Simulation analysis method and device of braking unit of converter, and medium

Abstract

The present disclosure provides a simulation analysis method, device and medium for a braking unit of a converter. The simulation analysis method comprises: performing thermal simulation on a three-dimensional structure of the braking unit to determine thermal resistance data between interfaces of the braking unit; establishing a thermodynamic circuit simulation model based on the thermal resistance data and setting simulation parameters of the thermodynamic circuit simulation model; and performing simulation calculation according to the simulation parameters to obtain at least one of loss data and temperature rise data of a switching element in the braking unit. The simulation analysis method for the braking unit of the converter can realize simulation evaluation of a short-time working state of a switching device in the braking unit.

Description

Technical Field

[0001] This invention generally relates to the field of converters, and more specifically, to a simulation analysis method, apparatus, and medium for the braking unit of a converter. Background Technology

[0002] A converter's braking unit is a device that dissipates excess electrical energy when needed. For example, the braking unit can employ a combination of IGBT and braking resistor for energy dissipation braking. As an example, when the IGBT is turned on, the braking resistor begins to work, releasing energy as heat in the resistor. When the IGBT is turned off, the braking resistor current freewheels through an anti-parallel diode.

[0003] The braking unit has the characteristics of short single operation time, complex operating conditions and non-periodic operation.

[0004] For thermal simulation of braking units operating under short-term conditions, transient thermal resistance parameters are extremely important. However, current general-purpose simulation software provided by IGBT manufacturers cannot set transient thermal resistance parameters between the IGBT and the heat sink, or between the heat sink and air or coolant. This makes it unsuitable for the operating conditions of braking units, unable to realize the simulation evaluation function of IGBT devices operating under short-term conditions, and thus unable to meet the design requirements of braking units. Summary of the Invention

[0005] One of the objectives of this disclosure is to provide a simulation analysis method that can simulate and evaluate the short-term operating state of switching devices in a braking unit.

[0006] According to a first aspect of this disclosure, a simulation analysis method for a braking unit of a converter is provided. The simulation analysis method includes: performing thermal simulation on the three-dimensional structure of the braking unit to determine the thermal resistance data between the interfaces of the braking unit; establishing a thermodynamic circuit simulation model based on the thermal resistance data and setting the simulation parameters of the thermodynamic circuit simulation model; and performing simulation calculations according to the simulation parameters to obtain at least one of the loss data and temperature rise data of the switching elements in the braking unit.

[0007] According to a second aspect of this disclosure, a computer-readable storage medium is provided, the computer-readable storage medium including program instructions or code that, when executed by a processor, implements the simulation analysis method of the above-described braking unit.

[0008] According to a third aspect of this disclosure, a simulation analysis apparatus for a braking unit of a converter is provided. The simulation analysis apparatus includes: a thermal simulation module for performing thermal simulation on the three-dimensional structure of the braking unit to determine the thermal resistance data between the interfaces of the braking unit; a thermodynamic simulation modeling unit for establishing a thermodynamic circuit simulation model based on the thermal resistance data and setting the simulation parameters of the thermodynamic circuit simulation model; and a thermodynamic simulation calculation unit for performing simulation calculations according to the simulation parameters to obtain at least one of the loss data and temperature rise data of the switching elements of the braking unit.

[0009] The simulation analysis method and simulation analysis apparatus according to embodiments of the present disclosure are capable of high-precision simulation of switching elements in a braking unit.

[0010] The simulation analysis method and simulation analysis apparatus according to the embodiments of this disclosure can confirm whether the configuration of each device (especially the switching element) and the cooling scheme in the braking unit meet the requirements of actual working conditions, thereby improving the accuracy of the heat dissipation performance evaluation of the braking unit. Attached Figure Description

