Hi
The same problem i faced in my experience and there i faced this problem because i havnt given any reference or base values to wind. When you directly connect a wind turbine to generator with out any reference value, at each and every simulation, level of harmonics may change. So you should give a reference value to the wind turbine and if you dont want to compare the results with the reference value, you can keep a constant block.
Try doing this and hope this helps you
