Incorrect speed reading in 6 step during PWM phase OFF

[Xavier75]

Hello,

I am currently working with MC Workbench 6.3.2.

I have a 2Pole pair motor 4800kV and I want to use the 6 step algorithm and Quasi-Synchronous Rectification.

In this configuration I can only make open loop because :

- When Sensing BEMF during PWM OFF phase --> Speed estimation is incorrect  (and very unstable)

- When Sensing BEMF during PWM ON phase --> Speed estimation is correct

I don't understand why the speed estimation in incorrect because the motor is running fine, so it commutes at the right time and the speed estimation should be ok ?

Here is a video to illustrate the issue : 

And this is my configuration in open loop :

Any advice ?

Thanks for your help !

Xavier

[Xavier75]

Hello,

Anybody can help on this ?

Additionnal info :

When Computation Delay step choice = 2, speed reading is incorrect during PWM OFF

When Computation Delay step choice = 1,  speed reading is correct during PWM OFF

Thanks for your help,

Xavier