A BLDC-type spoke-rotor electric motor has been considered. The goal was to ensure proper motor performance (characterized by torque and rotational velocity) at new design point while satisfying electric constraints: DС bus current, invertor MOSFET maximum current and line-line voltage. In addition, a lower limit of 75% has been specified for total efficiency. The customer’s demand to minimize design changes posed additional modelling difficulties.
The work has been performed in following steps:
- Model verification based on experimental data obtained for poorly performing baseline design
- Determining the cause of poor motor performance (turned out to be magnetic flux shunt inside the rotor)
- Winding redesign to reduce motor EMF
- Assessing new design performance on a virtual model
- Efficiency map creation for further use as vector control operation device look-up table
As a result, a new design decision has been made within a week to produce a new prototype. The new motor with redesign rotor and winding has successfully passed the testing.