IGBT module junction temperature prediction method and system, terminal device, and storage medium

Abstract

The application discloses an IGBT module junction temperature prediction method and system, a terminal device and a storage medium, and the method comprises the steps of determining the current I flowing through the chip in the IGBT module based on the vehicle working condition parameters c ; constructing an IGBT module loss model, inputting the current I flowing through the chip in the IGBT module into the IGBT module loss model, and obtaining the loss of the IGBT module c ; constructing a Cauer thermal network model, inputting the loss of the IGBT module into the Cauer thermal network model, and obtaining the current junction temperature of the IGBT module; feeding back the current junction temperature of the IGBT module into the IGBT module loss model, and realizing the junction temperature prediction of the IGBT module. The prediction of the junction temperature of the IGBT module based on the typical working condition or the real-time working condition of the vehicle is more in line with the actual situation, and the Cauer thermal network model which can reflect the actual physical structure of the IGBT module is used for the junction temperature prediction of the IGBT module.

Description

Technical Field

[0001] This disclosure generally relates to the field of power electronics technology, and in particular to a method, system, terminal device and storage medium for predicting junction temperature of IGBT modules. Background Technology

[0002] Insulated Gate Transistor (IGBT) modules are widely used in various fields such as rail transportation, smart grids, electric vehicles, and new energy. The junction temperature of an IGBT module is a crucial characteristic parameter for the reliable and stable operation of a power converter. Fluctuations in junction temperature directly affect the performance and reliability of the power converter, and long-term junction temperature fluctuations can lead to device aging and even failure. Therefore, estimating the junction temperature of IGBT modules is of great significance for the safe operation and health management of power electronic systems.

[0003] Currently, the junction temperature is generally estimated by calculating the IGBT module losses based on the torque and speed of the motor to obtain the current values ​​of each phase output by the inverter. However, in engineering, the initial input often only includes the operating conditions of the entire vehicle, without data such as the current in the IGBT module or the speed and torque of the motor. Therefore, estimating the junction temperature of the IGBT module from the input of the vehicle's operating conditions has important practical significance. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a method, system, terminal device and storage medium for predicting junction temperature of IGBT modules.

[0005] Firstly, a method for predicting the junction temperature of an IGBT module is provided, including:

[0006] The current I flowing through the chip in the IGBT module is determined based on the vehicle's operating parameters. c ;

[0007] Construct an IGBT module loss model, and convert the current I flowing through the chip in the IGBT module into a loss model. c Input the IGBT module loss model to obtain the IGBT module loss;

[0008] Construct a Cauer thermal network model, input the losses of the IGBT module into the Cauer thermal network model, and obtain the current junction temperature of the IGBT module;

[0009] The current junction temperature of the IGBT module is fed back into the IGBT module loss model to achieve junction temperature prediction of the IGBT module.

[0010] Secondly, an IGBT module junction temperature prediction system is provided, comprising:

[0011] The current determination module is used to determine the current I flowing through the chip in the IGBT module based on the vehicle's operating parameters. c ;

[0012] The loss determination module is used to construct the IGBT module loss model, and to determine the current I flowing through the chip in the IGBT module. c Input the IGBT module loss model to obtain the IGBT module loss;

[0013] The network model construction module is used to construct a Cauer thermal network model. The loss of the IGBT module is input into the Cauer thermal network model to obtain the current junction temperature of the IGBT module.

[0014] The junction temperature prediction module is used to input the current junction temperature of the IGBT module into the IGBT module loss model to realize the junction temperature prediction of the IGBT module.

[0015] Thirdly, a terminal device is provided, comprising:

[0016] One or more processors;

[0017] Memory, used to store one or more programs.

[0018] When one or more programs are executed by one or more processors, the one or more processors perform the IGBT module junction temperature prediction method as provided in the embodiments of this application.

[0019] Fourthly, a computer-readable storage medium storing a computer program is provided, which is executed by a processor as described in the embodiments of this application for predicting the junction temperature of an IGBT module.

[0020] According to the technical solution provided in the embodiments of this application, the real-time prediction of the junction temperature of the IGBT module based on the typical or real-time operating conditions of the whole vehicle is more consistent with the actual situation. Furthermore, the junction temperature prediction of the IGBT module is performed using the Cauer thermal network model, which reflects the actual physical structure of the IGBT module. The heat capacity and thermal resistance values ​​of the Cauer thermal network model have actual physical meaning, and the temperature of each layer of material in the IGBT module can be obtained during the real-time calculation process. Attached Figure Description

[0021] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0022] Figure 1 This is an exemplary flowchart of an existing method for estimating the junction temperature of an IGBT module;

[0023] Figure 2 for Figure 1 The structure diagram of the 4th-order Foster thermal network model in the image;

