A simulation method, device and equipment based on NVH optimization of an electric drive system

Abstract

This invention discloses a simulation method, apparatus, and device for NVH optimization of electric drive systems, relating to the technical field of vehicles. The simulation method for NVH optimization of electric drive systems includes: constructing an initial efficiency MAP of the electric drive system based on an electromagnetic simulation model and stator / rotor design, and mapping the vehicle's CLTC operating condition to the initial efficiency MAP; determining the nth harmonic current value and its current angle required to suppress the target vth harmonic torque; calculating the additional losses at the corresponding operating point due to the injected harmonic current, and generating an electric drive efficiency MAP after harmonic current injection based on the initial efficiency MAP; and verifying the vehicle's CLTC efficiency based on the electric drive efficiency MAP. If the CLTC efficiency is not met, the stator / rotor design needs to be adjusted, and the above steps are repeated. This method can minimize the need for secondary design of the stator / rotor design, reducing electric drive development costs; it also improves the effectiveness of calibration, significantly reduces the harmonic current calibration time on the prototype bench, and saves the electric drive development cycle.

Description

Technical Field

[0001] This invention belongs to the technical field of vehicles, and specifically relates to a simulation method, apparatus and equipment for NVH optimization based on electric drive systems. Background Technology

[0002] The direct cause of high-frequency noise (whistling) in electric drive systems is the presence of harmonic components related to the switching frequency in the inverter's output current. These harmonic currents interact with the motor's internal magnetic field and structure, generating electromagnetic force waves that excite vibration and noise. By actively "injecting" additional harmonics of a specific order and phase into the command current, a vibration with the same amplitude but opposite phase to the original noise source is created. Through the principle of interference cancellation, the original electromagnetic vibration is canceled out, significantly reducing the noise of the electric drive. However, the additionally injected harmonic current does not generate effective torque but instead generates additional heat (copper and iron losses) in the motor rotor and stator, leading to a decrease in the motor's energy conversion efficiency. In the prototype stage, due to the incomplete integration of the vehicle and the lack of complete cooling conditions, high-voltage battery pack, and vehicle control strategies, it was impossible to conduct standard CLTC (China Light-Duty Vehicle Test Cycle) cycle efficiency tests under real vehicle load and thermal management environments. Only after reaching the B prototype stage or even later can the NVH (Noise, Vibration, and Harshness) optimized electric drive prototype be mounted on a test bench for standard CLTC efficiency testing. Only after passing this test can the vehicle's range be determined. This means that if the test results are unsatisfactory, the NVH optimization work will need to be reworked, requiring a redesign of the harmonic injection strategy or even the motor itself, leading to extended development cycles and increased costs. Summary of the Invention

[0003] The purpose of this invention is to provide a simulation method based on NVH optimization of electric drive system, which can balance calibration workload and NVH performance while ensuring the overall energy consumption of the vehicle, thus achieving the optimal balance between development cycle and product performance.

[0004] The present invention also provides a simulation device based on NVH optimization of electric drive systems.

[0005] The present invention also provides an electronic device.

[0006] The present invention also provides a non-transitory computer-readable storage medium.

[0007] The technical solution adopted to solve the above-mentioned technical problems is as follows: The first aspect of this invention provides a simulation method for NVH optimization of an electric drive system, comprising: Based on the electromagnetic simulation model and stator / rotor design scheme, an initial efficiency MAP of the electric drive system is constructed, and the CLTC operating conditions of the whole vehicle are mapped to the initial efficiency MAP. The initial efficiency MAP includes the input power, output power and loss value at each operating point. Based on the electromagnetic simulation model and the CLTC operating condition of the whole vehicle, the value of the nth harmonic current and its current angle required to suppress the target vth harmonic torque are determined; where v is greater than 0 and n is greater than 0. Based on the nth harmonic current value to be injected and its current angle, calculate the additional loss due to the injected harmonic current at the corresponding operating point, and combine it with the initial efficiency MAP to generate the electric drive efficiency MAP after the harmonic current injection. Based on the electric drive efficiency MAP, the overall vehicle CLTC efficiency is checked. If the CLTC efficiency does not meet the requirements, the stator and rotor design needs to be adjusted and the above steps are repeated.

