Vibration noise simulation analysis method and system of range extender generator

Abstract

The invention discloses a vibration noise simulation analysis method and system for a range extender generator, and relates to the technical field of hybrid electric vehicle simulation calculation. The method comprises the following steps: establishing a generator structure model of the range extender generator; key points are that a structure model of a virtual rack interface model used for simulating a connection interface of a generator and an external component is established; virtually assembling the two to form an assembly simulation model, and applying boundary constraint to the model; and finally, applying the excitation load of the generator to the assembly simulation model and carrying out vibration noise simulation calculation. According to the method, the simplified virtual interface model is used for replacing a complex engine model, external excitation interference is eliminated, the NVH performance of the generator can be independently, rapidly and accurately evaluated, the simulation efficiency and precision are remarkably improved, and the product research and development period is shortened.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of hybrid vehicle simulation calculation technology, in particular to a simulation analysis method for noise, vibration and harshness (NVH) of a generator in a range extender assembly, and particularly relates to a vibration noise simulation analysis method and system for a range extender generator. BACKGROUND

[0002] With the rapid development of new energy vehicle technology, hybrid vehicles have received widespread attention from the market due to their consideration of both mileage and energy efficiency. As a core component of hybrid vehicles, the performance of the range extender directly affects the power performance, fuel economy and ride comfort of the vehicle. The range extender is usually composed of an engine, a generator, a transmission mechanism and the like, and the NVH (Noise, Vibration, Harshness) performance is a key indicator for evaluating the ride comfort of the vehicle.

[0003] During the operation of the range extender, multiple components such as the engine and the generator are running simultaneously, and there is a complex dynamic coupling between them, which together generates vibration and noise. Among them, the electromagnetic excitation of the generator itself is an important source of high-frequency noise such as whistling. In order to effectively predict and optimize the NVH performance of the generator at the product design stage, computer-aided engineering (CAE) is usually used for simulation analysis.

[0004] Currently, the mainstream method for simulation analysis of the NVH of the range extender generator in the industry is to build a complete simulation model of the entire range extender assembly, which includes the engine, the generator, the transmission mechanism, the suspension system and all other main components. Then, the cylinder pressure excitation of the engine and the electromagnetic excitation of the generator and other loads are applied to the assembly model for coupled calculation to analyze the vibration and noise response of the assembly.

[0005] However, this traditional simulation method has the following significant defects:

[0006] 1. The model is complex to build and the calculation cost is high. The range extender assembly, especially the engine, contains hundreds of fine components, and building a complete finite element model requires a lot of manpower. The number of grids in the final model is extremely large, resulting in a long simulation calculation period, extremely high requirements for computing hardware resources, and high simulation costs.

[0007] 2. The accuracy of the simulation results is insufficient. In assembly simulation, the mechanical excitation of the engine cylinder pressure is usually much greater in energy than the electromagnetic excitation of the generator. The responses of multiple excitation sources are coupled together, making the NVH contribution of the generator severely masked, so that it is difficult for the analyst to accurately separate the NVH performance of the generator itself from the complex simulation results, and the design of the generator body cannot be effectively evaluated.

[0008] Third, the development cycle is limited and cannot be iterated quickly. Because the engine, transmission and other related components must be designed before the overall model can be built and simulated, the NVH evaluation of the generator is severely delayed. In the early stages of product development, even if the generator design has been completed, it is not possible to independently and quickly and effectively predict the NVH performance, missing the best design optimization window, resulting in high cost and long cycle for later rectification.

[0009] Therefore, how to develop a method that can get rid of the dependence on the complete assembly model and can quickly, accurately and low-costly evaluate the NVH simulation of the range extender generator at the early stage of design is a technical problem to be solved in the field. SUMMARY

[0010] In view of the problems in the background art, such as complex range extender assembly NVH simulation model, high calculation cost, inability to accurately evaluate the NVH performance of the generator, and long development cycle, the present application aims to provide a vibration and noise simulation analysis method and system for a range extender generator, to realize independent, fast and accurate evaluation of the NVH performance of the generator.

