Weak Grid Model using Diesel Generator

Hi, I have a 100kW PV with 200kW load and I want to do the load frequency response with this steup for that I have to model a weak grid so that with the load change I can see the change in frequency and then use my frequncy controller to stabilise the frequency back to nominal avlue (50Hz). I am uncertain about the diesel generator modelling in Simulink. Currently, I have modelled it using Synchronous Machine with configuration as shown in the figure. Can you please tell me is this the correct way to model a weak grid using diesel genrator or not? Is there any better way to achieve this? I tried to do the load flow using powergui machine initialisation app to set the reference power for the SG during initialisation but it didn't worked so I have manually calcuated the value. In my case at initial conditions, the PV is providing 100kW and remaining 100kW should be provided by SM during initialisation so I have set the P_ref as 0.333.