[0008] According to the simulation method for NVH optimization of electric drive system according to the embodiment of the present invention, the step of "mapping the vehicle CLTC operating point to the initial efficiency MAP" includes dividing the initial efficiency MAP into regions with preset speed step size and torque step size within the effective speed range of harmonic injection, and extracting the CLTC operating point data corresponding to each region.

[0009] According to the simulation method for NVH optimization of electric drive systems according to embodiments of the present invention, the step of "determining the value of the nth harmonic current and its current angle required to suppress the target vth harmonic torque based on the electromagnetic simulation model and the vehicle CLTC operating condition" includes: Electromagnetic simulation was performed based on the electromagnetic simulation model and the stator and rotor scheme design to obtain the vth harmonic torque results at each operating point. The harmonic current formula, which includes the preset nth harmonic current value and current angle, is introduced into the simulation model for parametric scanning simulation. By analyzing the simulation results, the nth harmonic current value and current angle that can effectively optimize the vth harmonic torque were selected.

[0010] According to an embodiment of the present invention, the simulation method for NVH optimization of an electric drive system includes "introducing a harmonic current formula containing a preset nth harmonic current value and current angle into the simulation model and performing parametric scanning simulation" as follows: Add the following formula to the current formula in the electromagnetic simulation model; , n > 0; n≤5; n≤5; n > 5; n > 5; Where IA is the A-phase current of the motor, IB is the B-phase current of the motor, and IC is the C-phase current of the motor. f is the electric frequency of the motor, t is time, degn is the injected nth current angle, and In is the harmonic current value; where In ranges from 1 to 5A; and degn ranges from 0 to 350°.

[0011] According to an embodiment of the present invention, the simulation method for NVH optimization of an electric drive system, "generating an electric drive efficiency MAP after harmonic current injection", includes: The electric drive efficiency MAP after harmonic current injection is calculated using the following formula; ; Where η is the efficiency of the electric drive system; This represents the input power at the corresponding operating point when no harmonics are injected. The output power is the power at the corresponding operating point without harmonic injection; Loss is the additional loss value after the harmonic current is injected.

[0012] A second aspect of the present invention provides a motor design device based on the overall vehicle CLTC efficiency, comprising a control module. The control module is used to construct an initial efficiency MAP of the electric drive system based on an electromagnetic simulation model and stator / rotor design scheme, and to map the overall vehicle CLTC operating conditions to the initial efficiency MAP. The initial efficiency MAP includes the input power, output power, and loss values ​​at each operating point. The control module is also used to determine the value of the nth harmonic current and its current angle required to suppress the target vth harmonic torque based on the electromagnetic simulation model and the vehicle CLTC operating condition; where v is greater than 0 and n is greater than 0. The control module is also used to calculate the additional losses caused by the injected harmonic current at the corresponding operating point based on the value of the nth harmonic current to be injected and its current angle, and to generate the electric drive efficiency MAP after the harmonic current injection by combining the initial efficiency MAP. The control module is also used to check the overall vehicle CLTC efficiency based on the electric drive efficiency MAP. If the CLTC efficiency does not meet the requirements, the stator and rotor design needs to be adjusted and the above steps need to be repeated.

[0013] In some embodiments, the control module is further configured to divide the initial efficiency MAP into regions within the effective speed range of harmonic injection using preset speed step size and torque step size, and extract the CLTC operating point data corresponding to each region.

[0014] In some embodiments, the control module is further configured to perform electromagnetic simulation based on the electromagnetic simulation model and the stator and rotor scheme design, and obtain the vth harmonic torque results at each operating point; The harmonic current formula, which includes the preset nth harmonic current value and current angle, is introduced into the simulation model for parametric scanning simulation. By analyzing the simulation results, the nth harmonic current value and current angle that can effectively optimize the vth harmonic torque were selected.

[0015] A third aspect of the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor, when executing the program, implements a simulation method for NVH optimization of an electric drive system as described in any embodiment of the first aspect.

