A thermal resistance test method, system, device, and storage medium
By acquiring the power loss parameters and thermal resistance temperature test parameters of the motor controller, a thermal resistance junction temperature database is established, which solves the problem of inaccurate thermal resistance calculation in the existing technology and realizes accurate calculation of the thermal resistance of the motor controller and judgment of normal operation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHUZHOU CRRC TIMES ELECTRIC CO LTD COMMERCIAL VEHICLE ELECTRIC DRIVE BRANCH
- Filing Date
- 2024-12-19
- Publication Date
- 2026-06-30
AI Technical Summary
In existing technologies, the thermal resistance calculation of motor controllers is mainly done through thermal network modeling, which leads to inaccurate calculations.
A thermal resistance testing method is adopted. By acquiring power loss parameters and thermal resistance temperature test parameters, a thermal resistance junction temperature database is established. The thermal resistance between the power semiconductor of the motor controller and the coolant is calculated. Combined with the coolant flow rate, the accurate thermal resistance junction temperature is calculated.
It enables accurate calculation of the thermal resistance of the motor controller, and can calculate the junction temperature of the thermal resistance under any operating condition, so as to quickly determine whether the motor controller is operating normally.
Smart Images
Figure CN122307279A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of motor controllers, and specifically relates to a thermal resistance testing method, system, device, and storage medium. Background Technology
[0002] New energy vehicles are powered by electricity. Compared to traditional gasoline vehicles, electricity is cleaner and pollution-free, and its lower price makes it more widely accepted. In recent years, new energy vehicles have experienced rapid development. The motor controller is one of the core components of a new energy vehicle. It is an electronic device that manages and controls the operation of the electric motor, primarily adjusting its speed, torque, and direction. In new energy vehicles, the current capability of the motor controller is largely determined by the current capability of the IGBT / SiC power semiconductor module, which is limited by the module's maximum operating junction temperature.
[0003] In related technologies, thermal resistance calculation is mainly performed by modeling the thermal network using the Foster or Cauer model to obtain a thermal resistance model, and then using the thermal resistance model to obtain the module thermal resistance.
[0004] The aforementioned technologies only model the thermal network, rather than the entire heat dissipation system, resulting in inaccurate calculations of thermal resistance. Summary of the Invention
[0005] The technical problem to be solved by the present invention is to provide a thermal resistance testing method, system, device and storage medium that can accurately calculate the thermal resistance of a motor controller.
[0006] A method for testing thermal resistance, wherein the thermal resistance is the thermal resistance between the power semiconductor of a motor controller and the coolant, includes:
[0007] Obtain power loss parameters, including the effective value of the three-phase current of the motor, the power factor of the motor, and the modulation coefficient;
[0008] Based on the power loss parameters and thermal resistance loss model, the test thermal resistance conduction loss and thermal resistance test temperature corresponding to different power loss parameters are obtained.
[0009] Obtain the switching loss of the semiconductor device corresponding to the power loss parameter;
[0010] Based on the tested thermal resistance conduction loss and switching loss, the total loss of the semiconductor device is obtained, and the total loss under different power loss parameters is calculated to obtain the total loss set.
[0011] The thermal resistance temperature test parameters are obtained, including bus voltage, thermal resistance switching frequency, modulation coefficient, coolant temperature, and coolant flow rate.
[0012] In the junction temperature test system, the power loss parameter and the thermal resistance temperature test parameter are adjusted according to the thermal resistance test temperature so that the thermal resistance junction temperature is equal to the thermal resistance test temperature. The power loss parameter and the thermal resistance temperature test parameter are then matched with the total loss set to obtain the adjustment loss corresponding to the power loss parameter.
[0013] A thermal resistance junction temperature database is established based on the aforementioned power loss adjustment parameters, power loss adjustment parameters, and thermal resistance temperature adjustment parameters.
[0014] Match the current power loss parameters and current thermal resistance temperature test parameters with the thermal resistance junction temperature database to obtain the current thermal resistance junction temperature and current total loss under the current power loss parameters and current thermal resistance temperature test parameters.
[0015] Based on the current thermal resistance junction temperature, the current total loss, and the current coolant flow rate, the current thermal resistance under the current power loss parameters and the current thermal resistance temperature test parameters is obtained.
