Max. speed of marathon 5K33GN2A in the field weakening region

Ahmed,

Very easy to experiment yourself. For induction motors PowerWarp is an automatic controller of magnetizing current over the entire operating range. That means it will minimize Id at all times while still producing the requested torque or speed.

When running your motor simply enable PowerWarp, and set any speed you like up to 1.99 * the FULL SCALE FREQUENCY in user.h.  

Maximum speed depends on the flux of the machine, but typically you can see 200% no load. Recall that reducing your flux means you are reducing your available torque. 

You can take an opposite approach for producing 200%+ torque at startup. Disable PowerWarp and ADD positive IdRef_A. (magnetizing current). This is called field boosting. 

When running these tests you will need to be mindful of your speed controller. During field weakening you will need to reduce the stiffness (Kp). It can be challenging for PI tuning. I highly recommend using MOTION and the SpinTAC controller if you are using 69M controlCARD. Typically you may only need to reduce the SpinTAC bandwith once, just deep into field weakening. Much more stable. 

The SpinTAC controller also helps with low speed performance,making stiffness and fast response to load changes possible down to less that 0.5 Hz.