[0024] Figure 3 An exemplary flowchart of the IGBT module junction temperature prediction method provided in the embodiments of this application;

[0025] Figure 4 A detailed flowchart of the IGBT module junction temperature prediction method provided in the embodiments of this application;

[0026] Figure 5 Liquid cooling heat transfer path diagram of the IGBT module provided in the embodiments of this application;

[0027] Figure 6 A Cauer thermal network model diagram of the IGBT module provided in the embodiments of this application;

[0028] Figure 7 A simulation model diagram for predicting IGBT junction temperature provided in an embodiment of this application;

[0029] Figure 8 This is a schematic diagram of the structure of a terminal device provided in an embodiment of this application. Detailed Implementation

[0030] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0032] An IGBT module includes an insulated gate bipolar transistor (IGBT) and an anti-parallel freewheeling diode (FWD). The estimation of the junction temperature of the IGBT module includes the estimation of the junction temperature of both the IGBT chip and the FWD chip. The junction temperature refers to the actual temperature of the chip body.

[0033] like Figure 1 As shown, the existing method for measuring the junction temperature of an IGBT module is as follows: First, the current flowing through the chip is estimated using data such as the current in the IGBT module or the speed and torque of the motor. Then, the losses of the IGBT module are calculated based on the obtained current value. Finally, a fourth-order local (Foster) thermal network model is established based on the thermal impedance value given in the IGBT datasheet (e.g., ...). Figure 2(As shown). In engineering, however, the operating parameters of the entire vehicle are often directly obtained, rather than data such as current or motor speed and torque. Furthermore, the thermal resistance and heat capacity values ​​in the existing 4th-order Foster thermal network model are only numerical values ​​obtained through mathematical fitting methods and do not have actual physical meaning. Therefore, the temperature values ​​of each node on the heat transfer path of the IGBT module cannot be estimated through the Foster thermal network model.

[0034] To solve the above technical problems, please refer to Figure 3 The illustrated flowchart shows an exemplary method for predicting the junction temperature of an IGBT module. The IGBT module junction temperature prediction method provided by this invention includes:

[0035] S10: Determine the current I flowing through the chip in the IGBT module based on the vehicle's operating parameters. c ;

[0036] S20: Construct an IGBT module loss model, and calculate the current I flowing through the chip in the IGBT module. c Input the IGBT module loss model to obtain the IGBT module loss;

[0037] S30: Construct a Cauer thermal network model, input the losses of the IGBT module into the Cauer thermal network model, and obtain the current junction temperature of the IGBT module;

[0038] S40: Input the current junction temperature of the IGBT module into the IGBT module loss model to realize the junction temperature prediction of the IGBT module.

[0039] Specifically, this application predicts the junction temperature of the IGBT module based on the vehicle's operating conditions. Vehicle operating parameters are readily available, facilitating IGBT module junction temperature prediction. Furthermore, it employs a Cauer thermal network model for IGBT module junction temperature prediction. The Cauer thermal network model reflects the actual physical structure of the IGBT module, and its heat capacity and thermal resistance values ​​have practical physical meaning. During real-time calculations, the temperature of each layer of material in the IGBT module can be obtained. This application utilizes simulation estimation to quickly obtain the junction temperature of the IGBT module under a specific operating condition. By determining whether the junction temperature meets the expected design, the parameters of the cooling system, including the inlet temperature and flow rate, can be adjusted. Combined with 3D simulation calculations, this facilitates optimized water channel design and promotes IGBT module performance improvement.

[0040] In one embodiment, in step S10, the vehicle operating condition adopts the typical vehicle operating conditions NEDC and WLTC, or the real-time vehicle operating condition.

[0041] Specifically, such as Figure 4As shown, the input for the vehicle operating conditions can be selected from typical operating conditions, such as the New European Driving Cycle (NEDC) and the World Light Vehicle Test Cycle (WLTC), or actual process operating data can be collected for simulation. This application's prediction of the IGBT module junction temperature is based on typical or real-time vehicle operating conditions, which is more significant for system simulation and facilitates the prediction of the IGBT module's dynamic junction temperature by combining different actual operating conditions.

[0042] In one embodiment, step S10 specifically includes:

[0043] S101: Calculate driving force F based on vehicle operating parameters t ;

[0044] S102: According to the driving force F t Calculate motor torque T m ;

[0045] S103: According to the motor torque T m Calculate the current I flowing through the chip in the IGBT module. c .

[0046] In one embodiment, step S101 specifically includes:

[0047] S1011: Calculate the rolling resistance F based on the vehicle's operating parameters. f air resistance F w Acceleration resistance F j and slope resistance F i The details are as follows:

[0048] 1) Rolling resistance F f The calculation formula is:

[0049] F f =m·g·f

[0050] Where f is the rolling resistance coefficient, m is the vehicle mass, and g is the acceleration due to gravity.