[0016] Optionally, in the junction temperature testing system, the power loss parameters and the thermal resistance temperature test parameters are adjusted according to the thermal resistance test temperature so that the thermal resistance junction temperature equals the thermal resistance test temperature, thereby obtaining the adjusted power loss parameters and the adjusted thermal resistance temperature test parameters. These parameters are then matched with the total loss set to obtain the adjusted loss corresponding to the adjusted power loss parameters, including:
[0017] Based on the thermal resistance test temperature, the corresponding power loss parameters are obtained;
[0018] The power loss parameters are input into the junction temperature test system. The thermal resistance temperature test parameters and power loss parameters are adjusted so that the thermal resistance junction temperature is equal to the thermal resistance test temperature. The adjusted power loss parameters and the adjusted thermal resistance temperature test parameters are obtained. The adjusted power loss parameters and the adjusted thermal resistance temperature test parameters are matched with the total loss set to obtain the adjusted loss corresponding to the adjusted power loss parameters.
[0019] Optionally, the junction temperature testing system includes:
[0020] PC, thermal imager, high-voltage power supply, low-voltage power supply, motor, dynamometer, cooling system, black module and motor controller;
[0021] The PC is connected to the thermal imager and the motor controller; the high voltage and low voltage power supplies are connected to the motor controller; the cooling system and the motor are connected to the motor controller; and the motor is connected to the dynamometer and the cooling system.
[0022] The low-voltage power supply is used to power the motor controller, the high-voltage power supply is used to provide the bus voltage, the PC is used to control the start and stop of the motor controller, provide the three-phase current, display the motor control, and interact with the thermal imager to display the junction temperature, the cooling system is used to provide the specified coolant flow rate and temperature, the dynamometer is used to match the motor torque and speed, and the black module is used as the object for module junction temperature testing.
[0023] Optionally, obtaining the current thermal resistance based on the junction temperature, total loss, and current coolant flow rate, under the current power loss parameters and current thermal resistance temperature test parameters, includes:
[0024] The current thermal resistance is obtained by inputting the junction temperature of the thermal resistance, the total loss, and the current coolant flow rate into the thermal resistance formula.
[0025] The thermal resistance formula is:
[0026]
[0027] Among them, T f T represents the current coolant temperature. j P is the current thermal resistance junction temperature. d R represents the current thermal resistance loss power. th(j-f) This represents the current thermal resistance.
[0028] A method for determining whether a motor controller is operating normally includes:
[0029] A thermal resistance database for the motor controller is established based on power loss parameters, thermal resistance temperature test parameters, test thermal resistance, and thermal resistance junction temperature database. The test thermal resistance is the current thermal resistance obtained by the thermal resistance test method described above.
[0030] A thermal resistance database for the motor controller is established based on power loss parameters, thermal resistance temperature test parameters, test thermal resistance, and thermal resistance junction temperature database. The test thermal resistance is the current thermal resistance calculated using the current thermal resistance junction temperature, the current total loss, and the current coolant flow rate.
[0031] Obtain actual operating conditions, including actual power loss parameters and actual thermal resistance temperature parameters.
[0032] Based on the actual operating conditions and the thermal resistance database, the actual thermal resistance and actual total loss are obtained.
[0033] The actual junction temperature of the thermal resistance is calculated based on the actual thermal resistance, the actual total loss, and the coolant flow rate.
[0034] Determine whether the motor controller is operating normally based on the actual junction temperature of the thermal resistance.
[0035] Optionally, determining whether the motor controller is operating normally based on the actual junction temperature of the thermal resistance includes:
[0036] If the actual junction temperature is greater than the preset temperature threshold, an alarm message will be issued to confirm that the motor controller is not operating normally.
[0037] If the actual junction temperature is less than or equal to the preset temperature threshold, then the motor controller is determined to be operating normally.
[0038] A thermal resistance testing system, comprising:
[0039] The first acquisition module is used for power loss parameters, which include the effective value of the three-phase current of the motor, the power factor of the motor, and the modulation coefficient.
[0040] The first calculation module is used to obtain the test thermal resistance conduction loss and thermal resistance test temperature corresponding to different power loss parameters based on the power loss parameters and thermal resistance loss model.
[0041] The second acquisition module is used to acquire the switching loss of the semiconductor device corresponding to the power loss parameter;
[0042] The second calculation module is used to obtain the total loss of the semiconductor device based on the test thermal resistance conduction loss and switching loss, calculate the total loss under different power loss parameters, and obtain the total loss set.
[0043] The third acquisition module is used to acquire thermal resistance temperature test parameters, which include bus voltage, thermal resistance switching frequency, modulation coefficient, coolant temperature, and coolant flow rate.
[0044] The fourth acquisition module acquires thermal resistance temperature test parameters, including bus voltage, thermal resistance switching frequency, modulation coefficient, coolant temperature, and coolant flow rate.
