Direct-current bus capacitor electrothermal coupling simulation method, device, equipment and medium

Abstract

The invention relates to a direct current bus capacitor electrothermal coupling simulation method and device, equipment and a medium. The method comprises the following steps: acquiring a capacitance loss value of a simulation direct current bus capacitor in an electric drive controller simulation circuit; a built electric drive controller performance simulation model is obtained, the capacitance loss value serves as a simulation condition of a direct-current bus capacitance simulation sub-model in the electric drive controller simulation model, the electric drive controller simulation model is operated, and a simulation temperature diagram of the direct-current bus capacitance simulation sub-model is obtained; the real temperature value of each temperature detection point on the direct current bus capacitor of the electric drive controller is obtained; and adjusting the capacitor structure of the direct current bus capacitor according to the simulation temperature diagram and each real temperature value. By adopting the method, the direct-current bus capacitor sub-model can be subjected to simulation operation in the electric drive controller model, the simulation precision and the accuracy of determining the simulation temperature diagram are improved, and the capacitor structure of the direct-current bus capacitor can be adjusted more accurately according to the simulation temperature diagram and each real temperature value.

Description

Technical Field

[0001] The present application relates to the field of computer technology, and in particular to a method, device, equipment and medium for simulating the electrothermal coupling of a DC bus capacitor. Background Art

[0002] The DC bus capacitor connects the high-voltage DC input and the power module in the electric drive controller of new energy vehicles, and plays a role in transferring energy and suppressing bus voltage fluctuations. At present, the on-board DC bus capacitor generally uses metallized film capacitors. Due to the temperature resistance limit of the film material, the working hot spot temperature of the capacitor is required to be less than 105°C, which is lower than the maximum temperature limit of the power module, filter magnetic ring, printed circuit board (PCB), copper busbar and other components in the electric drive controller. It is easy to become the short board of the thermal performance of the electric drive controller. Therefore, how to accurately evaluate the thermal performance of the DC bus capacitor is crucial.

[0003] In the prior art, the DC bus capacitor is usually simulated as a whole capacitor and placed in a preset environment for simulation operation. The preset environment can be a fixed value set based on experience for the ambient temperature, cooling temperature, and heat transfer coefficient around the capacitor. The existing capacitor thermal simulation inputs a given current and loss that is converted through system indicators, which are generally fixed values. However, since the corresponding circuit performance of the capacitor current, capacitor loss, module loss, etc. under different speeds and torque conditions of the electric drive is different, this thermal simulation that uses system indicators as input cannot reflect the heating of the capacitor under specified conditions, resulting in a low degree of coupling between the thermal simulation and the electrical performance of the specified conditions of the electric drive controller, and a deviation between the simulation and the actual measurement.

[0004] Although this method can complete the simulation of the DC bus capacitor, there is a problem of large errors caused by the large difference between the simulated temperature and the actual temperature. Summary of the invention

[0005] Based on this, it is necessary to provide a DC bus capacitor electrothermal coupling simulation method, device, computer equipment and storage medium that can reduce errors in order to solve the above technical problems.

[0006] In a first aspect, the present application provides a DC bus capacitor electrothermal coupling simulation method, comprising:

[0007] Obtaining the capacitance loss value of the simulated DC bus capacitor in the electric drive controller simulation circuit;

[0008] Obtain the constructed electric drive controller performance simulation model, and use the capacitance loss value as the simulation condition of the DC bus capacitor simulation sub-model in the electric drive controller simulation model, run the electric drive controller simulation model, and obtain the simulation temperature diagram of the DC bus capacitor simulation sub-model;

[0009] Obtain the actual temperature value of each temperature detection point on the DC bus capacitor of the electric drive controller;

[0010] According to the simulated temperature diagram and the actual temperature values, the capacitance structure of the DC bus capacitor is adjusted.

[0011] In one embodiment, obtaining a capacitance loss value of a simulated DC bus capacitor in a simulation circuit of an electric drive controller includes:

[0012] Obtain the effective value of the current of the simulated DC bus capacitor in the electric drive controller simulation circuit;

[0013] The capacitance loss value of the simulated DC bus capacitor in the electric drive controller simulation circuit is determined according to the effective value of the current and the preset equivalent resistance of the capacitor core; wherein the simulated DC bus capacitor includes the capacitor core.

[0014] In one embodiment, the capacitance loss value is used as a simulation condition of a DC bus capacitance simulation sub-model in an electric drive controller simulation model, and the electric drive controller simulation model is run to obtain a simulation temperature graph of the DC bus capacitance simulation sub-model, including:

[0015] Obtaining the power loss value of the simulated power component in the electric drive controller simulation circuit;

[0016] The capacitance loss value is used as a simulation condition of the DC bus capacitance simulation sub-model in the electric drive controller simulation model, and the power loss value is used as a simulation condition of the power component sub-model in the electric drive controller simulation model. The electric drive controller simulation model is run to obtain a simulation temperature graph of the DC bus capacitance simulation sub-model.

