In DFIG model while using Three phase transformer(two windings) block whenever I change any parameter winding sign of the transformer block goes it shows three question marks

When I change Winding 1 connection Yg to Y and Winding 2 connection Yg to Y and units of parameter pu to SI, winding sign remains same but when i want to change any of the three parameters as my m file the winding sign of transformer block goes and instead there shows three question marks.

And also in command window its showing: "Warning: Could not evaluate MaskDisplay commands of block 'DFIGwithgridside/Three-Phase Transformer (Two Windings)1': Undefined variable "ST" or class "ST.satx"."

Answer 1

[Yoke Peng Leong]

I was able to change the three parameters programmatically without seeing any question marks.

>> gcb

ans =

    'untitled/Three-Phase
     Transformer
     (Two Windings)'

>> set_param(gcb,'Winding1Connection','Y')
>> set_param(gcb,'Winding2Connection','Y')
>> set_param(gcb,'Units','SI')

Based on the error message, your MATLAB script might have changed something incorrectly or changed something else apart from the parameters.