Power module three-phase inversion simulation method and related equipment

Abstract

The embodiment of the invention provides a power module three-phase inversion simulation method and related equipment, and belongs to the technical field of power electronic devices. The method comprises the following steps: acquiring actually measured data of a transfer characteristic curve, an output characteristic curve, turn-on loss and turn-off loss of the power semiconductor; data fitting is carried out on the relation between electrical parameters and power loss of the power semiconductor according to the actually measured data, a pure loss model is obtained, and the electrical parameters comprise junction temperature, drain-source voltage, gate-source voltage and switching frequency; building a three-phase inverter circuit according to the pure loss model, and operating the three-phase inverter circuit to obtain electrical simulation parameters; inputting the electrical simulation parameters into a pure loss model for power loss simulation processing to obtain a power loss simulation value; and inputting the power loss simulation value into a preset thermal resistance model for temperature rise simulation processing to obtain a temperature rise simulation value. According to the application, simulation is used for replacing proofing physical testing, so that the development period can be shortened, the cost can be reduced, and the testing accuracy and safety can be improved.

Description

Technical Field

[0001] This application relates to the field of power electronic device technology, and in particular to a simulation method and related equipment for a three-phase inverter of a power module. Background Technology

[0002] As a key component in electric vehicle drive systems, the three-phase inverter power module must meet design requirements in terms of electrical characteristics, thermal characteristics, and reliability. Currently, after the power module development and design are completed, prototyping is required followed by actual electrical and bench testing. However, tests often reveal performance indicators that do not meet design targets, necessitating adjustments to the packaging design and another round of prototyping and testing, resulting in a lengthy development cycle. Furthermore, there is a risk of short-circuit explosion under extreme testing conditions such as short circuits.

[0003] In summary, the technical problems of high cost, long cycle and high testing risk in the prototyping and physical testing of power modules in related technologies need to be improved. Summary of the Invention

[0004] The main objective of this application is to propose a three-phase inverter simulation method and related equipment for power modules, aiming to replace physical prototype testing with simulation, thereby shortening the development cycle, reducing costs, and improving the accuracy and safety of testing.

[0005] To achieve the above objectives, one aspect of this application proposes a three-phase inverter simulation method for a power module, the method comprising the following steps: Obtain measured data of the transfer characteristic curves, output characteristic curves, turn-on loss, and turn-off loss of power semiconductors; Based on the measured data, the relationship between the electrical parameters of the power semiconductor and the power loss is fitted to obtain a pure loss model, wherein the electrical parameters include junction temperature, drain-source voltage, gate-source voltage and switching frequency. A three-phase inverter circuit was built based on the pure loss model, and the electrical simulation parameters were obtained by running the three-phase inverter circuit. The electrical simulation parameters are input into the pure loss model to perform power loss simulation processing, and the power loss simulation value is obtained. The power loss simulation value is input into a preset thermal resistance model for temperature rise simulation processing to obtain the temperature rise simulation value. The thermal resistance model contains thermal resistance parameters for different heat dissipation structures.

[0006] In some embodiments, obtaining measured data of the transfer characteristic curve, output characteristic curve, turn-on loss, and turn-off loss of the power semiconductor includes the following steps: The transfer characteristic curves of the drain current of the power semiconductor as a function of the gate-source voltage were measured at different temperatures and different drain-source voltages to obtain the first characteristic data. The output characteristic curves of the power semiconductor as a function of drain current and drain-source voltage were measured at different temperatures and gate-source voltages to obtain the second characteristic data. The turn-on loss and turn-off loss of power semiconductors were measured under different bus voltages, load currents, junction temperatures, and gate resistances using a dual-pulse test to obtain the third characteristic data. The measured data are obtained by integrating the first characteristic data, the second characteristic data, and the third characteristic data.

[0007] In some embodiments, the step of fitting the relationship between the electrical parameters of the power semiconductor and power loss based on the measured data to obtain a pure loss model includes the following steps: Based on the measured data, a multivariate nonlinear fitting was performed on the relationship between junction temperature, drain-source voltage, gate-source voltage and drain current to obtain a current model. The conduction loss model is obtained by fitting the current model and the drain-source voltage. A switching loss model is obtained by fitting the switching loss based on the turn-on loss, the turn-off loss, and the switching frequency. By fitting the power loss model and the switching loss model, a pure loss model is obtained.

[0008] In some embodiments, the step of performing multivariate nonlinear fitting on the relationship between junction temperature, drain-source voltage, gate-source voltage and drain current based on the measured data to obtain a current model includes the following steps: Using junction temperature, drain-source voltage, and gate-source voltage as independent variables and drain current as dependent variable, a multivariate nonlinear equation is obtained by performing a polynomial regression analysis to obtain a multivariate nonlinear equation. The multivariate nonlinear equation includes a first nonlinear term of junction temperature and gate-source power supply, a second nonlinear term of junction temperature and drain-source power supply, a first linear term of gate-source voltage, and a second linear term of drain-source voltage. Based on the measured data, the fitting parameters of the multivariate nonlinear equation are optimized with the goal of minimizing the error, and the optimal parameter values ​​are obtained. The current model is obtained based on the multivariable nonlinear equation and the optimal parameter values.

[0009] In some embodiments, the process of constructing a three-phase inverter circuit based on the pure loss model and running the three-phase inverter circuit to obtain electrical simulation parameters includes the following steps: The power semiconductors of each arm in the three-phase inverter circuit are replaced with the pure loss model, and the three-phase inverter circuit is run based on the preset simulation environment conditions to obtain the electrical simulation parameters.