[0011] The above and other objects and features of exemplary embodiments of this disclosure will become clearer from the following description taken in conjunction with the accompanying drawings, which exemplarily illustrate the embodiments, wherein: Figure 1 This is a schematic diagram illustrating a braking unit according to an embodiment of the present disclosure; Figure 2 This is a flowchart illustrating a simulation analysis method according to an embodiment of the present disclosure; Figure 3 This is a flowchart illustrating the determination of thermal resistance data for each interface according to an embodiment of the present disclosure; Figure 4 This illustrates a thermodynamic circuit simulation model according to a first embodiment of the present disclosure; Figure 5 This illustrates a thermodynamic circuit simulation model according to a second embodiment of the present disclosure; Figure 6 This is a graph showing the wear data of the braking unit according to an embodiment of the present disclosure; Figure 7 It is a graph showing the temperature data of each interface of the braking unit according to an embodiment of the present disclosure; Figure 8 This is a block diagram illustrating a simulation analysis apparatus according to a first embodiment of the present disclosure; Figure 9 This is a block diagram illustrating a simulation analysis apparatus according to a second embodiment of the present disclosure. Detailed Implementation

[0012] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings, examples of which are illustrated in the drawings, wherein the same reference numerals always refer to the same parts. The embodiments will now be described with reference to the accompanying drawings in order to explain this disclosure.

[0013] The simulation analysis method and simulation analysis apparatus according to embodiments of this disclosure highly couple mechanical structure with electrical structure, and can be used to construct a thermodynamic model of a braking unit based on transient thermal resistance parameters, thereby simulating the temperature rise and loss of switching elements (e.g., IGBTs) in the braking unit.

[0014] The simulation analysis method and simulation analysis device according to the embodiments of this disclosure can solve the transient thermal resistance parameters between different materials in a three-dimensional structural thermal simulation mode, and can calculate loss data and temperature rise data.

[0015] Figure 1 This is a schematic diagram illustrating a braking unit according to an embodiment of the present disclosure.

[0016] The braking unit may include a braking resistor and a switching element. Additionally, the braking unit may also include a capacitor.

[0017] As an example, the braking unit may include a braking resistor and an IGBT as a switching element, wherein the braking resistor may be selectively connected in response to the switching of the IGBT to consume electrical energy.

[0018] like Figure 1 As shown, the braking unit according to an embodiment of the present disclosure may include a first braking resistor R1, a second braking resistor R2, a first switching element S1, a second switching element S2, a third switching element S3, a fourth switching element S4, a first capacitor C1, and a second capacitor C2.

[0019] like Figure 1 As shown, the first capacitor C1 and the second capacitor C2 can be connected in series between the first terminal DC+ and the second terminal DC-. As an example, the first capacitor C1 and the second capacitor C2 can be connected in series between the positive and negative DC buses.

[0020] The first braking resistor R1 can be connected in parallel with the first switching element S1, the second braking resistor R2 can be connected in parallel with the third switching element S3, the second switching element S2 can be connected between the first switching element S1 and the third switching element S3, the node N between the second switching element S2 and the third switching element S3 can be connected to the node NP between the first capacitor C1 and the second capacitor C2, and the fourth switching element S4 can be connected between the third switching element S3 and the second terminal DC-.

[0021] As an example, the first switching element S1, the second switching element S2, the third switching element S3, and the fourth switching element S4 can be IGBTs. Under extreme operating conditions, the first switching element S1, the second switching element S2, the third switching element S3, and the fourth switching element S4 can be selectively turned on or off, so that the first braking resistor R1 and / or the second braking resistor R2 are connected to the power consumption circuit, thereby consuming power through the first braking resistor R1 and / or the second braking resistor R2.

[0022] Taking wind power converters as an example, under extreme operating conditions such as high voltage ride-through and low voltage ride-through, the first switching element S1, the second switching element S2, the third switching element S3, and the fourth switching element S4 can be controlled by the controller to selectively turn on or off, thereby consuming instantaneous electrical energy and achieving the purpose of protecting related electronic devices.

[0023] The circuit structure of the braking unit described above is merely an example; the braking unit may also have other circuit structures.

[0024] Current simulations of braking units generally do not consider extreme application conditions or environments. In practical applications, many braking units cannot meet the usage requirements, especially the IGBTs used as switching elements in the braking unit.

[0025] The simulation analysis method according to the embodiments of this disclosure highly couples mechanical structure with electrical structure. The simulation analysis method of this disclosure will be described in detail below.

