DE102022208404A1 - Method and device for determining a simulation model for a power diode - Google Patents

Abstract

A method for determining a simulation model for a power diode (108), in particular a gallium oxide power diode, is presented, the method comprising a step of executing a basic model for the power diode (108) in order to obtain simulation curves which have a leakage current as a function of a reverse voltage and a temperature of the power diode (108), the basic model comprising a first factor and a second factor. Further, a step of changing a value of the first factor to change a shape of the simulation curves and/or a value of the second factor to cause a shift of the simulation curves, a step of repeating the steps of executing and changing to a changed one to obtain the value of the first factor and the second factor, in which the simulation curves are adapted to measurement curves of the power diode (108), and a step of determining the simulation model for the power diode (108) using the base model and the changed value of the first factor and of the second factor.

Description

The present invention relates to a method and a device for determining a simulation model for a power diode, in particular for a gallium oxide power diode.

The US 2011166847 A1 describes a model for a silicon controlled rectifier that includes three diode models connected in series, with the middle diode model reverse biased. Each diode model corresponds to a junction in the silicon controlled rectifier and can be configured to simulate DC operation. The model can be used to evaluate the behavior of a circuit containing the silicon controlled rectifier.

Against this background, the present invention provides an improved method and an improved device for determining a simulation model for a power diode, in particular for a gallium oxide power diode, according to the main claims. Advantageous refinements result from the subclaims and the following description.

The presented approach makes it possible to simulate, for example, the behavior of electrical components, in particular those that contain gallium oxide. Advantageously, the approach presented can also be used to determine which formulas and parameters can be used to describe the properties of the components, for example the diode properties. This is particularly advantageous for components based on gallium oxide, as the properties of different components can be very different.

A method for determining a simulation model for a power diode, in particular a gallium oxide power diode (Ga ₂ O ₃ ), is presented, the method comprising a step of executing a basic model for the power diode in order to obtain simulation curves that show a leakage current of the power diode in Represent dependence on a reverse voltage of the power diode and a temperature of the power diode. The basic model includes a first factor and a second factor. Furthermore, the method includes a step of changing a value of the first factor to change a shape of the simulation curves, and additionally or alternatively a value of the second factor to effect a shift of the simulation curves. The method further includes a step of repeating the steps of executing and changing to obtain a changed value of the first factor and a changed value of the second factor in which the simulation curves are adapted to measurement curves of the power diode, and a step of determining the simulation model for the power diode using the base model and the modified value of the first factor and the modified value of the second factor.

The power diode can be used, for example, in conjunction with a power converter, such as that used in vehicles. Using the presented method, simulations can be realized through which the behavior of the power diode can be simulated in conjunction with different leakage current values, reverse voltage values and temperature values. Advantageously, this can improve a safety aspect and operational capability of the power diode. The basic model can be based on a model supplemented by the first factor and the second factor, with which a diode that differs from the power diode can be modeled. Well-known models can be used for this purpose. The factors allow properties of the power diode to be taken into account that differ from the diode whose model was used as the basis for the basic model. To determine the simulation model, the variable factors can be changed based on initial values. Advantageously, the basic model can be adapted to the respective power diode in a time-efficient manner by continuously changing the values of the factors. The first factor allows the simulation curves to be deformed in the direction of a straight line or, for example, in the direction of a parabola. The second factor can be used to shift the position of the simulation curves in a diagram, for example. The measurement curves can be stored in a storage unit and represent measured behavior of the power diode. The simulation curves can be compared with the measurement curves to obtain a comparison result that can be used to evaluate agreement between a simulation curve and a measurement curve. In the determining step, the simulation model can advantageously be determined using at least one formula into which the factors can be inserted. Advantageously, simulation models can be created or determined in a simplified manner using the method.

For example, using the method, a simulation model for Ga ₂ O ₃ diodes suitable for a common simulation program can be created, which can be used for the design and analysis of electrical circuits. The simulation program is able to map characteristics of a power diode that differ significantly from standard diodes (e.g. Si, SiC). Advantageously, an APP can be implemented that is able to find necessary model parameters. This makes model creation easier and faster.

According to one embodiment, the method can include a step of reading in measurement data generating the measurement curves. The measurement curves can advantageously be read in from a storage unit or, for example, from a cloud. The measurement data can advantageously relate to actually measured and not calculated data of the power diode.

