Don't have damper winding.How to input Damper parameter of generator

You will have to derive your own synchronous machine model in order to have a model that truly does not model the damper effects.

However, with the existing machine models you can try the following: set the damper winding resistance to zero and the inductance to “inf”. You may also need to change the “Model” type to either Rotor Reference Frame or Full VBR, depending on your application. This approach may lead to numerical issues in some cases and therefore the best approach, as recommended above, is to implement your own model.