MCSDK 6.4.0 Flux weakening problem

[YungPin]

[PN]: EVLSERVO1
[VERSION]: 6.4.0
[TOOL]: MC Workbench
[DETAILS]:

Issue 1
After enabling Flux Weakening, I can achieve higher motor speeds; however, under a constant load the speed sometimes swings dramatically. My observation suggests that the control firmware is repeatedly switching between flux-weakening and base-speed modes, creating abrupt transitions.

Issue 2
With both Flux Weakening and Over-Modulation enabled, attempting to increase the motor speed causes the controller to keep raising the Iq reference instead of decreasing the Id reference. This prevents further acceleration and results in an unrealistically high commanded Iq.

[EXPECTED BEHAVIOR]:
Ensure that the motor operates stably after flux-weakening is enabled—without unexpected speed oscillations—and that it functions correctly when both flux-weakening and over-modulation are activated simultaneously.

[HOW TO REPRODUCE]:
Generate the motor model with Motor Control Workbench and Motor Pilot. Next, use Workbench to create the controller and run tests with flux-weakening and/or over-modulation enabled.

[GMA]

Hello @YungPin,

Issue 1: You can change the flux weakening regulator voltage limit threshold. If your use case is near this threshold, it could be the root cause.

Issue 2: We did not investigate such a configuration, as both methods are intended to increase the speed in two different manners. Does the achieved speed with one or the other algorithm fully meet your requirements?