Simulink-comsol-based igbt temperature simulation method, system, medium and device

Abstract

The application relates to the field of power device temperature simulation, and discloses an IGBT temperature simulation method, system, medium and equipment based on Simulink-COMSOL, which comprises the following steps: a loss calculation model is built on a Simulink platform, input end current, bus voltage and radiator temperature are taken as inputs, current distribution is carried out according to a time sequence switching process, and dynamic power loss data of each IGBT chip and FWD chip is calculated respectively; the loss data is exported to a MATLAB workspace and is preprocessed by decimation, so that data format of a time-loss corresponding relationship is obtained; a three-dimensional model of an IGBT module is established in COMSOL software, and thermal physical properties and boundary conditions are configured; the preprocessed loss data is loaded as a spatial heat source on the corresponding chip, transient heat conduction simulation is carried out, and temperature field distribution results are obtained. The application combines the high efficiency of Simulink in transient electrical process calculation with the high precision of COMSOL in three-dimensional temperature field solving, realizes bidirectional coupling simulation of electricity and heat, and is suitable for temperature prediction of the IGBT module under steady state, transient state and complex working conditions.

Description

Technical Field

[0001] This invention relates to the field of power device temperature simulation technology, and in particular to an IGBT temperature simulation method, system, medium, and device based on Simulink-COMSOL. Background Technology

[0002] High-power IGBT modules are the core power conversion units of motor controllers in heavy-duty electromechanical equipment transmission systems. They are key components connecting control commands and motor power output, and are widely used in electromechanical composite transmission equipment such as heavy-duty commercial vehicles and special-purpose vehicles. These types of equipment often operate under continuous and harsh conditions of alternating high and low temperatures, high vibration, and high loads, which can easily lead to thermal degradation of the IGBT modules. Since the IGBT module's chip temperature cannot be directly collected due to packaging limitations, establishing an accurate junction temperature calculation model and conducting thermal management research are crucial prerequisites for ensuring the reliable operation of the transmission system.

[0003] With the development of computer simulation technology, more accurate models can be established based on module size parameters and working principles. Co-simulation using computer simulation technology allows for the assessment of device performance and reduces testing costs. The parameters of the simulation model can also be adjusted according to the operational requirements of different modules. Therefore, constructing an accurate temperature simulation model is a prerequisite for studying device reliability.

[0004] Numerous studies have been conducted by scholars both domestically and internationally on electrothermal coupling modeling of IGBT devices. The physical thermal network method, based on the thermal-electric analogy principle, equates IGBT heat conduction to an RC network. The Cauer model fits the layered physical structure, while the Foster model, based on transient thermal impedance fitting, enables rapid virtual junction temperature calculation. The finite element method (FEM), based on multiphysics coupling theory, solves the Fourier heat conduction equation by discretizing the three-dimensional structure, integrating Joule heating and switching loss heat sources, and considering the temperature dependence of material parameters to achieve bidirectional electrothermal coupling simulation. Circuit simulation based on physical models can accurately characterize the electrical characteristics of IGBTs at different temperatures. However, due to the limitation of the number of nodes in the thermal network, the calculated temperature distribution is discontinuous, and it cannot simulate changes in IGBT electrothermal characteristics caused by package fatigue degradation. Therefore, it is generally used for regional junction temperature prediction. The FEM is a numerical solution method based on materials and structure, capable of accurately solving the temperature and stress characteristics of IGBTs. However, due to the unique semiconductor characteristics and structural scale differences of IGBTs, it cannot describe the transient switching process of electronic devices. Summary of the Invention

[0005] To address the aforementioned issues, the present invention aims to provide an IGBT temperature simulation method, system, medium, and device based on Simulink-COMSOL. Through co-simulation, the working principle of the IGBT module is analyzed, and the temperature changes under steady-state and transient input conditions are simulated using the module input current, bus voltage, and heat sink temperature as inputs, including the module junction temperature and temperature field distribution.

[0006] To achieve the above objectives, in a first aspect, the technical solution adopted by the present invention is as follows: an IGBT temperature simulation method based on Simulink-COMSOL, comprising: building a loss calculation model on the Simulink platform, wherein the loss calculation model takes the input current, bus voltage and heat sink temperature of the IGBT module as inputs, and performs current distribution according to the timing switching process of the IGBT module, and calculates the dynamic power loss data generated by each IGBT chip and each FWD chip respectively; exporting the calculated dynamic power loss data to the MATLAB workspace, and performing downsampling preprocessing on the dynamic power loss data to ensure that its data volume meets the compatibility requirements of the COMSOL software, and obtaining a data format containing the correspondence between time and loss; establishing a three-dimensional model of the IGBT module in the COMSOL software, and configuring thermophysical properties and boundary conditions; loading the downsampling preprocessed dynamic power loss data as a spatial heat source onto the corresponding IGBT chip and FWD chip in the three-dimensional model respectively, performing transient heat conduction simulation, and obtaining the simulation results of the temperature field distribution of the IGBT module.

[0007] Furthermore, the loss calculation model includes the calculation of conduction loss and switching loss; wherein, conduction loss is determined based on the tube voltage drop and collector current when conducting, and switching loss is determined based on the single switching energy and switching frequency.