[0010] In some embodiments, inputting the power loss simulation value into a preset thermal resistance model for temperature rise simulation processing to obtain the temperature rise simulation value includes the following steps: Determine the thermal resistance parameters of the thermal resistance model based on the simulation environment conditions. The simulated temperature rise value is calculated based on the simulated power loss value and the thermal resistance parameter.

[0011] To achieve the above objectives, another aspect of this application proposes a three-phase inverter simulation system for power modules, the system comprising: The measured data acquisition module is used to acquire measured data of the transfer characteristic curve, output characteristic curve, turn-on loss, and turn-off loss of power semiconductors. The data fitting module is used to fit the relationship between the electrical parameters of the power semiconductor and the power loss based on the measured data to obtain a pure loss model. The electrical parameters include junction temperature, drain-source voltage, gate-source voltage and switching frequency. The circuit simulation module is used to build a three-phase inverter circuit based on the pure loss model and run the three-phase inverter circuit to obtain electrical simulation parameters. The power loss simulation module is used to input the electrical simulation parameters into the pure loss model to perform power loss simulation processing and obtain power loss simulation values. The temperature rise simulation module is used to input the power loss simulation value into a preset thermal resistance model for temperature rise simulation processing to obtain the temperature rise simulation value. The thermal resistance model contains thermal resistance parameters for different heat dissipation structures.

[0012] To achieve the above objectives, another aspect of this application provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the above-described method.

[0013] To achieve the above objectives, another aspect of the embodiments of this application proposes a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method.

[0014] To achieve the above objectives, another aspect of this application provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0015] The embodiments of this application include at least the following beneficial effects: This application provides a three-phase inverter simulation method and related equipment for power modules. The scheme includes acquiring measured data of the transfer characteristic curve, output characteristic curve, turn-on loss, and turn-off loss of power semiconductors; performing data fitting on the relationship between the electrical parameters of power semiconductors and power losses based on the measured data to obtain a pure loss model, wherein the electrical parameters include junction temperature, drain-source voltage, gate-source voltage, and switching frequency; and establishing a pure loss model with electrical parameters as input and power loss as output through measured device characteristic curves and switching loss data. A three-phase inverter circuit was built based on a pure loss model, and the circuit was run to obtain electrical simulation parameters. The electrical simulation parameters were then input into the pure loss model for power loss simulation to obtain power loss simulation values. These power loss simulation values ​​were then input into a preset thermal resistance model for temperature rise simulation to obtain temperature rise simulation values. By using a modeling method based on a pure loss model to simulate three-phase inverters instead of prototyping physical components for actual testing, the simulation accuracy of three-phase inverters can be improved, simulation time can be significantly reduced, the development cycle of power modules can be shortened, cost investment can be reduced, and the accuracy and safety of testing can be improved. Attached Figure Description

[0016] Figure 1 This is a flowchart of the three-phase inverter simulation method for power modules provided in the embodiments of this application; Figure 2 This is a circuit diagram of the three-phase inverter circuit provided in the embodiments of this application; Figure 3 This is a circuit diagram of the control circuit provided in an embodiment of this application; Figure 4 This is a circuit diagram of the load circuit provided in an embodiment of this application; Figure 5 This is a circuit diagram of the thermal resistance model provided in the embodiments of this application; Figure 6 This is a schematic diagram of the system structure provided in the embodiments of this application; Figure 7 This is a schematic diagram of the hardware structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit it. In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of this application; they are merely examples of systems and methods consistent with some aspects of the embodiments of this application as detailed in the appended claims.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0019] The three-phase inverter simulation method for power modules provided in this application relates to the field of power electronic device technology. This three-phase inverter simulation method for power modules can be applied to terminals, servers, or software running on either terminal or server. In some embodiments, the terminal can be a smartphone, tablet, laptop, desktop computer, smart speaker, smartwatch, or vehicle terminal, but is not limited to these. The server can be configured as an independent physical server, a server cluster composed of multiple physical servers, or a distributed system. It can also be configured as a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDN, and big data and artificial intelligence platforms. The server can also be a node server in a blockchain network. The software can be an application implementing the three-phase inverter simulation method for power modules, but is not limited to the above forms.

[0020] This application can be used in a wide variety of general-purpose or special-purpose computer system environments or configurations. Examples include: personal computers, server computers, handheld or portable devices, tablet devices, multiprocessor systems, microprocessor-based systems, set-top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices. This application can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform specific tasks or implement specific abstract data types. This application can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0021] Figure 1 This is an optional flowchart of the three-phase inverter simulation method for power modules provided in the embodiments of this application. Figure 1 The method may include, but is not limited to, steps S101 to S105.

[0022] Step S101: Obtain the measured data of the power semiconductor's transfer characteristic curve, output characteristic curve, turn-on loss, and turn-off loss.

[0023] Step S102: Based on the measured data, perform data fitting on the relationship between the electrical parameters of the power semiconductor and the power loss to obtain a pure loss model.

[0024] Step S103: Build a three-phase inverter circuit based on the pure loss model, and run the three-phase inverter circuit to obtain electrical simulation parameters.

[0025] Step S104: Input the electrical simulation parameters into the pure loss model to perform power loss simulation processing and obtain the power loss simulation value.

[0026] Step S105: Input the power loss simulation value into the preset thermal resistance model for temperature rise simulation processing to obtain the temperature rise simulation value.