[0051] 2) Air resistance F w The calculation formula is:

[0052] F w =0.5·C d ·A·ρ a ·u 2

[0053] Among them, C d Where ρ is the air resistance coefficient, A is the frontal area, and ρ is the air resistance coefficient. a Let ρ be the density of air and u be the vehicle speed.

[0054] 3) Acceleration resistance F jThe calculation formula is:

[0055]

[0056] Where δ is the vehicle rotational mass conversion factor. Find the derivative of the vehicle speed with respect to time.

[0057] 4) Slope resistance F i The calculation formula is:

[0058] F i =m·g·sinα

[0059] Where α is the slope angle and g is the acceleration due to gravity.

[0060] S1012: According to the rolling resistance F f air resistance F w Acceleration resistance F j and slope resistance F i Calculate the driving force F t The specific calculation formula is as follows:

[0061] F t =F f +F w +F j +F i .

[0062] In one embodiment, in step S102, according to the driving force F t Calculate motor torque T m The specific calculation formula is as follows:

[0063]

[0064] Where, r d i is the tire radius. g i0 is the gear ratio of the transmission, i0 is the gear ratio of the main reducer, and η is the gear ratio of the gearbox. r This refers to the mechanical efficiency of the transmission system.

[0065] In one embodiment, in step S103, based on the motor torque T m Calculate the current I flowing through the chip in the IGBT module. c The specific calculation formula is as follows:

[0066]

[0067] Where, k t This is a motor constant.

[0068] Specifically, such as Figure 7The simulation model shown is for predicting the junction temperature of a single IGBT chip. The input condition is NEDC, but it supports any input condition. It was modeled using Simulink, with some logic encapsulated to support conversion into microcontroller-readable code. Figure 4 , Figure 7 As shown, based on the vehicle's operating parameters (vehicle speed u, rolling resistance coefficient f, vehicle mass m, and air resistance coefficient C)... d Frontal area A, air density ρ a Vehicle rotational mass conversion factor δ, slope angle α, tire radius r d The gear ratio i of the transmission g The transmission ratio i0 of the main reducer and the mechanical efficiency η of the transmission system. r Motor constant k t Calculate the current I flowing through the chip in the IGBT module. c The vehicle operating parameters are either pre-known data or data that can be measured in real time. Therefore, the current I flowing through the chip in the IGBT module can be directly determined using this known vehicle operating data. c The calculation is convenient and quick, and facilitates subsequent estimation of IGBT module junction temperature.

[0069] Specifically, in step S20, the IGBT module loss model is constructed, which includes the IGBT chip loss model and the FWD chip loss model. The calculation method of IGBT chip loss is similar to that of FWD chip loss. This application takes the calculation of IGBT chip loss as an example for illustrative explanation. Here, the heat loss of the chip refers to the heat generation power of the chip.

[0070] In one embodiment, in step S20, the construction of the IGBT module loss model involves converting the current I flowing through the chip in the IGBT module into a loss model. c By inputting the IGBT module loss model, the specific losses of the IGBT module are obtained as follows:

[0071] Construct conduction loss models and switching loss models for IGBT chips;

[0072] The current I flowing through the chip in the IGBT module c By inputting the conduction loss model and the switching loss model, the conduction loss and switching loss of the IGBT chip are calculated.

[0073] The total loss P of the IGBT module is obtained based on the conduction loss and the switching loss. tot_Tr .

[0074] Specifically, because the switching frequency of IGBTs is very high, the turn-on time of each switching cycle is very short, while the time constant of the inductive load is much larger than the switching cycle of the power module. Therefore, it can be assumed that the load current remains constant during the turn-on time of each switching cycle. The average conduction loss of the IGBT chip in the k-th switching cycle can then be expressed as:

[0075]

[0076] Among them, U ce I is the on-state voltage drop of the IGBT. c T represents the current flowing through the chip in the IGBT module. SW For the switching period, t k The simulation time is the kth switching cycle; where U is the on-state voltage drop of the IGBT. ce It can be represented as:

[0077] U ce =[U ce_25℃ +K v ·(T j -25)]+I c ·[R ce_25℃ +K r ·(T j -25)]

[0078] Among them, U ce_25℃ K is the rated on-state voltage of the IGBT at 25°C. v T is the temperature coefficient of the effect of temperature on the on-state voltage drop of the IGBT; j R is the junction temperature of the IGBT chip; ce_25℃ K is the rated on-state resistance of the IGBT at 25°C. r This is the temperature coefficient of the effect of temperature on the on-state resistance of the IGBT.

