Operating BLDC motor in Speed Control Mode

[JAM_1999]

Hello!

We are trying to run the BLDC Motor (BL34E34-01) in speed control.

A project was previously shared with us that allowed us to run the same motor in position control mode. Given a target position and duration, the motor reaches the final position smoothly.

However, when we used the same project, but changed from Position Control to Speed Control, the motor behavior is inconsistent. If we keep the same settings, or if we change to another BLDC motor settings (say BL17E19-02), the motor will rotates for 1-2 seconds and will come to a stop eventually. After coming to a stop, the current and power will still be high. 

By changing the encoder alignment from 0 to 90, there was no difference, but if we changed from 90 to 153, the duration of rotation increased by a couple of seconds, but it still comes to a stop later. 

The only situation where we have been able to rotate the motor, without coming to a halt is when we update the speed sensor mode (in the MC Workbench) from Quadrature Encoder to Sensorless Mode. In this mode, we are able to rotate the motor for an extended duration without coming to halt.

I have attached the original project which we received for performing position regulation.

Let me know if there is any other information you need. 

Thank you!

[GMA]

Hello @JAM_1999,

Sounds for me that when you have done your Speed Control test you were still running position control FW, as 2 second rotation corresponds to alignment phase, and once motor stops it remains powered.

When you are running your sensor less (STO PLL) test, could you please add encoders as auxiliary sensor and check with motor control pilot "Graph and record" display tool that STOPLL_EL_ANGLE and ENCODER_EL_ANGLE are aligned? And if it is the case, swap Main and Auxiliary Speed Sensing Selection.