Date: Nov 30, 2012 12:46 PM
Author: mado
Subject: algebraic loop error

when using Ipold= Ip in this embedded function code 

function [e,Pm,Ip] = new(In,Vn)
persistent Ipold ;
if isempty(Ipold)
Ipold=2; %initialized only once in the beginning
end
K1=2;
K2=-.195;
Pn= Vn*In
Pm=100*In
e= Pn-Pm
if Pn>Pm
Ip = Ipold+K1 *e
end
Ip = Ipold+K2 *e
Ipold=Ip



error message appeared
"Trouble solving algebraic loop containing 'chee_pv/pv6/Algebraic Constraint/Initial Guess' at time 0. Stopping simulation. There may be a singularity in the solution. If the model is correct, try reducing the step size (either by reducing the fixed step size or by tightening the error tolerances)"