[0045] The experimental module is used in the junction temperature test system to adjust the power loss parameter and the thermal resistance temperature test parameter according to the thermal resistance test temperature, so that the thermal resistance junction temperature is equal to the thermal resistance test temperature, to obtain the adjusted power loss parameter and the adjusted thermal resistance temperature test parameter, and to match the adjusted power loss parameter and the adjusted thermal resistance temperature test parameter with the total loss set to obtain the adjusted loss corresponding to the adjusted power loss parameter.
[0046] The database establishment module is used to establish a thermal resistance junction temperature database based on the power loss adjustment parameters, power loss adjustment parameters, and thermal resistance temperature adjustment test parameters.
[0047] The third calculation module is used to match the current power loss parameters and the current thermal resistance temperature test parameters with the thermal resistance junction temperature database to obtain the current thermal resistance junction temperature and the current total loss under the current power loss parameters and the current thermal resistance temperature test parameters.
[0048] The fourth calculation module is used to obtain the current thermal resistance under the current power loss parameters and the current thermal resistance temperature test parameters based on the current thermal resistance junction temperature, the current total loss, and the current coolant flow rate.
[0049] The experimental module includes:
[0050] The matching unit obtains the corresponding power loss parameters based on the thermal resistance test temperature;
[0051] An adjustment unit is used to input the power loss parameters into the junction temperature test system, adjust the thermal resistance temperature test parameters and the power loss parameters so that the thermal resistance junction temperature is equal to the thermal resistance test temperature, obtain the adjusted power loss parameters and the adjusted thermal resistance temperature test parameters, and match the adjusted power loss parameters and the adjusted thermal resistance temperature test parameters with the total loss set to obtain the adjusted loss corresponding to the adjusted power loss parameters.
[0052] A terminal device includes a memory and a processor. The memory stores a computer program that can run on the processor. When the processor loads and executes the computer program, a thermal resistance testing method is used.
[0053] A computer-readable storage medium storing a computer program, wherein the computer program employs a thermal resistance testing method when loaded and executed by a processor.
[0054] The beneficial effects of this invention are:
[0055] 1. Obtain the test thermal resistance parameters. Based on the test thermal resistance parameters and the thermal resistance loss model, obtain the corresponding conduction loss and switching loss, and calculate the total loss. Input the total loss, power loss parameters, and thermal resistance temperature test parameters into the junction temperature test system to conduct a junction temperature experiment, obtaining the adjusted power loss parameters, adjusted thermal resistance temperature test parameters, thermal resistance junction temperature, and total loss, forming a junction temperature database. Match the current power loss parameters and current thermal resistance temperature test parameters with the junction temperature database to obtain the current thermal resistance junction temperature and current total loss. Combine this with the current coolant flow rate to calculate the current thermal resistance. This application has the advantage of being unaffected by controller reception and being able to calculate the thermal resistance junction temperature under any operating condition. Compared with traditional thermal resistance calculation methods, this application can directly calculate the thermal resistance between the coolant and the heat source, rather than just calculating the thermal resistance of the thermal network.
[0056] 2. After calculating the thermal resistance, the thermal resistance, power loss parameters, and thermal resistance temperature parameters are managed to form a thermal resistance database. This makes it easy to calculate the thermal resistance junction temperature based on some parameters, or to calculate the thermal resistance junction temperature or thermal resistance itself based on some parameters when some data is lost. It can also quickly calculate the thermal resistance junction temperature to determine whether the motor controller is operating normally. Attached Figure Description
[0057] Figure 1 This is a schematic flowchart of a thermal resistance testing method according to the present invention;
[0058] Figure 2 This is a schematic diagram of the junction temperature testing system of the present invention.
[0059] Explanation of reference numerals in the attached diagram: 1. PC; 2. Thermal imager; 3. High-voltage power supply; 4. Low-voltage power supply; 5. Motor; 6. Dynamometer; 7. Cooling system; 8. Black module; 9. Motor controller. Detailed Implementation
[0060] The current capability of a motor controller is primarily determined by the current capability of the IGBT / SiC power semiconductor module, which is limited by the maximum operating junction temperature of the power semiconductor. Specifically, under any operating condition, the maximum junction temperature Tj of the power semiconductor chip must not exceed the maximum temperature required by the chip, with a certain margin.
[0061] The heat dissipation system of power semiconductors includes cooling fluid, heat sink, thermal grease, and power semiconductors. The thermal resistance of the power semiconductor is related to the overall heat dissipation.
[0062] A method for testing thermal resistance, where the thermal resistance is the thermal resistance between the power semiconductor of the motor controller and the coolant, such as... Figure 1 As shown, the present invention includes:
[0063] S1. Obtain power loss parameters, including the effective value of the three-phase current of the motor, the power factor of the motor, and the modulation coefficient.
