[0097] The maximum test voltage is preferably 31V.

[0098] In this embodiment, according to the overall voltage safety strategy of the system, the minimum test voltage is preferably 24V, and the maximum test voltage is preferably 31V.

[0099] In a second aspect, the present invention provides a MOS tube heat accumulation analysis device, comprising:

[0100] Data acquisition module: used to obtain the minimum test voltage and the maximum test voltage, and obtain the first time, the first voltage difference and the first current;

[0101] A state judgment module: used to monitor whether the motor is rotating to release pressure, and to monitor whether the first voltage difference is in the safe operation area of ​​the MOS tube;

[0102] Comprehensive calculation module: used to calculate the heat accumulation amount of the MOS tube within the first time based on the first time, the first voltage difference and the first current.

[0103] In a third aspect, the present invention proposes an electronic device, comprising a processor and a memory, wherein the memory stores a program that can be run on the processor, and when the program is executed by the processor, the MOS tube thermal aggregation analysis method described in the first aspect is implemented.

[0104] In a fourth aspect, the present invention proposes a storage medium having a computer program stored thereon, and when the computer program is executed by at least one processor, the MOS tube thermal aggregation analysis method described in the first aspect is implemented.

[0105] In summary, through the above analysis method, it is possible to analyze the reasons why MOS damage occurs in the vehicle motor control system even though all components are within the normal operating voltage range. Based on the analysis results, the damage range of MOS under actual working conditions can be obtained, and protection measures can be formulated to effectively control the damage.

[0106] Those of ordinary skill in the art will appreciate that the modules and algorithm steps described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0107] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described devices and equipment can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0108] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

[0109] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the embodiments of the present invention.

[0110] In addition, each functional module in the embodiment of the present invention may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module.

[0111] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the energy-saving signal sending / receiving method of each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

[0112] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

[0113] It should be understood that the size of the sequence number of each step in the content of the invention and the embodiments of the present invention does not absolutely 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 invention. For the purpose of example and description, the foregoing description of the implementation of the present disclosure has been given. The foregoing description is not exhaustive and is not intended to limit the present disclosure to the exact form disclosed. Various deformations and modifications may exist according to the above teachings, or various deformations and modifications may be obtained from the practice of the present disclosure. These embodiments are selected and described to illustrate the principles of the present disclosure and its practical application, so that those skilled in the art can use the present disclosure in various embodiments and various modifications suitable for the specific purpose conceived.

Claims

1. A method for analyzing heat accumulation of MOS tubes, characterized in that: The analysis method is used for a vehicle-mounted motor control system, which includes an execution chip, a MOS tube, a motor and a battery. The analysis method includes: Obtaining a minimum test voltage and a maximum test voltage, wherein the minimum test voltage and the maximum test voltage are input voltages of the drain of the MOS tube; Performing a gradient test based on the minimum test voltage and the maximum test voltage; If the motor does not rotate to release pressure, and the MOS tube is not fully turned on, and the voltage difference between the drain and source of the MOS tube is in a safe operation area, a first time, a first voltage difference, and a first current are obtained based on a gradient test, wherein the first time is the time from when the MOS tube is turned on to when it is damaged, the first voltage difference is the voltage difference between the drain and source of the MOS tube, and the first current is the current flowing through the drain and source of the MOS tube; Check whether the first voltage difference is within the safe operation area of ​​the MOS tube; If the first voltage difference is in the safe operation region of the MOS tube, calculating the heat accumulation amount of the MOS tube in the first time based on the first time, the first voltage difference and the first current; The heat accumulation amount within the first time is taken as the critical value of the heat accumulation amount of the MOS tube; The heat accumulation amount of the MOS tube in the first time is calculated based on the first time, the first voltage difference and the first current, and the calculation formula is: ； Wherein, J is the heat accumulation amount, t1 is the test start time, t2 is the test end time, For the first time, U DS is the first voltage difference, and I is the first current.

2. A MOS tube heat accumulation analysis method according to claim 1, characterized in that: The method further comprises: If the motor is rotating to release pressure, the MOS tube has been fully opened, and the MOS tube is not damaged, the test is stopped.

3. A MOS tube heat accumulation analysis method according to claim 1, characterized in that: The method further comprises: If the motor does not rotate to release pressure, and the first voltage difference exceeds the safe operation area of ​​the MOS tube, the first voltage difference is too large to damage the MOS tube, and the test is stopped.

4. A MOS tube heat accumulation analysis method according to claim 1, characterized in that: The obtaining of the minimum test voltage and the maximum test voltage comprises: Obtaining a voltage safety strategy for the vehicle-mounted motor control system; Determining the maximum operating voltage of the vehicle-mounted motor control system based on the voltage safety strategy; determining the maximum test voltage based on the maximum operating voltage; The voltage required for auxiliary starting of the whole vehicle is determined based on the voltage safety strategy, and the voltage required for auxiliary starting of the whole vehicle is used as the minimum test voltage.

5. A method for analyzing heat accumulation of a MOS tube according to claim 1, characterized in that: The gradient test comprises: The test is started from the minimum test voltage, and the fixed voltage values ​​are increased in sequence until the voltage value reaches the maximum test voltage; During the gradient test, the first time, the first voltage difference and the first current during the test at each voltage are collected at a fixed frequency.

6. A method for analyzing heat accumulation of a MOS tube according to claim 4, characterized in that: The minimum test voltage is 24V; The maximum test voltage is 31V.

7. A MOS tube heat accumulation analysis device, characterized in that: include: Data acquisition module: used to obtain the minimum test voltage and the maximum test voltage, and obtain the first time, the first voltage difference and the first current, wherein, when the motor does not rotate to release the pressure, and the MOS tube is not fully turned on, and the voltage difference between the drain and the source of the MOS tube is in the safe operation area, the first time, the first voltage difference and the first current are obtained based on the gradient test, the first time is the time from the MOS tube being turned on to being damaged, the first voltage difference is the voltage difference between the drain and the source of the MOS tube, and the first current is the current flowing through the drain and the source of the MOS tube; A state judgment module: used to monitor whether the motor is rotating to release pressure, and to monitor whether the first voltage difference is in the safe operation area of ​​the MOS tube; Comprehensive calculation module: used to calculate the heat accumulation amount of the MOS tube in the first time based on the first time, the first voltage difference and the first current, and the calculation formula is: ； Wherein, J is the heat accumulation amount, t1 is the test start time, t2 is the test end time, For the first time, U DS is the first voltage difference, and I is the first current.

8. An electronic device, characterized in that: The method comprises a processor and a memory, wherein the memory stores a program that can be run on the processor, and when the program is executed by the processor, the method for analyzing thermal aggregation of a MOS tube according to any one of claims 1 to 6 is implemented.

9. A storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by at least one processor, the MOS tube thermal aggregation analysis method according to any one of claims 1 to 6 is implemented.

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