[0016] A fourth aspect of the present invention provides a non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, when the computer program is executed by a processor, it implements the simulation method based on NVH optimization of an electric drive system as described in any embodiment of the first aspect.

[0017] The present invention has at least the following beneficial effects: In the early design phase of this invention, an efficiency MAP is obtained through electromagnetic simulation. This allows for the determination of losses, input power, and output power at various operating points without injected harmonic current. Then, regions within the efficiency MAP are marked based on the effective speed range for harmonic injection (typically 0-4000 rpm). The simulated torque results at each operating point in these regions are used to determine the corresponding v-th harmonic torque. The MAP of the nth harmonic current value and current angle is confirmed in advance through electromagnetic simulation, thus deriving the losses after harmonic current injection. This allows for the confirmation of the electric drive efficiency MAP after harmonic current injection during the design phase. Further assessment is then conducted to determine whether the electric drive efficiency MAP after harmonic current injection meets the vehicle's CLTC efficiency index, resulting in a design scheme that satisfies both "electric drive efficiency" and "NVH" (Noise, Vibration, and Harshness). This approach, while ensuring the accuracy of the stator and rotor design, minimizes the need for secondary stator and rotor design, reducing electric drive development costs. It also improves the effectiveness of calibration, significantly reducing the harmonic current calibration time on the prototype bench and saving on the electric drive development cycle. This invention effectively improves the selection accuracy of motor controllers, enhances the consistency of motor controller solutions during the selection and delivery stages, and avoids insufficient capability of motor controller solutions, which can easily lead to secondary matching and selection. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments; Figure 1 This is a flowchart illustrating the simulation method for NVH optimization of an electric drive system provided in an embodiment of the present invention. Figure 2 The diagram shows the optimization effect of 6-time torque ripple; Figure 3MAP represents the electric drive efficiency after harmonic current injection. Figure 4 This is a schematic diagram of the motor design device based on the overall vehicle CLTC efficiency provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the electronic device provided in the embodiment of the present invention.

[0019] The following labels are shown in the attached diagram: 101. Control module; 201. Processor; 202. Communication interface; 203. Memory; 204. Communication bus. Detailed Implementation

[0020] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0021] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0022] In the description of this invention, the use of terms such as "a number" means one or more, with "more than" meaning two or more. Terms like "greater than," "less than," and "exceeding" are understood to exclude the stated number, while terms like "above," "below," and "within" are understood to include the stated number. The use of terms like "first," "second," and "third" is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, the number of indicated technical features, or the sequential relationship between indicated technical features.

[0023] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0024] Reference Figures 1 to 4 The following are several embodiments of a simulation method, apparatus and device for NVH optimization of electric drive system according to the present invention.

[0025] like Figure 1 As shown, the first aspect of the present invention provides a simulation method for NVH optimization of an electric drive system, comprising: The first aspect of this invention provides a simulation method for NVH optimization of an electric drive system, comprising: Step S100: Based on the electromagnetic simulation model and stator / rotor design, construct the initial efficiency MAP of the electric drive system, and map the vehicle's CLTC operating conditions to the initial efficiency MAP; the initial efficiency MAP includes the input power, output power, and loss values ​​at each operating point; Modeling was performed using existing stator and rotor designs in electromagnetic simulation software (such as Ansys Maxwell, JMAG, etc.). Efficiency MAP simulation was conducted with a speed step size of 500 rpm and a torque step size of 10 Nm to calculate the initial efficiency MAP of the electric drive. The initial efficiency MAP includes the input power P at each operating point (i.e., each speed and torque combination point). in0 Output power P out0 And the loss value.

