How to model constraints of photovoltaic power generators in mpc.gen?

[hhuw...@163.com]

Hi all,
I'm using Matpower 7.1 to model PV and I want to add it into mpc.gen matrix to 
see how much PV generation can be consumed in opf. 
Here comes the problem: There is a relationship between the active power output 
and reactive power output of PV, but I do not see how to consider it in the 
mpc.gen matrix. (It seems I can only set upper/lower bounds for P and Q 
respectively?) So, is there any useful method to model PV in matpower? Plaese 
help me.
Thank you very much.