Calculation method and calculation device

Abstract

To provide a calculation method and a calculation device capable of calculating physical simulation for temperature characteristics in shorter time.SOLUTION: The calculation device comprises a model generation part, an execution processing part, and a heat model generation part. The model generation part generates a circuit model for connecting a plurality of element models having electrical characteristics information of a switching element. The execution processing part uses electrical characteristics information of each of the plurality of element models to time-sequentially calculate electric power generated by switching of the element model in each time step for a predetermined time-sequence input value. On the basis of the integrated value obtained by integrating electric power generated in each time step, the heat model generation part generates a heat model that generates representative value of the integrated value according to the switching of the element model.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates to a computing method and a computing device. [Background technology]

[0002] To evaluate the electrical operating characteristics of the electric circuit using the designed element, a circuit simulation is performed using a circuit simulator such as SPICE (Simulation Program with Integrated Circuit Emphasis), which strictly considers physical characteristics.

[0003] Furthermore, when designed elements are used in automobiles or aircraft, temperature characteristics are considered important for security reasons, and for this reason, temperature simulations are sometimes carried out to examine temperature characteristics in addition to electrical operating characteristics of electrical circuits.

[0004] In such circuit simulations, many elements of an electric circuit, such as transistors, resistors, and capacitors, are modeled as element models to calculate transient phenomena. On the other hand, temperature simulations are generally performed using the generated power of each element model.

[0005] However, temperature simulation requires a sufficiently long analysis time relative to the response time constant of each element, and therefore, rigorously calculating the transient phenomena of an electric circuit with many elements takes a significant amount of time. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-193513 Summary of the Invention [Problem to be solved by the invention]

[0007] The problem to be solved by the present invention is to provide a calculation method and a calculation device that can perform a physical simulation in a shorter time. [Means for solving the problem]

[0008] The calculation method according to this embodiment includes a model generation step, an execution processing step, and a thermal model generation step. The model generation step generates a circuit model that connects multiple element models, each having information on the electrical characteristics of a switching element. The execution processing step uses the information on the electrical characteristics of each of the multiple element models to time-series calculate the power generated at each time step by switching the element model in response to a predetermined time-series input value. The thermal model generation step generates a thermal model that outputs an output value based on an integrated value obtained by integrating the power generated at each time step in response to the switching of the element model. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a block diagram showing the configuration of a calculation device according to a first embodiment. [Figure 2] FIG. 1 is a diagram showing an example of a model configuration. [Figure 3] FIG. 10 is a diagram showing an example of an element model. [Figure 4] FIG. 10 is a diagram showing an example of displaying a plurality of selectable models. [Figure 5] FIG. 10 is a diagram showing an example in which a plurality of selectable element models are displayed on a monitor. [Figure 6] FIG. 10 is a diagram showing examples of selectable command values ​​for a selected model. [Figure 7] FIG. 10 is a diagram showing an example of an image displayed on a monitor during a simulation. [Figure 8] FIG. 10 is a diagram showing the results of a simulation of power generation during switching. [Figure 9] FIG. 10 is a diagram showing an example of an image during a simulation using a thermal model. [Figure 10] 10A and 10B are diagrams showing examples of simulations using a thermal model and a high-precision model. [Figure 11] 10 is a flowchart showing an example of calculation by the calculation device. [Figure 12] FIG. 10 is a block diagram showing the configuration of a calculation device according to a second embodiment. [Figure 13] FIG. 10 is a diagram showing an example of a simplified model obtained by simplifying an element model. [Figure 14] FIG. 10 is a diagram showing an example of an image of a model including a mechanical model. [Figure 15] FIG. 10 is a diagram showing an example of an image of a model including a mechanical model during a temperature simulation. [Figure 16] 10 is a flowchart showing an example of a temperature simulation of a circuit model. [Figure 17] FIG. 10 is a block diagram showing the configuration of a calculation device according to a third embodiment. [Figure 18] 10 is a flowchart showing an example of the operation of an execution processing unit. [Figure 19] 19 is a flowchart showing a detailed example of the process in step S402 of FIG. 18. [Figure 20] 20A to 20C are diagrams schematically illustrating the processing example of FIG. 19 in chronological order. [Figure 21] FIG. 10 is a block diagram showing the configuration of a calculation device according to a fourth embodiment. [Figure 22] 10 is a flowchart showing an example of the operation of an execution processing unit according to the fourth embodiment. [Figure 23] 23 is a flowchart showing a detailed example of processing in step S602 of FIG. 22. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a calculation method and a calculation device according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the embodiment described below is an example of an embodiment of the present invention, and the present invention should not be interpreted as being limited to these embodiments. Furthermore, in the drawings referred to in this embodiment, identical parts or parts having similar functions are given the same or similar reference numerals, and repeated explanations thereof may be omitted. Furthermore, for convenience of explanation, the dimensional ratios of the drawings may differ from the actual ratios, and some components may be omitted from the drawings. (First embodiment)

[0011] FIG. 1 is a block diagram showing the configuration of a computing device 1 according to a first embodiment. As shown in FIG. 1, the computing device 1 according to this embodiment is, for example, a SPICE, and is a circuit simulator device that executes circuit simulation. The computing device 1 includes an information input unit 10, a storage unit 20, a model generation unit 30, an execution processing unit 40, an output unit 50, a thermal model generation unit 60, and a display unit 70. Such a computing device 1 is realized by, for example, a desktop personal computer. That is, the computing device 1 is configured to include, for example, a CPU (Central Processing Unit).

[0012] The information input unit 10 includes, for example, a keyboard, a pointing device, etc., and outputs instruction signals in response to operations by a user of the arithmetic device 1 to the storage unit 20, the model generation unit 30, and the execution processing unit 40. For example, the instruction signals output by the information input unit 10 include any of circuit information, which is instruction information for configuring a circuit model, component information, which is instruction information for configuring an element model, and analysis setting information, which is a condition for executing a circuit simulation. Details of the instruction operation of the information input unit 10 will be described later using FIGS. 4 to 6.

[0013] The storage unit 20 is configured, for example, by an HDD (hard disk drive) or an SSD (solid state drive). The storage unit 20 has a model database 20a and an element model database 20b. The model database 20a stores information on a plurality of models 80. The element model database 20b stores a plurality of element models 88 that constitute the models 80. The storage unit 20 also stores various programs for executing simulations. As a result, the arithmetic device 1 configures each unit by, for example, executing the program stored in the storage unit 20. Note that each unit according to this embodiment is configured by executing the program stored in the storage unit 20, but is not limited to this. For example, the model generation unit 30, the execution processing unit 40, the output unit 50, and the thermal model generation unit 60 may be configured as circuits.