In addition, the method can include a step of acquiring the measurement data using a sensor device. This means that the measurement data can be recorded currently, for example, during a design or planning process for the use of the power diode. The sensor device can advantageously have at least one sensor and advantageously several sensors, such as temperature sensors, current sensors or voltage sensors, so that a behavior of the power diode can advantageously be recorded as completely as possible.

In the changing step, the value of the first factor and additionally or alternatively the value of the second factor can be changed randomly. For example, the values can be changed automatically or manually by a user.

According to one embodiment, in the step of changing, the value of the first factor and additionally or alternatively the value of the second factor can be changed using a mathematical optimization method. This makes it possible to approach optimal values for the factors.

In the changing step, the least squares method can be used as a mathematical optimization method. The least squares method can also be called least-square method. This allows the calculated or determined values to come as close as possible to an optimum.

Furthermore, the step of repeating can be carried out until the changed value of the first factor and the changed value of the second factor can achieve maximum agreement between the simulation curves and the measurement curves of the power diode. The values and thus the simulation curves can advantageously be calculated until the maximum agreement can be achieved. The maximum agreement can be assumed to have been achieved, for example, if further repetition of the steps does not lead to any further agreement between the simulation curves and the measurement curves.

According to one embodiment, the method may include a step of providing a display signal for displaying the simulation curves to an interface to a display unit in order to display the simulation curves on the display unit. The display unit can advantageously be used to graphically display the simulation curves. The simulation curves can advantageously be displayed in a diagram. This allows, for example, a graphical comparison of the simulation curves and the measurement curves.

For the basic model, a known model for mathematically calculating a parameter, for example the reverse current, of a diode can be used. For example, the basic model can be based on a thermionic model of the power diode.

The basic model can be based on the equation J _TFE (T,E) = FA(T,V) * a(E,T) * exp{ - b(T) * [SH(T)*c + d - g(E ,T)] }, where FA(T,V) can represent the first factor and SH(T) can represent the second factor. Advantageously, the base model can be created using the formula and the simulation model can be determined by changing the factors once or several times.

The first factor may include a first mathematical term GE(T) and a second mathematical term PA(T). The terms can therefore be described as variable components of the factors that can change the simulation curves.

The approach presented here also creates a device that is designed to carry out, control or implement the steps of a variant of a method presented here in corresponding devices. This embodiment variant of the invention in the form of a device can also solve the problem on which the invention is based quickly and efficiently.

A device can be an electrical device that processes electrical signals, for example sensor signals, and outputs control signals depending on them. The device can have one or more suitable interfaces, which can be designed in hardware and/or software. In the case of a hardware design, the interfaces can, for example, be part of an integrated circuit in which functions of the device are implemented. The interfaces can also be their own integrated circuits or at least partially consist of discrete components. In the case of software training, the interfaces can be software modules that are present, for example, on a microcontroller alongside other software modules.

Also advantageous is a computer program product with program code, which can be stored on a machine-readable medium such as a semiconductor memory, a hard drive memory or an optical memory and is used to carry out the method according to one of the embodiments described above if the program is on a computer or a device is performed.

• 1 eine schematische Darstellung eines Fahrzeugs gemäß einem Ausführungsbeispiel;
• 2 eine schematische Darstellung einer Leistungsdiode gemäß einem Ausführungsbeispiel;
• 3 ein Ausführungsbeispiel eines Schaltbilds eines elektrischen Blocks einer Leistungsdiode;
• 4 ein Ausführungsbeispiel eines Schaltbilds eines thermischen Blocks einer Leistungsdiode;
• 5 eine Diagrammdarstellung eines Ausführungsbeispiels eines Basismodells für eine Leistungsdiode;
• 6 eine Diagrammdarstellung eines Ausführungsbeispiels eines Basismodells für eine Leistungsdiode; und
• 7 eine Diagrammdarstellung eines Ausführungsbeispiels eines Basismodells für eine Leistungsdiode;
• 8 ein Ablaufdiagramm eines Ausführungsbeispiels eines Verfahrens zum Bestimmen eines Simulationsmodells für eine Leistungsdiode; und
• 9 ein Blockschaltbild einer Vorrichtung gemäß einem Ausführungsbeispiel.