[0079] The average on-state loss P of the IGBT chip in the kth switching cycle cond_Tr It can be represented as:

[0080]

[0081] The switching loss P of the IGBT chip sw_Tr The calculation formula is:

[0082]

[0083] Among them, f s E is the carrier frequency. on and E off For IGBT single-pulse turn-on and turn-off losses; I rated Reference current (the nominal current value given in the IGBT datasheet); Vcc V is the bridge arm voltage; rated Reference voltage (the nominal voltage value given in the IGBT datasheet); K sw_I K is the current coefficient representing the effect of current amplitude on IGBT switching losses. sw_V K is the voltage coefficient representing the effect of the bridge arm voltage on IGBT switching losses. sw_T This represents the temperature coefficient of the effect of temperature on IGBT switching losses.

[0084] The loss of the IGBT module is obtained based on the conduction loss and the switching loss, specifically by inputting the conduction loss and the switching loss into the following formula for calculation:

[0085] P tot_Tr =P cond_Tr +P sw_Tr

[0086] Among them, P tot_Tr P represents the total loss of the IGBT chip. cond_Tr For the conduction loss of the IGBT chip, P sw_Tr This refers to the switching losses of the IGBT chip.

[0087] During the simulation, an integrator was used to solve the problem, and the simulation time step was set to T. SW .

[0088] It should be noted that the total loss of the FWD chip is also divided into conduction loss and switching loss. The specific calculation process is similar to that of the IGBT chip, and will not be elaborated further in this application. This application calculates the total loss based on the current I flowing through the chip in the IGBT module. c And the circuit parameters of the IGBT module (IGBT on-state voltage drop U). ce The rated on-state voltage U of the IGBT at 25℃ ce_25℃ The temperature coefficient K of the effect of temperature on IGBT on-state voltage drop v The rated on-state resistance R of the IGBT at 25℃ ce_25℃ The temperature coefficient K of the effect of temperature on the on-state resistance of IGBT r Bridge arm voltage V cc Reference current I rated Reference voltage V rated The total chip loss of the IGBT module is calculated. Compared with existing IGBT modules where the loss value is given as a constant, the total chip loss value of the IGBT module in this application takes into account the change of loss with junction temperature, resulting in a smaller deviation from the actual situation, higher accuracy in three-dimensional simulation, and better conformity to reality. The circuit parameters of the IGBT module can be obtained by consulting the IGBT product manual or based on empirical values.

[0089] Specifically, Figure 5 This application provides an embodiment of an IGBT module liquid cooling heat transfer path diagram, which is shown in the diagram. Figure 5 As can be seen, an IGBT module includes, from top to bottom, an IGBT chip or FWD chip, solder layer 1, upper copper layer, ceramic plate, lower copper layer, solder layer 2, copper substrate, thermal grease layer, and heat sink layer. Each RC structure layer in the Cauer thermal network model is equivalent to each material layer in the IGBT module. The Cauer thermal network model can be further equivalent, such as equating the upper copper layer, ceramic plate, and lower copper layer as a DBC (direct bond copper, the substrate material of the IGBT chip) layer; the heat sink can also be further equivalent to a shell layer and a fluid layer.

[0090] Among them, the junction temperature T of the IGBT chip or FWD chip j Unmeasurable, copper substrate temperature T c Measurable inlet water temperature T cool_in Measurable, outlet temperature T cool_out Measurable.

[0091] In IGBT modules using liquid cooling, the inlet water temperature T is used as a reference. cool_in and outlet temperature T cool_out Calculate the temperature T of the radiator h Specifically:

[0092]

[0093] In one embodiment, in step S30, the heat capacity C of each layer of material in the Cauer thermal network model is first calculated. th Thermal resistance R th Based on the heat capacity and thermal resistance of each layer of material, the Cauer thermal network model is constructed using the lumped parameter method. The Cauer thermal network model is as follows: Figure 6 As shown in the diagram. Thermal resistance is the impedance characteristic of the heat transfer process; it is the ratio between the temperature difference across the object and the power of the heat source when heat is transferred through it. Heat capacity is the capacitive reactance characteristic of the heat transfer process; when the system's temperature rises by dT due to a small amount of heat dQ, dQ / dT is the system's heat capacity. The lumped parameter method is used when the temperature difference within an object is small. In this unsteady-state heat conduction process, the object's temperature distribution can be approximated as independent of coordinates and only changes with time. Therefore, the object's temperature can be represented by any point, while the object's mass and heat capacity are considered to be concentrated at a single point. This method is called the lumped parameter method.

[0094] Specifically, in the Cauer thermal network model, the heat capacity C of each layer of material is... th The calculation method is as follows:

[0095] Cth =m i ·c p =c p ·ρ·d·A

[0096] Where d is the thickness of the object perpendicular to the heat transfer path, A is the heat transfer contact area, and m i Let ρ be the mass of the object, and c be the density of the object. p Let be the specific heat capacity of the object.