[0011] To solve the above technical problems, in a first aspect, the present application provides a vibration and noise simulation analysis method for a range extender generator, comprising establishing a generator structure model of the range extender generator and obtaining an excitation load of the range extender generator, characterized in that the method further comprises:

[0012] establishing a structure model of a virtual test bench interface model, the virtual test bench interface model being used to simulate the connection interface between the range extender generator and external components;

[0013] virtually assembling the generator structure model and the structure model of the virtual test bench interface model to form an assembly simulation model;

[0014] applying boundary constraints to the assembly simulation model to simulate the state in which the virtual test bench interface model is fixed to the test bench;

[0015] applying the excitation load to the assembly simulation model and performing vibration and noise simulation calculation on the assembly simulation model to obtain vibration and noise response results caused only by the excitation load.

[0016] The present application can completely eliminate the interference of external excitation sources such as engines, so that the simulation results can accurately reflect the NVH performance caused by the excitation of the generator itself. At the same time, the significant simplification of the model significantly reduces the complexity of modeling and calculation, shortens the simulation period, reduces the cost, and makes it possible to independently evaluate the generator at an early design stage.

[0017] As a preferred scheme of the present application, the structure model of the generator structure model and the virtual test bench interface model is established by using the finite element method. By using the mature finite element method for modeling, the accuracy of the description of the structural dynamic characteristics can be ensured, and the reliability of the subsequent simulation calculation is ensured.

[0018] As a preferred scheme of the present application, the generator structure model includes sub-models of a shell, a stator assembly and a rotor assembly; the virtual assembly includes: establishing a connection relationship between the shell and the virtual test bench interface model; and establishing a connection relationship between the rotor assembly and the simulated test bench rotating shaft. By refining the modeling of the key components inside the generator and defining the connection relationship with the virtual test bench, the assembly state and the force transmission path of the generator in the quasi-test bench test environment can be more realistically simulated.

[0019] As a preferred scheme of the present application, the shell and the virtual test bench interface model are connected through a rigid element simulating bolt connection; the rotor assembly and the simulated test bench rotating shaft are connected through a rigid element. By using a rigid element (such as an RBE2 element) to simulate the bolt and shaft connection, the complex contact and thread modeling can be simplified under the premise of ensuring the accuracy of the connection stiffness transmission, further improving the modeling efficiency.

[0020] As a preferred scheme of the present application, the boundary constraint includes applying full degree of freedom constraints to the area on the virtual test bench interface model for simulating the connection with the test bench. By applying a solid support constraint, the real physical boundary that the generator assembly is firmly installed on the test bench can be accurately simulated, ensuring that the boundary conditions of the simulation calculation are consistent with the actual test environment.

[0021] As a preferred scheme of the present application, the excitation load is an electromagnetic excitation load; the step of obtaining the excitation load comprises: establishing a two-dimensional electromagnetic simulation model of the range extender generator; calculating electromagnetic force under a preset working condition through the two-dimensional electromagnetic simulation model; and mapping the electromagnetic force to a three-dimensional grid of the generator structure model to form the electromagnetic excitation load. Through one-way coupling of electromagnetic field simulation and structural dynamics simulation, the electromagnetic excitation as the main source of NVH can be accurately obtained and applied to the structural model, thereby ensuring the accuracy of the source input of the NVH analysis.

[0022] As a preferred scheme of the present application, the electromagnetic force is radial electromagnetic force and tangential electromagnetic force acting on the stator tooth portion of the generator. The radial and tangential electromagnetic force as the main excitation source conforms to the electromagnetic NVH mechanism of the permanent magnet synchronous motor, and can accurately capture the key physical quantity causing motor vibration and noise.

[0023] As a preferred scheme of the present application, the vibration noise response result comprises sound pressure level or sound power level at a preset virtual measurement point. Through calculation of sound pressure level, sound power level and other acoustic evaluation indexes, the noise level of the generator can be intuitively quantified, which is convenient for comparison and evaluation with design targets or test data.