[0014] FIG. 2 is a diagram showing an example of the configuration of a model 80. As shown in FIG. 2, the model 80 is, for example, a model of an inverter device that rotates a motor. This model 80 is a model configured from characteristic information of the inverter device that is the target of simulation. This model 80 has, for example, a circuit model 82, a command value input unit 84, and a control model 86. The circuit model 82 has a plurality of element models (detailed models) 88 and a motor model (operation model) 90. Details of the model 80 will be described later.

[0015] The model generation unit 30 constructs the model 80 according to the information input from the information input unit 10. The model generation unit 30 also constructs an element model 88 in the model 80 according to the input information. For example, the element model 88 in the model 80 can be changed according to the input from the information input unit 10.

[0016] The execution processing unit 40 uses information about the configured model 80 to calculate the current and voltage of each element model 88 and the wiring in the model 80 for each calculation step. The execution processing unit 40 calculates circuit equations, such as first-order linear differential equations and second-order linear differential equations according to physical laws such as Kirchhoff's, for each calculation step, and calculates the transient response of the current and voltage for each calculation step.

[0017] The output unit 50 stores the execution processing results of the execution processing unit 40 for each calculation step and outputs them to the thermal model generation unit 60. That is, the output unit 50 has an auxiliary storage unit. This auxiliary storage unit is configured, for example, with an HDD (hard disk drive) or an SSD (solid state drive). The output unit 50 also generates a display image and outputs it to the display unit 70.

[0018] The thermal model generation unit 60 integrates the power generated by switching of the element model 88, and generates, as an operation model, a thermal model that indicates a value corresponding to the power generated each time the element model 88 is switched. The thermal model generation unit 60 will also be described in detail later.

[0019] The detailed model according to this embodiment is a model in which the physical properties of each component are defined. The detailed model is a model that can operate with calculation steps that can also calculate transient responses, for example. In this embodiment, the detailed model may also be referred to as a high-precision model.

[0020] The simple model according to this embodiment is a simplified version of the detailed model, for example, a model in which the response characteristics of the detailed model are averaged over a longer time interval. Therefore, the calculation steps of the simple model can be configured to be longer than the calculation steps of the detailed model.

[0021] The behavioral model according to this embodiment is a simplified model in which the physical characteristics of the detailed model are specialized for a specific physical phenomenon. The calculation steps of the behavioral model can be configured to be longer than the interval between calculation steps of the detailed model, and shorter than the interval between calculation steps of the simplified model.

[0022] The display unit 70 is, for example, a monitor, and displays the image information input from the output unit 50.

[0023] Here, the model 80 will be described in detail. As shown in Fig. 2, the circuit model 82 has information on the electrical characteristics of the components that make up the circuit. The circuit model 82 has, for example, a plurality of element models 88 and a motor model 90. The element model 88 has information on the connection relationships of, for example, resistive elements, capacitive elements (capacitors), passive elements (coils) that store energy in a magnetic field, and switching elements (e.g., MOSFETs) that are active elements, and information on the electrical characteristics of each. The element model 88 will be described in detail later.

[0024] The motor model 90 has information on the electrical characteristics of the motor. For example, the motor model 90 defines information such as the relationship between the supplied current and voltage and the generated motor torque. As a result, when time-series current and voltage values ​​are supplied to the motor model 90, a time-series motor torque is output.

[0025] The command value input unit 84 inputs time-series command values ​​for operating the model 80. For example, if the model 80 is an inverter device, the command values ​​are control values ​​that generate time-series motor torque. Note that if the model 80 is an inverter device, a power supply model (not shown) is also included. The command values ​​and motor torque values ​​may be actual data acquired from, for example, an actual device. Alternatively, they may be simulation values ​​calculated in conjunction with a mechanical model, as described below. This makes it possible to calculate the electric and voltage values ​​for each calculation step when generating motor torque in the inverter device being simulated using the control command values. That is, in this embodiment, the relationship between the time-series command values ​​that generate time-series motor torque and the current and voltage values ​​that generate time-series motor torque constitutes the operation model.

[0026] The control model (operation model) 86 is a model that performs the operation of a control device that controls the model 80 in accordance with a time-series command value. The control model 86 has information about the circuit configuration within the control device, and is capable of outputting control signals to each component within the model 80 when a time-series command value is input to the control model 86. For example, if the model 80 is an inverter device, when a time-series control value that generates a time-series motor torque is input to the control model 86, the control model 86 controls the switching timing of each model element 88 so as to generate this time-series motor torque. In this case, power is supplied from the power supply model.

[0027] Fig. 3 is a diagram showing an example of the element model 88. As shown in Fig. 3, the element model 88 is, for example, a model of a MOSFET, which is an active element. When the element model 88 is, for example, a model of a MOSFET, which is an active element, information for calculating the transient response of the MOSFET is defined as electrical characteristics, such as the capacitances Cgs and Cgd of the oxide film, the junction capacitance Cds of the built-in diode, switching time information, and the threshold voltage VGS(th).

[0028] In addition to active elements, the element model 88 also includes passive elements such as resistive elements, capacitive elements (capacitors), and passive elements (coils) that store energy in magnetic fields. Information on these passive elements is specified as resistance values, capacitance values, and inductance values.

[0029] Here, the instruction operation of the information input unit 10 will be described in detail with reference to FIGS. FIG. 4 is a diagram showing an example in which a plurality of selectable models 80 are displayed on the monitor 700 of the display unit 70. As shown in FIG. Before starting a simulation, the output unit 80 of the arithmetic device 1 displays a plurality of models 80 whose electrical characteristics have already been defined on the monitor 700 of the display unit 70. The operator selects the model 80 to be simulated via the information input unit 10. The model generation unit 30 obtains information on the selected model 80 from the storage unit 20 and generates the model 80. This allows the operator to easily configure a model of the entire device to be simulated.

[0030] 5 is a diagram showing an example in which a plurality of element models 88 selectable for a selected model 80 are displayed on a monitor 700. A frame 70a shows a plurality of selectable element models 88.