[0017] In one embodiment, the capacitance loss value is used as a simulation condition of a DC bus capacitance simulation sub-model in an electric drive controller simulation model, and the electric drive controller simulation model is run to obtain a simulation temperature graph of the DC bus capacitance simulation sub-model, including:

[0018] Obtaining the circuit current value of the electric drive controller simulation circuit;

[0019] Determine the chip loss value of the chip sub-model in the electric drive controller simulation model according to the circuit current value;

[0020] The capacitor loss value is used as the simulation condition of the DC bus capacitor simulation sub-model in the electric drive controller simulation model, the power loss value is used as the simulation condition of the power component sub-model in the electric drive controller simulation model, and the chip loss value is used as the simulation condition of the chip sub-model in the electric drive controller simulation model. The electric drive controller simulation model is run to obtain a simulation temperature graph of the DC bus capacitor simulation sub-model.

[0021] In one embodiment, adjusting the capacitance structure of the DC bus capacitor according to the simulated temperature map and the actual temperature values ​​includes:

[0022] According to the simulation temperature diagram, determine the simulation temperature value of the DC bus capacitor simulation sub-model at each temperature detection point;

[0023] For each temperature detection point, the capacitance structure of the DC bus capacitor is adjusted according to the actual temperature value and the simulated temperature value at the temperature detection point.

[0024] In one embodiment, for each temperature detection point, adjusting the capacitance structure of the DC bus capacitor according to the actual temperature value and the simulated temperature value at the temperature detection point includes:

[0025] Determine the simulation error value of the electric drive controller simulation model according to the real temperature value and the simulation temperature value corresponding to each temperature detection point;

[0026] When the simulation error value meets the preset error threshold, the capacitance structure of the DC bus capacitor is adjusted according to the simulation temperature diagram of the electric drive controller simulation model.

[0027] In a second aspect, the present application also provides a DC bus capacitor electrothermal coupling simulation device, comprising:

[0028] A loss determination module, used to obtain a capacitance loss value of a simulated DC bus capacitor in a simulation circuit of an electric drive controller;

[0029] A simulation determination module is used to obtain the constructed electric drive controller performance simulation model, and use the capacitance loss value as the simulation condition of the DC bus capacitor simulation sub-model in the electric drive controller simulation model, run the electric drive controller simulation model, and obtain a simulation temperature diagram of the DC bus capacitor simulation sub-model;

[0030] A real determination module is used to obtain the real temperature value of each temperature detection point on the DC bus capacitor of the electric drive controller;

[0031] The structure adjustment module is used to adjust the capacitance structure of the DC bus capacitor according to the simulated temperature diagram and each real temperature value.

[0032] In a third aspect, the present application further provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0033] Obtaining the capacitance loss value of the simulated DC bus capacitor in the electric drive controller simulation circuit;

[0034] Obtain the constructed electric drive controller performance simulation model, and use the capacitance loss value as the simulation condition of the DC bus capacitor simulation sub-model in the electric drive controller simulation model, run the electric drive controller simulation model, and obtain the simulation temperature diagram of the DC bus capacitor simulation sub-model;

[0035] Obtain the actual temperature value of each temperature detection point on the DC bus capacitor of the electric drive controller;

[0036] According to the simulated temperature diagram and the actual temperature values, the capacitance structure of the DC bus capacitor is adjusted.

[0037] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

[0038] Obtaining the capacitance loss value of the simulated DC bus capacitor in the electric drive controller simulation circuit;

[0039] Obtain the constructed electric drive controller performance simulation model, and use the capacitance loss value as the simulation condition of the DC bus capacitor simulation sub-model in the electric drive controller simulation model, run the electric drive controller simulation model, and obtain the simulation temperature diagram of the DC bus capacitor simulation sub-model;

[0040] Obtain the actual temperature value of each temperature detection point on the DC bus capacitor of the electric drive controller;

[0041] According to the simulated temperature diagram and the actual temperature values, the capacitance structure of the DC bus capacitor is adjusted.

[0042] In a fifth aspect, the present application further provides a computer program product, including a computer program, which implements the following steps when executed by a processor:

[0043] Obtaining the capacitance loss value of the simulated DC bus capacitor in the electric drive controller simulation circuit;

[0044] Obtain the constructed electric drive controller performance simulation model, and use the capacitance loss value as the simulation condition of the DC bus capacitor simulation sub-model in the electric drive controller simulation model, run the electric drive controller simulation model, and obtain the simulation temperature diagram of the DC bus capacitor simulation sub-model;

[0045] Obtain the actual temperature value of each temperature detection point on the DC bus capacitor of the electric drive controller;

[0046] According to the simulated temperature diagram and the actual temperature values, the capacitance structure of the DC bus capacitor is adjusted.