[0024] To solve the above technical problems, in a second aspect, the present application provides a vibration noise simulation analysis system of a range extender generator, characterized in that it comprises:

[0025] a model establishing module, configured to establish a generator structure model of the range extender generator, and establish a structure model of a virtual bench interface model for simulating a connection interface of the range extender generator and external components;

[0026] a model assembling module, configured to virtually assemble the generator structure model and the structure model of the virtual bench interface model to form an assembly simulation model;

[0027] a load and constraint applying module, configured to obtain an excitation load of the range extender generator, and apply boundary constraints and the excitation load to the assembly simulation model, wherein the boundary constraints are used to simulate a state in which the virtual bench interface model is fixed to a test bench;

[0028] a simulation calculation module, configured to perform vibration noise simulation calculation on the assembly simulation model to which the boundary constraints and the excitation load are applied, so as to obtain vibration noise response results caused only by the excitation load.

[0029] As a preferred scheme of the present application, the model establishing module establishes the structure model by using the finite element method.

[0030] As a preferred embodiment of the present invention, the generator structure model includes sub-models of a housing, a stator assembly, and a rotor assembly; the model assembly module is specifically used to: establish the connection relationship between the housing and the virtual test bench interface model; and establish the connection relationship between the rotor assembly and the simulated test bench shaft.

[0031] In a preferred embodiment of the present invention, the excitation load is an electromagnetic excitation load; the load and constraint application module further includes an electromagnetic force calculation unit for obtaining the electromagnetic excitation load through electromagnetic simulation calculation.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. Improve simulation accuracy: This invention, by constructing a simplified model of "generator + virtual test bench interface", fundamentally eliminates the interference of strong external excitation sources such as engines, so that the simulation results can purely and accurately reflect the NVH performance of the generator unit under electromagnetic excitation. The order components of the analysis results are clear and strongly correlated with the generator, providing accurate guidance for design optimization.

[0034] 2. Improved simulation efficiency and reduced costs: This invention eliminates the step of modeling extremely complex engines, and the number of meshes in the assembly simulation model can be reduced by more than two-thirds compared to traditional methods. The reduction in model size greatly shortens the time for pre-processing modeling and back-end solution calculation, reduces the demand for computing hardware resources, and thus significantly reduces R&D costs.

[0035] 3. Shortened R&D cycle: The method of this invention does not rely on the design scheme of other components such as the engine. As long as the design data of the generator itself is determined, NVH simulation evaluation can be carried out independently. This allows NVH analysis to be carried out at a much earlier stage of design, enabling the timely identification and resolution of potential NVH risks, avoiding expensive mold modifications and design changes later, and effectively shortening the entire product development cycle. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments disclosed in this invention, the accompanying drawings of the embodiments will be briefly described below. These drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention.

[0037] Figure 1 This is a flowchart illustrating a vibration and noise simulation analysis method for a range extender generator provided in an embodiment of the present invention.

[0038] Figure 2 This is a schematic diagram of the finite element model after the generator assembly and the virtual test bench interface model are assembled, as described in a specific embodiment of the present invention.

[0039] Figure 3 This is a schematic diagram of the two-dimensional electromagnetic simulation model of the generator described in a specific embodiment of the present invention.

[0040] Figure 4 This is a waterfall diagram of generator speed-frequency-sound pressure level obtained from simulation in a specific embodiment of the present invention.

[0041] Figure 5 This is a comparison chart of the 12th-order sound pressure level results obtained from simulation in this embodiment of the invention and the design target.

[0042] Figure 6 This is a diagram showing the 12th-order sound pressure level results obtained from bench testing of the physical prototype in an embodiment of the present invention.

[0043] Figure 7 This is a schematic diagram of the functional modules of the vibration and noise simulation analysis system provided in this embodiment of the invention. Detailed Implementation

[0044] The technical solutions (including preferred technical solutions) of the present invention will be further described in detail below with reference to the accompanying drawings and by way of listing some optional embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0045] The terms "connection," "assembly," etc., used herein should be interpreted broadly unless otherwise explicitly specified and limited. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0046] Example 1

[0047] This embodiment provides a vibration and noise simulation analysis method for a range extender generator, such as... Figure 1 As shown, this method takes the range extender generator of a certain platform (codename IG3-90) as the analysis object, and the specific steps are as follows:

[0048] Step 1: Structural Model Establishment

[0049] The goal of this step is to create a high-fidelity three-dimensional finite element model for structural dynamics and acoustic simulation. This process is typically completed on a high-performance graphics workstation using professional CAE software such as CATIA or HyperMesh.