[0026] Figure 2 This is a flowchart illustrating a simulation analysis method according to an embodiment of the present disclosure. Figure 3 This is a flowchart illustrating the determination of thermal resistance data for each interface according to an embodiment of the present disclosure.

[0027] like Figure 2 As shown, the simulation analysis method according to the embodiments of this disclosure may include steps S210, S220 and S230.

[0028] In step S210, a thermal simulation is performed on the three-dimensional structure of the braking unit to determine the thermal resistance data between the interfaces of the braking unit. Here, the three-dimensional structure refers to the three-dimensional mechanical structure of the braking unit.

[0029] The three-dimensional structure of the braking unit can be created using 3D modeling software. For example, the solid structure of the braking unit can be drawn using SolidWorks. The solid structure of the braking unit may include switching elements (e.g., IGBTs), heat sinks, thermal grease layers, etc.

[0030] The interfaces of the braking unit refer to the interfaces between the physical structures of the braking unit and between the physical structures and the air, such as the interface between the IGBT and the air, the interface between the heat sink and the air, etc.

[0031] like Figure 3 As shown, step S210, which involves performing thermal simulation on the three-dimensional structure of the braking unit to determine the thermal resistance data between the interfaces of the braking unit, may include steps S310, S320, S330, and S340.

[0032] In step S310, the three-dimensional structural model of the braking unit is loaded.

[0033] For example, thermal analysis software can be used to perform thermal simulation of the three-dimensional structure of the braking unit. For instance, the three-dimensional structural model of the braking unit can be loaded using the thermal analysis software Icepak.

[0034] In step S320, thermal simulation parameters can be set for the three-dimensional structural model.

[0035] In the thermal analysis software, parameters such as the step size of the simulation calculation, the spatial interface of the three-dimensional structural model, the standard power of the IGBT, and the thermal properties of the interface materials in the braking unit can be set for the three-dimensional structural model.

[0036] In step S330, a transient solution is performed according to the set thermal simulation parameters to obtain the temperature data of each interface.

[0037] After setting the above thermal simulation parameters, a transient solution can be executed. After the solution is obtained, the temperature data (e.g., temperature curves) of each interface of the braking unit can be obtained.

[0038] In step S340, the thermal resistance data between each interface is determined based on the temperature data of each interface.

[0039] For example, after obtaining the temperature data of each interface, mathematical software can be used to calculate the thermal resistance data between the interfaces of the braking unit based on the obtained temperature data of each interface.

[0040] The thermal resistance data between the interfaces of the braking unit may include radiator-air thermal resistance data (Rth_ha), IGBT junction-case thermal resistance data (Rth_jc), and case-radiator thermal resistance data (Rth_ch).

[0041] In step S220, a thermodynamic circuit simulation model is established based on thermal resistance data, and the simulation parameters of the thermodynamic circuit simulation model are set.

[0042] As a key component in the braking unit, a thermodynamic simulation model can be established based on the current and voltage data of the switching elements during actual operation.

[0043] In one example, a thermodynamic simulation model can be established based on the thermal resistance data obtained from thermal simulation and the voltage and current data of the switching element.

[0044] To simulate the actual operating conditions of the switching elements, especially under extreme conditions, the aforementioned voltage and current data can be calculated based on the braking unit's braking operation under extreme conditions. For example, the voltage and current data can be calculated based on the braking unit's operation under high-voltage ride-through conditions. In this way, the loss and temperature rise data of the braking unit under extreme conditions can be simulated.

[0045] For example, a thermodynamic simulation model can be established using power electronics simulation software PSIM based on obtained thermal resistance data such as radiator-air thermal resistance data (Rth_ha), IGBT junction-case thermal resistance data (Rth_jc), and case-radiator thermal resistance data (Rth_ch), as well as voltage and current data, and the simulation parameters of the thermodynamic simulation model can be set.

[0046] The steps for setting the simulation parameters of the thermodynamic simulation model may include: setting the conduction loss and switching loss of the switching devices in the braking unit, the device parameters of the switching elements in the braking unit, the operating time of the braking unit, and the thermal resistance data between the interfaces in the braking unit.

