Re: understanding opf results on shadow prices

[Carlos E Murillo-Sanchez]

Wenlei Bai wrote: Dear community, I ran an ACOPF for a modified 118 case, it produced some results for shadow prices fo Branch Flow Constraints, but as I tried to check the values from resultsAC.nli.mu, the Sf and St values didn't match?  My understanding is that resultsAC.nli.mu means the shadow prices on nonlinear inequality constraints: .Sf are the flow limits at "from" end of branches. and St are the flow limits at "to" end of branches Can someone please help me understand the opf results on shadow prices? Wenlei Dear Wenlei: The implementation of the OPF uses a constraint on the square of |Sf| with Sf in per unit, as in    |Sf_pu|^2  <=  |Sf_pu_max|^2 Therefore, the multiplier in this constraint must be scaled to reflect the real multiplier on |Sf| <= Sfmax, with |Sf| in MW, like this:     mu_pu_MW = 2 * |Sf_pu| * results.nli.mu.Sf / results.baseMVA This is the number that appears in results.branch(:, MU_SF) Carlos.