[0050] 1.1 Preparation and Cleanup of Geometric Model

[0051] Export the geometric model of the range extender generator assembly and its connecting flanges from product 3D design software (e.g., STEP or IGES format). Before meshing, the geometric model must be cleaned; this step is crucial for ensuring mesh quality and computational convergence. Cleaning includes: removing minor features with negligible impact on structural stiffness, such as part numbers, logos, and small chamfers and fillets; and correcting potential geometric topology errors, such as broken surfaces and small gaps.

[0052] 1.2 Mesh Generation of the Generator Structural Model

[0053] The cleaned geometric model is discretized using the finite element method, i.e., meshed. Different meshing strategies are used for different components to balance computational accuracy and efficiency.

[0054] Shell and end caps: These components are typically complex cast aluminum parts with irregular geometries. Therefore, using second-order tetrahedral solid elements (such as SOLID187 elements) for meshing can well adapt to complex shapes. The global average mesh size is controlled at 4mm. In critical connection areas, such as bearing housing holes and bolt hole flange faces connecting to the virtual bench interface model 20, local mesh refinement is performed, with the size densified to 3mm. This is because these areas are the main load transfer paths and stress concentration areas, and a fine mesh can more accurately capture their local stiffness and deformation modes.

[0055] Stator Assembly: The stator assembly includes the stator core, windings, and insulating paper. The stator core is made of laminated silicon steel sheets. To ensure computational efficiency and accuracy, it is typically meshed using second-order hexahedral-dominated solid elements with a mesh size of 4mm. To simulate the anisotropy of the laminated structure, orthotropic material properties can be assigned, making its axial stiffness much smaller than its radial and tangential stiffness. The stator windings can be modeled in two ways: a) refined modeling, where solid models are created and meshed for both the slot windings and end windings; b) equivalent simplified modeling. To save computational resources, this method is used in this embodiment. The slot windings are equivalent to homogeneous solids with average densities of copper and insulating material. The end windings, while contributing little to structural stiffness but having a significant impact on mass, are connected to end nodes using RBE3 interpolation elements, with a mass point added at the center point to represent their mass and moment of inertia.

[0056] Rotor Assembly: The rotor assembly consists of the rotor core, permanent magnets, and rotor shaft. It is also meshed using second-order hexahedral-dominated solid elements with a size of 4mm. The permanent magnets are connected to the rotor core via tied contacts or shared nodes to simulate adhesive or embedded fastening relationships.

[0057] 1.3 Mesh Generation of the Virtual Test Bench Interface Model

[0058] The geometry of the virtual test bench interface model is derived from the engine block flange or the connecting plate of the actual test bench connected to the generator. Its material properties (such as elastic modulus, Poisson's ratio, and density) should also be consistent with the actual component (such as cast iron or cast aluminum). It is meshed using second-order tetrahedral solid elements; due to its relatively regular structure, the mesh size can be appropriately widened to 5mm. Accurately simulating the stiffness of this interface is crucial to ensuring the accuracy of the simulation boundary conditions.

[0059] Step 2: Virtual Assembly and Application of Boundary Conditions

[0060] This step connects the independent finite element models of the components into a whole and applies reasonable boundary conditions to simulate its actual working state on the test bench. For example... Figure 2 As shown.

[0061] Inter-component connections:

[0062] Bolted connections: The connections between the generator housing and the front and rear covers, as well as between the housing and the virtual test bench interface model, are all simulated using high-strength bolts. Specifically, a "spiderweb" of rigid beam elements (RBE2) is created on the nodes around each bolt hole, and the center points are connected to simulate the high-rigidity connection provided by the bolts after tightening.

[0063] Bearing Connection: The rotor shaft is connected to the housing bearing seat via bearings. Spring elements (such as CBUSH elements) are used to simulate the bearing's support stiffness. The radial and axial stiffness values ​​(Kx, Ky, Kz) of the spring elements are set according to the product datasheet provided by the bearing supplier to accurately reflect the bearing's force transmission characteristics.