[0026] Step S200: Based on the electromagnetic simulation model and the CLTC operating condition of the whole vehicle, determine the value of the nth harmonic current and its current angle required to suppress the target vth harmonic torque; where v is greater than 0 and n is greater than 0. The v-th harmonic torque value at various operating points is obtained through an electromagnetic simulation model. In this embodiment, the v-th harmonic torque can be a specific harmonic that causes electric drive whistling, such as the 6th harmonic torque. To suppress this v-th harmonic torque, a specific n-th harmonic current needs to be injected. According to motor theory, the selection of the n-th harmonic current is related to the v-th harmonic torque; for example, injecting 5th and 7th harmonic currents can effectively suppress the 6th harmonic torque. Figure 2 The diagram shows the optimization effect of the 6th order torque ripple. The green line represents the torque ripple before harmonic current injection, and the red line represents the torque ripple after harmonic current injection. Figure 2 It can be seen that by injecting harmonic current, the torque ripple amplitude of the electric drive system is significantly reduced, the high-frequency excitation force caused by electromagnetic force waves is weakened, thereby fundamentally improving the NVH performance of the electric drive system, reducing the vehicle's howling noise, and improving the smoothness and reliability of the transmission system.

[0027] Step S300: Based on the nth harmonic current value to be injected and its current angle, calculate the additional loss caused by the injected harmonic current at the corresponding operating point, and generate the electric drive efficiency MAP after the harmonic current injection by combining the initial efficiency MAP. The electric drive efficiency MAP after harmonic current injection can be used to confirm the electric drive efficiency MAP after harmonic current injection during the scheme design stage, and further determine whether the electric drive efficiency MAP after harmonic current injection can meet the CLTC efficiency index of the whole vehicle.

[0028] Step S400: Based on the electric drive efficiency MAP, check the overall vehicle CLTC efficiency. If the CLTC efficiency does not meet the requirements, the stator and rotor design needs to be adjusted, and the above steps are repeated.

[0029] In the early design phase of this invention, an efficiency MAP is obtained through electromagnetic simulation. This allows for the determination of losses, input power, and output power at various operating points without injected harmonic current. Then, regions within the efficiency MAP are marked based on the effective speed range for harmonic injection (typically 0-4000 rpm). The simulated torque results at each operating point in these regions are used to determine the corresponding v-th harmonic torque. The MAP of the nth harmonic current value and current angle is confirmed in advance through electromagnetic simulation, thus deriving the losses after harmonic current injection. This allows for the confirmation of the electric drive efficiency MAP after harmonic current injection during the design phase. Further assessment is then conducted to determine whether the electric drive efficiency MAP after harmonic current injection meets the vehicle's CLTC efficiency index, resulting in a design scheme that satisfies both "electric drive efficiency" and "NVH" (Noise, Vibration, and Harshness). This approach, while ensuring the accuracy of the stator and rotor design, minimizes the need for secondary stator and rotor design, reducing electric drive development costs. It also improves the effectiveness of calibration, significantly reducing the harmonic current calibration time on the prototype bench and saving on the electric drive development cycle. This invention effectively improves the selection accuracy of motor controllers, enhances the consistency of motor controller solutions during the selection and delivery stages, and avoids insufficient capability of motor controller solutions, which can easily lead to secondary matching and selection.

[0030] Existing technologies using harmonic injection in electric drives can reduce drive efficiency, potentially leading to secondary design issues in the motor stator and rotor schemes to meet the overall vehicle CLTC efficiency target. This invention addresses this by identifying the v-th order torque simulation results at various operating points during the design phase, simulating the nth order harmonic current and current angle at each point, determining the losses after harmonic current injection, and estimating the drive efficiency MAP (a two-dimensional coordinate system representing the performance distribution of a system or component) after harmonic current injection. This allows for verification of whether the overall vehicle CLTC efficiency is achieved. If not, the stator and rotor design (including stator and rotor structure, materials, magnet materials, winding distribution, etc.) can be quickly adjusted to meet the overall vehicle CLTC efficiency target. Figure 3 MAP represents the electric drive efficiency after harmonic current injection.

[0031] In some embodiments, the step of “mapping the vehicle CLTC operating point to the initial efficiency MAP” includes dividing the initial efficiency MAP into regions within the effective speed range of harmonic injection using preset speed step size and torque step size, and extracting the CLTC operating point data corresponding to each region.

[0032] For example, the CLTC operating point of the whole vehicle is inserted into the electric drive efficiency MAP. Taking the effective speed of harmonic injection at 4000rpm as an example, the marked areas are divided into 500rpm and 10Nm, so that the operating points of different areas can be differentiated in the future.