[0008] Furthermore, the dynamic power loss data generated by each IGBT chip and each FWD chip are calculated separately, including:

[0009] The output characteristic curves and switching characteristic curves of IGBT chips and FWD chips at multiple temperature points were extracted from the datasheets, and the current-voltage mapping relationship under continuous temperature was established by interpolation. Current distribution is performed according to the timing switching process of the IGBT module. The current distribution includes: when the DC bus current is input, the current flowing through the upper bridge IGBT chip, the lower bridge IGBT chip, the upper bridge FWD chip and the lower bridge FWD chip are determined according to the different current directions. The current flowing through any chip is determined by the product of the duty cycle and the DC bus current. The power loss generated by the chip is obtained by multiplying the current allocated to a single chip and the real-time saturation voltage drop corresponding to the chip's current and junction temperature, which is read from the current-voltage mapping relationship.

[0010] Furthermore, a thermal network model is built on the Simulink platform. The thermal network model is a Foster thermal network model. The thermal network model is used to calculate the junction temperature of the IGBT module based on the chip loss. The calculated junction temperature is fed back to the front end of the loss calculation model as input conditions to form electrothermal coupling.

[0011] Furthermore, the calculated dynamic power loss data is exported to the MATLAB workspace, and downsampling preprocessing is performed on the dynamic power loss data, including: The calculated dynamic power loss data was exported to the MATLAB workspace using the To workspace module in the Simulink platform for later use. Based on the compatibility requirements of COMSOL software for input data, the exported dynamic power loss data is downsampled and optimized. Linear interpolation or moving average methods are used to reduce the data density so that the amount of loss data in a single set is controlled within a preset threshold. Outliers exceeding the normal range in the loss data are removed. The preprocessed data is then converted into a text or MAT format supported by COMSOL software using a MATLAB script. This text or MAT format contains column identifiers indicating the correspondence between time and loss.

[0012] Furthermore, a three-dimensional model of the IGBT module is created in COMSOL software, and its thermophysical properties and boundary conditions are configured, including: The layered structural parts of the IGBT module are drawn using CAD software, and the assembled 3D model is imported into COMSOL to simplify non-critical structures. Based on the material properties of each layer, thermal conductivity, specific heat capacity and density are configured in the COMSOL material library, and temperature dependence settings are enabled, where the thermal conductivity of silicon decreases linearly with increasing temperature; The three-dimensional model is discretized using a triangular mesh and sweep method. The mesh is refined for the chip heat-generating area, solder layer and substrate contact surface. The optimal mesh scheme that balances computational accuracy and efficiency is determined by mesh independence verification. The heat dissipation method on the outer surface of the heat sink is equivalent to the convection heat transfer boundary. The convection heat transfer coefficient is set according to the actual working conditions, the ambient reference temperature is set, and the contact surface between the chip and the solder layer and the DCB substrate is set to perfect thermal contact conditions.

[0013] Furthermore, the downsampled preprocessed dynamic power loss data is used as a spatial heat source and loaded onto the corresponding IGBT chip and FWD chip in the 3D model, respectively, to perform transient heat conduction simulation, including: In the COMSOL software, select the transient heat conduction physics field; The dynamic power loss data after downsampling preprocessing is imported through the interpolation function module. The dynamic power loss data is a data format that includes the correspondence between time and loss. The imported dynamic power loss data is mapped to the spatial heat source of the chip area and loaded onto the corresponding IGBT chip and FWD chip in the 3D model respectively. Set the simulation time range to match the loss simulation cycle of the Simulink platform; use an adaptive time step for transient heat conduction simulation calculations and set convergence criteria; After the simulation is completed, the simulation results of the temperature field distribution will be output.

[0014] Secondly, the technical solution adopted by this invention is as follows: an IGBT temperature simulation system based on Simulink-COMSOL, comprising: a loss calculation module, which builds a loss calculation model on the Simulink platform, the loss calculation model taking the input current, bus voltage and heat sink temperature of the IGBT module as inputs, and performs current distribution according to the timing switching process of the IGBT module, and calculates the dynamic power loss data generated by each IGBT chip and each FWD chip respectively; a data preprocessing module, which exports the calculated dynamic power loss data to the MATLAB workspace, and performs downsampling preprocessing on the dynamic power loss data to make its data volume meet the compatibility requirements of the COMSOL software, and obtains a data format containing the correspondence between time and loss; a three-dimensional modeling module, which builds a three-dimensional model of the IGBT module in the COMSOL software and configures the thermophysical properties and boundary conditions; and a simulation execution module, which loads the downsampling preprocessed dynamic power loss data as a spatial heat source onto the corresponding IGBT chip and FWD chip in the three-dimensional model respectively, performs transient heat conduction simulation, and obtains the simulation results of the temperature field distribution of the IGBT module.

[0015] Thirdly, the technical solution adopted by the present invention is: a computer-readable storage medium for storing one or more programs, wherein the one or more programs include instructions, which, when executed by a computing device, cause the computing device to perform any of the methods described above.

