Overview

In the initial stages of motor design, if only the magnetic design is completed and the design proceeds to the later stages, rework may occur when it is discovered that the part temperature and stress do not meet the requirements. Such rework can be reduced by running multifaceted evaluations from the initial design stages, including not only magnetic design but also thermal and stress.
By using the templates included in JMAG-Express, you can create motor models and evaluate design plans both quickly and easily. In addition, by combining the prepared scenarios, you can run magnetic design, thermal design, and structural design all at the same time.
In this example, the efficiency map, part temperature, and stress, are evaluated at the same time for the motor design plan, and a design plan that meets the requirements is explored.

Design Requirements, Design Variables

Table 1 shows the design requirements, and Table 2 shows the cooling specifications.

Initial Design Plan Evaluation

Fig. 1, Fig. 2, and Fig. 3 show the efficiency map, maximum stress position, average temperature of each part, respectively, for the initial design plan. Table 3 shows the maximum stress value.
From Fig. 1, it can be seen that the maximum torque exceeds the requirement of 280 Nm and the efficiency at the rated point exceeds the requirement of 95 %.
Fig. 2 and Table 3 show that the maximum stress is below the requirement of 200 MPa.
On the contrary, Fig. 3 shows that the field coil temperature is 130 deg C. This indicates that adjustments are necessary in terms of the temperature.

Design Plan Adjustments

The design parameters are adjusted based on the results of the initial design plan.
In this example, the evaluation is run again with the cooling for the field coils changed from air cooling to oil cooling.
Fig. 4, Fig. 5, and Fig. 6 show the obtained efficiency map, maximum stress position, and average temperature of each part, respectively. Table 4 shows the maximum stress value.
From Fig. 4, it can be seen that the maximum torque exceeds the requirement of 280 Nm and the efficiency at the rated point exceeds the requirement of 95 %.
Fig. 5 and Table 4 show that the maximum stress is below the requirement of 200 MPa.
Fig. 6 show that the temperature of the armature coils and field coils is 130 deg C or less. From this, it can be seen that the design plan meets the requirements after the adjustments have been made.