[0047] The above-mentioned DC bus capacitor electrothermal coupling simulation method, device, equipment and medium obtain the capacitance loss value of the simulated DC bus capacitor in the electric drive controller simulation circuit; the computer equipment uses the capacitance loss value as the simulation condition of the DC bus capacitor simulation sub-model in the electric drive controller simulation model, runs the electric drive controller simulation model, and obtains the simulation temperature graph of the DC bus capacitor simulation sub-model; obtains the real temperature value of each temperature detection point on the DC bus capacitor of the electric drive controller; adjusts the capacitance structure of the DC bus capacitor according to the simulation temperature graph and each real temperature value. The present application simulates and runs the DC bus capacitor sub-model in the electric drive controller model, improves the accuracy of the simulation, and the accuracy of the simulation temperature graph, and then more accurately adjusts the capacitance structure of the DC bus capacitor according to the simulation temperature graph and each real temperature value. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0049] FIG1 is an application environment diagram of a DC bus capacitor electrothermal coupling simulation method provided by this embodiment;

[0050] FIG2 is a schematic flow chart of a first DC bus capacitor electrothermal coupling simulation method provided by this embodiment;

[0051] FIG3 is a schematic diagram of an electric drive controller simulation circuit provided by this embodiment;

[0052] FIG4 is a schematic diagram of an electric drive controller simulation model provided by this embodiment;

[0053] FIG5 is a schematic diagram of a DC bus capacitor simulation sub-model provided by this embodiment;

[0054] FIG6A is a first simulation temperature diagram provided by this embodiment;

[0055] Figure 6B A second simulation temperature diagram provided for this embodiment;

[0056] FIG7 is a schematic diagram of a ripple current and a ripple voltage provided by this embodiment;

[0057] FIG8 is a schematic diagram of module loss provided by this embodiment;

[0058] FIG9 is a structural block diagram of a DC bus capacitor electrothermal coupling simulation device provided in this embodiment;

[0059] FIG. 10 is a diagram showing the internal structure of a computer device provided in this embodiment. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0061] The DC bus capacitor electrothermal coupling simulation method provided in the embodiment of the present application can be applied to the application environment shown in FIG1. ​​Among them, the terminal 102 communicates with the server 104 through the network. The data storage system can store the data that the server 104 needs to process. The data storage system can be integrated on the server 104, or it can be placed on the cloud or other network servers. The computer device obtains the capacitance loss value of the simulated DC bus capacitor in the electric drive controller simulation circuit; the computer device obtains the built electric drive controller performance simulation model, and uses the capacitance loss value as the simulation condition of the DC bus capacitor simulation sub-model in the electric drive controller simulation model, runs the electric drive controller simulation model, and obtains the simulation temperature map of the DC bus capacitor simulation sub-model; obtains the real temperature value of each temperature detection point on the DC bus capacitor of the electric drive controller; according to the simulation temperature map and each real temperature value, adjusts the capacitance structure of the DC bus capacitor. Among them, the computer device can be either a terminal or a server. The terminal 102 can be, but is not limited to, various personal computers, laptops, smart phones, tablet computers, Internet of Things devices and portable wearable devices, and the Internet of Things devices can be smart speakers, smart TVs, smart air conditioners, smart car-mounted devices, etc. The portable wearable device may be a smart watch, a smart bracelet, a head-mounted device, etc. The server 104 may be implemented as an independent server or a server cluster consisting of multiple servers.

[0062] In an exemplary embodiment, as shown in FIG2 , a DC bus capacitor electrothermal coupling simulation method is provided, which is described by taking the method applied to the computer device in FIG1 as an example, and includes the following steps 201 to 204. Among them:

[0063] Step 201, obtaining a capacitance loss value of a simulated DC bus capacitor in a simulation circuit of an electric drive controller.

[0064] Among them, the electric drive controller simulation circuit can be a one-dimensional simulation circuit built according to the working principle of the electric drive controller. The power module in the electric drive controller simulation circuit builds a model according to the data manual provided by the module manufacturer, which includes a loss and current relationship curve. The module loss under the simulation condition can be directly obtained through circuit simulation. Exemplarily, as shown in the schematic diagram of the electric drive controller simulation circuit in Figure 3, the electric drive controller simulation circuit includes simulation components such as power supply, DC bus capacitor, power module, cable equivalent inductance, speed-torque load, etc. In the figure, Vdc represents the power supply voltage; L represents the cable equivalent inductance; C represents the capacitance value of the DC bus capacitor; idc represents the DC bus current; iac represents the current transmitted between the power module and the bus capacitor; iripple represents the ripple current of the DC bus capacitor; ia represents the phase current of motor phase A; ib represents the phase current of motor phase B; ic represents the phase current of motor phase C.

[0065] Specifically, the computer device runs the electric drive controller simulation circuit to obtain the capacitance loss value of the simulated DC bus capacitor in the electric drive controller simulation circuit.

[0066] It should be noted that in the process of thermal simulation through the electric drive controller performance simulation model, the added current effective value, capacitor loss value, and power loss value are all obtained through the electric drive controller simulation circuit, so the performance simulation result of the electric drive controller simulation circuit has a great influence on the thermal simulation result. According to the measured motor phase current, capacitor ripple voltage, DC bus current, inverter loss and other results, adjust the circuit parameters in the electric drive controller simulation circuit diagram shown in Figure 3, such as motor phase resistance, inductance, cable inductance, bus voltage, drive circuit switch resistance and other related circuit parameters, until the circuit simulation results are consistent with the actual measurement, ensure that the current effective value, capacitor loss value, and power loss value are consistent with the actual value, so as to ensure the accuracy of the input of the electric drive controller performance simulation model.

