TIDM-1003: Improve the High_speed BLDC motor load capacity under constant low speed

Hi.

We used the LaunchXL-F28027F+ Boostxl-DRV8305EVM demo board(Using the routine lab11a) to drive the 24V  sensorless BLDC. The motor needs to run stably inlow speed heavy load(300rpm) and high speed light load(40000rpm) two working conditions. 

However, it can only drive 50% of the rated load torque when the motor is constant at 300 RPM—— the output current of the motor will oscillate If the load continues to increase.

I don't understand what causes this? Is there a way to solve this problem using Ti related solutions?

Looking forward to your help,thanks!