[0016] Fourthly, the technical solution adopted by the present invention is: a computing device comprising: one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include instructions for performing any of the methods described above.

[0017] The present invention has the following advantages due to the adoption of the above technical solutions: 1. This invention considers the electrothermal coupling process in module loss calculation and uses a modeling approach based on external characteristics to characterize electrothermal coupling. It avoids the analysis path of directly introducing microscopic physical parameters such as carrier mobility and bandgap width, and instead starts from the output characteristic curve that can be measured in engineering to establish a loss coupling model that can be calculated in real time.

[0018] 2. The timing switching and current distribution model built by the present invention through the Simulink platform can accurately reproduce the fast switching process of IGBT devices, solving the problem that the traditional finite element method cannot describe transient electrical behavior; the three-dimensional temperature field simulation in COMSOL can output continuous and fine global temperature distribution, making up for the defect of discontinuous temperature distribution in the physical thermal network method.

[0019] 3. The model of this invention, through parametric design, can be adapted to different models of IGBT modules by adjusting the module structure size and material properties, based on key parameters such as those in the target module datasheet or experimentally measured characteristic curves, thus significantly improving the versatility of the technical solution.

[0020] 4. The model of this invention takes power loss as the core connection point and constructs a collaborative link between Simulink electrical loss simulation and COMSOL thermal conduction simulation. It retains Simulink's high efficiency in transient electrical process calculation and leverages COMSOL's high precision advantage in solving three-dimensional temperature fields. It achieves a balance between fast calculation and accurate results, and solves the problem that cross-software simulation methods are limited to microsecond-level short-circuit conditions. It can effectively adapt to the steady-state, transient and extremely complex conditions of heavy-duty equipment.

[0021] 5. The junction temperature and temperature distribution of the simulation module of this invention lay a good foundation for subsequent reliability research and can also provide data support for training neural networks. Attached Figure Description

[0022] Figure 1 This is a flowchart of the IGBT temperature simulation method based on Simulink-COMSOL in this embodiment of the invention; Figure 2 This is a three-dimensional model diagram of the IGBT module in an embodiment of the present invention; Figure 3This is the three-dimensional output characteristic surface of the IGBT chip after interpolation in the embodiments of the present invention; Figure 4 This is the three-dimensional output characteristic surface of the diode chip after interpolation in the embodiments of the present invention; Figure 5 This is a diagram of the Foster thermal network model used in the Simulink model in this embodiment of the invention; Figure 6 This is a schematic diagram of the Simulink loss calculation model in an embodiment of the present invention; Figure 7 This is a flowchart of loss data preprocessing and cross-platform interaction in an embodiment of the present invention. Detailed Implementation

[0023] The present invention proposes an IGBT temperature simulation method, system, medium, and device based on Simulink-COMSOL. The co-simulation model mainly consists of two parts. A complete electrothermal coupling loss calculation model is built on the Simulink platform, and the loss results are imported into COMSOL as a spatial heat source. The mathematical model built in Simulink can simulate the current distribution method of the device during switching, calculating the loss of each chip by the time the current flows through each chip. A three-dimensional model of the module is built in COMSOL, and the dynamic power loss data calculated by the loss calculation model is loaded onto the chip as a heat source to simulate the heat generation and heat transfer process of the module.

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0025] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0026] In one embodiment of the present invention, an IGBT temperature simulation method based on Simulink-COMSOL is provided. Using bus voltage, DC current, and other conditions as inputs, the input conditions during IGBT module operation are recreated. Loss calculations are performed in Simulink, and a mathematical loss calculation model is built based on the experimentally measured electrical parameter correspondences. A thermal network model is connected to the loss calculation backend, and after junction temperature calculation, the junction temperature is fed back to the front end of the loss calculation module as input for the corresponding relationship to calculate dynamic losses. The loss calculation results are then imported into COMSOL as the spatial heat source for chip heat generation to complete temperature field simulation. The model can calculate the temperature distribution in the three-dimensional space of the module while recreating the rapid switching behavior of the device.

[0027] Specifically, such as Figure 1 As shown, the IGBT temperature simulation method includes the following steps: 1) A loss calculation model was built on the Simulink platform. The model takes the input current, bus voltage, and heatsink temperature of the IGBT module as inputs and performs current distribution according to the timing switching process of the IGBT module. The dynamic power loss data generated by each IGBT chip and each FWD chip were calculated separately. Each repeating unit in the IGBT module consists of an IGBT chip and a freewheeling diode (FWD) chip. The IGBT chip controls the on / off state of the main circuit current, realizing controllable energy conversion. The FWD chip provides reverse recovery freewheeling, absorbs back electromotive force, and protects the IGBT chip. Both generate heat during operation.

[0028] 2) Export the calculated dynamic power loss data to the MATLAB workspace, and perform downsampling preprocessing on the dynamic power loss data to ensure that the data volume meets the compatibility requirements of the COMSOL software, so as to obtain a data format containing the correspondence between time and loss.

[0029] 3) Create a three-dimensional model of the IGBT module in COMSOL software and configure its thermophysical properties and boundary conditions.

