How I can get voltage of series pv array blocks to model partial shading?

My main problems with pv array block when I try to model partial shading are:

1.I have error massage:"Algebraic state in algebraic loop containing'PV ARRAY/I FILTER/FIRST-ORDER FILTER/MODE1/SUM1' computed at..." that i tried to solve it by adding a delay block, but it cause problems with library link.

2.when I use controlled voltage source in output of pv array and connect ramp generator to signal input of it,I don't know how to identify ramp generator's slope value.

Thanks for time you spend to answer