[0097] In the Cauer thermal network model, the thermal resistance R of each layer of material is... th The extraction was obtained by reverse engineering using a three-dimensional thermal simulation method. The main steps are as follows:

[0098] ① The three-dimensional geometric model of IGBT module heat dissipation is divided into meshes to form a discretized mesh model;

[0099] ② Set the material properties of the discretized mesh model and set the cold source temperature (i.e., the temperature T of the radiator). h ) and the total loss of the chip (total loss of the IGBT chip or FWD chip);

[0100] ③ Monitor and extract the average temperature T of the upper and lower surfaces of each component in the IGBT module. up and T down Simultaneously monitor and extract the heat flux density q flowing through each component. i ;

[0101] ④ Based on the average temperature of the upper and lower surfaces of the object obtained from monitoring and the heat flow rate through the object, use the ANSYS Fluent simulation software to run the solver to calculate the thermal resistance R of each layer of material in the Cauer thermal network model. th :

[0102]

[0103] Among them, T up T represents the average temperature of the upper surface of the object. down q is the average temperature of the lower surface of the object. i The heat flow rate is the heat flux through the object.

[0104] This application aims to ensure good chip soldering and packaging processes by establishing a thermal resistance network model that ignores the contact thermal resistance between materials. Since the IGBT module under study has a very high thermal conductivity (Bi ≤ 0.1), and local temperature differences within a single object are ignored, a Cauer thermal network model is established using the lumped parameter method. Here, Bi refers to the ratio of the thermal resistance per unit thermally conductive area to the heat transfer resistance per unit surface area within a solid.

[0105] In one embodiment, step S30, which involves inputting the losses of the IGBT module into the Cauer thermal network model to obtain the junction temperature of the IGBT module, specifically includes:

[0106] According to the thermal resistance R of each layer of material in the Cauer thermal network model th Calculate the thermal resistance R from the heatsink to the IGBT chip. h_j ;

[0107] According to the thermal resistance R from the heat sink to the IGBT chip h_j Total loss P of IGBT chip tot_Tr and the temperature T of the radiator h Calculate the junction temperature T of each IGBT chip j Among them, junction temperature T j Calculate using the following formula:

[0108] T j =T h +R h_j *P tot_Tr ;

[0109] The maximum junction temperature of all IGBT chips is taken as the junction temperature of the IGBT module.

[0110] Specifically, given the total losses of the chip and the thermal resistance of the heat transfer path, the junction temperature of the chip can be obtained. In this embodiment, the junction temperature of a single IGBT chip is calculated based on its losses. The method for predicting the junction temperature of other IGBT chips is the same, and the calculation method for the junction temperature of the freewheeling diode chip is similar. Generally, the junction temperature of the IGBT chip is higher than that of the freewheeling diode chip; therefore, the maximum junction temperature of all IGBT chips is taken as the junction temperature of the IGBT module.

[0111] In one embodiment, the method further includes:

[0112] According to the thermal resistance R of each layer of material in the Cauer thermal network model th Calculate the thermal resistance R from the heat sink to the i-th layer of material. h_i ;

[0113] Based on the thermal resistance R from the heat sink to the i-th layer material h_j Calculate the temperature T of the i-th layer material in the Cauer thermal network model. i :

[0114] T i =T h +R h_i *p i

[0115] Where, p iLet be the heat flux density flowing through the i-th layer of material.

[0116] Specifically, the temperature T of each layer of material in the IGBT module can be obtained during real-time calculation. i By using a thermal resistance network model that considers the influence of heat capacity, the temperature of each material layer can also be calculated. The temperature T of each material layer can then be obtained. i This facilitates verification with bench testing and helps in studying the aging characteristics of IGBT modules through the temperature of the chip and solder. A Cauer thermal network model is constructed using the lumped parameter method, which allows for obtaining the junction temperature of different parts of the IGBT module. This facilitates comparison and correction with actual test results. Compared to the Foster thermal network model, the Cauer thermal network model has more practical physical meaning.

[0117] In one embodiment, step S40, which involves inputting the current junction temperature of the IGBT module into the IGBT module loss model to predict the junction temperature of the IGBT module, specifically includes:

[0118] Let the junction temperature T of the IGBT chip be j Let T be the junction temperature T of the IGBT chip during the k-th switching cycle. j，k Using the junction temperature T of the IGBT chip during the kth switching cycle j，k Update the junction temperature-related parameters in the IGBT chip loss model to obtain the new total IGBT chip loss;

[0119] The total loss of the new IGBT chip is input into the Cauer thermal network model to obtain the junction temperature T of the IGBT chip in the (k+1)th switching cycle. j，k+1 .