[0033] In some embodiments, the step of "determining the value of the nth harmonic current and its current angle required to suppress the target vth harmonic torque based on the electromagnetic simulation model and the vehicle CLTC operating condition" includes: Electromagnetic simulation was performed based on the electromagnetic simulation model and the stator and rotor scheme design to obtain the vth harmonic torque results at each operating point. The harmonic current formula, which includes the preset nth harmonic current value and current angle, is introduced into the simulation model for parametric scanning simulation. By analyzing the simulation results, the nth harmonic current value and current angle that can effectively optimize the vth harmonic torque were selected.

[0034] In other words, through electromagnetic simulation, the injected harmonic current is obtained during the design phase to optimize noise under different operating conditions. The harmonic current formula, with preset nth harmonic current values ​​and current angles, is introduced into the simulation model to obtain the nth harmonic current value and current angle that can effectively optimize the vth harmonic torque. This setup clearly identifies the key optimization areas within the effective speed range of harmonic injection, avoiding over-simulation of non-critical operating points and improving simulation efficiency. It also balances calibration workload and NVH performance while ensuring overall vehicle energy consumption, achieving an optimal balance between development cycle and product performance.

[0035] In some embodiments, "introducing the harmonic current formula, which includes a preset nth harmonic current value and current angle, into the simulation model for parametric scanning simulation" includes: Add the following formula to the current formula in the electromagnetic simulation model; , n > 0; n≤5; n≤5; n > 5; n > 5; Where IA is the A-phase current of the motor, IB is the B-phase current of the motor, and IC is the C-phase current of the motor. f is the electric frequency of the motor, t is time, degn is the injected nth current angle, and In is the harmonic current value; where In ranges from 1 to 5A; and degn ranges from 0 to 350°.

[0036] The above formula ensures that the injected harmonic current is a balanced three-phase system, avoiding invalid simulations and facilitating the subsequent selection of the nth harmonic current value and current angle that can effectively optimize the vth harmonic torque. degn is the injected nth current angle, i.e., the initial phase angle of the injected nth harmonic current. When n is 5, the following holds: ; ; .

[0037] When n is 7, the following conditions are met: ; ; .

[0038] In some embodiments, "generating the electric drive efficiency MAP after harmonic current injection" includes: The electric drive efficiency MAP after harmonic current injection is calculated using the following formula; ; Where η is the efficiency of the electric drive system; This represents the input power at the corresponding operating point when no harmonics are injected. The output power is the power at the corresponding operating point without harmonic injection; Loss is the additional loss value after the harmonic current is injected.

[0039] Based on the above embodiments, the electric drive efficiency MAP after harmonic current injection can be accurately calculated, which is beneficial for subsequent verification of the vehicle's CLTC efficiency.

[0040] Figure 4 This is a schematic diagram of the motor design device based on the overall vehicle CLTC efficiency provided in an embodiment of the present invention; as shown. Figure 4 As shown, a second aspect embodiment of the present invention provides a motor design device based on the overall vehicle CLTC efficiency, including a control module 101. The control module 101 is used to construct an initial efficiency MAP of the electric drive system based on an electromagnetic simulation model and stator and rotor scheme design, and to map the overall vehicle CLTC operating conditions to the initial efficiency MAP. The initial efficiency MAP includes the input power, output power and loss value at each operating point. The control module 101 is also used to determine the value of the nth harmonic current and its current angle required to suppress the target vth harmonic torque based on the electromagnetic simulation model and the vehicle CLTC operating condition; where v is greater than 0 and n is greater than 0. The control module 101 is also used to calculate the additional losses caused by the injected harmonic current at the corresponding operating point based on the value of the nth harmonic current to be injected and its current angle, and to generate the electric drive efficiency MAP after the harmonic current injection by combining the initial efficiency MAP. The control module 101 is also used to check the overall vehicle CLTC efficiency based on the electric drive efficiency MAP. If the CLTC efficiency does not meet the requirements, the stator and rotor design needs to be adjusted and the above steps need to be repeated.

[0041] In some embodiments, the control module 101 is further configured to divide the initial efficiency MAP into regions within the effective speed range of harmonic injection using preset speed step size and torque step size, and extract the CLTC operating point data corresponding to each region.