[0031] Before starting a simulation, the output unit 80 displays a plurality of element models 88 whose electrical characteristics have already been defined on the monitor 700 of the display unit 70. The operator selects the element model 88 to be simulated via the information input unit 10. For example, the operator first designates the element model 88 in the model 80 shown in FIG. 2. Then, the operator designates the element model 88 displayed on the monitor 700 via the information input unit 10. This allows the element model 88 to be replaced.

[0032] 5, the operator can place a marker, the position of which is manipulated by the information input unit 10, on the element model 88, thereby displaying the electrical characteristics of the element on the monitor 700. For example, if the element model is a MOSFT, the electrostatic capacitances Cgs and Cgd of the set oxide film, the junction capacitance Cds of the built-in diode, switching time information, threshold voltage VGS(th), and the like are displayed on the monitor 700.

[0033] The operator can also register information on the electrical characteristics of a newly designed element model 88 in the element model database 20b. This allows the output unit 80 to display the newly designed element model 88 on the monitor 700 of the display unit 70 as a selectable element model 88. This allows the operator to select the newly designed element model 88 and simulate the electrical and temperature characteristics of the newly designed element model 88 with simpler operations.

[0034] 6 is a diagram showing examples of selectable command values ​​for the selected model 80. A frame 70b shows a plurality of selectable command values ​​700b.

[0035] Before the start of the simulation, the output unit 80 displays a plurality of selectable command values ​​700b on the monitor 700 of the display unit 70. The operator selects, via the information input unit 10, the command value 700b to be simulated.

[0036] 7 is a diagram showing an example of an image displayed on the monitor 700 during a simulation. When the model 80 or the like is selected according to the above explanation, the image shown in FIG.

[0037] Box 70c is a box showing an example of an element model being simulated. As mentioned above, there are multiple types of element models 88, including high-precision models (detailed models), thermal models (operational models), and simple models. By clearly indicating the type of model being used, the type of simulation can be easily determined. Here, a high-precision model is a model that calculates transient phenomena according to specified electrical characteristics. A high-precision model is used for simulating normal electrical characteristics. A thermal model is a model that models the heat generation situation and is used for simulating temperature characteristics. A simple model is a simplified version of a high-precision model that is used in characteristic simulations of mechanical models, which will be described later. A simple model is, for example, a switch model that has element resistance value information.

[0038] The command value being input and the simulation results are displayed in box 70b. If model 80 is an inverter device, command value 700b is a control command value for generating motor torque. The horizontal axis represents time, and the vertical axis represents the control command value. Arrow 700c indicates the first period in which a high-precision model is used for element model 88.

[0039] The simulation results are, for example, temperature changes for each element model 88. The horizontal axis represents time, and the vertical axis represents temperature. Simulations using high-precision models are performed to obtain information for generating a thermal model (operation model).

[0040] Returning to Fig. 1, the thermal model generation unit 60 will be described in detail with reference to Fig. 8. In Fig. 8, the right-hand diagram shows the results of a power generation simulation during switching in the high-precision model, while the left-hand diagram shows the results of a power generation simulation during switching in the thermal model. The diagrams show cases where the reactance connected to the element model 88 is 10 nH and 30 nH.

[0041] From the top, the drain current Id, drain-source voltage Vds, gate-source voltage Vgs, and generated power Power are shown as predetermined inputs to the element model 88. The horizontal axis represents time, and the vertical axis represents the drain current Id, drain-source voltage Vds, gate-source voltage Vgs, and generated power Power, respectively.

[0042] The power generation status of each element model 88 changes depending on the combination of element models 88, the combination of passive elements, resistors, capacitors, coils, etc. Therefore, in order to analyze the power generation status, it is necessary to precisely simulate transient phenomena, so a high-precision model is used.

[0043] On the other hand, the shape of the time change of the generated power Power tends to remain constant. As shown in Figure 8, for example, the time change of the generated power Power exhibits a spike-like shape depending on the switching timing. This spike-like shape is maintained even if the magnitudes of the drain current Id, drain-source voltage Vds, and gate-source voltage Vgs vary. In other words, when the magnitudes of the drain current Id, drain-source voltage Vds, and gate-source voltage Vgs vary, the spike-like shape remains similar, but the height of the spike changes depending on the magnitudes of the drain current Id, drain-source voltage Vds, and gate-source voltage Vgs.

[0044] The temperature of the element model 88 changes according to the integrated value of the generated power Power. Therefore, the temperature characteristics of an active element such as a MOSFET are simulated by calculating the generated power Power according to the switching timing.

[0045] On the other hand, the time constant of temperature change is larger than the time constant of the active element. Therefore, in the simulation of temperature characteristics, the results tend to depend on the integrated value of the spike shape but not on the shape itself. By focusing on these characteristics, the thermal model generation unit 60 according to this embodiment generates a thermal model that corresponds to the generated power of the high-precision model.

[0046] That is, first, the spike shape is precisely simulated using a high-precision model of the element model 88. Next, the thermal model generation unit 60 calculates the integrated value of the spike shape portion and determines a representative value proportional to the integrated value. For example, the representative value is calculated by dividing the integrated value by a predetermined time. Alternatively, the integrated value itself is used as the representative value.

[0047] As mentioned above, the bottom diagram on the left shows an example of the integrated power output of the thermal model. In this way, the thermal model outputs a rectangular power value corresponding to the switching timing. The height of this rectangle is linearly calculated based on the drain current Id, drain-source voltage Vds, and gate-source voltage Vgs. For example, the height of the rectangle is calculated to be linearly proportional to the drain current Id, drain-source voltage Vds, and gate-source voltage Vgs. In this way, the thermal model outputs an output value corresponding to the drain current Id, drain-source voltage Vds, and gate-source voltage Vgs through linear calculation using representative values. In other words, the thermal model digitizes and processes the input-output relationship. This allows the temperature characteristic simulation to output an integrated value of generated power (Power) equivalent to that of a high-precision model more quickly based on the drain current Id, drain-source voltage Vds, and gate-source voltage Vg, instead of a strict simulation of the active element. In this way, the integrated value of the generated power Power, which is the same as that of the high-precision model, is output digitally by linear calculation according to predetermined input values, thereby reducing the calculation load on the computer and further increasing the calculation speed of the computer.

[0048] In addition, in temperature simulations, passive elements generate heat proportional to the square of the current, so for passive elements, the normal element model is used even in temperature simulations.