The invention is explained in more detail using the accompanying drawings. Show it:

• 1 a schematic representation of a vehicle according to an exemplary embodiment;
• 2 a schematic representation of a power diode according to an exemplary embodiment;
• 3 an embodiment of a circuit diagram of an electrical block of a power diode;
• 4 an embodiment of a circuit diagram of a thermal block of a power diode;
• 5 a diagrammatic representation of an embodiment of a basic model for a power diode;
• 6 a diagrammatic representation of an embodiment of a basic model for a power diode; and
• 7 a diagrammatic representation of an embodiment of a basic model for a power diode;
• 8th a flowchart of an exemplary embodiment of a method for determining a simulation model for a power diode; and
• 9 a block diagram of a device according to an exemplary embodiment.

In the following description of preferred exemplary embodiments of the present invention, the same or similar reference numbers are used for the elements shown in the various figures and having a similar effect, with a repeated description of these elements being omitted.

1 shows a schematic representation of a vehicle 100 according to an exemplary embodiment. The vehicle 100 is, for example, a motor vehicle designed to transport people. According to this exemplary embodiment, the vehicle 100 has an energy supply unit 102, for example a battery, also a drive unit 104, such as an electric motor, and a power converter 106 with at least one power diode 108 connected between the energy supply unit 102 and the drive unit 104. The power converter 106 is designed to convert a direct voltage provided by the energy supply unit 102 into an alternating voltage for operating the drive unit 104. The power diode 108 is, for example, a gallium oxide power diode (Ga ₂ O ₃ ), which according to this exemplary embodiment is part of an electronic circuit of the power converter 106. Alternatively, however, the power diode 108 can also be used in connection with other devices of the vehicle 100 or another device.

2 shows a schematic representation of a power diode 108 according to an exemplary embodiment. The power diode 108 shown here corresponds to that in 1 described power diode 108 and can therefore be used, for example, for a vehicle and alternatively also for other areas. According to this embodiment, power diode is as a Ga ₂ O ₃ power diode 108 with an anode connection A and a cathode connection C. For example, a temperature of the power diode 108 can be measured. For example, a distinction is made between a junction temperature T _j , a housing temperature T _case and an ambient temperature T _amb . Before using the power diode 108, it makes sense to check the behavior of the power diode 108 at different temperature values. For this purpose, for example, a method for determining a simulation model is carried out, as will be described in more detail using the following figures.

3 shows an exemplary embodiment of a circuit diagram of an electrical block 300 of a power diode. The electrical block 300 describes, for example, electrical characteristics of the power diode, for example as shown in 2 is shown. The circuit diagram shows a first current source 302 and a second current source 304, the first current source 302 being arranged in a first line 306 connecting an anode connection A and a cathode connection C. From the first current source 302, a first current I ₁ is fed into the first line 306 depending on a voltage applied to the power diode and the junction temperature T _j . The second current source 304 is arranged in a second line 308 connecting the anode connection A and the cathode connection C. From the second current source 304, a second current I ₂ is fed into the second line 308 depending on a capacity of the power diode and a change over time in the voltage applied to the power diode. Accordingly, the current I ₁ is defined, for example, by I ₁ = f(V, T) and the current I ₂ , for example, by I ₂ = f(C _j ,dv/dt).

4 shows an exemplary embodiment of a circuit diagram of a thermal block 400 of a power diode. The thermal block 400 describes electrothermal characteristics of the power diode as shown in 2 is shown. According to this embodiment, thermal block 400 includes a third current source 402 for providing a third current I ₃ defined as I ₃ = f(V, I). The third current source 402 is connected between a potential equalization 404 and a line 406, which connects a first temperature connection 408 for the junction temperature T _j and a second temperature connection 410 for the housing temperature T _case . Another line 412 is connected to a third temperature connection 414 for the ambient temperature T _amb .

The thermal block models the electrothermal properties of the power diode. The third current source 402 is also referred to as BCS I ₃ and models the power dissipation of the diode based on the current flowing through the diode and the voltage across the diode. This power loss determines the junction temperature T _j of the diode. The change in the junction temperature T _j then automatically changes the current and voltage and thus the power loss of the diode.

In general, there are not just two resistors and capacitors, but almost any number (often 5 to 8 resistor-capacitor pairs, also called RC elements). The resistors and capacitors thus model the thermal resistance and thermal capacity of various layers in the structure (structure here means, for example, diode and connection layer to the substrate as well as substrate and connection layer to the heat sink and heat sink, i.e. the complete thermal path). Each RC link now represents a specific layer in this path. In the example in 4 For clarity, only two links are drawn, and potential further links are indicated with dots.