[0042] In some embodiments, the control module 101 is further configured to perform electromagnetic simulation based on the electromagnetic simulation model and the stator and rotor scheme design, and obtain the vth harmonic torque results at each operating point. The harmonic current formula, which includes the preset nth harmonic current value and current angle, is introduced into the simulation model for parametric scanning simulation. By analyzing the simulation results, the nth harmonic current value and current angle that can effectively optimize the vth harmonic torque were selected.

[0043] Figure 5 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 5 As shown, the electronic device may include: a processor 201, a communication interface 202, a memory 203, and a communication bus 204. The processor 201, communication interface 202, and memory 203 communicate with each other via the communication bus 204. The processor 201 can call logical instructions from the memory 203 to execute a simulation method based on NVH optimization of the electric drive system. This method includes: Based on the electromagnetic simulation model and stator / rotor design scheme, an initial efficiency MAP of the electric drive system is constructed, and the CLTC operating conditions of the whole vehicle are mapped to the initial efficiency MAP. The initial efficiency MAP includes the input power, output power and loss value at each operating point. Based on the electromagnetic simulation model and the CLTC operating condition of the whole vehicle, the value of the nth harmonic current and its current angle required to suppress the target vth harmonic torque are determined; where v is greater than 0 and n is greater than 0. Based on the nth harmonic current value to be injected and its current angle, calculate the additional loss due to the injected harmonic current at the corresponding operating point, and combine it with the initial efficiency MAP to generate the electric drive efficiency MAP after the harmonic current injection. Based on the electric drive efficiency MAP, the overall vehicle CLTC efficiency is checked. If the CLTC efficiency does not meet the requirements, the stator and rotor design needs to be adjusted and the above steps are repeated.

[0044] Furthermore, the logical instructions in the aforementioned memory 203 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes: a USB flash drive, a portable hard drive, and a read-only memory (ROM). Various media that can store program code, such as only memory, random access memory (RAM), magnetic disks or optical disks.

[0045] On the other hand, this application also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, is implemented to perform the simulation method based on NVH optimization of electric drive systems provided by the above methods, the method comprising: Based on the electromagnetic simulation model and stator / rotor design scheme, an initial efficiency MAP of the electric drive system is constructed, and the CLTC operating conditions of the whole vehicle are mapped to the initial efficiency MAP. The initial efficiency MAP includes the input power, output power and loss value at each operating point. Based on the electromagnetic simulation model and the CLTC operating condition of the whole vehicle, the value of the nth harmonic current and its current angle required to suppress the target vth harmonic torque are determined; where v is greater than 0 and n is greater than 0. Based on the nth harmonic current value to be injected and its current angle, calculate the additional loss due to the injected harmonic current at the corresponding operating point, and combine it with the initial efficiency MAP to generate the electric drive efficiency MAP after the harmonic current injection. Based on the electric drive efficiency MAP, the overall vehicle CLTC efficiency is checked. If the CLTC efficiency does not meet the requirements, the stator and rotor design needs to be adjusted and the above steps are repeated.

[0046] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0047] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A simulation method for NVH optimization of electric drive systems, characterized in that, The method includes: Based on the electromagnetic simulation model and stator / rotor design scheme, an initial efficiency MAP of the electric drive system is constructed, and the CLTC operating conditions of the whole vehicle are mapped to the initial efficiency MAP. The initial efficiency MAP includes the input power, output power and loss value at each operating point. Based on the electromagnetic simulation model and the CLTC operating condition of the whole vehicle, the value of the nth harmonic current and its current angle required to suppress the target vth harmonic torque are determined; where v is greater than 0 and n is greater than 0. Based on the nth harmonic current value to be injected and its current angle, calculate the additional loss due to the injected harmonic current at the corresponding operating point, and combine it with the initial efficiency MAP to generate the electric drive efficiency MAP after the harmonic current injection. Based on the electric drive efficiency MAP, the overall vehicle CLTC efficiency is checked. If the CLTC efficiency does not meet the requirements, the stator and rotor design needs to be adjusted and the above steps are repeated.