[0030] 4) The downsampled preprocessed dynamic power loss data is used as a spatial heat source and loaded onto the corresponding IGBT chip and FWD chip in the three-dimensional model respectively. Transient heat conduction simulation is performed to obtain the simulation results of the temperature field distribution of the IGBT module.

[0031] In step 1) above, the loss calculation model includes the calculation of conduction loss and switching loss; wherein, conduction loss is determined based on the tube voltage drop and collector current when conducting, and switching loss is determined based on the single switching energy and switching frequency.

[0032] In this embodiment, specifically, the loss composition of the IGBT module is calculated and analyzed to clarify the calculation methods for the module's on-state loss and switching loss; the thermal properties and structural dimensional parameters of each layer of material are determined. The calculation formulas for the on-state and switching losses of the IGBT module are compiled to prepare for the loss model construction below. The module's on-state loss is calculated using the following formula (1), and the module's switching loss is calculated using the following formula (2): (1) In equation (1), P cond For the on-state loss of the IGBT module V ce_sat The pressure drop across the tube when it is conducting. I c This is the collector current. This loss increases significantly with increasing current and is the main heat source for the module under steady-state operation.

[0033] (2) In equation (2), P sw This refers to the single-cycle switching loss of the device. （E on + E off ） Energy for a single switch operation f sw This refers to the switching frequency. The energy required for a single switching operation is extremely small, but repeated high-frequency switching can accumulate into considerable power consumption.

[0034] The total loss of an IGBT module is the sum of its conduction loss and switching loss over a period of time.

[0035] In step 1) above, the dynamic power loss data generated by each IGBT chip and each FWD chip is calculated, including the following steps: 1.1) Extract the output characteristic curves and switching characteristic curves of the IGBT chip and FWD chip at multiple temperature points from the datasheet, and establish the current-voltage mapping relationship under continuous temperature using the interpolation method.

[0036] In this embodiment, an interpolation method is used to establish a current-voltage mapping surface under continuous temperature to obtain the current and voltage required for power loss calculation, such as... Figure 3 , Figure 4 As shown.

[0037] 1.2) Current distribution is performed according to the timing switching process of the IGBT module. The current distribution includes: when the DC bus current is input, the current flowing through the upper bridge IGBT chip, the lower bridge IGBT chip, the upper bridge FWD chip and the lower bridge FWD chip are determined according to the different current directions. The current flowing through any chip is determined by the product of the duty cycle and the DC bus current.

[0038] Specifically, when the DC bus current is input, if the current flowing into the motor winding is positive, the current flowing through the upper bridge IGBT chip in one switching cycle is the product of the duty cycle and the DC bus current, and the current flowing through the lower bridge FWD chip is the product of (1 - duty cycle) and the DC bus current; if the current is negative, the current flowing through the lower bridge IGBT chip in one switching cycle is the product of the duty cycle and the DC bus current, and the current flowing through the upper bridge FWD chip is the product of (1 - duty cycle) and the DC bus current.

[0039] In this embodiment, as Figure 6 As shown, the current distribution module is established according to equations (3) and (4). After the DC bus current is input, the current flowing into the motor winding is defined as positive. At this time, the current flows through the upper bridge IGBT and the lower bridge diode for freewheeling. The current flowing through these two devices in one switching cycle is: (3) In the formula, i TH and i DL These represent the currents passing through the IGBT upper bridge and the diode lower bridge, respectively. dutycycle Duty cycle refers to the percentage of time the device is in the on state within one switching cycle; This represents the instantaneous bus current.

[0040] When the current is negative, it freewheels through the lower IGBT and the upper diode. The average current flowing through these two devices is: (4) In the formula, i TL and i DH These represent the currents passing through the IGBT lower bridge and the diode upper bridge, respectively.

[0041] 1.3) The power loss generated by the chip is obtained by multiplying the current allocated to a single chip and the real-time saturation voltage drop corresponding to the current and junction temperature of the chip, which is read from the current-voltage mapping relationship.

[0042] In this embodiment, the output characteristic curves and switching characteristic curves of the IGBT and FWD chips are extracted from the datasheet and used in the loss calculation module to calculate the power loss by multiplying the current and voltage. The datasheet provided by the manufacturer provides the corresponding curves of collector current and saturation voltage drop under test conditions of 25℃, 100℃ and 125℃. The power loss generated by a single chip is calculated by the following formula (5): (5) In the formula, P chip_i The power loss generated by the i-th chip; I c The magnitude of the current flowing through the collector is determined by the amount of current allocated to a single chip. V CE （T） This is to output the collector current and junction temperature corresponding to the real-time saturation voltage drop on the characteristic surface.

[0043] In this embodiment, a thermal network model (such as...) is also built on the Simulink platform. Figure 5 As shown), the thermal network model is the Foster thermal network model. The thermal network model is used to calculate the junction temperature of the IGBT module based on the chip loss, and feeds the calculated junction temperature back to the front end of the loss calculation model as input conditions to form electrothermal coupling.

[0044] In this embodiment, specifically, as shown in... Figure 6 As shown, the Foster thermal network model is established according to equations (6) to (11): The temperature difference between the two ends of each structural layer is T. i ,have: (6) In the formula, Ploss For chip wear; T i For the chip i The transient temperature rise of the layer at the current moment; R i This is the thermal resistance of the layer; C i This is the heat capacity of the layer.

