Hello, I have some related questions about the DC OPF baselines.

1. It seems that for many of the typical operating conditions, the DC approximation better minimizes the cost than the full AC solution. Is this expected? Does this factor in any constraint violations?

2. In some of the small angle difference cases, the objective values for the DC approximation are listed as "Inf". Does that indicate a constraint violation?

It seems none of the test cases in pglib-opf are radial? That makes it hard to use any of these benchmarks to use/extend them for models that require a consistent definition of upstream/downstream, e.g. as in [1] below.

I recall that the NESTA archive had a /rad m file collection. Was there any discussion on including that in pglib-opf? What happened to it?

[1] Dvorkin, V., Fioretto, F., Van Hentenryck, P., Kazempour, J., & Pinson, P. (2020). Differentially Private Optimal Power Flow for Distribution Grids, 1, 1–9. Retrieved from http://arxiv.org/abs/2004.03921

Hello Sir, i came to know about you from your videos of Convex Relaxations in Youtube... Sir i need help from you, i am stuck in my project work....i am trying to find an optimze a system 3m9b for test....

and i wrote the optimization problem like this.... for i=1:1 cvx_begin cvx_solver sedumi

variables u(npv,1) variable W(2n,2n) symmetric summ=trace(YYreal(:,:,1)*W); for i=2:n summ=summ+trace(YYreal(:,:,i)*W); end for i=1:npv u(i,1)==trace(YYreal(:,:,i+npq)W);
(This u contais the PV buses active power generation...(whose optimal value has to be found)) end minimize(w(sum(u)+trace(YYreal(:,:,n)*W)))

subject to for i=1:npq (this are equality constraints "calculated active power=specified active power" for pv&pq buses) trace(YYreal(:,:,i)*W)-(Pg(i,1)-Pl(i,1))==0; trace(YYreal(:,:,i)*W)-(Pg(i,1)-Pl(i,1))==0; end for i=1:npv (this bounds i thought to apply after getting a local optimal solution from Newtons Method) trace(YYreal(:,:,i+npq)*W)+Pl(i+npq,1)>=-0.2 trace(YYreal(:,:,i+npq)*W)+Pl(i+npq,1)<=3 end

for i=1:npq (this are equality constraints "calculated reactive power=specified reactive power" for only pq buses) trace(YYimag(:,:,i)*W)-(Qg(i,1)-Ql(i,1))==0; trace(YYimag(:,:,i)*W)-(Qg(i,1)-Ql(i,1))==0; end

W==semidefinite(2*n); W>=0; cvx_end w=w+1 for i=1:npv Pg(i+npq,1)=trace(YYreal(:,:,i+npq)*W)+Pl(i+npq,1); end end

Sir, in the paper it is "Zero Duality Gap In Optimal Power Flow" that rank of W matrix variable should come=1 when the duality gap is "0". and for that we applied weight method.(w is the weight)..

Sir.. for some values of w i get solution as 'NAN'. and for some i get an optimal solution...but the 'W matrix' never comes of rank 1...

i dont know where i am going wrong...but please help me with this....

Hi, first, thanks for your work aggregating and building this library!

I'm trying to use the 1354pegase case and am implementing my own simplified opf model where I want to impose line current constraints for line l = (i,j) according to

(|y_ij| |V_i - V_j|)^2 <= rhs

for V_i, V_j the complex voltages at buses i and j and |y_ij| is the magnitude of the (i,j) element of the admittance matrix. (Btw, I'm ignoring tap adjustments now...)

However, I'm not sure what the units of the rhs should be from the pglib case. According to Table V of the report (https://arxiv.org/abs/1908.02788), it seems that rateA is a thermal limit that was determined by the TL-UB method from Section V.B.2. Does this mean that the rateA is already normalized by baseMVA and given in p.u. form? Or should I divide rateA by 100 to get the p.u. (and then square it to set the value of the rhs).

Thanks!

In some cases all tap settings are 1.0, I check should be made so that this only occurs when the value is not 1.0 or the branch is connecting two voltage levels.

Some inactive generators have infeasible active power bounds (i.e. pmax < pmin). Resolve this by ensuring,

pmin = min(pmin,pmax)
pmax = min(pmin,pmax)

in all generators.

In pglib_opf_case1888_rte__api.m, the real power lower bound for the generator at bus 1689 (line 2,044 of the `.m' file) is 280.0, but the upper bound has been modified to be 64 (from 930 in the original case). Is this intentional? If so, what does it mean if the generator is turned on?

Thank you for your help!

Hello,

I got the following error when solving OPF for 2 test cases: case89_pegase__api and case240_pserc__api with the MATPOWER function runopf. It seems that there is a problem when generator bound Pmax is 0.

Error using makeAvl (line 52) makeAvl: either Qmin or Qmax must be equal to zero for each dispatchable load.

Error in opf_setup (line 171) [Avl, lvl, uvl] = makeAvl(baseMVA, gen);

Error in opf (line 198) om = opf_setup(mpc, mpopt);

Error in runopf (line 75) [r, success] = opf(casedata, mpopt);

Best regards,

Christian

Explore the possibility of including a network derived from the 68-Bus, 16-Machine, 5-Area Dynamic Test System.

Related Links:

• http://sites.ieee.org/pes-psdp/benchmark-systems-2/
• https://electricgrids.engr.tamu.edu/electric-grid-test-cases/
• http://icseg.iti.illinois.edu/new-england-68-bus-test-system/
• http://sites.ieee.org/pes-resource-center/files/2015/08/PES_TR18_Benchmark-Systems-for-Small-Signal-Stability-Analysis-and-Control.pdf
• http://www.sel.eesc.usp.br/ieee/NETS68/New_England_New_York_68_Bus_System_study_report.pdf