Dear Prof Ray I studied extended OPF function to adopt my problem to be run with MATPOWER package as you recommended already, so I could avoid implementing standard OPF constraints like line loadings and voltage range. As I am running a multi-objective congestion management problem (equivalently, maybe called multi-objective OPF), is it possible to include other objective functions separately in the OPF cost function? for example :
f1= I have my own cost function, so I can minus the existed cost function to cancel it and add my own cost functions that are still directly depended on the optimization vector. f1=sum(X[i].Bup[i]+Y[i].Bdown[i]), where X and Y are up and down generation shift of unit i and Bup[i] and Bdown[i] are their corresponding bid. f2= security function. f2 is also directly depended on the optimization vector. f2=sum(X[i].S[i]), where x[i] is up generation shift of unit i and S[i] is its corresponding sensitivity to the stability margin. Your help is much appreciated. On Fri, Apr 10, 2015 at 9:11 PM, Electric <[email protected]> wrote: > Dear Prof Ray and Shiri > Thank you so much for your help. I am going to study opf_consfcn() > <http://www.pserc.cornell.edu//matpower/docs/ref/matpower5.1/opf_consfcn.html> > and find out how to implement the constraints I want. > Kind regards. > > On Fri, Apr 10, 2015 at 5:43 PM, Ray Zimmerman <[email protected]> wrote: > >> Specifically, you might look at how the power flow and line limit >> constraints are implemented in opf_consfcn() >> <http://www.pserc.cornell.edu//matpower/docs/ref/matpower5.1/opf_consfcn.html>. >> However, for a problem that includes the standard OPF constraints I still >> think it would be simpler and cleaner to set up your problem to use the >> extended OPF formulation in MATPOWER, unless of course you have some >> requirement the precludes that option. >> >> Ray >> >> >> On Apr 9, 2015, at 10:40 PM, Abhyankar, Shrirang G. <[email protected]> >> wrote: >> >> http://www.pserc.cornell.edu//matpower/docs/ref/ >> >> On Apr 9, 2015, at 4:00 PM, "Electric" <[email protected]> >> wrote: >> >> Dear Shri >> Thanks for your answer. But I don't want to use runopf(). I want to >> write these constraint manually with Ybus and equations I've written. Is >> that possible? How should I start? >> >> Thank you. >> >> On Fri, Apr 10, 2015 at 1:24 AM, Abhyankar, Shrirang G. < >> [email protected]> wrote: >> >>> I don't know what your algorithm does but I think you can do the same, >>> determine optimal generation and load, using MATPOWER's optimal power flow >>> (runopf). runopf supports all the constraints that you've listed. >>> >>> >>> Shri >>> >>> ------------------------------ >>> >>> *From:* [email protected] [ >>> [email protected]] on behalf of Electric [ >>> [email protected]] >>> *Sent:* Thursday, April 09, 2015 3:18 PM >>> *To:* MATPOWER discussion forum >>> *Subject:* How to verify the feasibility of your solution without >>> running Power flow? >>> >>> 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 >>> >>> >>> >> >> >
