As an effective approach to reducing cogging torque, electromagnetic vibration, and noise, skewing is widely applied in the design of motors. For example, in the electric car Tesla Model 3, the rotor adopts a kind of step-skewing design, as shown below:
When performing an electromagnetic analysis of motors with a step-skewed rotor, due to its non-uniformity in the axial direction, it is impossible to perform two-dimensional equivalents directly through the cross-section. Generally, a three-dimensional model needs to be established for analysis, as shown below:
However, the 3D model-based analysis will require a relatively long solving time. The solver Flux provided another 2D model-based analysis method for the motor with step-skewing. The principle is to establish several 2D cross-sections for the motor (depending on the layer number of step-skewing). After solving these 2D problems, the results of the 3D model can be obtained by a homogenization technique. The above process can be realized in the SimLab EM solution – MT Skew.
This tutorial shows how to use SimLab-MTSkew to design and run the electromagnetic analysis for an electric motor with a step-skewed rotor.
Motor modeling
After building a 2D motor model, the step-skewing of the rotor can be defined in the solution settings.
Basic EM analysis
All physics definitions of the motor can be realized with the proposed [MT2D Workflow] tool bar:
The final physical description is shown below, with a coupled circuit:
After solving the scenario, SimLab can provide some basic post-processing for the EM analysis, including the isovalue visualization (in a 3D domain) and the physical quantity plotting.
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Example access
All files corresponding to this example are accessible with this link:
Step to follow:
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