[0067] Step 202, obtain the constructed electric drive controller performance simulation model, and use the capacitor loss value as the simulation condition of the DC bus capacitor simulation sub-model in the electric drive controller simulation model, run the electric drive controller simulation model, and obtain a simulation temperature diagram of the DC bus capacitor simulation sub-model.

[0068] Among them, the electric drive controller simulation model can be built based on the three-dimensional structure of the electric drive controller, simplifying the structural features that are not related to the thermal performance of the capacitor, deleting the holes, fillets, reinforcement ribs and other structures on the electric drive controller housing that do not affect the heat dissipation, and reducing the complexity of the electric drive controller simulation model by simplifying the structure of the electric drive controller. Exemplarily, as shown in FIG4, the electric drive controller simulation model includes sub-models such as the top cover, PCB board, chip, power module, AC busbar, DC bus capacitor, inverter box, cooling water channel and cooling water inlet. The electric drive controller simulation model adopts the space vector pulse width modulation (SVPWM) control strategy, and the power supply can simulate the charging and discharging process. Input a given speed-torque condition, and output performance simulation results such as voltage, current, power module loss, and motor power. Through performance simulation, the effective value of the bus capacitor ripple current, power module loss, and circuit current under specific conditions are obtained.

[0069] Among them, the DC bus capacitor simulation sub-model can be built based on the three-dimensional structure of the DC bus capacitor, simplifying the structural features in the DC bus capacitor that are not related to the thermal performance of the capacitor. Since the DC bus capacitor is composed of positive and negative copper bars, a winding core, a potting compound, and a plastic shell, the ripple current is absorbed by the core, causing the core to heat up. Therefore, the constructed DC bus capacitor simulation sub-model can be shown as a schematic diagram of the DC bus capacitor simulation sub-model in Figure 5, and the DC bus capacitor simulation sub-model includes components such as positive and negative copper bars, a capacitor core, a potting compound, and a shell.

[0070] Among them, the simulation temperature diagram represents the temperature distribution on the DC bus capacitor sub-model.

[0071] Specifically, the constructed electric drive controller performance simulation model is obtained, and the obtained capacitance loss value is input into the simulation software and set as the simulation condition of the DC bus capacitor simulation sub-model. At the same time, different working conditions are set, and the operation of the electric drive controller simulation model under different working conditions is simulated in the simulation software to obtain the simulation results of the DC bus capacitor simulation sub-model under the corresponding working conditions, and the simulation temperature diagram of the DC bus capacitor under the corresponding working conditions is determined according to each simulation result.

[0072] It should be noted that, for example, FIG. 6A and Figure 6B The simulated temperature diagram provided for this embodiment. "(1)" in FIG. 6A represents the simulated temperature diagram of the surface of the DC bus capacitor sub-model; "(2)" in FIG. 6A represents the simulated temperature diagram of the surface of the capacitor core sub-component of the DC bus capacitor sub-model; Figure 6B “(1)” in FIG. 1 represents the simulated temperature diagram of the top mounting surface of the DC bus capacitor sub-model; Figure 6B “(2)” in FIG. 1 represents the simulated temperature diagram of the side mounting surface of the DC bus capacitor sub-model.

[0073] Step 203, obtaining the real temperature value of each temperature detection point on the DC bus capacitor of the electric drive controller.

[0074] Among them, the temperature detection point can be the position on the DC bus capacitor that is prone to serious heat generation. According to the heating mechanism of the capacitor, the main factors affecting the thermal performance of the capacitor include: the temperature of the connection position between the capacitor and the high-voltage input connector, the temperature of the copper bar connecting the capacitor and the power module, the external ambient temperature of the capacitor, and the cooling temperature of the bottom mounting surface of the capacitor. Therefore, the temperature detection points can include the bottom mounting surface, capacitor core, capacitor counterpart (such as power module), external copper bar, capacitor shell and other locations that feedback the temperature rise of the capacitor.

[0075] Optionally, the temperature detection point can be determined by, for each operating environment, determining whether the operating environment corresponding to the simulated temperature map belongs to a severe operating condition based on the simulated temperature map; selecting a severe operating condition as a thermal test operating condition for the electric drive controller; and selecting a location with a higher temperature in the simulated temperature map based on the simulated temperature map corresponding to the severe operating condition as a temperature detection point on the DC bus capacitor of the electric drive controller. The temperature in the simulated temperature map represents the severity of the internal heating of the DC bus capacitor.

[0076] Exemplarily, based on the simulated temperature graph, determining whether the operating environment corresponding to the simulated temperature graph belongs to a harsh operating condition includes: for the simulated temperature graph under each operating environment, determining the average simulated temperature value of the simulated temperature graph; if the average simulated temperature value is greater than a preset temperature threshold, determining that the operating environment corresponding to the simulated temperature graph belongs to a harsh operating condition; if the average simulated temperature value is not greater than the preset temperature threshold, determining that the operating environment corresponding to the simulated temperature graph does not belong to a harsh operating condition.