[0027] In this embodiment, power semiconductors are electronic devices that realize the conversion or control of electrical energy. According to the device structure, existing power semiconductors can be divided into diodes, power transistors, thyristors, etc. Among them, power transistors are divided into bipolar junction transistors (BJTs, triodes), junction field-effect transistors (JFETs), metal-oxide field-effect transistors (MOSFETs), and insulated gate bipolar transistors (IGBTs), etc.

[0028] Specifically, in this embodiment, measured data are obtained from the transfer characteristic curve (Id-Vgs), output characteristic curve (Id-Vds), turn-on loss (Eon), and turn-off loss (Eoff) of the power semiconductor as the basis for subsequent modeling.

[0029] The transfer characteristic curve is a curve with gate-source voltage (Vds) on the x-axis and drain current (Id) on the y-axis, representing the relationship between Id and Vgs. The output characteristic curve is a curve with drain-source voltage (Vds) on the x-axis and drain current on the y-axis, representing the relationship between Id and Vds. By reading the transfer characteristic curve and the output characteristic curve, the Id value at different Vgs and Vds can be obtained.

[0030] Since the switching on and off of power semiconductors is not instantaneous, there is an overlap between voltage and current during the transition time, resulting in switching losses. These switching losses include turn-on losses and turn-off losses. Turn-on losses represent the losses caused by a single turn-on of the power semiconductor, while turn-off losses represent the losses caused by a single turn-off of the power semiconductor.

[0031] Next, after obtaining comprehensive measured data, data fitting software was used to fit the power loss semiconductor based on the measured transfer and output characteristic curves. Appropriate equations were selected to establish the relationship between electrical parameters and power loss, creating a pure loss model with electrical parameters as input and power loss as output. This model simplifies the complex semiconductor physics solution process to a mapping between electrical parameters and power loss, fundamentally reducing computational complexity and improving the simulation accuracy of three-phase inverters. The electrical parameters include junction temperature (Tj), drain-source voltage, gate-source voltage, and switching frequency (f_sw). Junction temperature represents the actual operating temperature of the power semiconductor, and switching frequency represents the number of times the power semiconductor operates per second.

[0032] It should be noted that this embodiment is merely exemplary. For other types of power semiconductors, as long as their corresponding electrical parameters are obtained and the relationship between electrical parameters and power loss is fitted with data, a pure loss model can be obtained. This embodiment does not impose any specific limitations.

[0033] After completing the pure loss model modeling, a three-phase inverter circuit containing the pure loss model is built in a circuit simulation environment for system simulation. When running this circuit simulation, the simulation engine will solve the electrical simulation parameters (Tj, Vds, Vgs and f_sw) required for each pure loss model input port in real time according to the circuit topology and control logic.

[0034] Power loss simulation is performed synchronously with circuit simulation. During the circuit simulation, each pure loss model receives electrical simulation parameters representing its current operating state from the circuit simulation in real time. It then uses the pre-set equations and data within the model to immediately perform calculations based on these input parameters, quickly calculating the power loss generated by the power semiconductor replaced by the pure loss model at that moment, and obtaining the simulated power loss value.

[0035] Finally, the power loss simulation value output by the pure loss model is used as input to a preset thermal resistance model. The thermal resistance model has pre-stored thermal resistance parameters for different heat dissipation structures. The mapping relationship between power loss and temperature rise data can be queried according to the current simulation environment, and the simulated temperature rise value can be calculated.

[0036] It should be noted that the thermal resistance model is a pre-set mapping model similar to input loss and output temperature rise. This model has different thermal resistance models depending on the heat dissipation structure, water flow rate, and initial reference temperature. The thermal resistance model can be modeled by thermal simulation software.

[0037] Optionally, the calculated simulated temperature rise value can be used to update the junction temperature and fed back to the pure loss model as data for the next calculation, thereby forming a dynamic, closed-loop electrothermal co-simulation that accurately predicts the state of the power module under real operating conditions.

[0038] In this embodiment, measured data is used to construct a pure loss model to replace physical prototyping testing. By establishing the relationship between electrical parameters and power loss, a reliable virtual verification environment is constructed. Any operating condition can be set for repeated verification and optimization, thereby simplifying the process of "design-prototyping-testing-failure-redesign" to "design-simulation-optimization". This greatly reduces the dependence on physical objects, avoids the risk of device damage due to test failure, improves test safety, and also shortens the development cycle and reduces cost.

[0039] In some embodiments, step S101 may include, but is not limited to, steps S201 to S204.

[0040] Step S201: Measure the transfer characteristic curves of the drain current of the power semiconductor as a function of the gate-source voltage at different temperatures and different drain-source voltages to obtain the first characteristic data.

[0041] Step S202: Measure the output characteristic curves of the drain current of the power semiconductor as a function of drain-source voltage at different temperatures and different gate-source voltages to obtain the second characteristic data.

[0042] In step S203, a dual-pulse test is used to measure the turn-on loss and turn-off loss of the power semiconductor under different bus voltages, different load currents, different junction temperatures, and different gate resistances to obtain the third characteristic data.

[0043] Step S204: Integrate the first characteristic data, the second characteristic data, and the third characteristic data to obtain the measured data.

[0044] In this embodiment, measurements are taken at different temperatures and different Vds to obtain a curve (Id-Vgs) showing the variation of Id with Vgs at different temperatures, thus obtaining the first characteristic data.