The thermal block 400 further has two resistors 416, 418 which are connected in series between the first temperature connection 408 and the second temperature connection 410. Furthermore, the thermal block 400 has two capacitors 420, 422, which are arranged between the line 406 and the further line 412. More specifically, the first capacitor 420 of the capacitors 420, 422 is connected between the first temperature connection 408 for the junction temperature T _j and the third temperature connection 414 for the ambient temperature T _amb . The second capacitor 422 is connected between a connection point of the resistors 416, 418 and the third temperature connection 414.

5 shows a diagrammatic representation of an exemplary embodiment of a basic model 500 for a power diode, as used in at least one of the 1 to 2 was described. The basic model is not yet adapted to the power diode and is therefore only partially suitable for modeling the power diode. The reverse voltage of the power diode is plotted on the abscissa 502. The leakage current (reverse current) of the power diode is plotted on the ordinate 504. According to this exemplary embodiment, the base model 500 includes simulation curves 506, 508, with the first simulation curve 506 representing the behavior of the power diode at low temperatures and the second simulation curve 508 at high temperatures. Since the base model 500 is a starting point for the in 2 mentioned and in 8th The method described for determining a simulation model represents the simulation curves 506, 508 according to this embodiment have an almost identical shape and are simply arranged in a shifted manner. Starting from a low blocking voltage, the simulation curves 506, 508 initially rise steeply and then steadily but flatly.

6 shows a diagrammatic representation of an exemplary embodiment of a simulation model 600 for a power diode. The simulation model 600 is based on the 5 mentioned basic model, but is adapted to the power diode and is therefore suitable for modeling the power diode. The abscissa 502 is correspondingly: 5 the reverse voltage and the leakage current (reverse current) of the power diode is plotted on the ordinate 504. Due to the adaptation to the power diode, the simulation curves 506, 508 show in comparison to those in 5 The curves shown represent a changed course. The adaptation is achieved by changing and/or adapting factors of the base model. This allows the basic model to be adapted, for example, to the material of the power diode, in particular gallium oxide.

The first simulation curve 506, which applies to a low temperature, rises in an approximately parabolic manner due to the adaptation. The second simulation curve 506, which applies to a high temperature, increases approximately linearly due to the adaptation. The first simulation curve 506 intersects the second simulation curve 508.

Gallium oxide (Ga ₂ O ₃ ) is a wide bandgap semiconductor used in power electronics. Measurements on first Ga ₂ O ₃ diodes 108 show that typical diode properties of gallium oxide, such as current-voltage characteristics, can differ greatly from known standard diodes such as silicon diodes (Si) or silicon carbide diodes (SiC).

Against this background, the model described here and in the following figures is based on the in 3 described electrical block 300 and the in 4 thermal block described. Physical formulas and dependencies are implemented using Behavioral Current Sources (BCS) included in the 3 and 4 have been described as first power source, second power source and third power source. The electrical block models the purely electrical properties of the diode. The first current source models the forward and reverse currents and the second current source models the current flowing through the capacitance. The thermal block models the pure thermal properties of the diode.

For example, the capacitance of the diode is implemented with a lookup table of actual measured measurement data to achieve maximum precision. Alternatively, the capacity can be implemented as a function of the voltage using standard formulas.

The current through the capacitance is caused, for example, by a change in the voltage across the capacitance. The current through the capacitance is therefore modeled as a function f(C, dV/dt). According to one embodiment, the current I ₁ is divided into two parts that are separated by an if condition. If the voltage is greater than 0V, a current flows in the forward direction. In this case, a standard model of thermal or thermionic emission is implemented. $$J_D=J_S\left[exp\left(\frac{q\left(v_D-J_D{R}_{On,sp}\right)}{nkT}\right)-1\right]$$

J _D represents the current through the diode, J _s the saturation current, q the electron charge, V _D the voltage across the diode (diode voltage), R _on the series resistance of the diode (on-resistance) , n represents the emission coefficient (ideality factor) and T the diode temperature (junction temperature).

The series resistance and the emission coefficient can be implemented either as a formula to describe the change of the parameters with temperature or as a lookup table with actually measured values. By using lookup tables, features that cannot be described by the standard formula (1) are taken into account.