[0049] FIG. 9 is a diagram showing an example of an image displayed on the monitor 700 during a simulation using a thermal model. The thermal model generation unit 60 generates a thermal model when a simulation of temperature characteristics begins and the rigorous simulation results using the high-precision model are accumulated in the output unit 50. Next, the thermal model generation unit 60 replaces the element model 88 from the high-precision model with the thermal model. When the element model 88 is replaced with the thermal model, the display within the frame 70c changes to indicate that the thermal model is being used. An arrow 700e indicates a second period during which the thermal model is used. The second period 700e is set to be longer than the first period 700c. This reduces the calculation time compared to when the second period is calculated using a high-precision model.

[0050] Figure 10 shows an example of a comparison between a simulation using a thermal model and a simulation using a high-precision model. The horizontal axis indicates time, and the vertical axis indicates the temperature of the element model. As shown, when using a thermal model, it is possible to obtain simulation results equivalent to those when using a high-precision model. As a result, while a simulation of temperature characteristics using a high-precision model required a computer load of the order of 10 hours, by using a thermal model, it is possible to calculate similar results with a computer load of the order of a few minutes.

[0051] Fig. 11 is a flowchart showing an example of calculation by the calculation device 1. As shown in Fig. 11, first, the operator inputs information about a high-precision model that is to be subjected to temperature simulation via the information input unit 10 (step S100).

[0052] Next, the model generating unit 30 generates a model using a high-precision model for the element model 88 based on the input information (step S102). Next, the execution processing unit 40 calculates a transient response for each calculation step using the high-precision model in accordance with the set time-series command values ​​(step S104).

[0053] Next, the execution processing unit 40 determines whether or not the set first period has ended (step S106). If it has not ended (N in step S106), the processing from step S104 is repeated.

[0054] On the other hand, if the execution processing unit 40 determines that the first period has ended (Y in step S106), it outputs the data accumulated in the output unit 50 to the thermal model generation unit 60, and the thermal model generation unit 60 generates a thermal model (step S108). Subsequently, the thermal model generation unit 60 replaces the high-precision model with the thermal model.

[0055] Next, the execution processing unit 40 calculates the temperature response for each calculation step using the thermal model in accordance with the remaining time-series command values ​​that have been set (step S110). Next, the execution processing unit determines whether or not the set second period has ended (step S112). If it has not ended (N in step S112), the processing from step S112 is repeated.

[0056] On the other hand, if the execution processing unit 40 determines that the second period has ended (Y in step S106), it causes the output unit 50 to generate a display form showing the change in temperature over time for each element model 88, displays it on the display unit 70, and then terminates the overall processing.

[0057] As described above, according to this embodiment, the execution processing unit 40 uses information on the electrical characteristics of the element model 88 to calculate, in time series, the power generated at each time step by switching of the element model 88 in response to input values ​​(drive voltage and drive current values). Then, the thermal model generation unit 60 generates a thermal model that outputs the power generated by switching of the element model 88 in accordance with predetermined input values ​​(drive voltage and drive current values) based on an integrated value obtained by integrating the power generated at each time step.

[0058] Since the integrated value of the generated power in the high-precision model of element model 88 is changed linearly in response to the input value, the thermal model can linearly calculate in response to the input value the generated power caused by switching of element model 88. As a result, the thermal model digitally outputs the same integrated value of the generated power Power as the high-precision model through linear calculation in response to a predetermined input value, thereby reducing the calculation load on the computer and further increasing the calculation speed of the computer.

[0059] (Second embodiment) The arithmetic device 1 according to the second embodiment differs from the arithmetic device 1 according to the first embodiment in that the model generation unit 30 is capable of generating a mechanical model that performs mechanical operations. The differences from the arithmetic device 1 according to the first embodiment will be described below.

[0060] FIG. 12 is a block diagram showing the configuration of a calculation device 1 according to a second embodiment. As shown in FIG. 2, the calculation device 1 according to this embodiment is capable of generating a mechanical model. More specifically, the storage unit 20 further includes a mechanical model database 20c and a mechanical part database 20d. Note that each unit according to this embodiment is configured by executing a program stored in the storage unit 20, but is not limited to this. For example, a simplified mechanical model generation unit 75, which will be described later, may be configured as an additional circuit.

[0061] The element model database 20b also stores a simplified model obtained by simplifying the element model 88. 13 is a diagram showing an example of a simplified model 88a obtained by simplifying the element model 88. An active element such as a MOSFET can be represented by a combination of passive elements if it is approximated with a larger time constant. For this reason, the simplified model 88a can be configured as a switch model having element resistance information, as described above.

[0062] The mechanical model database 20c stores information on multiple mechanical models (detailed models) 92. The mechanical part database 20d stores information on mechanical parts in the mechanical models 92. This enables the model generation unit 30 to generate a mechanical model 92 that operates in conjunction with, for example, a circuit model (simple model) 82, in accordance with input from the information input unit 10. The model generation unit 30 can also replace mechanical parts 94 in the mechanical model 92 in accordance with input from the information input unit 10. The mechanical parts 94 are, for example, gears, handlebars, tires, etc.

[0063] The simplified mechanical model generation unit 75 generates an operation model for the mechanical model 92. For example, a time-series motor torque 700g of a motor model 90 (described later) and a command value 700b for generating the motor torque 700g form the operation model for the mechanical model 92. The time constants of the circuit model 82 and the mechanical model 92 are significantly different, and using a high-precision model of the circuit model 82 to simulate the mechanical model 92 would require an unrealistic amount of calculation time. Therefore, when simulating the mechanical model 92, a simplified model 88a is used. On the other hand, when simulating the circuit model 82, a simplified mechanical model (operation model) that simply represents the operation of the mechanical model 92, for example, a time-series motor torque 700g and a command value 700b for generating the motor torque 700g, is used to separate the mechanical model 92 and perform the simulation.

[0064] 14 is a diagram showing an example image of a model 80 including a mechanical model 92 displayed on a monitor 700 during a simulation. As described above, the frame 70c is a frame showing an example of an element model during simulation, and indicates that a simple model is being used. In other words, the operation of the mechanical model 92 is being simulated. The length of a calculation step for simulating the operation of the mechanical model 92 is set to be, for example, about 100 times longer than the time of a calculation step when simulating the circuit model 80.

[0065] As shown in FIG. 14, the mechanical model 92 is a model of a steering assist drive device of an automobile, which is driven by the circuit model 82 of an inverter device, for example.