[0077] Specifically, an electric drive controller is prefabricated as a sample, and a temperature sensor is installed at each temperature detection point on the DC bus capacitor of the electric drive controller. The computer device obtains the real temperature value of each temperature detection point through the temperature sensor.

[0078] Step 204: adjusting the capacitance structure of the DC bus capacitor according to the simulated temperature map and the actual temperature values.

[0079] Specifically, for the simulated temperature diagram under the same working conditions and the actual temperature values ​​detected at each temperature detection point, the simulated temperature value of each temperature detection point is determined in the simulated temperature diagram; for the simulated temperature value and the actual temperature value of the same temperature detection point under the same working conditions, the capacitance structure of the DC bus capacitor is adjusted.

[0080] It should be noted that the capacitor structure of the DC bus capacitor may include adjusting the copper bar area, copper bar thickness, copper bar shape, capacitor core arrangement, and DC bus capacitor external structure.

[0081] The above-mentioned DC bus capacitor electrothermal coupling simulation method obtains the capacitance loss value of the simulated DC bus capacitor in the electric drive controller simulation circuit; obtains the constructed electric drive controller performance simulation model, and uses the capacitance loss value as the simulation condition of the DC bus capacitor simulation sub-model in the electric drive controller simulation model, runs the electric drive controller simulation model, and obtains the simulation temperature graph of the DC bus capacitor simulation sub-model; obtains the real temperature value of each temperature detection point on the DC bus capacitor of the electric drive controller; adjusts the capacitance structure of the DC bus capacitor according to the simulation temperature graph and each real temperature value. The present application simulates and runs the DC bus capacitor sub-model in the electric drive controller model, improves the accuracy of the simulation, and the accuracy of the simulation temperature graph, and then more accurately adjusts the capacitance structure of the DC bus capacitor according to the simulation temperature graph and each real temperature value.

[0082] In some embodiments, obtaining the capacitance loss value of the simulated DC bus capacitor in the electric drive controller simulation circuit includes: obtaining the effective value of the current of the simulated DC bus capacitor in the electric drive controller simulation circuit; and determining the capacitance loss value of the simulated DC bus capacitor in the electric drive controller simulation circuit based on the effective value of the current and a preset capacitor core equivalent resistance.

[0083] The simulated DC bus capacitor includes a capacitor core. The preset equivalent resistance of the capacitor core can be obtained through testing or capacitor specification.

[0084] Specifically, the ripple current value and ripple voltage value of the simulated DC bus capacitor in the electric drive controller simulation circuit are obtained; the effective current value of the simulated DC bus capacitor is determined based on the ripple current value and the ripple voltage value; based on the effective current value and the preset capacitor core equivalent resistance, the capacitance loss value of the simulated DC bus capacitor in the electric drive controller simulation circuit is determined by the following formula (1-1).

[0085] (1-1)

[0086] Among them, P loss is the capacitance loss value, is the effective value of current, and ESR is the equivalent resistance of the capacitor core, which can be obtained through testing or capacitor specification sheets.

[0087] It should be noted that, as shown in the schematic diagram of ripple current and ripple voltage in Figure 7, the green ripple in the figure represents the ripple voltage value at each time, the horizontal axis represents time, and the vertical axis represents the ripple voltage value; the blue ripple in the figure represents the ripple current value at each time, the horizontal axis represents time, and the vertical axis represents the ripple current value.

[0088] In this embodiment, the capacitance loss value of the simulated DC bus capacitor in the electric drive controller simulation circuit can be determined more accurately according to the effective value of the current and the preset equivalent resistance of the capacitor core.

[0089] In some embodiments, the capacitor loss value is used as a simulation condition of the DC bus capacitor simulation sub-model in the electric drive controller simulation model, the electric drive controller simulation model is run, and a simulation temperature graph of the DC bus capacitor simulation sub-model is obtained, including: obtaining a power loss value of a simulated power component in the electric drive controller simulation circuit; using the capacitor loss value as a simulation condition of the DC bus capacitor simulation sub-model in the electric drive controller simulation model, and using the power loss value as a simulation condition of the power component sub-model in the electric drive controller simulation model, running the electric drive controller simulation model, and obtaining a simulation temperature graph of the DC bus capacitor simulation sub-model.

[0090] Specifically, the computer device obtains a module loss diagram of a simulated power component in an electric drive controller simulation circuit; determines a power loss value based on the module loss diagram; uses the capacitor loss value as a simulation condition for a DC bus capacitor simulation sub-model in the electric drive controller simulation model, and uses the power loss value as a simulation condition for a power component sub-model in the electric drive controller simulation model, runs the electric drive controller simulation model, and obtains a simulation temperature diagram of the DC bus capacitor simulation sub-model.

[0091] Optionally, according to the module loss graph, an optional implementation method for determining the power loss value may be to directly use the loss value at each time in the module loss graph as the power loss value at the corresponding time; or, according to the module loss graph, determine the average value of the module loss at each time in the module loss graph, and use the average value as the power loss value. It should be noted that the module loss graph may be a module loss schematic diagram as shown in FIG8 , in which the horizontal axis of the module loss schematic diagram represents time, and the vertical axis represents module loss.