[0064] Specifically, power loss parameters affect the conduction loss of power semiconductors under different parameters. The temperature at which thermal resistance is measured also varies under different power loss parameters; therefore, each power loss parameter corresponds to a specific conduction loss and thermal resistance test temperature.
[0065] S2. Based on the power loss parameters and the thermal resistance loss model, obtain the test thermal resistance conduction loss and thermal resistance test temperature corresponding to different power loss parameters.
[0066] Specifically, based on the thermal resistance loss model, the loss calculation formula is as follows:
[0067]
[0068] Among them, I p Here, is the effective value of the three-phase current of the motor, and m is the modulation coefficient. V is the motor power factor. ceo For the threshold voltage, R ce This is the on-state slope resistor.
[0069] S3. Obtain the switching losses of the semiconductor devices corresponding to the power loss parameters, calculate the total losses under different power loss parameters, and obtain the total loss set.
[0070] Specifically, switching losses are determined by the semiconductor device itself and can be obtained through chopping experiments. Switching losses are mainly related to the effective value of the three-phase current of the motor.
[0071] S4. Based on the tested thermal resistance conduction loss and switching loss, obtain the total loss of the semiconductor device, calculate the total loss under different power loss parameters, and obtain the total loss set.
[0072] Total loss = conduction loss + switching loss.
[0073] S5. Obtain thermal resistance temperature test parameters, including bus voltage, thermal resistance switching frequency, modulation coefficient, coolant temperature, and coolant flow rate.
[0074] S6. In the junction temperature test system, adjust the power loss parameters and the thermal resistance temperature test parameters according to the thermal resistance test temperature so that the thermal resistance junction temperature is equal to the thermal resistance test temperature. This yields the adjusted power loss parameters and the adjusted thermal resistance temperature test parameters. Match the adjusted power loss parameters and the adjusted thermal resistance temperature test parameters with the total loss set to obtain the adjusted loss corresponding to the adjusted power loss parameters.
[0075] Specifically, since the total loss corresponding to the power loss parameters has been calculated using the loss model, and the total loss has a corresponding thermal resistance temperature, the total loss at a certain thermal resistance junction temperature can be clearly known. However, the thermal resistance temperature test parameters affect the thermal resistance junction temperature. Therefore, a junction temperature experiment needs to be performed in the junction temperature test system to adjust the thermal resistance temperature test parameters and the power loss parameters so that the thermal resistance junction temperature equals the thermal resistance test temperature. Under a constant temperature, the total loss of the thermal resistance is known and can be found by looking up the total loss set.
[0076] At this point, the total loss, thermal resistance temperature, power loss parameters, and thermal resistance temperature parameters are all known, so the thermal resistance can be calculated.
[0077] In the junction temperature testing system, the power loss parameters and the thermal resistance temperature test parameters are adjusted according to the thermal resistance test temperature to make the thermal resistance junction temperature equal to the thermal resistance test temperature. This yields the adjusted power loss parameters and the adjusted thermal resistance temperature test parameters. These parameters are then matched with the total loss set to obtain the adjusted loss corresponding to the adjusted power loss parameters, which includes:
[0078] Based on the thermal resistance test temperature, the corresponding power loss parameters are obtained;
[0079] Input the power loss parameters into the junction temperature test system, adjust the thermal resistance temperature test parameters and the power loss parameters so that the thermal resistance junction temperature is equal to the thermal resistance test temperature, and obtain the adjusted power loss parameters and the adjusted thermal resistance temperature test parameters. Match the adjusted power loss parameters and the adjusted thermal resistance temperature test parameters with the total loss set to obtain the adjusted loss corresponding to the adjusted power loss parameters.
[0080] Specifically, after determining the temperature to be tested, the conduction loss and corresponding power loss parameters at that temperature must first be determined, and the corresponding power loss parameters must be input into the junction temperature testing system. Then, since the thermal resistance temperature test parameters will affect the thermal resistance junction temperature, the thermal resistance temperature parameters also need to be adjusted so that the temperature detected by the thermal imager is the same as the thermal resistance test temperature.
[0081] like Figure 2 As shown, the junction temperature testing system includes:
[0082] 1. PC, 2. Thermal imager, 3. High voltage power supply, 4. Low voltage power supply, 5. Motor, 6. Dynamometer, 7. Cooling system, 8. Black module, and 9. Motor controller;
[0083] PC 1 is connected to thermal imager 2 and motor controller 9, high voltage power supply 3 and low voltage power supply 4 are connected to motor controller 9, cooling system 7 and motor 5 are connected to motor controller 9, and motor 5 is connected to dynamometer 6 and cooling system 7.
