Case studies: Optimizing the magnetic quality of the Formula Electric Belgium and the Innoptus Solar Team electric race cars
As a proud sponsor of both the Belgian Formula Student and the Belgian Innoptus Solar electric race teams, Magcam has effectively employed its magnetic field camera technology and application expertise to enhance the performance of the permanent magnet rotors used in the electric motors in their respective electric race cars.
The Formula Electric car is powered by four radial-flux motors, whereas the Innoptus Solar car operates with an axial-flux motor. In both scenarios, we started the optimization process by measuring a large quantity of individual magnets using our magnetic field camera scanner. From the resulting magnetic field maps, detailed quality parameters were extracted, including overall magnet strength, magnetization angle error and localized magnetic homogeneity. By ranking these magnets based on the derived quality parameters, we were able to select the highest quality magnets for rotor assembly. This first crucial step assures that only qualified magnets are used. The assembled rotors were subsequently measured by Magcam's advanced radial/axial-flux rotor scanner.
This revealed the detailed magnetic field distribution of the rotors, which was further analyzed in detail to extract a wide variety of magnetic quality parameters using powerful analysis algorithms, including pole sizes, pole strength uniformity, N/S symmetry, pole skewing, cogging torque, FFT harmonics, THD, runout, and more. This final rotor measurement reveals potential issues in the assembly such as magnet position shifts, electrical steel alignment, which could impact the magnetic field distribution and, consequently, critical motor performance metrics including cogging torque, vibration, and noise. The results show clear improvements in the optimized rotors compared to those assembled with lesser quality magnets.
These case studies illustrate the invaluable role of magnetic field camera scanners in the development and production phases of both radial- and axial-flux PM rotors. As the demand for electric and hybrid vehicles grows, ensuring the quality of permanent magnet rotors for electric drive motors is becoming increasingly important, both in R&D and production stages. It is clear that the magnetic properties of PM rotors are of critical importance for achieving optimal motor performance.