[0120] Specifically, such as Figure 4 As shown, the junction temperature of the IGBT chip at time k is first obtained. This junction temperature is then used to update the parameters related to the junction temperature in the total loss calculation process, such as the rated on-state voltage U of the IGBT at 25℃. ce_25℃ The rated on-state resistance R of the IGBT at 25℃ ce_25℃ Then, the total loss of the new IGBT chip is used to predict the chip junction temperature at the next moment.

[0121] It should be noted that although the operations of the method of the present invention are described in a specific order in the accompanying drawings, this does not require or imply that these operations must be performed in that specific order, or that all of the operations shown must be performed to achieve the desired result. On the contrary, the steps depicted in the flowchart may be performed in a different order.

[0122] Secondly, an IGBT module junction temperature prediction system is provided, comprising:

[0123] The current determination module is used to determine the current I flowing through the chip in the IGBT module based on the vehicle's operating parameters. c ;

[0124] The loss determination module is used to construct the IGBT module loss model, and to determine the current I flowing through the chip in the IGBT module. c Input the IGBT module loss model to obtain the IGBT module loss;

[0125] The network model construction module is used to construct a Cauer thermal network model. The loss of the IGBT module is input into the Cauer thermal network model to obtain the junction temperature of the IGBT module.

[0126] The junction temperature prediction module is used to input the current junction temperature of the IGBT module into the IGBT module loss model to realize the junction temperature prediction of the IGBT module.

[0127] In one embodiment, the current determination module includes a driving force unit and a current unit; wherein, the driving force unit is used to calculate the driving force F based on the vehicle operating parameters. t ;

[0128] Current unit, used to determine the driving force F t Calculate motor torque T m According to the motor torque T m Calculate the current I flowing through the chip in the IGBT module. c .

[0129] Specifically, driving force F t Motor torque T m The current I flowing through the chip in the IGBT module c The calculation formulas are as described above, and will not be repeated here.

[0130] In one embodiment, the loss determination module includes a conduction loss unit, a switching loss unit, and a total loss unit; wherein...

[0131] The conduction loss unit is used to construct the conduction loss model of the IGBT chip, and to convert the current I flowing through the chip in the IGBT module into a conduction loss model. c Input the aforementioned conduction loss model to obtain the conduction loss of the IGBT chip;

[0132] The switching loss unit is used to construct the switching loss model of the IGBT chip, and to convert the current I flowing through the chip in the IGBT module into a switching loss model. c Input the switching loss model to obtain the switching loss of the IGBT chip;

[0133] The total loss unit is used to obtain the total loss P of the IGBT module based on the conduction loss and the switching loss. tot_Tr .

[0134] Specifically, the loss determination module is used to determine the total loss of the IGBT chip. During the process of determining the total loss of the IGBT chip, the conduction loss unit is used to calculate the conduction loss P of the IGBT chip. cond_Tr The switching loss unit is used to calculate the switching loss P of the IGBT chip. sw_Tr The specific calculation method is as described above; the total loss unit is used to obtain the total loss P of the IGBT module based on the conduction loss and switching loss. tot_Tr The method for determining the total loss of the FWD chip is similar to that of the IGBT chip, and will not be described in detail here.

[0135] In one embodiment, the network model is specifically constructed based on the heat capacity C of each layer of material in the Cauer thermal network model. th The thermal resistance R of each layer of material th The Cauer thermal network model is constructed using the lumped parameter method based on the heat capacity and thermal resistance of each layer of material.

[0136] Specifically, the heat capacity C of each layer of material th The thermal resistance R of each layer of material th The calculation method and the construction method of the Cauer thermal network model have been described above, and will not be repeated here.

[0137] In one embodiment, the junction temperature prediction module is further configured to predict the junction temperature based on the inlet temperature T. cool_in and outlet temperature T cool_out Determine the temperature T of the radiator h .

[0138] In one embodiment, the junction temperature prediction module is further configured to:

[0139] According to the thermal resistance R of each layer of material in the Cauer thermal network model th Calculate the thermal resistance R from the heatsink to the IGBT chip. h_j ;

[0140] According to the thermal resistance R from the heat sink to the IGBT chip h_j Total loss P of IGBT chip tot_Tr and the temperature T of the radiator h Calculate the junction temperature T of each IGBT chip j :

[0141] The maximum junction temperature of all IGBT chips is taken as the junction temperature of the IGBT module.

[0142] In one embodiment, the junction temperature prediction module is further configured to:

[0143] According to the Cauer thermal network model, the thermal resistance R of each layer of material is... th Calculate the thermal resistance R from the heat sink to the i-th layer of material. h_i ;

[0144] And for the thermal resistance R from the heat sink to the i-th layer material h_j Calculate the temperature T of the i-th layer material in the Cauer thermal network model. i .

