I am using an algorithm that changes the amount of demand and
generation at each bus (Pd,Pg) to mitigate over load of lines and enhance
the security. The output of my algorithm (Pd,Pg) must be checked to insure
that they are feasible. So, it is obvious that by assigning this new
calculated values instead of old Pg and Pd (generation and demand ) at each
bus and running a simple power flow (pf), I can find out if the calculated
results are feasible.
However, this is an optimization problem. Therefore, feasibility of
the suggested values of Pd and Pg by fmincon must be verified at each
iteration(1000 times). Basically, it can be accomplished by running a power
flow in constraint function of fmincon and checking lines loading and
voltage range.
But, doing so is very time consuming and takes more than an hours to
calculate the feasible Pg and Pd. So I was wonder if there is another
faster way to check the feasibility of the calculated Pd,Pg without running
power flow.
I think, if the solution (calculated Pd,Pg) satisfies these constraints,the
answer is then feasible and there is no need to run power flow.
But I have some problems in considering the constraints 5,8,9,10.
1) Pgmin(j) <Pg(j) <Pgmax(j) % j indicates buses with generator
2) Qgmin(j) <Qg(j) <Qgmax(j) % j indicates buses with generator
3) Pdmin(k) <Pd(k) <Pdmax(k) % k indicates buses with demand
4) Qd(k)=Pd(k)*tan(phi(k)) % ph(k) is load P.F at bus K
Nodal active balance:
5) Pg(n) -Pd(n)=|V(i)| sum( |Y(h,n)| .V(h)*Cos(del(n)-del(h)-teta(n,h)))
where Pg(n) is nodal generation which is calculated as:
6) Pg(n)=sum (Pg(j)) at bus n
7) Pd(n)=sum (Pd(k)) at bus n
teta(n,h) is the angle of Y(n,h), del(n) and del(h) are bust angle of n and
h.
Nodal reactive balance:
8) Qg(n) -Qd(n)=|V(i)| sum( |Y(h,n)| .V(h)*Sin(del(n)-del(h)-teta(n,h)))
9) Vmin(n)<V(n)<Vmax(n) % voltage range at all buses.
10) S(i,j)<Smax(i,j). transmitted apparent power from i,j must be less
than capacity of line.
Thanks in advance