[0045] For example, measurements are taken at multiple junction temperatures and multiple Vds points, including but not limited to obtaining the transfer characteristic curves of the power semiconductor at multiple Vds points at a junction temperature and obtaining the transfer characteristic curves of the power semiconductor at multiple junction temperatures at a Vds point.

[0046] By measuring at different temperatures and different Vgs, the curves (Id-Vds) showing the variation of Id with Vds at different temperatures can be obtained, thus yielding the second characteristic data.

[0047] For example, measurements are taken at multiple junction temperatures and multiple Vgs points, including but not limited to obtaining the output characteristic curves of the power semiconductor at multiple Vgs points at a single junction temperature and obtaining the output characteristic curves of the power semiconductor at multiple junction temperatures at a single Vgs point.

[0048] By performing dual-pulse tests on power semiconductors under different bus voltages (Vdc), different load currents (Id), different junction temperatures (Tj), and different gate resistances (Rg, a typical value using the target driver), different switching losses (Eon, Eoff) can be obtained, thus yielding third characteristic data.

[0049] Specifically, the turn-on loss Eon and the turn-off loss Eoff can be obtained by the following formula: (1); (2); in, tid This indicates the time corresponding to Id = 10% steady-state current Id. TVDS This indicates the moment when Vds = 10% of the DC bus voltage Vdc.

[0050] The actual measurement data is collected through steps S201 to S203, providing a data foundation for subsequent modeling.

[0051] In some embodiments, step S102 may include, but is not limited to, steps S301 to S304.

[0052] Step S301: Based on the measured data, perform multivariate nonlinear fitting on the relationship between junction temperature, drain-source voltage, gate-source voltage and drain current to obtain the current model.

[0053] Step S302: Fit the conduction loss based on the current model and drain-source voltage to obtain the conduction loss model.

[0054] Step S303: Fit the switching loss based on the turn-on loss, turn-off loss and switching frequency to obtain the switching loss model.

[0055] Step S304: Fit the power loss based on the conduction loss model and the switching loss model to obtain the pure loss model.

[0056] In this embodiment, the measured data covers the complete output characteristics of power semiconductors under different junction temperatures, different gate-source voltages, and different drain-source voltage combinations. Considering that the effects of temperature and voltage on current are coupled rather than independent, in order to accurately capture the complex coupling effect between junction temperature, drain-source voltage, and gate-source voltage, a multivariate nonlinear analysis method is used to fit the relationship between junction temperature, drain-source voltage, gate-source voltage, and drain current, and a current model is established with junction temperature, drain-source voltage, and gate-source voltage as inputs and drain current as output.

[0057] The essence of conduction loss is the power consumed when current flows through a device. It obeys Ohm's law. Based on this, the conduction loss model is obtained by fitting the drain current output from the current model with the drain-source voltage in the electrical parameters. This model can calculate the product of the drain current and the drain-source voltage using a multiplier to fit the conduction loss of the power semiconductor. The calculation formula is as follows: P_cond=Id×Vds(3; Where P_cond represents the conduction loss.

[0058] The switching loss model is used to quantify the power consumed by power semiconductors during switching transients. This model relies on turn-on and turn-off losses acquired through dual-pulse testing. Furthermore, since a higher switching frequency indicates more switching operations per unit time, the cumulative switching loss increases linearly. After fitting the switching loss data, the expression for the switching loss model is obtained as follows: P_sw=f_sw×(Eon+Eoff)(4); Where P_sw represents the switching loss, f_sw is the modulation frequency of the high-frequency triangular wave during three-phase inverter operation, i.e., the switching frequency, and Eon and Eoff are the turn-on loss and turn-off loss in the measured data.

[0059] Finally, power synthesis is performed to complete the construction of the pure loss model. The pure loss model is an integrated calculation module whose function is to sum the shared conduction loss and switching loss. An adder is used to add the output of the conduction loss model and the output of the switching loss model to obtain the total power loss.

[0060] The formula for calculating power loss is: P_loss=P_cond+P_sw(5; Where P_loss represents power loss.

[0061] In some embodiments, step S301 may include, but is not limited to, steps S401 to S403.

[0062] Step S401: Perform a polynomial regression analysis with junction temperature, drain-source voltage, and gate-source voltage as independent variables and drain current as dependent variable to obtain a multivariate nonlinear equation.

[0063] Step S402: Based on the measured data, optimize the fitting parameters of the multivariable nonlinear equation with the goal of minimizing the error to obtain the optimal parameter values.

[0064] Step S403: Obtain the current model based on the multivariable nonlinear equation and the optimal parameter values.

[0065] In this embodiment, junction temperature (Tj), gate-source voltage (Vgs), and drain-source voltage (Vds) are set as independent variables, drain current (Id) is set as dependent variable, and a functional form that can reflect the coupling relationship is selected as the basic framework for fitting.

[0066] Specifically, multinomial regression is a regression analysis method that uses higher-order terms of independent variables to fit nonlinear relationships in data. Compared to simple linear regression, multinomial regression can better capture the complex characteristics of data. This embodiment designs a multivariate nonlinear equation as a fitting framework, including a first nonlinear term related to junction temperature and gate-source power supply, a second nonlinear term related to junction temperature and drain-source power supply, a first linear term related to gate-source voltage, and a second linear term related to drain-source voltage. The expression of the multivariate nonlinear equation is as follows: Id=k1×Tj×Vgs k2 +k3×Vgs+k4×Tj×Vds k5 +k6×Vds+k7(6) Where k1, k2, k3, k4, k5, k6, and k7 are the parameters to be fitted, Id is in units of A, Tj is in units of K, and Vgs and Vds are in units of V.

