function pxi=NcalGCum(cgi, ngi, pgi)

% calculate cumulants of each generator
%cgi - perunit
%ngi- No. of generator
%pgi-availability

afa1=pgi;
afa2=pgi;
afa3=pgi;


px1=afa1;
px2=afa2-px1^2;
px3=afa3-3*px1*px2-px1^3;

pxi=zeros(1,3);
pxi(1,1)=ngi*cgi*px1;
pxi(1,2)=ngi*cgi^2*px2;
pxi(1,3)=ngi*cgi^3*px3;

return