2. The simulation method for NVH optimization of electric drive systems according to claim 1, characterized in that, The phrase "mapping the vehicle's CLTC operating points to the initial efficiency MAP" includes dividing the initial efficiency MAP into regions within the effective speed range of harmonic injection using preset speed and torque step sizes, and extracting the CLTC operating point data corresponding to each region.

3. The simulation method for NVH optimization of electric drive systems according to claim 1, characterized in that, The phrase "based on the electromagnetic simulation model and the vehicle CLTC operating conditions, determining the value of the nth harmonic current and its current angle required to suppress the target vth harmonic torque" includes: Electromagnetic simulation was performed based on the electromagnetic simulation model and the stator and rotor scheme design to obtain the vth harmonic torque results at each operating point. The harmonic current formula, which includes the preset nth harmonic current value and current angle, is introduced into the simulation model for parametric scanning simulation. By analyzing the simulation results, the nth harmonic current value and current angle that can effectively optimize the vth harmonic torque were selected.

4. The simulation method for NVH optimization of electric drive systems according to claim 3, characterized in that, "Introducing the harmonic current formula, which includes preset nth harmonic current values ​​and current angles, into the simulation model for parametric scanning simulation" includes: Add the following formula to the current formula in the electromagnetic simulation model; ，n＞0； ，n≤5； ，n≤5； ，n＞5； ，n＞5； Among them, I A I is the A-phase current of the motor. B I is the B-phase current of the motor. C Let f be the C-phase current of the motor, t be the electrical frequency of the motor, degn be the angle of the injected current at the nth time, and I be the current at the nth time. n Here, I represents the harmonic current value; n The value range of is 1-5A; the value range of degn is 0-350°.

5. The simulation method for NVH optimization of electric drive systems according to claim 1, characterized in that, "Generate electric drive efficiency MAP after harmonic current injection", including: The electric drive efficiency MAP after harmonic current injection is calculated using the following formula; ； Where η is the efficiency of the electric drive system; This represents the input power at the corresponding operating point when no harmonics are injected. The output power is the power at the corresponding operating point without harmonic injection; Loss is the additional loss value after the harmonic current is injected.

6. A simulation device for NVH optimization of electric drive systems, characterized in that, The system includes a control module, which is used to construct an initial efficiency MAP of the electric drive system based on an electromagnetic simulation model and stator / rotor design, and to map the vehicle's CLTC operating conditions to the initial efficiency MAP; the initial efficiency MAP includes the input power, output power, and loss values ​​at each operating point. The control module is also used to determine the value of the nth harmonic current and its current angle required to suppress the target vth harmonic torque based on the electromagnetic simulation model and the vehicle CLTC operating condition; where v is greater than 0 and n is greater than 0. The control module is also used to calculate the additional losses caused by the injected harmonic current at the corresponding operating point based on the value of the nth harmonic current to be injected and its current angle, and to generate the electric drive efficiency MAP after the harmonic current injection by combining the initial efficiency MAP. The control module is also used to check the overall vehicle CLTC efficiency based on the electric drive efficiency MAP. If the CLTC efficiency does not meet the requirements, the stator and rotor design needs to be adjusted and the above steps need to be repeated.

7. The simulation device based on NVH optimization of electric drive system according to claim 6, characterized in that, The control module is also used to divide the initial efficiency MAP into regions within the effective speed range of harmonic injection using preset speed step size and torque step size, and extract the CLTC operating point data corresponding to each region.

8. The simulation device based on NVH optimization of electric drive system according to claim 6, characterized in that, The control module is also used to perform electromagnetic simulation based on the electromagnetic simulation model and the stator and rotor scheme design, and to obtain the vth harmonic torque results at each operating point. The harmonic current formula, which includes the preset nth harmonic current value and current angle, is introduced into the simulation model for parametric scanning simulation. By analyzing the simulation results, the nth harmonic current value and current angle that can effectively optimize the vth harmonic torque were selected.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the simulation method based on NVH optimization of electric drive system as described in any one of claims 1 to 5.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the simulation method based on NVH optimization of electric drive system as described in any one of claims 1 to 5.

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