[0067] Junction temperature and the first nonlinear term of the gate-source power supply (Tj×Vgs) k2 It is used to quantify the coupling effect between junction temperature and gate-source voltage, and can describe how temperature changes modulate the gate-source voltage's control efficiency on current.

[0068] Specifically, due to the gate-source voltage Vgs's control over the channel current (i.e., transconductance, which is typically related to Vgs) k2The nonlinearity (related to the gate's control efficiency) is not fixed but strongly dependent on the junction temperature. Its physical nature stems from the combined effect of two competing mechanisms: a decrease in carrier mobility with increasing temperature and a linear decrease in threshold voltage with increasing temperature. To reflect in real-time how temperature changes affect the gate's control efficiency, this embodiment uses this nonlinear term to characterize the nonlinear modulation effect of junction temperature on the device's transconductance, thereby accurately describing the difference in current generated by the same gate voltage at different temperatures.

[0069] Junction temperature and the second nonlinear term of the drain-source power supply (Tj×Vds) k5 It is used to quantify the coupling effect between junction temperature and drain-source voltage, and can describe how temperature changes modulate the control efficiency of drain-source voltage on current.

[0070] Specifically, the effect of drain-source voltage Vds on current (such as the channel length modulation effect, the strength of which is usually related to Vds) k5 (Related) Temperature modulation. The physical essence is that increased temperature intensifies carrier scattering, leading to mobility degradation and altering the control efficiency of the drain electric field (proportional to Vds) over the current. To dynamically capture how temperature changes affect the effectiveness of the drain electric field, this embodiment uses this nonlinear term to characterize the modulation effect of junction temperature on the output conductance, thereby accurately simulating the slope change of the output characteristic curve at different temperatures.

[0071] It should be noted that the parameter k4 is usually negative, which physically reflects the negative weakening effect of temperature increase on carrier mobility.

[0072] Understandably, by using the first and second nonlinear terms to take the junction temperature as the core variable, and coupling it with the nonlinear effects of the gate-source and drain-source electric fields respectively, the mathematical model directly describes the "temperature-electric field" cross-coupling effect, which greatly improves the accuracy and universality of the model in a wide temperature range and a wide voltage range.

[0073] In data fitting software (such as MATLAB, Origin, etc.), the nonlinear least squares method is used to iteratively optimize the parameters to be fitted, with the goal of minimizing the root mean square error between the calculated model value and the measured data points.

[0074] For example, seven parameters to be fitted are initialized with reasonable initial values. Then, the difference between the model's predicted values ​​and the measured data points is calculated by iterative calculation, and the parameters to be fitted are continuously updated along the direction that minimizes the difference, eventually obtaining a set of optimal parameter values.

[0075] Substituting the optimal parameter values ​​back into the multivariable nonlinear equation, i.e., formula (6), yields a parameter-determined and computable expression, which is the current model.

[0076] This embodiment constructs a current model that can be embedded in circuit simulation. By inputting junction temperature, drain-source voltage, and gate-source voltage, it outputs the predicted drain current, providing an accurate description of current characteristics for subsequent loss calculation and electrothermal joint simulation.

[0077] In some embodiments, step S103 may include, but is not limited to, step S501.

[0078] Step S501: Replace the power semiconductors of each bridge arm in the three-phase inverter circuit with pure loss models, and run the three-phase inverter circuit based on preset simulation environment conditions to obtain electrical simulation parameters.

[0079] In this embodiment, refer to Figure 2 , Figure 2 The serial number labels U, V, and W represent three phases, while H and L represent upper and lower bridges. U, V, W, H, and L are only used to identify the different positions of the same device in a three-phase inverter circuit. For example, U_H represents the upper bridge of phase U, and W_L represents the lower bridge of phase W.

[0080] Specifically, a typical three-phase two-level voltage-source inverter bridge topology is first constructed. The components in the three-phase inverter circuit include a DC power supply (Vdc). Figure 2 (E_DS), bus capacitor C1, ideal diode D, load (e.g., E_DS), Figure 4 The loads (R, L_load), ideal switches, etc. Figure 3 As shown, the control circuit of the three-phase inverter circuit includes a carrier (triangle wave) generator E_Triangle, a modulation wave (sine wave) generator E_sinU, E_sinV, E_sinW, a PWM modulator COMP_DIG_U, COMP_DIG_V, COMP_DIG_W, a dead time generator DEADTIME1, and gate driver models Dri_U_H, Dri_U_L, Dri_V_H, Dri_V_L, Dri_W_H, Dri_W_L (output target drive voltage Vgs).

[0081] Since ideal switches in simulation software cannot accurately simulate losses, the ideal switches in the upper and lower arms of the three-phase bridge are replaced with pure loss models. These pure loss models are connected to each power device, ensuring correct electrical connections during the replacement process. The voltage signals across the original switches are connected to the Vds input port of the pure loss model; for example... Figure 2 As shown, the voltage between Pin_HG and Pin_HS is the Vgs voltage of the H-bridge of this phase, which is used to drive the MOSFET. Therefore, after replacing it with the pure loss model, the drive voltage Vgs output by the gate driver model is connected to the Vgs input port of the pure loss model.