[0047] In addition, the steps for setting the simulation parameters of the thermodynamic simulation model may also include setting the step size of the simulation calculation, the boundary conditions of the simulation calculation, and the total duration of the simulation calculation. The boundary conditions can be determined by the working time, voltage and current curves of the braking unit.

[0048] In step S230, simulation calculations are performed based on simulation parameters to obtain at least one of the loss data and temperature rise data of the switching element in the braking unit.

[0049] As an example, the simulation analysis method according to an embodiment of the present disclosure may further include: determining whether the braking unit meets the design requirements based on at least one of the loss data and temperature rise data.

[0050] For example, based on the loss data and temperature rise data of a specific IGBT model obtained from simulation calculations, the maximum value of the total loss of the IGBT and the time when the maximum value of the total loss occurs, the highest junction temperature of the IGBT and the time when the highest junction temperature occurs, and compare them with the design values ​​that meet the requirements, thereby determining whether the specific IGBT model meets the design requirements, and thus determining whether the braking unit meets the design requirements.

[0051] In particular, the simulation analysis method according to the embodiments of this disclosure loads a control signal corresponding to the braking condition under extreme operating conditions of the braking unit onto the switching element during the thermodynamic simulation process, thereby simulating the extreme operating conditions. Then, based on the relevant data of the IGBT under extreme operating conditions, it is finally determined whether the IGBT meets the design requirements.

[0052] The extreme operating conditions here can include high-voltage ride-through conditions and low-voltage ride-through conditions. During the simulation analysis, the switching element can record the control strategies under high-voltage ride-through conditions and low-voltage ride-through conditions respectively, thereby determining the relevant data of the IGBT under the corresponding operating conditions. Finally, based on these data, it is determined whether the IGBT meets the design requirements. The thermodynamic simulation model of this disclosure is described below.

[0053] Figure 4 This illustrates a thermodynamic circuit simulation model according to a first embodiment of the present disclosure. Figure 5 This is a simulation model of a thermodynamic circuit according to a second embodiment of the present disclosure.

[0054] like Figure 4 As shown, the thermodynamic circuit simulation model according to the embodiments of this disclosure may include a first model circuit 110, a second model circuit 120 and a third model circuit 130.

[0055] The first model circuit 110 can be a thermodynamic model of the IGBT and an external connection circuit. In other words, the first model circuit 110 can establish a power circuit connection relationship of the IGBT that is consistent with the actual working conditions. That is to say, the circuit structure of the first model circuit 110 will differ depending on the difference in the peripheral circuit of the IGBT in the braking unit.

[0056] As an example, when setting the parameters of the thermodynamic circuit simulation model, the device parameters of the IGBT, the terminal voltage and current function formulas of the IGBT can be set for the first model circuit 110. The device parameters of the IGBT, the terminal voltage and current function formulas can all be provided by the IGBT manufacturer, for example, they can be obtained from the IGBT product manual.

[0057] Furthermore, after the control strategy is applied to the IGBT in the first model circuit 110, loss data can be calculated. This loss data can be applied to the third model circuit 130. After the loss data is applied, the third model circuit 130 can calculate temperature data, which can then be applied to the first model circuit 110. In these model circuits, voltage corresponds to temperature, and current corresponds to loss. Applying different voltages means applying different temperature data, and applying different currents means applying different loss data. In other words, the first model circuit 110 and the third model circuit 130 can be highly coupled to each other. After the first model circuit 110 applies temperature data, it can obtain different loss data; after the third model circuit 130 applies different loss data, it can obtain different temperature data.

[0058] like Figure 5 As shown, the first model circuit 110 may include an IGBT model 1101 and peripheral circuits 1102 of the IGBT model. The IGBT model 1101 can load the signal output from the second model circuit 120 through terminal P. The IGBT model 1101 can output a current signal, which can be loaded into the third model circuit 130 through terminals P1, P2, P3, and P4. The current (i.e., loss data) loaded into the third model circuit 130 through terminals P1, P2, P3, and P4 can be the conduction loss data of the transistor in the IGBT, the switching loss data of the transistor in the IGBT, the conduction loss data of the diode in the IGBT, and the switching loss data of the diode in the IGBT, respectively.