[0084] Low-voltage power supply 4 supplies power to motor controller 9, high-voltage power supply 3 provides the given bus voltage, PC 1 controls the start / stop of motor controller 9, provides three-phase current, displays motor 5 control information, and interacts with thermal imager 2 for junction temperature display. Cooling system 7 provides the specified coolant flow rate and temperature. Dynamometer 6 matches the torque and speed of motor 5. Black module 8 is used as the object for thermal resistance junction temperature testing. Specifically, during the junction temperature experiment, low-voltage power supply 4 first supplies power to motor controller 9. Then, based on the tested thermal resistance parameters, it provides the corresponding bus voltage, effective value of motor three-phase current, motor speed, motor power factor, thermal resistance switching frequency, modulation coefficient, coolant temperature, and coolant flow rate to enable the junction temperature testing system to run. The thermal imager 2 then obtains the thermal resistance junction temperature under the power loss parameters and thermal resistance temperature test parameters.
[0085] Specifically, junction temperature testing is usually conducted under the same coolant flow rate, as the thermal resistance differs depending on the coolant flow rate.
[0086] S7. Establish a thermal resistance junction temperature database based on the power loss adjustment parameters, power loss adjustment parameters, and thermal resistance temperature adjustment parameters.
[0087] Specifically, by conducting multiple experiments, the power loss parameters and thermal resistance temperature test parameters corresponding to different thermal resistance test temperatures can be obtained, and a thermal resistance junction temperature database can be established.
[0088] S8 matches the current power loss parameters and current thermal resistance temperature test parameters with the thermal resistance junction temperature database to obtain the current thermal resistance junction temperature and current total loss under the current power loss parameters and current thermal resistance temperature test parameters.
[0089] S9. Based on the current thermal resistance junction temperature, current total loss, and current coolant flow rate, obtain the current power loss parameters and the current thermal resistance under the current thermal resistance temperature test parameters.
[0090] Input the thermal resistance junction temperature, total loss, and current coolant flow rate into the thermal resistance formula to obtain the current thermal resistance;
[0091] The thermal resistance formula is:
[0092]
[0093] Among them, T f T represents the current coolant temperature. j P is the current thermal resistance junction temperature. d R represents the current thermal resistance loss power. th(j-f) This represents the current thermal resistance.
[0094] The thermal resistance formula is:
[0095]
[0096] Among them, T f T represents the current coolant temperature. j P is the current thermal resistance junction temperature. d R represents the current thermal resistance loss power. th(j-f) This represents the current thermal resistance.
[0097] A method for determining whether a motor controller is operating normally includes:
[0098] Based on power loss parameters, thermal resistance temperature test parameters, test thermal resistance, and thermal resistance junction temperature database, a thermal resistance database for motor controllers is established. The test thermal resistance is the current thermal resistance obtained through thermal resistance testing methods.
[0099] Obtain actual operating conditions, including actual power loss parameters and actual thermal resistance and temperature parameters.
[0100] Based on actual operating conditions and thermal resistance database, the actual thermal resistance and actual total loss are obtained;
[0101] The actual junction temperature of the thermal resistance is calculated based on the actual thermal resistance, the actual total loss, and the coolant flow rate.
[0102] Determine whether the motor controller is operating normally based on the actual junction temperature of the thermal resistance.
[0103] Specifically, the thermal resistance junction temperature database can obtain the corresponding total loss and thermal resistance junction temperature from power loss parameters and thermal resistance temperature test parameters. Then, after calculating the thermal resistance, the thermal resistance junction temperature database is established by combining the thermal resistance under different thermal resistance parameters. The thermal resistance junction temperature database includes power loss parameters, thermal resistance temperature test parameters, corresponding thermal resistance junction temperatures, and thermal resistance.
[0104] Then, the actual junction temperature of the thermal resistance is calculated using the junction temperature formula:
[0105] T j =T f +P d ×R th(j-f)
[0106] Among them, T j P is the junction temperature of thermal resistance. d R is the power loss due to thermal resistance. th(j-f) For thermal resistance, T f This refers to the coolant temperature.
[0107] Therefore, as long as the power loss parameters and thermal resistance temperature test parameters are available, the corresponding thermal resistance junction temperature can be calculated. Then, by using the thermal resistance junction temperature, it can be determined whether the motor controller can operate normally.
[0108] Determining whether the motor controller is operating normally based on the actual junction temperature includes:
[0109] Determine whether the actual junction temperature is greater than the preset temperature threshold.
[0110] If the actual junction temperature is greater than the preset temperature threshold, an alarm message will be issued to confirm that the motor controller is not operating normally.