[0064] Interference fit: The stator core and the generator housing are usually in an interference fit. In the finite element model, by setting a binding contact algorithm or a common node method, the nodes on the outer surface of the stator core are coupled with the nodes in the corresponding area of ​​the inner surface of the housing to simulate their inseparable connection state.

[0065] Boundary conditions are applied:

[0066] To simulate the entire assembly being rigidly fixed to the test bench, constraints need to be defined on the virtual bench interface model. All nodes in the bolt hole region used for fixing to the bench are selected on the model, and full-degree-of-freedom constraints in six directions (i.e., displacement and rotation constraints, Tx=Ty=Tz=Rx=Ry=Rz=0) are applied. This is equivalent to simulating an infinitely rigid test bench, which is the standard boundary condition for component-level NVH bench testing.

[0067] Step 3: Obtaining and Applying Excitation Load

[0068] Electromagnetic force is the direct source of electromagnetic noise in generators. This step involves accurately calculating this excitation through electromagnetic field simulation.

[0069] Two-dimensional electromagnetic field modeling: Given that the magnetic circuit of this permanent magnet synchronous motor is mainly in the radial and tangential planes, a two-dimensional cross-sectional electromagnetic simulation model can be established (e.g., Figure 3 (As shown) to significantly improve computational efficiency. In electromagnetic simulation software (such as Ansys Maxwell), based on the 12-pole, 72-slot design, two-dimensional models of the stator and rotor cores, permanent magnets, and windings are established. Precise material properties are assigned to each component, such as the BH curve of the silicon steel sheet and the demagnetization curve of the permanent magnet.

[0070] Electromagnetic force calculation: The generator's operating conditions are set, i.e., at different speeds (500 rpm to 4500 rpm). Based on its external characteristic curve, corresponding sinusoidal current excitation is applied to the three-phase windings. Transient electromagnetic field solutions are performed, and the air gap magnetic flux density acting on each stator tooth surface is calculated using the Maxwell tensor method, thereby obtaining the time-varying radial and tangential electromagnetic forces.

[0071] Excitation load mapping: The calculated time-domain electromagnetic force data is transformed to the frequency domain using a Fast Fourier Transform (FFT). Then, the frequency-domain electromagnetic force on each stator tooth in the two-dimensional electromagnetic model is mapped and loaded onto all nodes of the corresponding tooth section of the stator core in the three-dimensional structural finite element model established in the first step using a spatial interpolation algorithm. Since the two-dimensional model represents a cross-section, the force value needs to be uniformly distributed along the entire length of the core along the axial direction. This force mapping process from the 2D electromagnetic mesh to the 3D structural mesh is a key step in multiphysics coupling, and it is necessary to ensure that the total amplitude and phase of the force remain consistent before and after mapping. In this embodiment, the electromagnetic force is transmitted in UNV file format.

[0072] Step 4: Vibration and Noise Simulation Calculation and Result Analysis

[0073] Sound field modeling: An envelope sound field is established outside the assembled and loaded assembly simulation model. This typically involves creating a closed air mesh whose inner surface shares nodes with the outer surface of the generator assembly. Simultaneously, virtual microphone measurement points are set at a distance of 1 meter from the model surface, according to national or industry testing standards, to pick up sound pressure levels.

[0074] Solution and Calculation: Modal frequency response analysis is performed using an acoustic simulation solver (such as MSC Nastran SOL 111 combined with ACTRAN). The solver first calculates the mode shapes and natural frequencies of the structure, and then calculates the vibration response of the structure at each frequency under the aforementioned electromagnetic force excitation (such as the normal vibration velocity of surface nodes). Finally, using the surface vibration velocity as the sound source, the sound pressure level at each microphone measurement point in the external sound field is calculated using the boundary element method (BEM) or the finite element method (FEM).

[0075] Results analysis and verification:

[0076] Waterfall plot analysis: The sound pressure level spectrum at all rotational speeds is integrated and plotted as follows. Figure 4 The diagram shows a three-dimensional waterfall plot of speed-frequency-sound pressure level. The bright diagonal lines in the plot represent the "order," and their frequency is proportional to the speed. For a 12-pole motor, the main electromagnetic excitation orders are the 12th and 24th, etc. The plot clearly identifies which orders of noise contribute the most in which speed ranges.