[0059] The peripheral circuit 1102 described above can have different structures, such as... Figure 5 As shown, the peripheral circuit 1102 may include a diode D1 and a current component I2 connected in series with the diode D1. The diode D1 and the current component I2 form a first branch. The current component I1 and the voltage component V2 may be connected in parallel with the first branch. The current components I1, I2 and the voltage component V2 may respectively simulate the peripheral circuit of the IGBT, thereby applying corresponding voltage and current to the input terminal of the IGBT.

[0060] like Figure 4 As shown, the second model circuit 120 can be a control circuit that can provide control strategies for the IGBT under specific operating conditions. For example, it can be used to provide control strategies for the IGBT under high voltage ride-through and low voltage ride-through conditions.

[0061] As an example, such as Figure 5As shown, the second model circuit 120 may include components such as a programmable voltage generator 1204, a comparator 1201, and a reference voltage generation unit 1203. The comparator 1201 can output a corresponding control voltage, that is, the comparator can output a control pulse signal of the IGBT that is consistent with the actual operating conditions of the power circuit. The control pulse signal can be applied to the control terminal of the IGBT in the first model circuit 110.

[0062] like Figure 4 As shown, the third model circuit 130 and the first model circuit 110 can be highly coupled, such as Figure 5 As shown, the third model circuit 130 can be a thermal resistance model circuit for each interface. The third model circuit 130 may include a first thermal resistance model circuit 1301 and a second thermal resistance model circuit 1302 composed of multiple RC circuits (e.g., four RC circuits connected in series in parallel). The loss data input through terminals P1, P2, P3, and P4 can be input to the current components Pd_Qt, Psw_Qt, Pd_Dt, and Psw_Dt, respectively. The output terminals of the current components Pd_Qt and Psw_Qt can be connected to node Q, and then connected via node Q... The current component Ptot_Qt is connected to node Q. The current component Ptot_Qt is used to characterize the total loss data of the transistor. The voltage component Tj_Qt can be set at node Q. The voltage component Tj_Qt is used to characterize the temperature data of the transistor. The voltage component Tj_Dt can be set at node D. The voltage component Tj_Dt is used to characterize the temperature data of the diode. The output terminals of the current components Pd_Dt and Psw_Dt can be connected to node D, and then connected to the current component Ptot_Dt via node D. The current component Ptot_Dt is used to characterize the total loss data of the diode.

[0063] like Figure 5 As shown, the first thermal resistance model circuit 1301 can be connected between the current component Ptot_Qt and the programmable voltage generator V1, and the second thermal resistance model circuit 1302 can be connected between the current component Ptot_Dt and the voltage component Tc_D. The voltage component Tc_D is used to characterize the case temperature data of the diode.

[0064] As mentioned above, such as Figure 5 The thermodynamic model circuit shown is merely an example; thermodynamic model circuits can have different constructions.

[0065] As mentioned above, after establishing and setting the thermodynamic simulation model, simulation calculations can be performed according to the set simulation parameters to obtain the IGBT loss data and temperature rise data.

[0066] The following will combine Figure 6 and Figure 7 Describe the loss data and temperature rise data obtained from the simulation calculation.

[0067] Figure 6 This is a graph showing the wear data of the braking unit according to an embodiment of the present disclosure. Figure 7 This is a graph showing the temperature data of each interface of the braking unit according to an embodiment of the present disclosure.

[0068] like Figure 6 As shown, curve G1 represents the total loss of the IGBT, curve G2 represents the conduction loss of the IGBT, and curve G3 represents the switching loss of the IGBT.

[0069] from Figure 6 It can be seen that the maximum total IGBT loss is 1522W, and the maximum total IGBT loss occurs at 0.39 seconds.

[0070] like Figure 7 As shown, curve G11 represents the junction temperature of the IGBT, curve G12 represents the case temperature of the IGBT, curve G13 represents the heat sink temperature of the braking unit, and curve G14 represents the ambient temperature.