[0045] Taking the Laplace transform of equation (6) yields: (7) In the formula, S The complex frequency of the Laplace transform is used to convert the thermal dynamics equations in the time domain to the frequency domain for solution and analysis. The total temperature is: (8) From (8), we obtain the difference equation: (9) In the formula, z The difference equation and recursive formula calculate the junction temperature at the current time step based on the temperature and power loss of the previous time step, thus achieving the recursive calculation of the junction temperature: (10) In the formula, a , b The coefficients of the difference equation are given, and the overall recursive formula for the module junction temperature is: (11) In the formula, T total_k This is the junction temperature of the module.

[0046] In step 2) above, the calculated dynamic power loss data is exported to the MATLAB workspace, and the dynamic power loss data is downsampled and preprocessed, such as... Figure 7 As shown, it includes the following steps: 2.1) Use the To workspace module in the Simulink platform to export the calculated dynamic power loss data to the MATLAB workspace for later use.

[0047] In this embodiment, the To workspace module is used to export the calculated loss results to the MATLAB workspace for later use. In COMSOL, if the amount of input data is too dense, the calculation may fail to read it. Simulink simulation results are generally much larger than the amount of data in the function edited in COMSOL. The downsampling method should be selected according to the amount of data and the characteristics of the function.

[0048] The data format is defined as a "time-loss" two-column time series matrix.

[0049] 2.2) Based on the compatibility requirements of COMSOL software for input data, the exported dynamic power loss data is downsampled and optimized. Linear interpolation or moving average methods are used to reduce the data density so that the amount of loss data in a single set is controlled within a preset threshold.

[0050] In this embodiment, to address COMSOL's compatibility requirements with input data, data downsampling optimization is performed: based on the upper limit of the time step size for COMSOL transient simulation (it is recommended that the ratio to the Simulink simulation step size not exceed 5:1), linear interpolation or moving average methods are used to reduce data density, ensuring that the amount of loss data per set is controlled within 10. 5 Within a certain limit, avoid overflow in the COMSOL function editor.

[0051] 2.3) Perform data validation and format conversion. Remove outliers from the loss data that are outside the normal range. Use a MATLAB script to convert the preprocessed data into a text or MAT format supported by COMSOL software. This text or MAT format contains column identifiers indicating the correspondence between time and loss ("Time / s", "Ploss / W") to ensure the continuity of time series and the accuracy of numerical values.

[0052] In this embodiment, it should be noted that attention should be paid to the sampling frequency when exporting the working area to avoid excessively dense timing loss data that would prevent COMSOL from recognizing it.

[0053] In step 3) above, a three-dimensional model of the IGBT module is created in COMSOL software, and its thermophysical properties and boundary conditions are configured, including the following steps: 3.1) As Figure 2 As shown, the layered structure parts of the IGBT module are drawn using CAD software, and the assembled 3D model is imported into COMSOL to simplify non-critical structures.

[0054] In this embodiment, the layered structure parts drawing of the IGBT module is drawn using CATIA and assembled, and then the non-critical structures are simplified after being imported into COMSOL.

[0055] 3.2) Based on the material properties of each layer, configure parameters such as thermal conductivity, specific heat capacity and density in the COMSOL material library, and enable temperature dependence settings, where the thermal conductivity of silicon decreases linearly with increasing temperature.

[0056] In this embodiment, the temperature dependence setting refers to setting the material's thermophysical property parameters (such as thermal conductivity, specific heat capacity, density, etc.) as a function of temperature change, rather than a constant value, during the COMSOL simulation modeling process. For example, the thermal conductivity of silicon decreases linearly with increasing temperature.

[0057] 3.3) The three-dimensional model is discretized using a triangular mesh and sweep method. The mesh is refined for the chip heat-generating area, solder layer and substrate contact surface. The optimal mesh scheme that balances computational accuracy and efficiency is determined by mesh independence verification.

[0058] Specifically, since the IGBT structure layer is approximately a cuboid structure, a triangular mesh and sweeping method is used to discretize the model. The mesh is refined for key heat transfer interfaces such as the chip heating area, solder layer and substrate contact surface, while a coarser mesh is used for non-critical areas. The optimal mesh scheme that balances computational accuracy and efficiency is determined through mesh independence verification.

[0059] 3.4) The heat dissipation method of the outer surface of the heat sink is equivalent to the convection heat transfer boundary. The convection heat transfer coefficient is set according to the actual working conditions, the ambient reference temperature is set, and the contact surface between the chip and the solder layer and the DCB substrate is set to perfect thermal contact conditions.

[0060] In this embodiment, the ambient reference temperature is set to 25°C.

[0061] In step 4) above, the temperature field is calculated. After the simulation is completed, the time-step simulation results of the IGBT temperature field and the simulation results of the maximum temperature point at the Simulink terminal can be obtained. Specifically, the downsampled preprocessed dynamic power loss data is used as a spatial heat source and loaded onto the corresponding IGBT chip and FWD chip in the 3D model respectively, and transient heat conduction simulation is performed, including the following steps: 4.1) Select the transient heat conduction physics field in the COMSOL software.

