Motor behavior is suspect when performing motor starting study

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I'm performing a motor starting study and used IMD to create my CIM5BL dynamic model for 3600 HP motor.

 1327 'CIM5BL'     L9           2
     0.02180       0.1200       2.8900       0.04800      0.0075
     0.00800       0.0180       1.0000       0.10000      1.2500    
      0.4000       3.1400        0.0000       0.63249      0.0000    
      0.0000       0.0000        0.0300       0.86127    /

Based on some other forums, I've changed my time step and frequency step as noted below. The other forums recommend time step of 0.001 seconds but after experience non-convergence and "NAN" errors, the time step was further modified.

psspy.dynamicssolutionparam2([i,i,i,i,i,i,i,i],[0.5,f, 0.00075,0.004,f,f,f,f])

The motor's response time and the speed deviation don't perform as expected. Initially there's a 0.5 second flat start before turning the motor load on, as discussed in the Program Application Guide 2. The torque spikes at 0.7 seconds and reaches nominal torque around 2 seconds. The current spikes to a value not quite LRC and is already approaching unity by 1 second. The speed deviation oscillates slightly rather than a smooth curve approaching 0.

I'm at a loss at to what to do. The motor curves in IMD match the motor documents, but not seeing those same curves when running dynamic analysis in PSS/e.