[0082] Before starting circuit simulation, set simulation parameters to construct the simulation environment conditions. Simulation parameters include, but are not limited to, junction temperature, DC power supply voltage, bus capacitance, modulation frequency, carrier frequency, gate resistance Rg, dead time, MOSFET switching voltage, simulation duration, etc. Among these parameters, the modulation frequency is f_sw, which is usually set in the carrier generator before simulation. The rest are fixed values ​​in the fixed-condition simulation. In a single simulation (same operating condition), if the operating condition remains unchanged, the fixed values ​​do not need to be changed. They have already been set in the device internal parameter page during the circuit diagram drawing process.

[0083] When running a three-phase inverter circuit simulation, the simulation engine will automatically solve the circuit state based on the circuit topology and component characteristics, calculate Vgs and Vds information in real time, and together with f_sw and Tj set in the simulation environment conditions, constitute the electrical simulation parameters.

[0084] It should be noted that Tj can be a fixed value set in the simulation environment conditions, or it can be a new Tj calculated using the temperature rise data output by the thermal resistance model. The new Tj is fed back to the pure loss model as the input for the next simulation step.

[0085] In some embodiments, step S105 may include, but is not limited to, steps S601 to S602.

[0086] Step S601: Determine the thermal resistance parameters of the thermal resistance model based on the simulation environment conditions.

[0087] Step S602: Calculate the simulated temperature rise value based on the simulated power loss value and thermal resistance parameter.

[0088] In this embodiment, the simulation environment conditions also include setting the heat dissipation structure, water flow rate, and initial temperature. The thermal resistance model with different heat dissipation structures, different water flows, and different initial reference temperatures will have different internal thermal resistance parameters (R_th-jf).

[0089] Specifically, taking different pinfin heat dissipation structures as an example, the common types of pinfin structures currently include circular, elliptical, rhomboid, teardrop, labyrinthine, and combined shapes. Under the same water flow rate and the same initial temperature, the thermal resistance parameters in the thermal resistance models corresponding to different types of heat dissipation structures are different.

[0090] Taking different water flow rates as an example, increasing the water flow rate usually improves heat exchange efficiency. The larger the water flow rate, the more heat is removed per unit time, thereby reducing thermal resistance. Therefore, under the same heat dissipation structure and the same initial temperature, the thermal resistance parameters in the thermal resistance model corresponding to different water flow rates are different.

[0091] Taking different initial temperatures as an example, the initial temperature is positively correlated with the thermal resistance. Under the same heat dissipation structure and the same water flow rate, the higher the initial temperature, the higher the corresponding thermal resistance. Therefore, the thermal resistance parameters in the thermal resistance model are different for different initial temperatures.

[0092] After determining the thermal resistance parameters of the thermal resistance model based on the heat dissipation structure, water flow rate, and initial temperature, the simulated power loss value P_loss is input, and the simulated temperature rise value is calculated by multiplying the simulated power loss value by the thermal resistance parameter R_th-jf determined inside the thermal resistance model. The formula for calculating the simulated temperature rise value is as follows: ΔT= P_loss×(R_th-jf)(7); Where ΔT represents the simulated temperature rise value.

[0093] For example, refer to Figure 5 The output terminals U_H_P_loss of the pure loss model of the U-phase upper bridge, U_L_P_loss of the pure loss model of the U-phase lower bridge, V_H_P_loss of the pure loss model of the V-phase upper bridge, V_L_P_loss of the pure loss model of the V-phase lower bridge, W_H_P_loss of the pure loss model of the W-phase upper bridge, and W_L_P_loss of the pure loss model of the W-phase lower bridge are respectively connected to the first input terminal input1, the second input terminal input2, the third input terminal input3, the fourth input terminal input4, the fifth input terminal input5, and the sixth input terminal input6 of the thermal resistance model. This allows the simulated power loss values ​​calculated by each pure loss model to be input into the thermal resistance model. The thermal resistance parameters corresponding to the simulation environment conditions are called, and the calculated simulated temperature rise values ​​are output through the first output terminal output01, the second output terminal output02, the third output terminal output03, the fourth output terminal output04, the fifth output terminal output05, and the sixth output terminal output06.

[0094] This embodiment significantly improves simulation speed by directly using the thermal resistance model after outputting the simulated power loss value from the pure loss model.

[0095] The following is a detailed description and explanation of the solutions in the embodiments of the present invention, using specific application examples: This application takes a silicon carbide metal-oxide-semiconductor field-effect transistor (SiC MOSFET) as an example. First, the transfer characteristic curve, output characteristic curve, and switching loss data are measured. Next, a suitable equation is selected to complete the pure loss model modeling. Then, a thermal resistance model is constructed based on the relationship between power loss and temperature rise. After three-phase inversion, the power loss is provided by the pure loss model, and the temperature rise information is output by the thermal resistance model.

[0096] Specifically, the transfer characteristic curve (Id-Vgs) of the SiC MOSFET was obtained by actual measurement at multiple junction temperatures (such as 25℃, 150℃, and 175℃). The Vgs test range was -10~20V, and the Vds test range was 5~50V.

[0097] The output characteristic curves (Id-Vds) of the SiC MOSFET were obtained through actual measurements at multiple junction temperatures (e.g., 25°C, 150°C, 175°C) and multiple Vgs points (slightly above the threshold voltage Vth, e.g., 10V, 15V, 20V). The Vds test range was 0~5V, 5~50V, 50~800V, and the Vgs test range was 0~20V.

