Speed measurement methods in VisSim
Altair EmployeeSubmitted by lukasovich on Thu, 12/08/2011 - 04:46
Hi,
I have been working with TI PFC & Motor Control Developers Kit. Kit contains development board with F28035 Piccolo processor and 2 PMSM motors with built-in Hall sensors.
I tried to spin motors with speed feedback, so I found several examples (for example pmsm31B3) included with VisSim 8.0. I didn't succeed, and I got no signals. I suppose that people how made this example used quadrature encoder? Is possible to measure speed using Hall sensors (included with motors in TI kit) using VisSim 8.0? Is there any example?
Thank you.
Answers
-
Submitted by Anders89 on Sat, 12/10/2011 - 04:07.
You will see a Speed Calc block inside both the pmsm2motor-28035 diagram and the DRV8312EVM-pmsm-28035 examples. It works fine in our labs. It takes a fraction of full rotation as input (a constant velocity motor would produce a sawtooth with amplitude 1). The output is the fraction of full rated speed. This doesn't matter how you get the angle, either sensorless algorithm or quadrature encoder so long as you rescale the measure to unit operation. In the quadrature encoder case you must divide by the number of ticks in a full rotation.
A speed calc block is attached to this post.
We have tried the hall sensors on the Anaheim motor in the TI Multi-axis DMC EVM kit, but we could not get reliable Hall signals from the board. We don't know if the problem is the board or the hall sensors on the Anaheim motor. Of course you can treat the hall sensor as an encoder with 6 ticks.0