Reducing NVH in Electric Motors Using EMWorks Multiphysics
Minimizing NVH in electric motors using EMWorks Multiphysics involves leveraging the software's ability to perform integrated electromagnetic, thermal, and structural simulations. This allows for a comprehensive approach to identifying and mitigating the sources of NVH from the design stage. Here's how you can utilize EMWorks Multiphysics for NVH reduction in electric motors:
Setting NVH Performance Targets
Start with clear objectives regarding the acceptable levels of vibration, and harshness for your electric motor application. Understanding the specific NVH criteria will guide your simulation and optimization efforts.
Comprehensive Electric Motor Modeling
- Detailed Geometry: Begin by creating an accurate 3D model of your electric motor, including all key components like the stator, rotor, windings, and housing. This serves as the foundation for all subsequent analyses., as shown in Figure 1.
Figure 1: CAD Models of the motor and housing
- Material Properties: Assign accurate electromagnetic, thermal, and mechanical properties to all components, as shown in Figure 2. The precision in this step is crucial for reliable simulation outcomes.
Figure 2: Material properties list
Electromagnetic Simulation
- Magnetic Force Analysis: Perform electromagnetic simulations to determine the distribution of magnetic forces within the motor, as depicted in Figures 3-4. Pay attention to the fluctuating forces that can induce vibration.
Figure 3: Stator teeth force distribution
Figure 4: Radial and Tangential force curves
- Harmonic Analysis: Identify the harmonic content of the electromagnetic forces and their frequencies. This is essential for understanding how these forces might interact with the natural frequencies of the motor components, as shown in Figure 5.
Figure 5: DFT decomposition of Radial force
Thermal Analysis
- Identify Hot Spots: Use the thermal simulation capabilities of EMWorks Multiphysics to identify areas of excessive heat generation that could lead to material expansion and contribute to NVH issues, as shown in Figure 6.
Figure 6: Temperature distribution across the motor stator
- Cooling Strategies: Optimize cooling designs within the simulation to ensure uniform temperature distribution and minimize thermal-induced deformation or stress.
Structural and Vibrational Analysis
- Modal Analysis: Conduct a modal analysis to determine the natural frequencies of the motor and its components. This step is vital for identifying potential resonances with electromagnetic force frequencies, as shown in Figure 7.
Figure 7: Mode shapes of the stator
- Stress and Deformation Analysis: Simulate the mechanical stress and deformation induced by electromagnetic forces and thermal expansion. Analyze these results to pinpoint areas where NVH could be generated, as shown in Figure 8-9.
Figure 8: Frequency response displacement of the stator