[0077] Order slice analysis and comparative verification: In order to quantitatively evaluate the accuracy of the simulation method and guide engineering practice, a detailed analysis of the key orders is required.

[0078] First, such as Figure 5 As shown in the figure, this graph illustrates the simulation results of the key 12th-order noise extracted from the waterfall plot. The graph contains two curves: the curve labeled "Upper_1m" represents the simulated predicted sound pressure level calculated using the method of this invention, and the curve labeled "Target" represents the NVH performance target limit set during product development. From Figure 5 As can be seen intuitively, the simulation method of the present invention can predict during the design stage that the 12th-order noise level of the generator may exceed the design target in the speed range of approximately 1500 rpm to 2500 rpm, thereby providing an early warning of potential NVH risks.

[0079] Secondly, such as Figure 6 As shown, this figure illustrates the 12th-order noise sound pressure level results obtained from actual testing of the manufactured physical prototype on an NVH test bench in the later stages of the project. This figure represents objective physical measurement data.

[0080] Finally, Figure 5 The simulation results shown are consistent with Figure 6 By comparing and analyzing the experimental results shown, the following conclusions can be drawn:

[0081] 1. Highly consistent trends: Figure 5 The simulation curves and Figure 6 The test curves in the test showed almost identical fluctuation trends across the entire speed range.

[0082] 2. Key feature points match: Both show the first significant noise peak around 1500 rpm, and the magnitude of the peak (about 60-65 dB) is also very close.

[0083] 3. Accurate prediction of problem range: The simulation predicts the speed range that exceeds the design target, which highly overlaps with the problem range exposed by the test.

[0084] In summary, through Figure 5 and Figure 6 The rigorous comparison fully demonstrates that the simulation analysis method proposed in this invention has extremely high accuracy and reliability, and its simulation results can form a good correspondence with the actual physical test results. This shows that this invention can serve as an effective, upfront R&D tool, replacing expensive and time-consuming physical prototype testing in the early stages of product development, thereby enabling rapid iteration and optimization of generator NVH performance.

[0085] Example 2

[0086] This embodiment provides a vibration and noise simulation analysis system for a range extender generator. This system can be one or more high-performance computers or servers working collaboratively. The system deploys software modules that implement the method of this invention. The system includes:

[0087] Model building module 100: Composed of commercial or self-developed CAE preprocessing software, such as HyperMesh, ANSA, etc. This module provides a graphical interface and command-line tools for reading the three-dimensional geometric data of the generator and virtual test bench interface, performing high-quality finite element mesh generation, and finally generating the sub-models as described in Example 1.

[0088] Model assembly module 200: Also embedded in the pre-processing software. This module provides various connection units (such as RBE2, RBE3) and contact definition tools to perform the virtual assembly process described in Example 1, connecting the sub-models into a complete assembly simulation model.

[0089] Load and Constraint Application Module 300: This module includes two sub-units. One is a boundary condition application unit, used to apply boundary constraints to the assembly simulation model. Specifically, the boundary constraints include applying full-degree-of-freedom constraints to the area on the virtual test bench interface model used to simulate the connection with the test bench. The other is an excitation load interface unit, which can read electromagnetic force files generated by electromagnetic field simulation software (such as Ansys Maxwell, which can be regarded as the electromagnetic force calculation unit of this module) and automatically or semi-automatically map them to the corresponding nodes on the stator tooth surface.

[0090] Simulation Calculation Module 400: Composed of structural and acoustic solvers, such as Nastran and OptiStruct. This module receives the solution file generated by the aforementioned modules, which contains complete model, boundary, and load information, performs frequency response analysis and acoustic calculations, and finally outputs result data files such as structural vibration, sound pressure, and sound power.

[0091] In addition, the system includes a post-processing module for visualizing the results output by the simulation calculation module 400, such as generating... Figure 4 , Figure 5 , Figure 6 The charts shown are provided for analysis by engineering and technical personnel.

[0092] The various modules of the system work together to automatically complete the simulation analysis process described in Example 1, providing users with an efficient and accurate generator NVH evaluation platform.