[0111] If the actual junction temperature is less than or equal to the preset temperature threshold, the motor controller is considered to be operating normally.
[0112] Specifically, the preset threshold is the highest allowable thermal resistance junction temperature. In practice, in order to protect power semiconductors, a margin is always left for the highest thermal resistance junction temperature. For example, if the highest thermal resistance junction temperature is A, then the actual set highest junction temperature is AB, where B is the margin. The thermal resistance junction temperature can be quickly obtained based on the power loss parameters and thermal resistance temperature test parameters, thereby quickly confirming whether the motor controller is operating normally.
[0113] A thermal resistance testing system, comprising:
[0114] The first acquisition module is used for power loss parameters, which include the effective value of the three-phase current of the motor, the power factor of the motor, and the modulation coefficient.
[0115] The first calculation module is used to obtain the test thermal resistance conduction loss and thermal resistance test temperature corresponding to different power loss parameters based on the power loss parameters and thermal resistance loss model.
[0116] The second acquisition module is used to acquire the switching loss of the semiconductor device corresponding to the power loss parameters;
[0117] The second calculation module is used to obtain the total loss of the semiconductor device based on the test thermal resistance conduction loss and switching loss, calculate the total loss under different power loss parameters, and obtain the total loss set.
[0118] The third acquisition module is used to acquire thermal resistance temperature test parameters, including bus voltage, thermal resistance switching frequency, modulation coefficient, coolant temperature, and coolant flow rate.
[0119] The fourth acquisition module acquires thermal resistance temperature test parameters, including bus voltage, thermal resistance switching frequency, modulation coefficient, coolant temperature, and coolant flow rate.
[0120] The experimental module is used in the junction temperature test system to adjust the power loss parameters and the thermal resistance temperature test parameters according to the thermal resistance test temperature, so that the thermal resistance junction temperature is equal to the thermal resistance test temperature, to obtain the adjusted power loss parameters and the adjusted thermal resistance temperature test parameters, and to match the adjusted power loss parameters and the adjusted thermal resistance temperature test parameters with the total loss set to obtain the adjusted loss corresponding to the adjusted power loss parameters.
[0121] The database creation module is used to create a thermal resistance junction temperature database based on the power loss adjustment parameters, power loss adjustment parameters, and thermal resistance temperature adjustment test parameters.
[0122] The third calculation module is used to match the current power loss parameters and the current thermal resistance temperature test parameters with the thermal resistance junction temperature database to obtain the current thermal resistance junction temperature and the current total loss under the current power loss parameters and the current thermal resistance temperature test parameters.
[0123] The fourth calculation module is used to obtain the current power loss parameters and the current thermal resistance under the current thermal resistance temperature test parameters based on the current thermal resistance junction temperature, the current total loss, and the current coolant flow rate.
[0124] The experimental modules include:
[0125] The matching unit obtains the corresponding power loss parameters based on the thermal resistance test temperature;
[0126] The adjustment unit is used to input power loss parameters into the junction temperature test system, adjust the thermal resistance temperature test parameters and power loss parameters so that the thermal resistance junction temperature is equal to the thermal resistance test temperature, obtain the adjusted power loss parameters and the adjusted thermal resistance temperature test parameters, match the adjusted power loss parameters and the adjusted thermal resistance temperature test parameters to the total loss set, and obtain the adjusted loss corresponding to the adjusted power loss parameters.
[0127] This application also discloses a terminal device, including a memory and a processor. The memory stores a computer program that can run on the processor. When the processor loads and executes the computer program, a thermal resistance testing method is used.
[0128] The terminal device can be a computer device such as a desktop computer, a laptop computer, or a cloud server. The terminal device includes, but is not limited to, a processor and a memory. For example, the terminal device may also include input / output devices, network access devices, and buses.
[0129] The processor can be a central processing unit (CPU). Of course, depending on the actual use, it can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), off-the-shelf programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc., and this application does not limit it in this regard.
[0130] The memory can be an internal storage unit of the terminal device, such as a hard disk or RAM of the terminal device, or an external storage device of the terminal device, such as a plug-in hard disk, smart memory card (SMC), secure digital card (SD), or flash memory card (FC) equipped on the terminal device. Furthermore, the memory can be a combination of internal storage units and external storage devices of the terminal device. The memory is used to store computer programs and other programs and data required by the terminal device. The memory can also be used to temporarily store data that has been output or will be output. This application does not limit this.
[0131] In this terminal device, a thermal resistance testing method from the above embodiments is stored in the terminal device's memory and loaded and executed on the terminal device's processor for convenient use.
