this depends on the Simulink Block type that you are using within your Simulink model. For more information, you can refer the following link from Mathworks:
Thank you so much. I am working on MPPT for PV system and am using continuous simulation type. I noticed that the controller changes the duty cycle every 0.00001 seconds. I found that the sampling time equals to 0.5*(frequency^-1). Frequency is 50000 which is the frequency of the PWM generator.
0.5* (50000^-1) =0.00001 second
I need to change the sampling time during the simulation. For example, the sampling time will be smaller when there is a sudden change in the operating condition (0.000005 seconds).