If the voltage is less than 0V, the current flows in the reverse direction. In principle, the thermionic field emission model is implemented here. It has the basic shape $${\text{J}}_{\text{TFE}}\left(\text{T}\text{,E}\right)=\text{a}\left(\text{E}\text{,T}\right)*\text{exp}\left\{-\text{b}\left(\text{T}\right)*\left[\text{c}+\text{d}-\text{G}\left(\text{E}\text{,T}\right)\right]\right\}$$

a, b, c, g represent constants derived from physical parameters, E represents the electric field at the junction and T represents the temperature.

In order to describe the properties of the power diode described here, two crucial purely mathematical functions FA(T,V) and SH(T) are inserted and equation (2) is expanded to include them: $${\text{J}}_{\text{TFE}}\left(\text{T}\text{,E}\right)=\text{FA}\left(\text{T}\text{,V}\right)*\text{a}\left(\text{E}\text{,T}\right)*\text{exp}\left\{-\text{b}\left(\text{T}\right)*\left[\text{SH}\left(\text{T}\right)\text{*c}+\text{d}-\text{G}\left(\text{E}\text{,T}\right)\right]\right\}$$

These factors FA(T,V) and SH(T) adjust the offset of the current-voltage curves in the reverse direction and also the shape of the curve to achieve the necessary properties of Ga ₂ O ₃ . The factor FA=FA(GE(T),PA(T),V) consists of two mathematical terms GE(T) and PA(T). These factors are used to subtract or add a straight line or parabola to the known standard profiles. The SH(T) factor shifts the entire curve up or down. This leads to good model accuracy.

7 shows a diagrammatic representation of an exemplary embodiment of a simulation model 600 for a power diode, as shown, for example, in 5 was described. According to this exemplary embodiment, however, in addition to a simulation curve 706, the diagram has a plurality of measurement curves 700 with which the simulation curve 706 can be compared. The measurement curves 700 represent the behavior of the power diode at different temperatures, here for example between 25 ° C and 150 ° C. For example, the measurement curves 700 are based on measurement data from the power diode. The aim is to use the simulation curve 706 in the following 8th described method to approximate as closely as possible to that of the measurement curves 700, which represents the behavior of the power diode at the same temperature as the simulation curve 706.

According to this exemplary embodiment, the simulation curve 706 is shown as a continuous line, which here shows the behavior of the power diode at a temperature of 150 ° C. The measurement curves 700 are shown in dotted lines according to this exemplary embodiment and represent, for example, the behavior of the power diode with regard to reverse voltage and leakage current at temperatures of 25 ° C, 50 ° C, 75 ° C, 100 ° C, 125 ° C and 150 ° C. The temperatures are shown in the diagram by means of a legend 702 for an overview, via which the individual measurement curves 700 can be assigned to the corresponding temperature, for example by means of color coding.

As an example, a temperature is specified for which the simulation model should be created, here 150°C. One of the measurement curves 700 assigned to this temperature has a course that almost completely coincides with the course of the simulation curve 706. In order to obtain this simulation curve 706, factors of the base model are continuously adjusted, for example. In addition, according to one exemplary embodiment, data relating to the material of the power diode is set, entered or, for example, called up.

Advantageously, parameters SH(T) can be determined by entering values to be used manually and checking whether these values are appropriate based on an automatic update of the simulation curve 706. Alternatively, the best parameters can be calculated using a program, for example using the least-squares method. Values to be used manually can also be entered for an interpolation of values of the simulation curve 706 and it can be checked whether these values are suitable based on an automatic update of the simulation curve 706. Alternatively, the best parameters can be calculated using a program, for example using the least-squares method. Advantageously, parameters FA(T) can be determined when modeling the simulation curve 706 as a parabola by manually entering values to be used and checking whether these values are appropriate based on an automatic update of the simulation curve 706. Alternatively, the best parameters can be calculated using a program, for example using the least-squares method.

8th shows a flowchart of an exemplary embodiment of a method 800 for determining a simulation model for a power diode, in particular a gallium oxide power diode, as described, for example, in one of 6 to 7 was described. The method 800 is applied, for example, to a power diode, as shown, for example, in 1 to 2 was described.