[0092] In some embodiments, the capacitor loss value is used as a simulation condition for a DC bus capacitor simulation sub-model in an electric drive controller simulation model, and the power loss value is used as a simulation condition for a power component sub-model in the electric drive controller simulation model, and the electric drive controller simulation model is run to obtain a simulation temperature graph of the DC bus capacitor simulation sub-model, including: obtaining a circuit current value of the electric drive controller simulation circuit; determining a chip loss value of a chip sub-model in the electric drive controller simulation model based on the circuit current value; using the capacitor loss value as a simulation condition for the DC bus capacitor simulation sub-model in the electric drive controller simulation model, using the power loss value as a simulation condition for the power component sub-model in the electric drive controller simulation model, and using the chip loss value as a simulation condition for the chip sub-model in the electric drive controller simulation model, and running the electric drive controller simulation model to obtain a simulation temperature graph of the DC bus capacitor simulation sub-model.

[0093] It should be noted that since the electric drive controller contains many copper busbar structures, the heat generated by the copper busbar has a great influence on the temperature distribution in the controller. Therefore, in this embodiment, structures such as the AC busbar, DC busbar, capacitor positive and negative busbars, and power module copper busbar can be imported into the electric field analysis simulation software (such as HFSS), and the effective value of the current obtained by the electric drive controller simulation circuit can be added at the same time; the ohmic loss on the copper busbar and the electric field distribution simulation results can be obtained through the electric field analysis simulation software.

[0094] It should be noted that, in order to make the determined simulation temperature map more accurate, in order to realize thermal coupling simulation, the simulation conditions set in this embodiment may include, but are not limited to: the external environment temperature and heat source conditions of the electric drive controller simulation model; the temperature and flow rate of the coolant inlet sub-model; the power loss value of the power component sub-model; the capacitance loss value of the DC bus capacitor; the chip loss value and copper loss value of the chip sub-model (PCB board); the electric field distribution simulation results, etc. At the same time, this implementation also needs to complete the simulation pre-processing work such as material setting, meshing, and solution condition setting of the electric drive controller simulation model.

[0095] In this embodiment, a more accurate simulation temperature graph can be obtained by setting a variety of simulation conditions and running the electric drive controller simulation model under each simulation condition.

[0096] In some embodiments, the capacitor structure of the DC bus capacitor is adjusted according to the simulated temperature map and each real temperature value, including: determining the simulated temperature value of the DC bus capacitor simulation sub-model at each temperature detection point according to the simulated temperature map; for each temperature detection point, adjusting the capacitor structure of the DC bus capacitor according to the real temperature value and the simulated temperature value at the temperature detection point.

[0097] Specifically, according to the simulation temperature graph, the simulation temperature value of the DC bus capacitor simulation sub-model at each temperature detection point is obtained from the simulation temperature graph; according to the real temperature value and the simulation temperature value under the same working condition and the same temperature detection point, the capacitance structure of the DC bus capacitor is adjusted.

[0098] In some embodiments, for each temperature detection point, the capacitance structure of the DC bus capacitor is adjusted according to the actual temperature value and the simulated temperature value at the temperature detection point, including: determining the simulation error value of the electric drive controller simulation model according to the actual temperature value and the simulated temperature value corresponding to each temperature detection point; when the simulation error value meets a preset error threshold, adjusting the capacitance structure of the DC bus capacitor according to the simulation temperature graph of the electric drive controller simulation model.

[0099] Specifically, the simulation error value of the electric drive controller simulation model is determined according to the actual temperature value and the simulated temperature value corresponding to each temperature detection point; if the simulation error value is greater than the preset error threshold, it is determined that the error of the electric drive controller simulation model is large, therefore, the parameter setting of the electric drive controller simulation model is adjusted; if the simulation error value is less than the preset error threshold, it is determined that the error of the electric drive controller simulation model is small and the accuracy is high, therefore, it can be determined whether the thermal performance of the DC bus capacitor meets the thermal performance requirements based on the simulation temperature diagram of the electric drive controller simulation model; when the thermal performance does not meet the thermal performance requirements, the capacitance structure of the DC bus capacitor is adjusted.

[0100] Exemplarily, the method of adjusting the parameter setting of the electric drive controller simulation model may include: adjusting the input condition parameters of the electric drive controller simulation model, such as the effective value of the current input to the electric drive controller simulation model, the capacitance loss value, the power loss value, etc.; adjusting the environmental condition parameters in the thermal simulation process performed by the electric drive controller simulation model, such as the measured inverter ambient temperature and cooling water temperature, which deviate from the environmental condition parameters set in the thermal simulation process, directly affecting the external ambient temperature of the capacitor and the cooling temperature of the bottom mounting surface of the capacitor. Therefore, the measured inverter ambient temperature and cooling water temperature may be re-input into the thermal simulation model to complete the optimization; adjusting the model structure of the electric drive controller simulation model, such as adjusting the contact resistance. Since there is contact resistance at the overlap position of the copper busbar, if there is a deviation in the contact resistance setting, the simulation temperature will also deviate (for example, if the contact resistance is too large, the simulation temperature will be too high; if the contact resistance is too small, the simulation temperature will be too low). Therefore, the simulated copper busbar temperature in the electric drive controller simulation model should be compared with the measured copper busbar temperature, and the contact resistance should be adjusted accordingly.