[0098] Tests were conducted under different bus voltages (e.g., 400V, 600V, 800V), different load currents (Id), different junction temperatures (e.g., 25°C, 100°C, 150°C, 175°C), and different gate resistances (Rg, typical value using the target driver). Double-pulse testing was performed on the SiC MOSFET to obtain measured data for (Eon, Eoff).

[0099] Based on the measured data of SiC MOSFET, the measured data is fitted using formula (6) to obtain the current model. Then, the output of the current model is fitted with the drain-source voltage Vds to obtain the conduction loss model P_cond.

[0100] When fitting the conduction loss, the switching loss model P_sw is obtained by simultaneously fitting the measured Eon and Eoff data and the switching frequency f_sw.

[0101] Finally, by integrating the conduction loss model and the switching loss model, the pure loss model P_loss is obtained.

[0102] A library of thermal resistance parameters for different heat dissipation structures is pre-set, and a thermal resistance model is constructed. This model has different thermal resistance models depending on the PinFin structure, water flow rate, and initial reference temperature.

[0103] After obtaining the pure loss model and the thermal resistance model, a three-phase inverter circuit integrating both models was constructed for simulation testing. The pure loss model was used to calculate the simulated power loss value, which was then input into the thermal resistance model to obtain the corresponding temperature rise. The thermal resistance model was pre-set with a water flow rate of 8 L / min and an initial temperature of 65°C. A unit step power (i.e., the simulated power loss value calculated by the pure loss model, such as 125W) was applied to each chip. The thermal response curve ΔT_j(t) from the junction to the fluid was extracted, and the thermal resistance (R_th-jf) was obtained. The thermal resistance model used the input power loss and the internal thermal resistance parameters to calculate the simulated temperature rise value corresponding to the power loss. After the simulation, the simulated temperature rise value output by the thermal resistance model was read as the test result.

[0104] The above simulation method can improve the accuracy and certainty of loss and temperature rise data obtained from three-phase inverter simulation, and reduce the possibility of the module deviating from the design value.

[0105] Optionally, the simulated power loss value output by the pure loss model can be used as an intermediate value or as part of the output results.

[0106] In summary, this application provides a three-phase inverter simulation method and related equipment for power modules. The method includes acquiring measured data of the power semiconductor's transfer characteristic curves, output characteristic curves, turn-on losses, and turn-off losses; fitting the relationship between the power semiconductor's electrical parameters and power losses based on the measured data to obtain a pure loss model, where the electrical parameters include junction temperature, drain-source voltage, gate-source voltage, and switching frequency. A pure loss model is established with electrical parameters as input and power loss as output, using measured device characteristic curves and switching loss data. A three-phase inverter circuit is built based on the pure loss model, and the circuit is run to obtain electrical simulation parameters. These parameters are then input into the pure loss model for power loss simulation processing to obtain simulated power loss values. Finally, the simulated power loss values ​​are input into a preset thermal resistance model for temperature rise simulation processing to obtain simulated temperature rise values. By using a modeling method based on the pure loss model for three-phase inverter simulation instead of physical prototype testing, the simulation accuracy of three-phase inverters can be improved, simulation time significantly reduced, power module development cycle shortened, cost reduced, and testing accuracy and safety improved.

[0107] Reference Figure 6 This application also provides a three-phase inverter simulation system for power modules, which can implement the above-mentioned method. The system includes: The measured data acquisition module is used to acquire measured data of the transfer characteristic curve, output characteristic curve, turn-on loss, and turn-off loss of power semiconductors. The data fitting module is used to fit the relationship between the electrical parameters of power semiconductors and power loss based on measured data to obtain a pure loss model. The electrical parameters include junction temperature, drain-source voltage, gate-source voltage and switching frequency. The circuit simulation module is used to build a three-phase inverter circuit based on a pure loss model and run the three-phase inverter circuit to obtain electrical simulation parameters. The power loss simulation module is used to input electrical simulation parameters into a pure loss model to perform power loss simulation processing and obtain power loss simulation values. The temperature rise simulation module is used to input the power loss simulation value into the preset thermal resistance model for temperature rise simulation processing to obtain the temperature rise simulation value. The thermal resistance model contains thermal resistance parameters for different heat dissipation structures.

[0108] It is understood that the content of the above method embodiments is applicable to this system embodiment. The specific functions implemented in this system embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0109] This application also provides an electronic device, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the above-described method. This electronic device can be any smart terminal, including tablet computers, in-vehicle computers, etc.

[0110] It is understood that the content of the above method embodiments is applicable to this device embodiment. The specific functions implemented by this device embodiment are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0111] Reference Figure 7 , Figure 7 The hardware structure of an electronic device according to another embodiment is illustrated. The electronic device includes: The processor 901 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this application.

[0112] The memory 902 can be implemented as a read-only memory (ROM), static storage device, dynamic storage device, or random access memory (RAM). The memory 902 can store the operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 902 and is called and executed by the processor 901 using the methods described in the embodiments of this application.

[0113] The input / output interface 903 is used to implement information input and output.

[0114] The communication interface 904 is used to enable communication and interaction between this device and other devices. Communication can be achieved through wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).

[0115] Bus 905 transmits information between various components of the device, such as processor 901, memory 902, input / output interface 903, and communication interface 904.

[0116] The processor 901, memory 902, input / output interface 903, and communication interface 904 are connected to each other within the device via bus 905.

[0117] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method.

[0118] It is understood that the content of the above method embodiments is applicable to this storage medium embodiment. The specific functions implemented in this storage medium embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0119] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method.