[0066] In Figure 14, the input command value to model 80 is a time series of steering wheel angle 700f of a car. The time constant of the response time of mechanical model 92 is significantly larger than the time constant of circuit model 82. For this reason, as described above, the element model 88 used when calculating mechanical model 92 is changed to a simplified model. This enables faster calculations.

[0067] That is, the mechanical model 92 takes as input a time-series angle 700f of the steering wheel of the automobile, and outputs, as a result of the simulation, a time-series motor torque 700g of the motor model 90 required for assisted driving of the steering wheel, and a command value 700b for generating the motor torque 700g.

[0068] The simple mechanical model generation unit 75 approximates the motor torque 700g and the command value 700b using a spline model or the like, thereby generating, as an operation model, the motor torque 700g and the command value 700b that correspond to the calculation steps of the circuit model 80, which are approximately 1 / 100 times shorter than the calculation steps of the mechanical model 92.

[0069] Next, the execution processing unit 40 uses the command value 700b and the motor torque 700g generated by the simple mechanical model generating unit 75 to execute a temperature simulation similar to that in the first embodiment.

[0070] 15 is a diagram showing an example image of the model 80 including the mechanical model 92 displayed on the monitor 700 during a temperature simulation of the circuit model 82. As described above, the frame 70c is a frame showing an example of the element model under simulation, and indicates that the thermal model is being used. In other words, the temperature of the circuit model 82 is being simulated.

[0071] Since the lengths of the calculation steps of the circuit model 82 and the mechanical model 92 are different, for example, during a temperature simulation of the circuit model 82, the mechanical model 92 is simulated separately. For this reason, a motor torque of 700 g is used as the motor torque of the motor model 90 that operates in conjunction with the mechanical model 92.

[0072] Fig. 16 is a flowchart showing an example of a temperature simulation of the circuit model 82 that operates in cooperation with the mechanical model 92. As shown in Fig. 16, first, the operator inputs information about the mechanical model 92 and the circuit model 82 that are the targets of the temperature simulation via the information input unit 10 (step S300).

[0073] Next, the model generating unit 30 generates the model 80 using the simplified model as the element model 88 based on the input information (step S302). Next, the execution processing unit 40 uses the simple model in accordance with the set time-series command values ​​to output the motor torque 700g and the command value 700b for each first calculation step to the output unit 50, which then stores them (step S304).

[0074] Next, the execution processing unit 40 determines whether or not the set period has ended (step S306). If the period has not ended (N in step S306), the processing from step S304 is repeated.

[0075] On the other hand, if the execution processing unit 40 determines that the period has ended (Y in step S306), it outputs the accumulated data from the output unit 50 to the simplified mechanical model generation unit 75, and the simplified mechanical model generation unit 75 generates a motor torque 700g and a command value 700b for each second calculation step (step S108). The second calculation step is, for example, 1 / 100 the time of the first calculation step. Next, the thermal model generation unit 60 replaces the high-precision model with a thermal model (step S310).

[0076] Next, the execution processing unit 40 calculates the temperature response for each calculation step using a thermal model in accordance with the set time-series command value 700b and motor torque 700g (step S320). Next, the execution processing unit determines whether or not the set second period has ended (step S322). If it has not ended (N in step S332), the processing from step S320 is repeated.

[0077] On the other hand, if the execution processing unit 40 determines that the second period has ended (Y in step S322), it causes the output unit 50 to generate a display form showing the change in temperature over time for each element model 88, displays it on the display unit 70, and then terminates the overall processing.

[0078] As described above, according to this embodiment, first, the operation of the mechanical model 92 is simulated in a first calculation step using a simplified model of the circuit model 82, and the time-series command values ​​700b and motor torque 700g output by the mechanical model 92 to the control model 86 are stored. Next, the simplified mechanical model generation unit 75 is caused to generate the time-series command values ​​700b and motor torque 700g corresponding to the second calculation step. Then, a temperature simulation of the circuit model 82 is performed in the second calculation step using the time-series command values ​​700b and motor torque 700g corresponding to the second calculation step. This allows the temperature simulation of the circuit model 82, which cooperates with the mechanical model 92, whose calculation steps are about 100 times larger, to be calculated in a shorter time.

[0079] (Third embodiment) The computing device 1 according to the third embodiment differs from the computing device 1 according to the second embodiment in that the model generating unit 30 further has a function of automatically generating an operation model from among a plurality of models. The differences from the computing device 1 according to the first embodiment will be described below.

[0080] 17 is a block diagram showing the configuration of a computing device 1 according to the third embodiment. As shown in FIG. 17, the computing device 1 according to the present embodiment is capable of automatically generating an behavior model using multiple models, and includes an behavior model generation unit 100.

[0081] The storage unit 20 has, for example, a plurality of models 20e to 20g. The plurality of models 20e to 20g are physical models, and have information on time responsiveness, a detailed model, and a simple model. That is, in the initial state, no behavioral model has been generated.

[0082] Behavior model generation section 100 generates an behavior model according to the purpose using detailed and simplified models of models 20e to 20g. As described above, the detailed model according to this embodiment is a model in which the physical characteristics of each component are defined, and is capable of calculating, for example, transient responses. The simple model is a model that simplifies the detailed model, and is, for example, a model in which the response characteristics of the detailed model are averaged over a longer time interval. The behavior model is, for example, a model that corresponds to a specific physical phenomenon, and is, for example, a model in which the response characteristics of the thin model are averaged over a longer time interval and a shorter time interval than the simple model.

[0083] For example, model 20e is a circuit model. The detailed model of model 20e is a circuit model that connects multiple element models that have information on the electrical characteristics of switching elements. This detailed model can also calculate the transient response of switching elements. A simplified model of model 20e is, for example, a model that represents the electrical characteristics of a switching element in an element model as a resistance characteristic by averaging the response characteristics of the detailed model over a longer time interval. An operating model of model 20e is, for example, a thermal model that outputs heat in response to the switching of the element model. However, as described above, the thermal model is in a "null" state and is not generated in the initial state.

[0084] The time response of the detailed model of model 20e is, for example, 100 nanoseconds, and the time response of the detailed model of model 20f is, for example, 0.1 seconds, which are different in time order by several orders of magnitude. Similarly, the time response of the detailed model of model 20g is larger than the time response of the detailed model of model 20f by several orders of magnitude.

