How to turn off the partial defocusing function

Hi, Paul
Due to the nature of our project (industry heat generation), we actually do not need the SCA to defocus in case there is excess solar power available at the solar field. We have sufficient heat sink resources to take what solar filed can generate. In that regards, I would like  to turn off the "Allow partial defocusing" function, and allow the SAM to generate more power than design if it can. So is there a way to do this in SAM?
An potential alternative way ( I think) can be to define a higher over design operation value (default is 1.05). But I am not able to find where to change this either. Could you please direct me to see if there is a way to do this? 
Thank you!
Harry

Hi Harry,

The heat sink output fraction variable for the IPH Trough model is on the System Control page.

Best regards,
Paul.