The method 800 includes a step 802 of executing a basic model for the power diode in order to obtain simulation curves that represent a leakage current of the power diode as a function of a reverse voltage of the power diode and a temperature of the power diode. The basic model includes a first factor and a second factor. For example, the basic model is based on a formula J _TFE (T,E) = FA(T,V) * a(E,T) * exp{ -b(T) * [SH(T)*c + d - g(E ,T)]}, where FA(T,V) represents the first factor and SH(T) represents the second factor. As long as the factors have not yet been adapted to the power diode, the simulation curves are not yet suitable for modeling the power diode, as can be done, for example, using 5 is shown.

Furthermore, the method 800 includes a step 804 of changing a value of the first factor to change a shape of the simulation curves and/or a value of the second factor to cause a shift in the simulation curves. The shape of the simulation curves can be adapted to the shape of a straight line or a parabola, for example. The simulation curves are shifted, for example, along the abscissa and/or along the ordinate in the 5 and 6 diagrams shown.

In a repeating step 806, the executing step 802 and the modifying step 804 are repeated to obtain a modified value of the first factor and a modified value of the second factor in which the simulation curves are adapted to measurement curves of the power diode. Corresponding simulation curves are, for example, in 6 shown.

Only optionally are the simulation curves compared with measurement curves of the power diode, for example using 7 is described. The measurement curves are advantageously adapted to diode properties of the power diode, such as a material of the power diode. By means of a corresponding comparison, it can be determined whether a simulation curve is already sufficiently adapted to an assigned measurement curve, and thus a further repetition of steps 802, 804 of executing and changing at least for the simulation curve, which is assigned to a specific temperature, for example, can be omitted .

Furthermore, the method 800 includes a step 808 of determining the simulation model for the power diode using the base model and the changed value of the first factor and the changed value of the second factor, for which there was a maximum or sufficient agreement between the measurement curve and the simulation curve.

For example, in step 806 of repeating, the value of the first factor and/or the value of the second factor is changed randomly, for example manually, or using a mathematical optimization method, such as the least squares method, also known as the least square method is. In addition, values or data can be taken into account for which, for example, there are no measurement data (yet).

According to one embodiment, step 806 of repeating is carried out until the changed value of the first factor and the changed value of the second factor result in a maximum agreement between the simulation curves and the measurement curves of the power diode. This means that the method 800, or the step 806 of repeating, is carried out until a best possible result for the power diode or the simulation model has been determined or calculated.

Only optionally does the method 800 additionally include a step 810 of reading in the measurement data that generates the measurement curves. The measurement data represent, for example, diode properties, which can relate, among other things, to the material. For this purpose, the measurement data is acquired, for example, in a step 812 of acquisition using a sensor device on a real power diode that is in operation. For example, using the sensor device at different temperatures for different voltages applied to the diode, the resulting currents are detected through the diode.

In a likewise optional step 814 of providing, a display signal for displaying the simulation curves is provided to an interface to a display unit and thus graphically depicted as a diagram, as shown, for example, in 7 was described.

According to one embodiment, method 800 displays data used to generate the simulation model, such as an LTspice model. For this purpose, for example, the basic data, which is also referred to as model data, is compared with the measurement data. For example, the factors FA(T,V) and SH(T) can be set manually and the result is directly visible. Furthermore, an automatic calculation of so-called best-fit values for the factors FA(T,V) and SH(T,V) can be carried out and a necessary code can be created.

9 shows a block diagram of a device 900 according to an exemplary embodiment. The device 900 is designed, for example, to control or carry out a method as described in 8th was described. For this purpose, the device 900 has an evaluation unit 902 which is designed to execute a basic model 500 for the power diode in order to obtain simulation curves which represent a leakage current of the power diode as a function of a reverse voltage of the power diode and a temperature of the power diode. The basic model 500 is only optionally stored on a storage unit 904 or can be accessed from one. The basic model includes a first factor and a second factor. Furthermore, the evaluation unit 902 is designed to change a value of the first factor in order to change a shape of the simulation curves, and/or to change a value of the second factor in order to cause a shift in the simulation curves. The evaluation unit 902 repeats these two processes in order to obtain a changed value of the first factor and a changed value of the second factor, in which the simulation curves are adapted to measurement curves of the power diode. In addition, the evaluation unit 902 is designed to determine the simulation model 600 for the power diode using the base model and the changed value of the first factor and the changed value of the second factor. Only optionally does the device 900 according to this exemplary embodiment have a reading unit 906, which is designed to read in the measurement data 908 generating the measurement curves, which were detected, for example, by a sensor device 910 on a real power diode. Furthermore, optionally, the device 900 has a provision unit 912, which is designed to provide a display signal 914 for displaying the simulation curves of the simulation model 600 to an interface to a display unit 916 in order to display the simulation curves on the display unit 916 and thus graphically depict them.