[0062] 4.2) Import the downsampling preprocessed dynamic power loss data through the interpolation function module. The dynamic power loss data is a data format that includes the correspondence between time and loss.

[0063] 4.3) The imported dynamic power loss data is mapped to the spatial heat source of the chip area and loaded onto the corresponding IGBT chip and FWD chip in the three-dimensional model respectively.

[0064] 4.4) Set the simulation time range to be consistent with the loss simulation cycle of the Simulink platform; use an adaptive time step for transient heat conduction simulation calculations and set convergence criteria.

[0065] In this embodiment, the convergence criterion is a relative error ≤ 1e-4.

[0066] 4.5) Output the simulation results of the temperature field distribution after the simulation is completed.

[0067] In this embodiment, the simulation results of the temperature field distribution include two categories: (1) Temperature field time-step evolution data, including three-dimensional temperature distribution cloud map at different times and temperature gradient curve of chip center section.

[0068] (2) Temperature time series data of feature points, including the maximum junction temperature calculated by the Simulink end, the temperature change curves of key nodes such as the chip center at the COMSOL end, the upper surface of the DCB substrate, and the lower surface of the heat sink.

[0069] In this embodiment, all results are exported in Excel (data table), PNG / EPS (image), and MAT (raw data) formats to provide standardized data support for subsequent IGBT reliability analysis, thermal management optimization, and neural network training.

[0070] In summary, this invention uses the parameters in the target module datasheet as a basis and employs interpolation to establish a current-voltage mapping surface under continuous temperature to obtain the current and voltage required for power loss calculation. Referring to the constructed characteristic surface, and considering the input temperature and the flowing current, the power loss calculation results are obtained. By further refining the mesh in the key heat-generating areas of the chip, both computational accuracy and efficiency are considered, and the heat dissipation condition is equivalent to the convective heat transfer coefficient.

[0071] In one embodiment of the present invention, an IGBT temperature simulation system based on Simulink-COMSOL is provided, comprising: The loss calculation module builds a loss calculation model on the Simulink platform. The loss calculation model takes the input current of the IGBT module, the bus voltage and the heat sink temperature as inputs, and performs current distribution according to the timing switching process of the IGBT module to calculate the dynamic power loss data generated by each IGBT chip and each FWD chip respectively. The data preprocessing module exports the calculated dynamic power loss data to the MATLAB workspace and performs downsampling preprocessing on the dynamic power loss data to ensure that the data volume meets the compatibility requirements of the COMSOL software, resulting in a data format that includes the correspondence between time and loss. The 3D modeling module creates a 3D model of the IGBT module in COMSOL software and configures its thermophysical properties and boundary conditions. The simulation execution module loads the downsampled and preprocessed dynamic power loss data as a spatial heat source onto the corresponding IGBT chip and FWD chip in the three-dimensional model, respectively, and performs transient heat conduction simulation to obtain the simulation results of the temperature field distribution of the IGBT module.

[0072] In the above embodiments, the loss calculation model includes the calculation of conduction loss and switching loss; wherein, conduction loss is determined based on the tube voltage drop and collector current when conducting, and switching loss is determined based on the single switching energy and switching frequency.

[0073] In the above embodiments, the dynamic power loss data generated by each IGBT chip and each FWD chip are calculated, including: The output characteristic curves and switching characteristic curves of IGBT chips and FWD chips at multiple temperature points were extracted from the datasheets, and the current-voltage mapping relationship under continuous temperature was established by interpolation. Current distribution is performed according to the timing switching process of the IGBT module. The current distribution includes: when the DC bus current is input, the current flowing through the upper bridge IGBT chip, the lower bridge IGBT chip, the upper bridge FWD chip and the lower bridge FWD chip are determined according to the different current directions. The current flowing through any chip is determined by the product of the duty cycle and the DC bus current. The power loss generated by the chip is obtained by multiplying the current allocated to a single chip and the real-time saturation voltage drop corresponding to the chip's current and junction temperature, which is read from the current-voltage mapping relationship.

[0074] In the above embodiments, a thermal network model is built on the Simulink platform. The thermal network model is a Foster thermal network model. The thermal network model is used to calculate the junction temperature of the IGBT module based on the chip loss. The calculated junction temperature is fed back to the front end of the loss calculation model as input conditions to form electrothermal coupling.

[0075] In the above embodiments, exporting the calculated dynamic power loss data to the MATLAB workspace and performing downsampling preprocessing on the dynamic power loss data includes: The calculated dynamic power loss data was exported to the MATLAB workspace using the To workspace module in the Simulink platform for later use. Based on the compatibility requirements of COMSOL software for input data, the exported dynamic power loss data is downsampled and optimized. Linear interpolation or moving average methods are used to reduce the data density so that the amount of loss data in a single set is controlled within a preset threshold. Outliers exceeding the normal range in the loss data are removed. The preprocessed data is then converted into a text or MAT format supported by COMSOL software using a MATLAB script. This text or MAT format contains column identifiers indicating the correspondence between time and loss.