[0071] from Figure 7 It can be seen that the highest junction temperature of the IGBT is 162℃, and the highest junction temperature of the IGBT occurs at 1.29 seconds.

[0072] The IGBT's performance is determined by analyzing its loss data (e.g., total loss) and temperature rise data (e.g., maximum junction temperature). For example, if both the maximum junction temperature and the total loss are below a certain threshold, the IGBT is considered to meet the design requirements. If either the maximum junction temperature or the total loss does not meet the design requirements, a different type of IGBT can be used.

[0073] Figure 8 This is a block diagram illustrating a simulation analysis apparatus according to a first embodiment of the present disclosure. Figure 9 This is a block diagram illustrating a simulation analysis apparatus according to a second embodiment of the present disclosure.

[0074] The simulation analysis apparatus according to the first embodiment of the present disclosure may include a thermal simulation module 810, a thermodynamic simulation modeling unit 820, and a thermodynamic simulation calculation unit 830.

[0075] The thermal simulation module 810 can perform thermal simulation on the three-dimensional structure of the braking unit to determine the thermal resistance data between the interfaces of the braking unit.

[0076] Specifically, the thermal simulation module 810 can load a three-dimensional structural model of the braking unit; set thermal simulation parameters for the three-dimensional structural model; perform transient solutions based on the set thermal simulation parameters to obtain temperature data for each interface; and determine the thermal resistance data between each interface based on the temperature data of each interface.

[0077] In one example, the thermal simulation module 810 can set parameters such as the step size of the simulation calculation, the spatial interface of the three-dimensional structural model, the standard power of the IGBT, and the thermal properties of the interface materials in the braking unit for the three-dimensional structural model.

[0078] In addition, the thermal simulation module 810 can perform transient solutions based on the set thermal simulation parameters to obtain temperature data for each interface. For example, after setting the above thermal simulation parameters, a transient solution can be performed, and after the solution is obtained, the temperature data (e.g., temperature curves) for each interface of the braking unit can be obtained.

[0079] Furthermore, the thermal simulation module 810 can determine the thermal resistance data between each interface based on the temperature data of each interface.

[0080] For example, after obtaining the temperature data of each interface, the thermal simulation module 810 can calculate the thermal resistance data between the interfaces of the braking unit based on the obtained temperature data of each interface.

[0081] The thermal resistance data between the interfaces of the braking unit may include radiator-air thermal resistance data (Rth_ha), IGBT junction-case thermal resistance data (Rth_jc), and case-radiator thermal resistance data (Rth_ch).

[0082] The thermodynamic simulation modeling unit 820 can establish a thermodynamic circuit simulation model based on thermal resistance data and set the simulation parameters of the thermodynamic circuit simulation model.

[0083] The thermodynamic circuit simulation model established by the thermodynamic simulation modeling unit 820 can be like Figure 4 and Figure 5 As previously mentioned, I will not repeat myself here.

[0084] The thermodynamic simulation modeling unit 820 can set the conduction and switching losses of the switching devices in the braking unit, the device parameters of the switching elements in the braking unit, the operating time of the braking unit, and the thermal resistance data between the interfaces in the braking unit. In addition, the thermodynamic simulation modeling unit 820 can also set the simulation calculation step size, the simulation calculation boundary conditions, and the total simulation calculation time. The boundary conditions can be determined by the operating time, voltage, and current curves of the braking unit.

[0085] The thermodynamic simulation calculation unit 830 can perform simulation calculations based on simulation parameters to obtain at least one of the loss data and temperature rise data of the switching element in the braking unit.

[0086] like Figure 9 As shown, the simulation analysis device according to the second embodiment of the present disclosure may further include an auxiliary design unit 840, which can determine whether the braking unit meets the design requirements based on at least one of the loss data and temperature rise data.