[0085] In this way, when a physical model is generated by linking detailed models with different time orders, the detailed model with short time response becomes the limiting factor for the simulation time, as mentioned above, and the simulation time becomes unrealistic. Therefore, the execution processing unit 40 according to this embodiment first generates the desired behavior model by combining detailed models and simplified models according to the time response of the detailed models.

[0086] Fig. 18 is a flowchart showing an example of the operation of the execution processing unit 40. As shown in Fig. 18, first, the execution processing unit 40 determines the characteristics to be observed in the system (step S400). The characteristics to be observed are, for example, the thermal characteristics of a circuit that drives a motor.

[0087] Next, behavior model generation unit 100 generates a behavior model according to the characteristics to be observed in order to enable longer-term observation (step S402). In the step of generating a behavior model, behavior model generation unit 100 generates a behavior model according to the response times of multiple detailed models. Details of the step of generating a behavior model will be described later using Figures 19 and 20.

[0088] Next, the characteristics to be observed are calculated by simulation using the generated behavioral model (step S404). In this way, by generating a behavioral model according to the characteristics to be observed and performing a more efficient simulation, it becomes possible to obtain simulation results according to the characteristics to be observed in a shorter time.

[0089] Fig. 19 is a flowchart showing a detailed example of the process in step S402 in Fig. 18. Fig. 20 is a diagram showing a schematic diagram of the process example in Fig. 19 in chronological order.

[0090] 19, the execution processing unit 40 selects the detailed model with the highest responsiveness from among the multiple models 20e to 20g that do not have behavior models (step S500). That is, as shown in S20 of FIG. 20, the detailed model of model 20g is selected.

[0091] Next, the model generation unit 30 generates a first physical model using the detailed model of model 20g and the simplified models of models 20e and 20f (step S502), as shown in S20 of Fig. 20. Here, the simplified models are used for the remaining models 20e and 20f, which do not have behavioral models.

[0092] Next, execution processing unit 40 performs a model simulation using the first physical model to generate data for generating an behavior model of model 20g (step S504). Subsequently, behavior model generation unit 100 generates an behavior model of model 20g using the data obtained in step S502.

[0093] Then, as shown in S22 of FIG. 20, the model generation unit 30 replaces the detailed model of the model 20g with the behavior model (step S506).

[0094] Next, the execution processing unit 40 determines whether all models have been replaced with behavioral models (step S508). If all models have not been replaced with behavioral models (N in step S508), the processing from step S500 is repeated. As a result, detailed models are replaced with behavioral models in order, as shown in S24 and S26 in FIG. 20. On the other hand, if all models have been replaced with behavioral models (Y in step S508), the processing ends.

[0095] As described above, according to this embodiment, detailed models and simplified models are combined according to the time response of the detailed model to generate a target behavior model, and after all behavior models have been generated, a simulation is performed according to the characteristics to be observed. This makes it possible to perform a more efficient simulation, and to obtain simulation results according to the characteristics to be observed in a shorter time.

[0096] (Fourth embodiment) The computing device 1 according to the fourth embodiment differs from the computing device 1 according to the second embodiment in that the model generating unit 30 further has a function of automatically generating an operation model from an FET model and a mechanical model. The differences from the computing device 1 according to the second embodiment will be described below.

[0097] 21 is a block diagram showing the configuration of a computing device 1 according to the fourth embodiment. As shown in FIG. 3, the computing device 1 according to this embodiment is capable of automatically generating an operation model using a FET model h and a mechanical model i, and includes an operation model generation unit 100. The operation model generation unit 100 includes a thermal model generation unit 60 and a simplified mechanical model generation unit 75.

[0098] The storage unit 20 includes, for example, a FET model 20h and a mechanical model 20i. The FET model 20h and the mechanical model 20i are physical models, and include information on time response, a detailed model, and a simplified model. In other words, in the initial state, no behavioral model is generated.

[0099] The behavioral model generation unit 100 generates a behavioral model according to the purpose using the detailed model and simplified model of the FET model 20h and the mechanical model 20i. The detailed model of the FET model 20h includes information on the connection relationships between, for example, resistive elements, capacitive elements (capacitors), passive elements (coils) that store energy in a magnetic field, and active switching elements (e.g., MOSFETs), as well as information on their respective electrical characteristics. For example, the information includes information such as the capacitances Cgs and Cgd of the oxide films set in the switching elements, the junction capacitance Cds of the built-in diodes, switching time information, and threshold voltage VGS(th). The simplified model of the FET model 20h is, for example, a switch model that includes resistance value information of the elements.

[0100] The detailed model of the mechanical model 20i is a model that performs mechanical operations. The detailed model of the mechanical model 20i is a combination of mechanical parts such as gears, handles, and tires, and the mechanical parts have defined operating characteristics. The simplified model of the mechanical model 20i is a model that simplifies the operation of each mechanical part, and indicates, for example, average input / output characteristics over a longer calculation step than the detailed model.

[0101] The operation model of the FET model 20h is, for example, a thermal model that outputs heat in response to the switching of the element model. However, the thermal model is in a "null" state and is not generated in the initial state. Similarly, the operation model of the mechanical model 20i is, for example, a model that indicates the relationship between the motor torque and the command value 700b corresponding to the calculation steps of the FET model 20h. The operation model of the mechanical model 20i is in a "null" state and is not generated in the initial state.

[0102] The time response of the detailed model of the FET model 20h is, for example, 100 nanoseconds, and the time response of the detailed model of the mechanical model 20i is, for example, 0.1 seconds. In this way, the time response of the detailed model of the FET model 20h and the time response of the detailed model of the mechanical model 20i differ by several orders of magnitude.

[0103] When a physical model is generated by linking detailed models with different time orders, as described above, the detailed model with short time response becomes the limiting factor for the simulation time, and the simulation time becomes unrealistic. Therefore, the execution processing unit 40 according to this embodiment first generates the target behavior model by combining detailed models and simplified models according to the time response of the detailed models in the ET model 20h and the mechanical model 20i.

[0104] Fig. 22 is a flowchart showing an example of the operation of the execution processing unit 40. As shown in Fig. 22, first, the execution processing unit 40 determines the characteristics to be observed in the system (step S600). The characteristics to be observed are, for example, the thermal characteristics of the FET that drives the motor.

[0105] Next, behavior model generation unit 100 generates a behavior model according to the characteristics to be observed in order to enable longer-term observation (step S602). In the step of generating a behavior model, behavior model generation unit 100 generates a behavior model according to the response times of multiple detailed models. Details of the step of generating a behavior model will be described later using FIG. 23.

