Hey all,

I need your help. I develop a SOCP formulation for optimal power flow. However, The following error shows

**** Variable enters more than one =C= equation

X(i1)

**** Variable enters more than one =C= equation

X(i2)

**** Variable enters more than one =C= equation

X(i3)

**** Variable enters more than one =C= equation

X(i4)

**** Variable enters more than one =C= equation

X(i5)

Here is the model

*** SETS

set i bus /i1*i5/;

alias (i,j);

*** PARAMETERS

table G(i,j)

$include g.txt

;

table B(i,j)

$include b.txt

;

*** VARIABLES

variable obj

variable P(i)

variable Q(i)

variable X(i)

variable R(i,j)

variable Y(i,j)

*** EQUATION DECLARATION

equations

power_loss

active_power(i)

reactive_power(i)

cone(i,j)

;

*** EQUATION

X.fx(i)$(ord(i)=1)=1.06*1.06/sqrt(2);
power_loss…
obj =e= sum((i,j),G(i,j)*(sqrt(2)*X(i)+sqrt(2)

*X(j)-2*R(i,j)));

active_power(i)…

P(i) =e= sum(j,G(i,j)*R(i,j)+B(i,j)*Y(i,j));

reactive_power(i)…

Q(i) =e= sum(j,-B(i,j)*R(i,j)+G(i,j)*Y(i,j));

cone(i,j)…

X(i)+X(j) =C= R(i,j)+Y(i,j);

model ep /all/;

option limrow = 10000;

option lp=mosek;

solve ep using lp minimizing obj;

g.txt (758 Bytes)

b.txt (766 Bytes)