MU_PMIN and MU_QMIN are shadow prices on the minimum generation limits for real and reactive power. Constraint shadow prices, also called Kuhn-Tucker multipliers, are a standard output of most all constrained optimization solvers. See any book on constrained optimization for a description of their meaning and how they are computed for any given algorithm.
In MATPOWER, the shadow prices are computed by whichever solver is used. For example, in the case of the default MIPS solver, they are included in the mu variable in equation (A.32) in Appendix A. The value is computed in mips.m. I should probably mention also that in the case of trapezoidal generator capability curves (see Section 5.4.3 in the manual), if one of the sloped portions of the curve is binding, its shadow price is decomposed into components for the corresponding real and reactive limits. -- Ray Zimmerman Senior Research Associate 419A Warren Hall, Cornell University, Ithaca, NY 14853 phone: (607) 255-9645 On Mar 25, 2012, at 7:08 PM, Carol Francesca wrote: > Dear Prof. Zimmerman, > > I have a question: > > When I do runmarkt sometimes price and Lambdas are not equal and its because > of network congestion and losses. > In MATPOWER, how MU_PMIN and MU_QMIN are calculated? Could you please address > the m.file which calculates these? > How they affect the prices? There is no sufficient explanation about it in > the manual. I am sorry but I cannot understand how they are calculated. > > Best Regards > > Carol