[0106] Next, the characteristics to be observed are calculated by simulation using the generated behavioral model (step S604). In this way, by generating a behavioral model according to the characteristics to be observed and performing a more efficient simulation, it becomes possible to obtain simulation results according to the characteristics to be observed in a shorter time.

[0107] Fig. 23 is a flowchart showing a detailed processing example of step S602 in Fig. 22. As shown in Fig. 23, the execution processing unit 40 selects the detailed model with the greatest responsiveness from among the FET model 20h, which does not have an operation model, and the mechanical model 20i (step S500). In other words, the detailed model of the mechanical model 20i is selected.

[0108] Next, the model generating unit 30 generates a first physical model using the detailed model of the mechanical model 20i and the simplified model of the FET model 20h (step S702).

[0109] Next, the execution processing unit 40 performs a model simulation using the first physical model to generate data for generating an operation model of the mechanical model 20i (step S704). Subsequently, the simplified mechanical model generation unit 75 of the operation model generation unit 100 uses the data obtained in step S704 to generate an operation model of the mechanical model 20i as a first operation model (step S706).

[0110] The model generating unit 30 then replaces the simplified model of the FET model 20h with the detailed model (step S708), and further replaces the detailed model of the mechanical model 20i with the first behavior model to generate a second physical model (step S710).

[0111] Next, execution processing unit 40 performs a model simulation using the second physical model to generate data for generating an operation model of FET model 20h (step S712). Subsequently, thermal model generation unit 60 of operation model generation unit 100 uses the data obtained in step S712 to generate a thermal model of FET model 20h as a second operation model (step S714).

[0112] Then, the model generating section 30 replaces the detailed model of the FET model 20h with the second behavioral model to generate a third physical model (step S716), and ends the process.

[0113] As described above, according to this embodiment, the detailed model and the simplified model are combined according to the time response of the detailed models of the FET model 20h and the mechanical model 20i to generate the desired operation model, and after all operation models are generated, a simulation is performed according to the thermal characteristics of the FET model 20h to be observed. This makes it possible to perform a more efficient simulation and obtain simulation results according to the thermal characteristics of the FET model 20h to be observed in a shorter time.

[0114] At least a part of the above-described arithmetic device 1 may be configured with hardware or software. When configured with software, a program that realizes at least a part of the functions of the arithmetic device may be stored on a recording medium such as a flexible disk or CD-ROM and read and executed by a computer. The recording medium is not limited to removable recording media such as magnetic disks and optical disks, but may also be fixed recording media such as a hard disk unit or memory.

[0115] In addition, a program that realizes at least a part of the functions of the arithmetic device 1 may be distributed via a communication line (including wireless communication) such as the Internet. Furthermore, the program may be encrypted, modulated, or compressed and distributed via a wired line or wireless line such as the Internet, or stored on a recording medium.

[0116] Although several embodiments have been described above, these embodiments are presented only as examples and are not intended to limit the scope of the invention. The novel devices, methods, and programs described in this specification can be embodied in various other forms. Furthermore, various omissions, substitutions, and modifications can be made to the forms of the devices, methods, and programs described in this specification without departing from the spirit of the invention.

[0117] Note that the calculation method and calculation device described in the following supplementary notes are conceivable.

[0118] (Appendix 1) a model generation step of generating a circuit model in which a plurality of element models each having information on the electrical characteristics of a switching element are connected; an execution processing step of calculating, in a time series manner, power generated at each time step by switching of the element model in response to a predetermined time series input value, using information on the electrical characteristics of each of the plurality of element models; a thermal model generating step of generating a thermal model that outputs an output value based on an integrated value obtained by integrating the power generated for each time step in response to switching of the element model; A calculation method comprising:

[0119] (Appendix 2) 2. The calculation method according to claim 1, wherein the thermal model generating step outputs the output value based on a value obtained by dividing the integrated value by a predetermined time or a representative value obtained by using the integrated value as a representative value.

[0120] (Appendix 3) 3. The calculation method according to claim 2, wherein the thermal model uses the representative value to output the output value through linear calculation according to the predetermined input value.

[0121] (Appendix 4) the execution processing step calculates, in time series, power generated at each time step using information on electrical characteristics of each of the plurality of element models in accordance with a time-series command value for a first period; The calculation method according to appendix 1, wherein the thermal model is used to calculate the generated power for each time step of the element model in a time series manner in accordance with a time series command value for a second period that is longer than the first period.

[0122] (Appendix 5) 5. The calculation method according to claim 4, wherein the execution processing step calculates the temperature of the element model for each time step in time series using power generated using the thermal model.

[0123] (Appendix 6) an output step of generating a display form showing a time change of temperature occurring in the element model, The calculation method according to any one of Supplementary Notes 1 to 5, further comprising:

[0124] (Appendix 7) 7. The calculation method according to any one of claims 1 to 6, wherein the circuit model is selectable from a plurality of different circuit models.

[0125] (Appendix 8) 8. The calculation method according to any one of Supplementary notes 1 to 7, wherein the element model is selectable from a plurality of different element models.

[0126] (Appendix 9) the circuit model further includes information on a motor model; 9. The calculation method according to any one of claims 1 to 8, wherein the model generation step generates a mechanical model of a mechanical structure driven by the motor model.

[0127] (Appendix 10) The calculation method according to claim 9, wherein the execution processing step, when the mechanical model is included, calculates the operation of the mechanical model for each second time step longer than the time step in accordance with a time-series command value for the mechanical model.

[0128] (Appendix 11) the command value of the circuit model is a torque command value output from the mechanical model and commanding a torque output of the motor model, and a motor torque of the motor; 11. The calculation method according to claim 10, wherein the execution processing step, when calculating the torque command value and the motor torque, replaces the electrical characteristics of the switching elements in the element model with a simplified model represented by resistance characteristics.

[0129] (Appendix 12) The calculation method described in Appendix 11, wherein the execution processing step, when calculating the temperature of the element model when driving the mechanical model, calculates the temperature for each time step using the torque instruction value, the motor torque, and the thermal model instead of the mechanical model.