[0076] In the above embodiments, a three-dimensional model of the IGBT module is created in COMSOL software, and its thermophysical properties and boundary conditions are configured, including: The layered structural parts of the IGBT module are drawn using CAD software, and the assembled 3D model is imported into COMSOL to simplify non-critical structures. Based on the material properties of each layer, thermal conductivity, specific heat capacity and density are configured in the COMSOL material library, and temperature dependence settings are enabled, where the thermal conductivity of silicon decreases linearly with increasing temperature; The three-dimensional model is discretized using a triangular mesh and sweep method. The mesh is refined for the chip heat-generating area, solder layer and substrate contact surface. The optimal mesh scheme that balances computational accuracy and efficiency is determined by mesh independence verification. The heat dissipation method on the outer surface of the heat sink is equivalent to the convection heat transfer boundary. The convection heat transfer coefficient is set according to the actual working conditions, the ambient reference temperature is set, and the contact surface between the chip and the solder layer and the DCB substrate is set to perfect thermal contact conditions.

[0077] In the above embodiments, the downsampling preprocessed dynamic power loss data is used as a spatial heat source and loaded onto the corresponding IGBT chip and FWD chip in the three-dimensional model, respectively. The transient heat conduction simulation includes: In the COMSOL software, select the transient heat conduction physics field; The dynamic power loss data after downsampling preprocessing is imported through the interpolation function module. The dynamic power loss data is a data format that includes the correspondence between time and loss. The imported dynamic power loss data is mapped to the spatial heat source of the chip area and loaded onto the corresponding IGBT chip and FWD chip in the 3D model respectively. Set the simulation time range to match the loss simulation cycle of the Simulink platform; use an adaptive time step for transient heat conduction simulation calculations and set convergence criteria; After the simulation is completed, the simulation results of the temperature field distribution are output. The simulation results of the temperature field distribution include three-dimensional temperature distribution cloud maps at different times, temperature gradient curves of the chip center section, and temperature change curves of key nodes including the maximum junction temperature calculated by the Simulink end, the chip center at the COMSOL end, the upper surface of the DCB substrate, and the lower surface of the heat sink.

[0078] The system provided in this embodiment is used to execute the above-described method embodiments. For specific processes and details, please refer to the above embodiments, which will not be repeated here.

[0079] In one embodiment of the present invention, a computing device is provided. This computing device can be a terminal and may include a processor, a communication interface, memory, a display screen, and an input device. The processor, communication interface, and memory communicate with each other via a communication bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system and computer programs. When the computer programs are executed by the processor, they implement the methods described in the above embodiments. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The communication interface is used for wired or wireless communication with external terminals. Wireless communication can be achieved through Wi-Fi, a network management system, NFC (Near Field Communication), or other technologies. The display screen can be a liquid crystal display (LCD) or an e-ink display. The input device can be a touch layer covering the display screen, or buttons, a trackball, or a touchpad mounted on the casing of the computing device, or an external keyboard, touchpad, or mouse. The processor can call logical instructions stored in the memory to execute the above methods.

[0080] In one embodiment of the present invention, a computer program product is provided, the computer program product including a computer program stored on a non-transitory computer-readable storage medium, the computer program including program instructions, and when the program instructions are executed by a computer, the computer is able to perform the methods provided in the above-described method embodiments.

[0081] In one embodiment of the present invention, a non-transitory computer-readable storage medium is provided, which stores server instructions that cause a computer to perform the methods provided in the above embodiments.

[0082] The computer-readable storage medium provided in the above embodiments has a similar implementation principle and technical effect to the above method embodiments, and will not be described again here.

[0083] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1A device that provides the functions specified in one or more boxes.

[0084] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0085] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for simulating IGBT temperature based on Simulink-COMSOL, characterized in that, include: A loss calculation model was built on the Simulink platform. The loss calculation model takes the input current of the IGBT module, the bus voltage and the heat sink temperature as inputs, and performs current distribution according to the timing switching process of the IGBT module. The dynamic power loss data generated by each IGBT chip and each FWD chip are calculated respectively. The calculated dynamic power loss data is exported to the MATLAB workspace, and the dynamic power loss data is downsampled and preprocessed to make its data volume meet the compatibility requirements of COMSOL software, so as to obtain a data format containing the correspondence between time and loss. Create a 3D model of the IGBT module in COMSOL software and configure its thermophysical properties and boundary conditions; The downsampled preprocessed dynamic power loss data is used as a spatial heat source and loaded onto the corresponding IGBT chip and FWD chip in the three-dimensional model respectively. Transient heat conduction simulation is performed to obtain the simulation results of the temperature field distribution of the IGBT module.

2. The IGBT temperature simulation method based on Simulink-COMSOL as described in claim 1, characterized in that, The loss calculation model includes the calculation of conduction loss and switching loss; Among them, the conduction loss is determined based on the tube voltage drop and collector current when the tube is turned on, and the switching loss is determined based on the single switching energy and switching frequency.

