What are the calculation methods for the temperature rise of permanent magnet brushless motors?

The difference between the permanent magnet brushless motor's maximum temperature and the surrounding ambient temperature is referred to as the temperature rise during operation. Overheating of the motor, failure of the motor winding insulation, and permanent demagnetization of the permanent magnet are just a few of the issues that will arise from an excessive rise in motor temperature. The permanent magnet brushless motor's temperature rise calculation method will be explained in the paragraphs that follow.

1 Determine the various motor losses using the standard approach, convert the results to a heat density, load the heat density to the temperature field's corresponding heat generation density, and load the heat density to the temperature field's corresponding heat generation part. This approach is: The change in the material's thermal characteristics brought on by the temperature rise in the time dimension is not taken into account by the loss calculation at the highest beginning temperature.

2. Through the coupling of the temperature field in the electromagnetic field, the loss distributed in the three-dimensional electromagnetic field is used as a heat source to assign the temperature field to calculate the temperature rise, which solves the problem of loss distribution in the process of the permanent magnet brushless motor thermometer and makes the loss distribution closer to reality. , but ignoring that the loss is affected by temperature changes in actual operation.

3. Using the fluid-structure coupling approach, a permanent magnet brushless motor's temperature is calculated, and the effect of the air hole's size on the motor's temperature rise is compared and investigated. This is a technique for exploiting the ventilation hole to lower the temperature rise of the permanent magnet brushless motor.

4. This method does not take into account the axial fluctuation of the motor while doing the thermal analysis of the permanent magnet brushless motor using the two-dimensional temperature field.

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