[0093] Those skilled in the art will understand that the core idea of ​​this invention—namely, using a simplified virtual interface model to replace complex adjacent assemblies for independent performance evaluation of target components—is not limited to range extender generators. This method is also applicable to other scenarios requiring similar independent NVH performance evaluation. For example, in the development of pure electric vehicles, the method of this invention can be used to evaluate the NVH performance of a single drive motor. In this case, simply constructing the "virtual bench interface model" as a structural model simulating the connection interface between the drive motor and the reducer housing, and replacing the excitation load with the electromagnetic excitation of the drive motor under driving or braking conditions, allows for rapid and accurate prediction of the drive motor's own howling noise level, without the need to build a complete electric drive axle model containing complex components such as gears and bearings. These variations and applications all fall within the scope of protection of this invention.

[0094] Example 3

[0095] This embodiment provides a specific case that highly replicates the technology development process, and its content completely corresponds to the solution described in the original technical documents, to illustrate in detail the specific practice process of the present invention. This case also uses the IG3-90 platform generator assembly as the research object.

[0096] (a) Construction of generator model and test bench interface model

[0097] This step is completed using HyperMesh software.

[0098] Step 1: Perform geometric modeling of the generator housing. The housing uses a second-order tetrahedral mesh with an average mesh size of 4mm. To ensure accuracy in critical areas, a 3mm mesh size is used for local refinement at the bearing housing and bolt hole locations.

[0099] Step 2: Perform finite element modeling on the cover plate type parts. In this case, the controller cover plate is a cast aluminum plate, using a second-order tetrahedral mesh with a mesh size of 4mm.

[0100] Step 3: Perform detailed modeling of the stator assembly. The stator core, windings, and insulation paper are all modeled using a second-order hexagonal mesh with a mesh size of 4mm. Common node connections are used between the stator core and the insulation paper, and between the insulation paper and the in-slot windings. The end windings are simplified using an RBE3+ centroid approach, assigning only mass properties and disregarding stiffness.

[0101] Step 4: Perform detailed modeling of the rotor. The rotor uses a second-order hexagonal mesh with a mesh size of 4mm. The permanent magnets are represented by their centers of mass.

[0102] Step 5: Perform finite element modeling on the test bench connection plate, which serves as the virtual test bench interface model. The connection plate has a relatively regular structure and uses a second-order tetrahedral mesh with a size of 5mm.

[0103] Step Six: Assemble the assembly. Assemble the finite element models of the various sub-components established above, such as... Figure 2 As shown, the stator model is connected to the generator housing via common nodes in the contact area; the rotor is connected to the test bench connecting shaft using RBE2 rigid elements; the test bench connecting plate is connected to the generator assembly using RBE2 rigid elements. Finally, six degrees of freedom constraints are applied to the bolt holes at the test bench connecting plate.

[0104] (ii) Electromagnetic excitation loading of generator

[0105] This step was completed using Ansys Maxwell simulation software.

[0106] Step 1: Based on the structural parameters and 3D assembly model provided by the generator structural design department, draw a 2D model of the generator in Maxwell software to establish the generator system model, such as... Figure 3 As shown. This case is a three-phase built-in permanent magnet synchronous motor, a 12-pole, 72-slot design, with a power of 90kW.

[0107] Step 2: Set the excitation source for components such as windings. In this case, a sinusoidal current is used to ensure that the three-phase current has no harmonic components, so that the generator output torque can be consistent with the actual torque.

[0108] Step 3: Set the boundary conditions such as generator operating status, environment, and load. In this case, the operating condition is 500-4500 rpm under the engine's external characteristics.

[0109] Step 4: Set the solver parameters, including the number of iterations, time step, convergence conditions, etc., and then solve the problem to output the electromagnetic force at the root of the stator tooth (i.e., the tooth surface). The output format is a UNV file.

[0110] Step 5: Stretch the output electromagnetic force to cover the entire axial length of the stator, and then apply it to the stator tooth surface grid. Through the one-to-one mapping between the electromagnetic force and the stator tooth surface, the electromagnetic excitation loading is completed.

[0111] (III) NVH Simulation and Data Processing

[0112] Step 1: Perform coupling calculations between electromagnetic excitation and the structural model. In the simulation model, set up vibration measurement points and microphone measurement points identical to those used in the actual bench test. In this case, microphone detection points were specifically set at the top, left, front, and rear of the generator surface, 1m away.