[0120] It is understood that the content of the above method embodiments is applicable to the embodiments of this program product. The specific functions implemented by the embodiments of this program product are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0121] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory may optionally include memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0122] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

[0123] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.

[0124] The system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0125] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0126] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0127] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0128] In the embodiments provided in this application, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the system embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between systems or units may be electrical, mechanical, or other forms.

[0129] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0130] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0131] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes multiple instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing programs, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0132] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. A simulation method for a three-phase inverter power module, characterized in that, The method includes the following steps: Obtain measured data of the transfer characteristic curves, output characteristic curves, turn-on loss, and turn-off loss of power semiconductors; Based on the measured data, the relationship between the electrical parameters of the power semiconductor and the power loss is fitted to obtain a pure loss model, wherein the electrical parameters include junction temperature, drain-source voltage, gate-source voltage and switching frequency. A three-phase inverter circuit was built based on the pure loss model, and the electrical simulation parameters were obtained by running the three-phase inverter circuit. The electrical simulation parameters are input into the pure loss model to perform power loss simulation processing, and the power loss simulation value is obtained. The power loss simulation value is input into a preset thermal resistance model for temperature rise simulation processing to obtain the temperature rise simulation value. The thermal resistance model contains thermal resistance parameters for different heat dissipation structures.

2. The method according to claim 1, characterized in that, The acquisition of measured data on the transfer characteristic curves, output characteristic curves, turn-on loss, and turn-off loss of power semiconductors includes the following steps: The transfer characteristic curves of the drain current of the power semiconductor as a function of the gate-source voltage were measured at different temperatures and different drain-source voltages to obtain the first characteristic data. The output characteristic curves of the power semiconductor as a function of drain current and drain-source voltage were measured at different temperatures and gate-source voltages to obtain the second characteristic data. The turn-on loss and turn-off loss of power semiconductors were measured under different bus voltages, load currents, junction temperatures, and gate resistances using a dual-pulse test to obtain the third characteristic data. The measured data are obtained by integrating the first characteristic data, the second characteristic data, and the third characteristic data.

3. The method according to claim 1, characterized in that, The step of fitting the relationship between the electrical parameters of the power semiconductor and power loss based on the measured data to obtain a pure loss model includes the following steps: Based on the measured data, a multivariate nonlinear fitting was performed on the relationship between junction temperature, drain-source voltage, gate-source voltage and drain current to obtain a current model. The conduction loss model is obtained by fitting the current model and the drain-source voltage. A switching loss model is obtained by fitting the switching loss based on the turn-on loss, the turn-off loss, and the switching frequency. By fitting the power loss model and the switching loss model, a pure loss model is obtained.

4. The method according to claim 3, characterized in that, The process of performing multivariate nonlinear fitting on the relationship between junction temperature, drain-source voltage, gate-source voltage, and drain current based on the measured data to obtain a current model includes the following steps: Using junction temperature, drain-source voltage, and gate-source voltage as independent variables and drain current as dependent variable, a multivariate nonlinear equation is obtained by performing a polynomial regression analysis to obtain a multivariate nonlinear equation. The multivariate nonlinear equation includes a first nonlinear term of junction temperature and gate-source power supply, a second nonlinear term of junction temperature and drain-source power supply, a first linear term of gate-source voltage, and a second linear term of drain-source voltage. Based on the measured data, the fitting parameters of the multivariate nonlinear equation are optimized with the goal of minimizing the error, and the optimal parameter values ​​are obtained. The current model is obtained based on the multivariable nonlinear equation and the optimal parameter values.

5. The method according to claim 1, characterized in that, The process of constructing a three-phase inverter circuit based on the pure loss model and running the three-phase inverter circuit to obtain electrical simulation parameters includes the following steps: The power semiconductors of each arm in the three-phase inverter circuit are replaced with the pure loss model, and the three-phase inverter circuit is run based on the preset simulation environment conditions to obtain the electrical simulation parameters.

6. The method according to claim 5, characterized in that, The step of inputting the power loss simulation value into a preset thermal resistance model for temperature rise simulation to obtain the temperature rise simulation value includes the following steps: Determine the thermal resistance parameters of the thermal resistance model based on the simulation environment conditions. The simulated temperature rise value is calculated based on the simulated power loss value and the thermal resistance parameter.

7. A three-phase inverter simulation system for power modules, characterized in that, The system includes: The measured data acquisition module is used to acquire measured data of the transfer characteristic curve, output characteristic curve, turn-on loss, and turn-off loss of power semiconductors. The data fitting module is used to fit the relationship between the electrical parameters of the power semiconductor and the power loss based on the measured data to obtain a pure loss model. The electrical parameters include junction temperature, drain-source voltage, gate-source voltage and switching frequency. The circuit simulation module is used to build a three-phase inverter circuit based on the pure loss model and run the three-phase inverter circuit to obtain electrical simulation parameters. The power loss simulation module is used to input the electrical simulation parameters into the pure loss model to perform power loss simulation processing and obtain power loss simulation values. The temperature rise simulation module is used to input the power loss simulation value into a preset thermal resistance model for temperature rise simulation processing to obtain the temperature rise simulation value. The thermal resistance model contains thermal resistance parameters for different heat dissipation structures.

8. An electronic device, characterized in that, The electronic device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the method according to any one of claims 1 to 6.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the method of any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the method of any one of claims 1 to 6.

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