[0101] Exemplary methods of adjusting the capacitor structure of the DC bus capacitor may include: if the simulated temperature of the temperature detection point corresponding to the external copper busbar in the simulated temperature diagram is abnormal, such as the temperature of the external copper busbar is too high, the copper busbar may be widened and thickened to reduce the current density and reduce the heat generation of the copper busbar; if the simulated temperature of the temperature detection point corresponding to the capacitor core in the simulated temperature diagram is abnormal, such as the temperature of the capacitor core is too high, the ripple current may be reduced to reduce the core loss and thus reduce the heat generation; if the simulated temperature of the temperature detection point corresponding to the capacitor counterpart in the simulated temperature diagram is abnormal, such as the temperature of the power module is too high, the power module design may be optimized to reduce the temperature of the connection position between the power module and the DC bus capacitor.

[0102] This embodiment can make the capacitance temperature prediction of the DC bus capacitor more accurate based on the constructed more accurate electric drive controller simulation model; according to the simulation temperature diagram, the number of thermal test operating points is reduced, and the capacitance structure of the DC bus capacitor is adjusted, so there is no need to manufacture a DC bus capacitor prototype for testing, thereby reducing development costs and shortening the development cycle.

[0103] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0104] Based on the same inventive concept, the embodiment of the present application also provides a DC bus capacitor electrothermal coupling simulation device for implementing the DC bus capacitor electrothermal coupling simulation method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more DC bus capacitor electrothermal coupling simulation device embodiments provided below can refer to the limitations of the DC bus capacitor electrothermal coupling simulation method above, and will not be repeated here.

[0105] In an exemplary embodiment, as shown in FIG9 , a DC bus capacitor electrothermal coupling simulation device is provided, comprising: a loss determination module 10, a simulation determination module 11, a real determination module 12 and a structure adjustment module 13, wherein:

[0106] The loss determination module 10 is used to obtain the capacitance loss value of the simulated DC bus capacitor in the electric drive controller simulation circuit;

[0107] The simulation determination module 11 is used to obtain the constructed electric drive controller performance simulation model, and use the capacitance loss value as the simulation condition of the DC bus capacitor simulation sub-model in the electric drive controller simulation model, run the electric drive controller simulation model, and obtain the simulation temperature diagram of the DC bus capacitor simulation sub-model;

[0108] A true determination module 12 is used to obtain the true temperature value of each temperature detection point on the DC bus capacitor of the electric drive controller;

[0109] The structure adjustment module 13 is used to adjust the capacitance structure of the DC bus capacitor according to the simulated temperature map and the actual temperature values.

[0110] In one embodiment, the loss determination module 10 in Figure 9 is also used to obtain the effective value of the current of the simulated DC bus capacitor in the electric drive controller simulation circuit; determine the capacitance loss value of the simulated DC bus capacitor in the electric drive controller simulation circuit based on the effective value of the current and the preset capacitor core equivalent resistance; wherein the simulated DC bus capacitor includes a capacitor core.

[0111] In one embodiment, the simulation determination module 11 in Figure 9 is also used to obtain the power loss value of the simulated power component in the electric drive controller simulation circuit; use the capacitor loss value as the simulation condition of the DC bus capacitor simulation sub-model in the electric drive controller simulation model, and use the power loss value as the simulation condition of the power component sub-model in the electric drive controller simulation model, run the electric drive controller simulation model, and obtain the simulation temperature diagram of the DC bus capacitor simulation sub-model.

[0112] In one embodiment, the simulation determination module 11 in Figure 9 is also used to obtain the circuit current value of the electric drive controller simulation circuit; determine the chip loss value of the chip sub-model in the electric drive controller simulation model according to the circuit current value; use the capacitor loss value as the simulation condition of the DC bus capacitor simulation sub-model in the electric drive controller simulation model, use the power loss value as the simulation condition of the power component sub-model in the electric drive controller simulation model, and use the chip loss value as the simulation condition of the chip sub-model in the electric drive controller simulation model, run the electric drive controller simulation model, and obtain a simulation temperature diagram of the DC bus capacitor simulation sub-model.

[0113] In one embodiment, the structure adjustment module 13 in Figure 9 is also used to determine the simulated temperature value of the DC bus capacitor simulation sub-model at each temperature detection point based on the simulated temperature graph; for each temperature detection point, the capacitor structure of the DC bus capacitor is adjusted according to the actual temperature value and the simulated temperature value at the temperature detection point.

[0114] In one embodiment, the structure adjustment module 13 in Figure 9 is also used to determine the simulation error value of the electric drive controller simulation model based on the actual temperature value and the simulated temperature value corresponding to each temperature detection point; when the simulation error value meets the preset error threshold, the capacitor structure of the DC bus capacitor is adjusted according to the simulation temperature diagram of the electric drive controller simulation model.

[0115] Each module in the above DC bus capacitor electrothermal coupling simulation device can be implemented in whole or in part by software, hardware and their combination. Each module can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory in the computer device in the form of software, so that the processor can call and execute the corresponding operations of each module.

