Low-Speed Startup Torque Issue with STEVAL-SPIN3201

[Ashad27]

Working on STEVAL-SPIN3201 board and need help in expected low-speed torque performance using Field-Oriented Control (FOC).

System Configuration:

• Motor Driver Board: STEVAL-SPIN3201
• Motor: 3-phase BLDC (Rated torque=0.25Nm)
• Position Feedback: Hall sensors

Observed Behavior

During testing, I observed that the motor struggles to start at lower commanded speeds when a load is applied.

Load: 0.05Nm

• 1000–1500 rpm: Motor struggles to start.
• 2000 rpm: Motor starts reliably.

Load: 0.1 Nm

• 1000 rpm: Motor does not start.
• 1500–2000 rpm: Motor struggles to start.
• 3000 rpm: Motor starts reliably.

 

Whether this behavior is expected and advise on any key parameters (e.g., startup current, Hall alignment, or rev-up settings) that should be optimized?
Is there any startup current limitation in STEVAL-SPIN3201 firmware?

FOC should provide high torque at low speeds, including during startup. However, the current behavior suggests that the available starting torque may be limited.

[GMA]

Hello @Ashad27,

You can tune live the Speed PI regulator by using MC Pilot Advanced Configuration (increasing Kp to be more sensitive to low-speed values).

[Ashad27]

As per my test result For a load of 0.05Nm, motor struggle to start at 1000 rpm-1500rpm 

Motor is rated for 0.25Nm torque and when we are starting the motor below rated torque and at lower speed it's not starting.
Does increasing the proportional gain (Kp) make the motor start at lower rpm with higher torque.
In my application during startup, I need higher torque or torque boost 

[GMA]

Hello @Ashad27,

Refer to A priori determination of speed regulator PI gains chapter of the MCSDK User Manual available through "Workbench tool">About>Documentations>Documentation for more detail.