[0145] Thirdly, such as Figure 8 As shown, this application also provides a terminal device 400, including one or more central processing units (CPUs) 401, which can perform various appropriate actions and processes according to programs stored in read-only memory (ROM) 402 or programs loaded from storage portion 408 into random access memory (RAM) 403. The RAM 403 also stores various programs and data required for system operation. The CPU 401, ROM 402, and RAM 403 are interconnected via a bus 404. An input / output (I / O) interface 405 is also connected to the bus 404.

[0146] The following components are connected to I / O interface 405: an input section 406 including a keyboard, mouse, etc.; an output section 407 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and speakers, etc.; a storage section 408 including a hard disk, etc.; and a communication section 409 including a network interface card such as a LAN card, modem, etc. The communication section 409 performs communication processing via a network such as the Internet. A drive 410 is also connected to I / O interface 405 as needed. A removable medium 411, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on drive 410 as needed so that computer programs read from it can be installed into storage section 408 as needed.

[0147] In particular, according to embodiments of this disclosure, the above references Figure 3-4 The described process can be implemented as a computer software program. For example, embodiments of this disclosure include a computer program product comprising a computer program tangibly embodied on a machine-readable medium, the computer program containing program code for performing an IGBT module junction temperature prediction method. In such embodiments, the computer program can be downloaded and installed from a network via communication section 409, and / or installed from removable medium 411.

[0148] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0149] Fourthly, this application also provides a computer-readable storage medium, which may be the computer-readable storage medium included in the apparatus described in the above embodiments; or it may be a standalone computer-readable storage medium not assembled into the device. The computer-readable storage medium stores one or more programs, which are used by one or more processors to execute the IGBT module junction temperature prediction method described in this application.

[0150] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified function or operation, or by a combination of dedicated hardware and computer instructions.

[0151] The units or modules described in the embodiments of this application can be implemented in software or hardware. The described units or modules can also be located in a processor; for example, each unit can be a software program located in a computer or mobile smart device, or a separately configured hardware device. The names of these units or modules do not, in some cases, constitute a limitation on the unit or module itself.

[0152] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A method for predicting the junction temperature of an IGBT module, characterized in that, include: The current flowing through the chip in the IGBT module is determined based on the vehicle's operating parameters. Among them, the driving force is calculated based on the vehicle's operating parameters. The driving force Rolling resistance air resistance Acceleration resistance and slope resistance The sum, based on the driving force Calculate the current flowing through the chip in the IGBT module The vehicle operating parameters include at least: vehicle mass, rolling resistance coefficient, air resistance coefficient, frontal area, vehicle speed, vehicle rotational mass conversion factor, and slope angle. Construct an IGBT module loss model, and include the current flowing through the chip in the IGBT module. Input the IGBT module loss model to obtain the IGBT module loss; A Cauer thermal network model is constructed, and the losses of the IGBT module are input into the Cauer thermal network model to obtain the current junction temperature of the IGBT module; wherein, the Bior number Bi of the IGBT module is ≤0.1, and the Cauer thermal network model is established using the lumped parameter method; The current junction temperature of the IGBT module is fed back into the IGBT module loss model to achieve junction temperature prediction of the IGBT module.

2. The IGBT module junction temperature prediction method according to claim 1, characterized in that, The current flowing through the chip in the IGBT module is determined based on the vehicle's operating parameters. include: Calculate driving force based on vehicle operating parameters ; According to the driving force Calculate motor torque ; According to the motor torque Calculate the current flowing through the chip in the IGBT module .

3. The IGBT module junction temperature prediction method according to claim 2, characterized in that, According to the driving force Calculate motor torque The calculation formula is as follows: in, For the tire radius, This refers to the gear ratio of the transmission. The transmission ratio of the main reducer. This refers to the mechanical efficiency of the transmission system.

4. The IGBT module junction temperature prediction method according to claim 2, characterized in that, The according to the motor torque Calculate the current flowing through the chip in the IGBT module The calculation formula is as follows: in, This is a motor constant.

5. The IGBT module junction temperature prediction method according to claim 1, characterized in that, The construction of the IGBT module loss model involves the current flowing through the chip in the IGBT module. By inputting the IGBT module loss model, the specific losses of the IGBT module are obtained as follows: Construct conduction loss models and switching loss models for IGBT chips; The current flowing through the chip in the IGBT module By inputting the conduction loss model and the switching loss model, the conduction loss and switching loss of the IGBT chip are calculated. The total loss of the IGBT module is obtained based on the conduction loss and the switching loss. .