[0116] In an exemplary embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be shown in FIG10. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. The processor, the memory and the input / output interface are connected via a system bus, and the communication interface is connected to the system bus via the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a DC bus capacitor electrothermal coupling simulation method is implemented.

[0117] Those skilled in the art will understand that the structure shown in FIG. 10 is merely a block diagram of a partial structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different arrangement of components.

[0118] In one embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above method embodiments when executing the computer program.

[0119] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0120] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0121] It should be noted that the data involved in this application (including but not limited to data used for analysis, stored data, displayed data, etc.) are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0122] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0123] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0124] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A DC bus capacitor electrothermal coupling simulation method, characterized in that: The method comprises: Obtaining the capacitance loss value of the simulated DC bus capacitor in the electric drive controller simulation circuit; Acquire the constructed electric drive controller performance simulation model, and use the capacitance loss value as a simulation condition of a DC bus capacitance simulation sub-model in the electric drive controller simulation model, run the electric drive controller simulation model, and obtain a simulation temperature graph of the DC bus capacitance simulation sub-model; Obtain the actual temperature value of each temperature detection point on the DC bus capacitor of the electric drive controller; According to the simulated temperature graph and the actual temperature values, the capacitance structure of the DC bus capacitor is adjusted.

2. The method according to claim 1, characterized in that The obtaining of the capacitance loss value of the simulated DC bus capacitance in the electric drive controller simulation circuit includes: Obtain the effective value of the current of the simulated DC bus capacitor in the electric drive controller simulation circuit; The capacitance loss value of the simulated DC bus capacitor in the electric drive controller simulation circuit is determined according to the effective value of the current and the preset equivalent resistance of the capacitor core; wherein the simulated DC bus capacitor includes the capacitor core.

3. The method according to claim 1, characterized in that The method of using the capacitance loss value as a simulation condition of a DC bus capacitance simulation sub-model in an electric drive controller simulation model, running the electric drive controller simulation model, and obtaining a simulation temperature graph of the DC bus capacitance simulation sub-model includes: Obtaining the power loss value of the simulated power component in the electric drive controller simulation circuit; The capacitance loss value is used as a simulation condition of a DC bus capacitance simulation sub-model in an electric drive controller simulation model, and the power loss value is used as a simulation condition of a power component sub-model in an electric drive controller simulation model. The electric drive controller simulation model is run to obtain a simulation temperature diagram of the DC bus capacitance simulation sub-model.

4. The method according to claim 3, characterized in that The method of using the capacitance loss value as a simulation condition of a DC bus capacitance simulation sub-model in an electric drive controller simulation model, and using the power loss value as a simulation condition of a power component sub-model in the electric drive controller simulation model, running the electric drive controller simulation model, and obtaining a simulation temperature graph of the DC bus capacitance simulation sub-model includes: Obtaining the circuit current value of the electric drive controller simulation circuit; Determining a chip loss value of a chip sub-model in the electric drive controller simulation model according to the circuit current value; The capacitor loss value is used as a simulation condition for a DC bus capacitor simulation sub-model in an electric drive controller simulation model, the power loss value is used as a simulation condition for a power component sub-model in an electric drive controller simulation model, and the chip loss value is used as a simulation condition for a chip sub-model in an electric drive controller simulation model. The electric drive controller simulation model is run to obtain a simulation temperature graph of the DC bus capacitor simulation sub-model.

5. The method according to claim 1, characterized in that The adjusting the capacitance structure of the DC bus capacitor according to the simulated temperature map and each of the real temperature values ​​comprises: Determining the simulated temperature value of the DC bus capacitor simulation sub-model at each of the temperature detection points according to the simulated temperature graph; For each temperature detection point, the capacitance structure of the DC bus capacitor is adjusted according to the real temperature value and the simulated temperature value at the temperature detection point.

6. The method according to claim 5, characterized in that The step of adjusting the capacitance structure of the DC bus capacitor according to the real temperature value and the simulated temperature value at each temperature detection point comprises: Determining a simulation error value of the electric drive controller simulation model according to the actual temperature value and the simulated temperature value corresponding to each temperature detection point; When the simulation error value meets a preset error threshold, the capacitance structure of the DC bus capacitor is adjusted according to a simulation temperature diagram of the electric drive controller simulation model.

7. A DC bus capacitor electrothermal coupling simulation device, characterized in that: The device comprises: A loss determination module, used to obtain a capacitance loss value of a simulated DC bus capacitor in a simulation circuit of an electric drive controller; A simulation determination module is used to obtain the constructed electric drive controller performance simulation model, and use the capacitance loss value as a simulation condition of a DC bus capacitor simulation sub-model in the electric drive controller simulation model, run the electric drive controller simulation model, and obtain a simulation temperature diagram of the DC bus capacitor simulation sub-model; A real determination module is used to obtain the real temperature value of each temperature detection point on the DC bus capacitor of the electric drive controller; The structure adjustment module is used to adjust the capacitance structure of the DC bus capacitor according to the simulated temperature map and each of the real temperature values.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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

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