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;
afa4=pgi;
afa5=pgi;

px1=afa1;
px2=afa2-px1^2;
px3=afa3-3*px1*px2-px1^3;
px4=afa4-3*px2^2-4*px1*px3-6*px1^2*px2-px1^4;
px5=afa5-5*px1*px4-10*px2*px3-10*px1^2*px3-15*px1*px2^2-10*px1^3*px2-px1^5;

pxi=zeros(1,5);
pxi(1,1)=ngi*cgi*px1;
pxi(1,2)=ngi*cgi^2*px2;
pxi(1,3)=ngi*cgi^3*px3;
pxi(1,4)=ngi*cgi^4*px4;
pxi(1,5)=ngi*cgi^5*px5;

return