6. The IGBT module junction temperature prediction method according to claim 5, characterized in that, The conduction loss model is as follows: in, This is the rated on-state voltage of the IGBT at 25℃; This is the temperature coefficient of the effect of temperature on the on-state voltage drop of the IGBT; This refers to the junction temperature of the IGBT chip. The rated on-state resistance of the IGBT at 25°C; This is the temperature coefficient of the effect of temperature on the on-state resistance of an IGBT; For switching cycles; For the first Simulation time for one switching cycle; The switching loss model is as follows: in, For carrier frequency; and For IGBT single-pulse turn-on and turn-off losses; Reference current; This refers to the bridge arm voltage; Reference voltage; The current coefficient represents the effect of current amplitude on IGBT switching losses. The voltage coefficient representing the effect of the bridge arm voltage on IGBT switching losses; This is the temperature coefficient representing the effect of temperature on IGBT switching losses. The loss of the IGBT module is obtained based on the conduction loss and the switching loss, specifically by inputting the conduction loss and the switching loss into the following formula for calculation: in, This represents the total loss of the IGBT chip. For the conduction loss of the IGBT chip, This refers to the switching losses of the IGBT chip.

7. The IGBT module junction temperature prediction method according to claim 1, characterized in that, The construction of the Cauer thermal network model specifically includes: Calculate the heat capacity of each layer of material in the Cauer thermal network model. : Calculate the thermal resistance of each layer of material in the Cauer thermal network model. : The Cauer thermal network model is constructed using the lumped parameter method based on the heat capacity and thermal resistance of each layer of material.

8. The IGBT module junction temperature prediction method according to claim 7, characterized in that, The step of inputting the losses of the IGBT module into the Cauer thermal network model to obtain the junction temperature of the IGBT module specifically includes: Based on the thermal resistance of each layer of material in the Cauer thermal network model Calculate the thermal resistance from the heatsink to the IGBT chip. ; Based on the thermal resistance from the heat sink to the IGBT chip and the total loss of IGBT chips Calculate the junction temperature of each IGBT chip. Among them, junction temperature Calculate using the following formula: , The temperature of the radiator; The maximum junction temperature of all IGBT chips is taken as the junction temperature of the IGBT module.

9. The IGBT module junction temperature prediction method according to claim 8, characterized in that, The temperature of the radiator Calculate using the following formula: in, The inlet water temperature, This refers to the outlet temperature.

10. An IGBT module junction temperature prediction system, characterized in that, The prediction system is used to execute the IGBT module junction temperature prediction method according to any one of claims 1-9, the prediction system comprising: The current determination module is used to determine the current flowing through the chips in the IGBT module based on the vehicle's operating parameters. ; The loss determination module is used to construct a loss model for the IGBT module, and to determine the current flowing through the chip in the IGBT module. Input the IGBT module loss model to obtain the IGBT module loss; The network model construction module is used to construct a Cauer thermal network model. The loss of the IGBT module is input into the Cauer thermal network model to obtain the current junction temperature of the IGBT module. The junction temperature prediction module is used to input the current junction temperature of the IGBT module into the IGBT module loss model to realize the junction temperature prediction of the IGBT module.

11. The IGBT module junction temperature prediction system according to claim 10, characterized in that, The current determination module includes a driving force unit and a current unit; wherein... The drive force unit is used to calculate the drive force based on the vehicle's operating parameters. ; Current unit, used to determine the driving force Calculate motor torque According to the motor torque Calculate the current flowing through the chip in the IGBT module .

12. The IGBT module junction temperature prediction system according to claim 10, characterized in that, The loss determination module includes a conduction loss unit, a switching loss unit, and a total loss unit; wherein... The conduction loss unit is used to construct the conduction loss model of the IGBT chip, and to measure the current flowing through the chip in the IGBT module. Input the aforementioned conduction loss model to obtain the conduction loss of the IGBT chip; The switching loss unit is used to construct the switching loss model of the IGBT chip, and to measure the current flowing through the chip in the IGBT module. Input the switching loss model to obtain the switching loss of the IGBT chip; The total loss unit is used to obtain the total loss of the IGBT module based on the conduction loss and the switching loss. .

13. The IGBT module junction temperature prediction system according to claim 10, characterized in that, The network model construction module is specifically used for: Calculate the heat capacity of each layer of material in the Cauer thermal network model. : Calculate the thermal resistance of each layer of material in the Cauer thermal network model. : The Cauer thermal network model is constructed using the lumped parameter method based on the heat capacity and thermal resistance of each layer of material.

14. A terminal device, characterized in that, include: One or more processors; Memory, used to store one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors perform the IGBT module junction temperature prediction method as described in claims 1-9.

15. A computer-readable storage medium storing a computer program, characterized in that, When executed by the processor, this program implements the IGBT module junction temperature prediction method as described in claims 1-9.

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