[0113] Step Two: Process and analyze the calculation results. Compare the sound pressure level data at each measuring point obtained from the simulation calculation with the measured data from the bench test. For example... Figure 5 and Figure 6 The comparison shows that the simulation results of the measuring point located 1m above are ( Figure 5 The results showed that the noise began to rise significantly and exceed the target limit after approximately 1500 rpm, a trend consistent with experimental test results. Figure 6 The results are completely consistent, verifying the effectiveness and accuracy of the method of the present invention.

[0114] It will be readily understood by those skilled in the art that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, combinations, substitutions, improvements, etc., made under the spirit and principles of the present invention are included within the protection scope of the present invention.

Claims

1. A vibration and noise simulation analysis method for a range extender generator, comprising establishing a generator structural model of the range extender generator and obtaining the excitation load of the range extender generator, characterized in that, The method further includes: A structural model of a virtual test bench interface model is established, which is used to simulate the connection interface between the range extender generator and external components. The generator structure model and the virtual bench interface model are virtually assembled to form an assembly simulation model. Boundary constraints are applied to the assembly simulation model to simulate the state in which the virtual bench interface model is fixed to the test bench; The excitation load is applied to the assembly simulation model, and vibration and noise simulation calculations are performed on the assembly simulation model to obtain the vibration and noise response results caused only by the excitation load.

2. The method according to claim 1, characterized in that, Structural models of the generator structural model and the virtual test bench interface model are established using the finite element method. The generator structural model includes sub-models of the housing, stator assembly, and rotor assembly; The virtual assembly includes: establishing a connection between the housing and the virtual bench interface model; And to establish the connection between the rotor assembly and the simulated bench shaft.

3. The method according to claim 2, characterized in that, The housing is connected to the virtual test bench interface model via a rigid unit that simulates bolt connections; the rotor assembly is connected to the simulated test bench shaft via a rigid unit.

4. The method according to claim 1, characterized in that, The boundary constraints include applying full-degree-of-freedom constraints to the area on the virtual bench interface model used to simulate the connection with the test bench.

5. The method according to claim 1, characterized in that, The excitation load is an electromagnetic excitation load; The steps for obtaining the excitation load include: establishing a two-dimensional electromagnetic simulation model of the range extender generator; and calculating the electromagnetic force under preset operating conditions using the two-dimensional electromagnetic simulation model. The electromagnetic force is mapped onto the three-dimensional mesh of the generator structural model to form the electromagnetic excitation load.

6. The method according to claim 5, characterized in that, The electromagnetic force is the radial electromagnetic force and the tangential electromagnetic force acting on the stator teeth of the generator.

7. The method according to claim 1, characterized in that, The vibration and noise response results include the sound pressure level or sound power level at a preset virtual measuring point.

8. A vibration and noise simulation analysis system for a range extender generator, characterized in that, include: The model building module is used to build a generator structure model of the range extender generator, and to build a structural model of a virtual bench interface model for simulating the connection interface between the range extender generator and external components. The model assembly module is used to virtually assemble the generator structure model with the structure model of the virtual bench interface model to form an assembly simulation model. The load and constraint application module is used to acquire the excitation load of the range extender generator and apply boundary constraints and the excitation load to the assembly simulation model, wherein the boundary constraints are used to simulate the state in which the virtual test bench interface model is fixed to the test bench. The simulation calculation module is used to perform vibration and noise simulation calculations on the assembly simulation model with applied boundary constraints and excitation loads, so as to obtain the vibration and noise response results caused only by the excitation loads.

9. The system according to claim 8, characterized in that, The model building module uses the finite element method to build the structural model. The generator structural model includes sub-models of the housing, stator assembly, and rotor assembly; The model assembly module is specifically used to: establish the connection between the housing and the virtual test bench interface model; and establish the connection between the rotor assembly and the simulated test bench shaft.

10. The system according to claim 8, characterized in that, The excitation load is an electromagnetic excitation load; the load and constraint application module also includes an electromagnetic force calculation unit, which is used to obtain the electromagnetic excitation load through electromagnetic simulation calculation.

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