[0087] For example, the auxiliary design unit 840 can use the loss data and temperature rise data of a specific IGBT model obtained from simulation calculations. The specific loss and temperature rise data can be obtained as follows: Figure 6 and Figure 7 As shown, the maximum total loss of the IGBT and the time when the maximum total loss occurs, the highest junction temperature of the IGBT and the time when the highest junction temperature occurs are determined, and these are compared with the design values ​​that meet the requirements, so as to determine whether the IGBT of this specific model meets the design requirements.

[0088] It should be understood that the various units or modules in the simulation analysis apparatus according to exemplary embodiments of the present invention can be implemented as hardware components and / or software components. Those skilled in the art can implement the various units, for example, using field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), software algorithms, etc., depending on the processing performed by each defined unit.

[0089] Each of the above steps can be programmed as a software program or instruction. Therefore, the simulation analysis method according to the exemplary embodiments of the present disclosure can be implemented via software. The computer-readable storage medium of the exemplary embodiments of the present disclosure can store a computer program that, when executed by a processor, implements the simulation analysis method according to the embodiments of the present disclosure.

[0090] According to various embodiments of this disclosure, apparatus (e.g., modules or their functions) or methods can be implemented by programs or instructions stored in a computer-readable storage medium. When such instructions are executed by a processor, the processor can perform a function corresponding to the instruction or perform a method corresponding to the instruction. At least a portion of a module can be implemented (e.g., executed) by a processor. At least a portion of a programmed module can include modules, programs, routines, instruction sets, and procedures for performing at least one function. In one example, the instructions or software include machine code (such as machine code generated by a compiler) that is directly executed by one or more processors or computers. In another example, the instructions or software include higher-level code that is executed by one or more processors or computers using an interpreter. Instructions or software can be written using any programming language based on the block diagrams and flowcharts shown in the accompanying drawings and the corresponding descriptions in the specification.

[0091] Computer-readable storage media include magnetic media such as floppy disks and magnetic tapes, optical media (including optical disc (CD) ROMs and DVD ROMs), magneto-optical media such as flexible optical discs, hardware devices such as ROMs and RAMs designed for storing and executing program commands, and flash memory. The program commands include language code executable by a computer using an interpreter and machine language code generated by a compiler. The aforementioned hardware devices can be implemented by one or more software modules for performing the operations of the various embodiments of this disclosure.

[0092] The modules or programming modules disclosed herein may include at least one of the aforementioned components, with some components omitted or others added. The operations of the modules, programming modules, or other components may be executed sequentially, in parallel, cyclically, or probingly. Furthermore, some operations may be executed in a different order, may be omitted, or may be extended with other operations.

[0093] The simulation analysis method and simulation analysis apparatus according to the embodiments of this disclosure can realize the simulation evaluation of the short-time operating state of the switching devices in the braking unit.

[0094] The simulation analysis method and simulation analysis apparatus according to embodiments of the present disclosure can perform high-precision simulation of the switching elements in the braking unit.

[0095] The simulation analysis method and simulation analysis apparatus according to the embodiments of this disclosure can confirm whether the device configuration and cooling scheme of the braking unit meet the requirements of actual working conditions, and improve the accuracy of the heat dissipation performance evaluation of the braking unit.

[0096] While some exemplary embodiments of the invention have been shown and described, those skilled in the art will understand that modifications can be made to these embodiments without departing from the principles and spirit of the invention as defined by the claims and their equivalents. For example, technical features of different embodiments can be combined.

Claims

1. A simulation analysis method for a converter braking unit, characterized in that, include: Thermal simulation of the three-dimensional structure of the braking unit was performed to determine the thermal resistance data between the interfaces of the braking unit. A thermodynamic circuit simulation model is established based on the thermal resistance data, and the simulation parameters of the thermodynamic circuit simulation model are set. Simulation calculations are performed based on the simulation parameters to obtain at least one of the loss data and temperature rise data of the switching elements in the braking unit. The steps for establishing a thermodynamic circuit simulation model based on the thermal resistance data include: The thermodynamic circuit simulation model is established based on the thermal resistance data and the voltage and current data of the switching element, wherein the voltage and current data are calculated based on the braking unit under extreme operating conditions. The steps for performing thermal simulation on the three-dimensional structure of the braking unit to determine the thermal resistance data between the interfaces of the braking unit include: Load the three-dimensional structural model of the braking unit; Set thermal simulation parameters for the three-dimensional structural model; Perform transient solutions based on the set thermal simulation parameters to obtain temperature data for each interface; The thermal resistance data between each interface is determined based on the temperature data of each interface.