Reference symbols

100

vehicle

102

Energy supply facility

104

electric machine

106

Power converter

108

power diode

A

Anode connection

C

Cathode connection

Tj

junction temperature

Tcase

Case temperature

Tamb

Ambient temperature

300

electrical block

302

first power source

304

second power source

306

first line

308

second line

I1

first stream

I2

second stream

400

thermal block

402

third power source

404

Potential equalization

406

Line

408

first temperature connection

410

second temperature connection

412

further line

414

third temperature connection

416

first resistance

418

second resistance

420

first capacitor

422

second capacitor

I3

third stream

500

Basic model

502

X axis

504

y axis

506

first simulation curve

508

second simulation curve

600

Simulation model

700

Measurement curves

702

Legend

706

Simulation curve

800

Method for determining a simulation model

802

Execute step

804

step of change

806

Repeat step

808

Step of determining

810

Reading step

812

Step of capturing

814

Deployment step

900

contraption

902

Evaluation unit

904

Storage unit

906

Reading unit

908

Measurement data

910

Sensor device

912

Provision unit

914

Display signal

916

Display unit

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2011166847 A1 [0002]

Claims (14)

Method (800) for determining a simulation model (600) for a power diode (108), in particular a gallium oxide power diode, the method (800) comprising the following steps: Executing (802) a base model (500) for the power diode (108) in order to obtain simulation curves (506, 508; 706) which show a leakage current of the power diode (108) as a function of a reverse voltage of the power diode (108) and a temperature of the represent power diode (108), wherein the base model (500) includes a first factor and includes a second factor; changing (804) a value of the first factor to change a shape of the simulation curves (506, 508; 706) and/or a value of the second factor to cause a shift of the simulation curves (506, 508; 706); Repeating (806) the steps (802, 804) of performing and changing to obtain a changed value of the first factor and/or a changed value of the second factor at which the simulation curves (506, 508; 706) are at Measurement curves (700) of the power diode (108) are adapted; and Determining (808) the simulation model (600) for the power diode (108) using the base model (500) and the changed value of the first factor and the changed value of the second factor. Procedure (800) according to Claim 1 , with a step (810) of reading in measurement data (908) generating the measurement curves (700). Procedure (800) according to Claim 2 , with a step (812) of acquiring the measurement data (908) using a sensor device (910). Method (800) according to one of the preceding claims, wherein in the step (804) of changing the value of the first factor and/or the value of the second factor is or are changed randomly. Method (800) according to one of Claims 1 until 3 , wherein in step (804) of changing, the value of the first factor and / or the value of the second factor is or are changed using a mathematical optimization method. Procedure (800) according to Claim 5 , wherein in step (804) of changing, the least squares method is used as the mathematical optimization method. Method (800) according to one of the preceding claims, wherein the step (806) of repeating is carried out until the changed value of the first factor and the changed value of the second factor achieve a maximum agreement between the simulation curves (506, 508; 706) and the Measurement curves (700) of the power diode (108) are achieved. Method (800) according to one of the preceding claims, with a step (814) of providing a display signal (914) for displaying the simulation curves (506, 508; 706) to an interface to a display unit (916) in order to display the simulation curves (506, 508; 706) on the display unit (916). Method (800) according to one of the preceding claims, wherein the basic model (500) is based on a thermionic model of the power diode (108). Method (800) according to one of the preceding claims, wherein the base model (500) is based on the equation J _TFE (T,E) = FA(T,V) * a(E,T) * exp{ -b(T) * [ SH(T)*c + d - g(E,T)] }, where FA(T,V) represents the first factor and SH(T) represents the second factor. Method (800) according to one of the preceding claims, wherein the first factor comprises a first mathematical term GE(T) and a second mathematical term PA(T). Device (900) which is set up to carry out the steps (802, 804, 806, 808, 810, 812, 814) of the method (800) according to one of the preceding claims in corresponding units (902, 906, 912) and/ or to control. Computer program that is designed to carry out the steps (802, 804, 806, 808, 810, 812, 814) of the method (800) according to one of Claims 1 until 11 to execute and/or control. Machine-readable storage medium on which the computer program can be written Claim 13 is stored.

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