3. The IGBT temperature simulation method based on Simulink-COMSOL as described in claim 1, characterized in that, Calculate the dynamic power loss data generated by each IGBT chip and each FWD chip separately, including: The output characteristic curves and switching characteristic curves of IGBT chips and FWD chips at multiple temperature points were extracted from the datasheets, and the current-voltage mapping relationship under continuous temperature was established by interpolation. Current distribution is performed according to the timing switching process of the IGBT module. The current distribution includes: when the DC bus current is input, the current flowing through the upper bridge IGBT chip, the lower bridge IGBT chip, the upper bridge FWD chip and the lower bridge FWD chip are determined according to the different current directions. The current flowing through any chip is determined by the product of the duty cycle and the DC bus current. The power loss generated by the chip is obtained by multiplying the current allocated to a single chip and the real-time saturation voltage drop corresponding to the chip's current and junction temperature, which is read from the current-voltage mapping relationship.

4. The IGBT temperature simulation method based on Simulink-COMSOL as described in claim 1, characterized in that, A thermal network model was built on the Simulink platform. The thermal network model is the Foster thermal network model. The thermal network model is used to calculate the junction temperature of the IGBT module based on chip losses. The calculated junction temperature is fed back to the front end of the loss calculation model as input conditions to form electrothermal coupling.

5. The IGBT temperature simulation method based on Simulink-COMSOL as described in claim 1, characterized in that, The calculated dynamic power loss data is exported to the MATLAB workspace, and downsampling preprocessing of the dynamic power loss data includes: The calculated dynamic power loss data was exported to the MATLAB workspace using the To workspace module in the Simulink platform for later use. Based on the compatibility requirements of COMSOL software for input data, the exported dynamic power loss data is downsampled and optimized. Linear interpolation or moving average methods are used to reduce the data density so that the amount of loss data in a single set is controlled within a preset threshold. Outliers exceeding the normal range in the loss data are removed. The preprocessed data is then converted into a text or MAT format supported by COMSOL software using a MATLAB script. This text or MAT format contains column identifiers indicating the correspondence between time and loss.

6. The IGBT temperature simulation method based on Simulink-COMSOL as described in claim 1, characterized in that, Create a 3D model of the IGBT module in COMSOL software and configure its thermophysical properties and boundary conditions, including: The layered structural parts of the IGBT module are drawn using CAD software, and the assembled 3D model is imported into COMSOL to simplify non-critical structures. Based on the material properties of each layer, thermal conductivity, specific heat capacity and density are configured in the COMSOL material library, and temperature dependence settings are enabled, where the thermal conductivity of silicon decreases linearly with increasing temperature; The three-dimensional model is discretized using a triangular mesh and sweep method. The mesh is refined for the chip heat-generating area, solder layer and substrate contact surface. The optimal mesh scheme that balances computational accuracy and efficiency is determined by mesh independence verification. The heat dissipation method on the outer surface of the heat sink is equivalent to the convection heat transfer boundary. The convection heat transfer coefficient is set according to the actual working conditions, the ambient reference temperature is set, and the contact surface between the chip and the solder layer and the DCB substrate is set to perfect thermal contact conditions.

7. The IGBT temperature simulation method based on Simulink-COMSOL as described in claim 1, characterized in that, The downsampled preprocessed dynamic power loss data is used as a spatial heat source and loaded onto the corresponding IGBT chip and FWD chip in the 3D model, respectively. Transient heat conduction simulation is then performed, including: In the COMSOL software, select the transient heat conduction physics field; The dynamic power loss data after downsampling preprocessing is imported through the interpolation function module. The dynamic power loss data is a data format that includes the correspondence between time and loss. The imported dynamic power loss data is mapped to the spatial heat source of the chip area and loaded onto the corresponding IGBT chip and FWD chip in the 3D model respectively. Set the simulation time range to match the loss simulation cycle of the Simulink platform; use an adaptive time step for transient heat conduction simulation calculations and set convergence criteria; After the simulation is completed, the simulation results of the temperature field distribution will be output.

8. An IGBT temperature simulation system based on Simulink-COMSOL, characterized in that, include: The loss calculation module builds a loss calculation model on the Simulink platform. The loss calculation model takes the input current of the IGBT module, the bus voltage and the heat sink temperature as inputs, and performs current distribution according to the timing switching process of the IGBT module to calculate the dynamic power loss data generated by each IGBT chip and each FWD chip respectively. The data preprocessing module exports the calculated dynamic power loss data to the MATLAB workspace and performs downsampling preprocessing on the dynamic power loss data to ensure that the data volume meets the compatibility requirements of the COMSOL software, resulting in a data format that includes the correspondence between time and loss. The 3D modeling module creates a 3D model of the IGBT module in COMSOL software and configures its thermophysical properties and boundary conditions. The simulation execution module loads the downsampled and preprocessed dynamic power loss data as a spatial heat source onto the corresponding IGBT chip and FWD chip in the three-dimensional model, respectively, and performs transient heat conduction simulation to obtain the simulation results of the temperature field distribution of the IGBT module.

9. A computer-readable storage medium for storing one or more programs, characterized in that, The one or more programs include instructions that, when executed by a computing device, cause the computing device to perform any of the methods described in claims 1 to 7.

10. A computing device, characterized in that, include: One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including instructions for performing any of the methods described in claims 1 to 7.

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