[0130] (Appendix 13) a model generation unit that generates a circuit model in which a plurality of element models each having information on the electrical characteristics of a switching element are connected; an execution processing unit that calculates, in time series, power generated at each time step by switching of the element model in response to a predetermined time-series input value using information on electrical characteristics of each of the plurality of element models; a thermal model generation unit that generates a thermal model that outputs an output value based on an integrated value obtained by integrating the power generated for each time step in response to switching of the element model; A computing device comprising:

[0131] (Appendix 14) A method for calculating a physical property to be observed using a plurality of detailed models and simplified models corresponding to each of the plurality of detailed models, the simplified models having a longer interval between calculation steps than the corresponding detailed models, acquiring a physical property of the system that one wishes to observe; a behavioral model generation step of generating a behavioral model corresponding to the physical characteristic to be observed, the behavioral model having a longer interval between calculation steps than the corresponding detailed model; an observation step of simulating physical characteristics to be observed using the behavioral model generated in the behavioral model generation step; Equipped with The behavior model generating step is a calculation method for generating the behavior model in accordance with response times of the plurality of detailed models.

[0132] (Appendix 15) The behavior model generating step includes: a step of calculating an operation model corresponding to at least one of the plurality of detailed models using a plurality of detailed models and simplified models corresponding to each of the plurality of detailed models, wherein a first model generation step of generating a first physical model using a first detailed model having the longest response time among the plurality of detailed models and each simplified model among the plurality of detailed models corresponding to a detailed physical model other than the first detailed model; a first execution processing step of calculating, in time series, physical phenomena occurring at each time step that matches the time response of the first detailed model, using the first physical model; a first generation step of generating a first behavior model of the first detailed model based on the physical phenomenon occurring at each time step; 15. The method of claim 14, comprising:

[0133] (Appendix 16) a second model generation step of generating a second physical model using at least the first operational model and a second detailed model having the second longest response time among the plurality of detailed physical models; and a second execution processing step of calculating, in time series, physical phenomena occurring at each time step in accordance with the time response of the second detailed model using the second physical model. a second generation step of generating a second behavior model of the second detailed model based on the physical phenomenon occurring at each time step; 16. The method of claim 15, comprising:

[0134] (Appendix 17) 17. The method of claim 16, further comprising generating the second physical model using a simplified model corresponding to the second detailed model.

[0135] (Appendix 18) a third model generation step of generating a third physical model using at least the first behavioral model, the second behavioral model, and a third detailed model having the third longest response time among the plurality of detailed physical models; a third execution processing step of calculating, in time series, physical phenomena occurring at each time step that matches the time response of the third detailed model, using the third physical model; a third generation step of generating a third behavior model of the third detailed model based on the physical phenomenon occurring at each time step; 18. The method of claim 17, comprising:

[0136] (Appendix 19) a fourth model generation step of generating a fourth physical model using at least the first behavioral model, the second behavioral model, and the third behavioral model; a third execution processing step of calculating, in time series, a physical phenomenon occurring at each time step that matches the time response of any one of the first, second, and third operation models, using the fourth physical model; 19. The method of claim 18, comprising:

[0137] (Appendix 20) the first detailed model is a mechanical model, and the second detailed model is a circuit model in which a plurality of FET models each having information on electrical characteristics of a switching element are connected; the first model generating step generates the physical model using the mechanical model and a simplified model that indicates electrical characteristics of a switching element in the FET model of the circuit model by resistance characteristics; 16. The calculation method according to claim 15, wherein the first generation step generates, as the first operation model, a time-series value of a motor torque corresponding to a torque command value of the mechanical model. [Explanation of symbols]

[0138] 1: Calculation device, 30: Model generation unit, 40: Execution processing unit, 50: Output unit, 60: Thermal model generation unit, 70: Display unit, 75: Simple mechanical model generation unit, 82: Circuit model, 88: Element model, 90: Motor model, 92: Mechanical model, 700b: Command value, 700f: Steering wheel angle, 700g: Motor torque.

Claims

1. A computing method executed by a computing device, comprising: an execution processing step in which information for calculating a transient response is defined and a transient response value for a predetermined time-series input value is simulated for an element model having information on electrical characteristics of a switching element in a first calculation step; a behavioral model generating step of generating a behavioral model that outputs an output value based on an integrated value of the transient response value at a predetermined timing, the behavioral model having a calculation step interval longer than the corresponding first calculation step; a model generation step of generating a circuit model that connects a plurality of the element models; Equipped with The execution processing step uses information on electrical characteristics of each of the plurality of element models to calculate, in time series, the power generated at each time step by switching of the element model in response to a predetermined time series input value as the transient response value; the operation model generating step generates, as the operation model, a thermal model that outputs an output value based on an integrated value obtained by integrating the power generated for each time step in accordance with a switching timing of the element model; The operation model generating step outputs the output value based on a value obtained by dividing the integrated value by a predetermined time or the integrated value as a representative value.

2. The calculation method according to claim 1 , wherein the thermal model uses the representative value to output the output value through linear calculation according to the predetermined input value.

3. the execution processing step calculates, in time series, power generated for each of the first calculation steps using information on electrical characteristics of each of the plurality of element models in accordance with a time-series command value for a first period; The calculation method according to claim 1 , further comprising: calculating a time-series generated power for each time step of the element model using the thermal model in accordance with a time-series command value for a second period longer than the first period.

4. 4. The calculation method according to claim 3, wherein the execution processing step calculates the temperature of the element model for each time step in time series using power generated using the thermal model.

5. an output step of generating a display form showing a time change of temperature occurring in the element model, The method according to claim 1 , further comprising:

6. 6. The method according to claim 1, wherein the circuit model is selectable from a plurality of different circuit models.

7. The method according to claim 1 , wherein the element model is selectable from a plurality of different element models.

8. the circuit model further includes information on a motor model; The calculation method according to claim 1 , wherein the model generation step generates a mechanical model of a mechanical structure driven by the motor model.

9. 9. The calculation method according to claim 8, wherein, when the mechanical model is included, the execution processing step calculates the operation of the mechanical model for each second time step longer than the time step in accordance with a time-series command value for the mechanical model.

10. the command value of the circuit model is a torque command value output from the mechanical model and commanding a torque output of the motor model, and a motor torque of the motor model; 10. The calculation method according to claim 9, wherein the execution processing step, when calculating the torque command value and the motor torque, performs calculations by replacing electrical characteristics of switching elements in the element model with simplified models represented by resistance characteristics.

11. 11. The calculation method according to claim 10, wherein the execution processing step, when calculating the temperature of the element model when driving the mechanical model, calculates the temperature for each time step using the torque command value, the motor torque, and the thermal model instead of the mechanical model.

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