[0132] This application also discloses a computer-readable storage medium, which stores a computer program, wherein when the computer program is executed by a processor, it employs a thermal resistance testing method described in the above embodiments.
[0133] The computer program can be stored in a computer-readable medium. The computer program includes computer program code, which can be in the form of source code, object code, executable file, or certain middleware. The computer-readable medium includes any entity or device capable of carrying computer program code, recording media, USB flash drive, portable hard drive, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the computer-readable medium includes, but is not limited to, the above-mentioned components.
[0134] The thermal resistance testing method described in the above embodiments is stored in the computer-readable storage medium and loaded and executed on the processor to facilitate the storage and application of the above method.
[0135] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of protection of this application is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of one or more embodiments of this application as described above, which are not provided in detail for the sake of brevity.
[0136] One or more embodiments in this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments in this application should be included within the protection scope of this application.
Claims
1. A method for testing thermal resistance, wherein the thermal resistance is the thermal resistance between the power semiconductor of a motor controller and the coolant, characterized in that, include: Obtain power loss parameters, including the effective value of the three-phase current of the motor, the power factor of the motor, and the modulation coefficient; Based on the power loss parameters and thermal resistance loss model, the test thermal resistance conduction loss and thermal resistance test temperature corresponding to different power loss parameters are obtained. Obtain the switching loss of the semiconductor device corresponding to the power loss parameter; Based on the tested thermal resistance conduction loss and switching loss, the total loss of the semiconductor device is obtained, and the total loss under different power loss parameters is calculated to obtain the total loss set. The thermal resistance temperature test parameters are obtained, including bus voltage, thermal resistance switching frequency, modulation coefficient, coolant temperature, and coolant flow rate. In the junction temperature test system, the power loss parameter and the thermal resistance temperature test parameter are adjusted according to the thermal resistance test temperature so that the thermal resistance junction temperature is equal to the thermal resistance test temperature. The power loss parameter and the thermal resistance temperature test parameter are then matched with the total loss set to obtain the adjustment loss corresponding to the power loss parameter. A thermal resistance junction temperature database is established based on the aforementioned power loss adjustment parameters, power loss adjustment parameters, and thermal resistance temperature adjustment parameters. Match the current power loss parameters and current thermal resistance temperature test parameters with the thermal resistance junction temperature database to obtain the current thermal resistance junction temperature and current total loss under the current power loss parameters and current thermal resistance temperature test parameters. Based on the current thermal resistance junction temperature, the current total loss, and the current coolant flow rate, the current thermal resistance under the current power loss parameters and the current thermal resistance temperature test parameters is obtained.
2. The thermal resistance testing method as described in claim 1, characterized in that, In the junction temperature testing system, the power loss parameters and the thermal resistance temperature test parameters are adjusted according to the thermal resistance test temperature so that the thermal resistance junction temperature equals the thermal resistance test temperature. This yields the adjusted power loss parameters and the adjusted thermal resistance temperature test parameters. These parameters are then matched with the total loss set to obtain the adjusted loss corresponding to the adjusted power loss parameters, which includes: Based on the thermal resistance test temperature, the corresponding power loss parameters are obtained; The power loss parameters are input into the junction temperature test system. The thermal resistance temperature test parameters and power loss parameters are adjusted so that the thermal resistance junction temperature is equal to the thermal resistance test temperature. The adjusted power loss parameters and the adjusted thermal resistance temperature test parameters are obtained. The adjusted power loss parameters and the adjusted thermal resistance temperature test parameters are matched with the total loss set to obtain the adjusted loss corresponding to the adjusted power loss parameters.
3. The thermal resistance testing method as described in claim 2, characterized in that, The junction temperature testing system includes: PC, thermal imager, high-voltage power supply, low-voltage power supply, motor, dynamometer, cooling system, black module and motor controller; The PC is connected to the thermal imager and the motor controller; the high voltage and low voltage power supplies are connected to the motor controller; the cooling system and the motor are connected to the motor controller; and the motor is connected to the dynamometer and the cooling system. The low-voltage power supply is used to power the motor controller, the high-voltage power supply is used to provide the bus voltage, the PC is used to control the start and stop of the motor controller, provide the three-phase current, display the motor control, and interact with the thermal imager to display the junction temperature, the cooling system is used to provide the specified coolant flow rate and temperature, the dynamometer is used to match the motor torque and speed, and the black module is used as the object for module junction temperature testing.