2. The simulation analysis method for the braking unit of the converter according to claim 1, characterized in that, In the thermodynamic circuit simulation model, the switching element is loaded with a control signal corresponding to the braking condition under extreme operating conditions of the braking unit.

3. The simulation analysis method for the braking unit of the converter according to claim 2, characterized in that, The extreme operating conditions include at least one of high voltage ride-through conditions and low voltage ride-through conditions.

4. The simulation analysis method for the braking unit of the converter according to claim 1, characterized in that, The steps for setting the simulation parameters of the thermodynamic circuit simulation model include: setting the conduction loss and switching loss of the switching element in the braking unit, the device parameters of the switching element in the braking unit, the operating time of the braking unit, and the thermal resistance data between the interfaces in the braking unit.

5. The simulation analysis method for the braking unit of the converter according to claim 1, characterized in that, The thermal resistance data between the interfaces of the braking unit includes radiator-air thermal resistance data, IGBT junction-case thermal resistance data, and case-radiator thermal resistance data.

6. The simulation analysis method for the braking unit of the converter according to any one of claims 1 to 5, characterized in that, The braking unit includes a braking resistor and an IGBT as the switching element. The braking resistor is selectively connected in response to the switching of the IGBT, thereby consuming electrical energy.

7. The simulation analysis method for the braking unit of the converter according to any one of claims 1 to 5, characterized in that, The simulation analysis method further includes: determining whether the braking unit meets the design requirements based on at least one of the loss data and temperature rise data.

8. A computer-readable storage medium, characterized in that, It includes program instructions or code, which, when executed by a processor, implement the simulation analysis method for the braking unit according to any one of claims 1-7.

9. A simulation analysis device for the braking unit of a converter, characterized in that, include: The thermal simulation module performs thermal simulation on the three-dimensional structure of the braking unit to determine the thermal resistance data between the interfaces of the braking unit. The thermodynamic simulation modeling unit establishes a thermodynamic circuit simulation model based on the thermal resistance data and sets the simulation parameters of the thermodynamic circuit simulation model. The thermodynamic simulation calculation unit performs simulation calculations based on the simulation parameters to obtain at least one of the loss data and temperature rise data of the switching element of the braking unit. The thermodynamic simulation modeling unit is configured to: establish a thermodynamic circuit simulation model based on the thermal resistance data and the voltage and current data of the switching element, wherein the voltage and current data are calculated based on the braking conditions of the braking unit under extreme operating conditions. The thermal simulation module is configured as follows: Load the three-dimensional structural model of the braking unit; Set thermal simulation parameters for the three-dimensional structural model; Perform transient solutions based on the set thermal simulation parameters to obtain temperature data for each interface; The thermal resistance data between each interface is determined based on the temperature data of each interface.

10. The simulation analysis device for the braking unit of the converter according to claim 9, characterized in that, In the thermodynamic circuit simulation model, the switching element is loaded with a control signal corresponding to the braking condition under extreme operating conditions of the braking unit.

11. The simulation analysis device for the braking unit of the converter according to claim 9, characterized in that, The thermodynamic simulation modeling unit is further configured to: set the conduction loss and switching loss of the switching element of the braking unit, the device parameters of the switching element in the braking unit, the operating time of the braking unit, and the thermal resistance data between the interfaces of the braking unit.

12. The simulation analysis device for the braking unit of the converter according to claim 9, characterized in that, The thermal resistance data between the interfaces of the braking unit includes radiator-air thermal resistance data, IGBT junction-case thermal resistance data, and case-radiator thermal resistance data.

13. The simulation analysis apparatus for the braking unit of the converter according to any one of claims 9 to 12, characterized in that, The simulation analysis device further includes an auxiliary design unit, which is configured to determine whether the braking unit meets the design requirements based on at least one of the loss data and temperature rise data.

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