Problem with simplified SI unit synchronous generator

I wish to understand how to use the synchronous generator model in simulink and construct a simple model with just one synchronous generator and one load. However when i choose the synchronous machine SI fundamental and select the 50Hz 400V 16kVA 1500rpm type with a constant mechanical input (Pm) of 10kW and 400V (Vf), the voltage and current out of the generator is totally distorted. May I know what are the reasons of such problem and how can I solve it? How should I define the parameters for a synchronous generator of 13.5kVA to supply a microgrid of 400V p-p ? Thank you.