4. The thermal resistance testing method as described in claim 1, characterized in that, The process of obtaining the current thermal resistance based on the current thermal resistance junction temperature, the total current loss, and the current coolant flow rate, under the current power loss parameters and current thermal resistance temperature test parameters, includes: The current thermal resistance is obtained by inputting the junction temperature of the thermal resistance, the total loss, and the current coolant flow rate into the thermal resistance formula. The thermal resistance formula is: Among them, T f T represents the current coolant temperature. j P is the current thermal resistance junction temperature. d R represents the current thermal resistance loss power. th(j-f) This represents the current thermal resistance.
5. A method for determining whether a motor controller is operating normally, characterized in that, include: A thermal resistance database for the motor controller is established based on power loss parameters, thermal resistance temperature test parameters, test thermal resistance, and thermal resistance junction temperature database. The test thermal resistance is the current thermal resistance obtained by the thermal resistance test method as described in any one of claims 1-4. Obtain actual operating conditions, including actual power loss parameters and actual thermal resistance temperature parameters. Based on the actual operating conditions and the thermal resistance database, the actual thermal resistance and actual total loss are obtained. The actual junction temperature of the thermal resistance is calculated based on the actual thermal resistance, the actual total loss, and the coolant flow rate. Determine whether the motor controller is operating normally based on the actual junction temperature of the thermal resistance.
6. The method for determining whether a motor controller is operating normally as described in claim 5, characterized in that, Determining whether the motor controller is operating normally based on the actual junction temperature of the thermal resistance includes: Determine whether the actual junction temperature is greater than a preset temperature threshold. If the actual junction temperature is greater than the preset temperature threshold, an alarm message will be issued to confirm that the motor controller is not operating normally. If the actual junction temperature is less than or equal to the preset temperature threshold, then the motor controller is determined to be operating normally.
7. A thermal resistance testing system, characterized in that, include: The first acquisition module is used for power loss parameters, which include the effective value of the three-phase current of the motor, the power factor of the motor, and the modulation coefficient. The first calculation module is used to obtain the test thermal resistance conduction loss and thermal resistance test temperature corresponding to different power loss parameters based on the power loss parameters and thermal resistance loss model. The second acquisition module is used to acquire the switching loss of the semiconductor device corresponding to the power loss parameter; The second calculation module is used to obtain the total loss of the semiconductor device based on the test thermal resistance conduction loss and switching loss, calculate the total loss under different power loss parameters, and obtain the total loss set. The third acquisition module is used to acquire thermal resistance temperature test parameters, which include bus voltage, thermal resistance switching frequency, modulation coefficient, coolant temperature, and coolant flow rate. The fourth acquisition module acquires thermal resistance temperature test parameters, including bus voltage, thermal resistance switching frequency, modulation coefficient, coolant temperature, and coolant flow rate. The experimental module is used in the junction temperature test system to adjust the power loss parameter and the thermal resistance temperature test parameter according to the thermal resistance test temperature, so that the thermal resistance junction temperature is equal to the thermal resistance test temperature, to obtain the adjusted power loss parameter and the adjusted thermal resistance temperature test parameter, and to match the adjusted power loss parameter and the adjusted thermal resistance temperature test parameter with the total loss set to obtain the adjusted loss corresponding to the adjusted power loss parameter. The database establishment module is used to establish a thermal resistance junction temperature database based on the power loss adjustment parameters, power loss adjustment parameters, and thermal resistance temperature adjustment test parameters. The third calculation module is used to match the current power loss parameters and the current thermal resistance temperature test parameters with the thermal resistance junction temperature database to obtain the current thermal resistance junction temperature and the current total loss under the current power loss parameters and the current thermal resistance temperature test parameters. The fourth calculation module is used to obtain the current thermal resistance under the current power loss parameters and the current thermal resistance temperature test parameters based on the current thermal resistance junction temperature, the current total loss, and the current coolant flow rate.
8. The thermal resistance testing system as described in claim 7, characterized in that, The experimental module includes: The matching unit obtains the corresponding power loss parameters based on the thermal resistance test temperature; The adjustment unit is used to input the power loss parameters into the junction temperature test system, adjust the thermal resistance temperature test parameters and the power loss parameters so that the thermal resistance junction temperature is equal to the thermal resistance test temperature, obtain the adjusted power loss parameters and the adjusted thermal resistance temperature test parameters, and match the adjusted power loss parameters and the adjusted thermal resistance temperature test parameters with the total loss set to obtain the adjusted loss corresponding to the adjusted power loss parameters.
9. A terminal device, comprising a memory and a processor, characterized in that, The memory stores a computer program that can run on a processor, and when the processor loads and executes the computer program, it employs the thermal resistance testing method as described in any one of claims 1 to 4.
10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is loaded and executed by the processor, the thermal resistance test method as described in any one of claims 1 to 4 is used.