Thank you! It works fine with polynomial cost.
>From: Ray Zimmerman <[email protected]> >Reply-To: "MATPOWER discussion forum" <[email protected]> >To: MATPOWER discussion forum <[email protected]> >Subject: Re: AC-OPF load shedding >Date:Thu, 23 Dec 2010 11:54:27 -0500 > >You should not need to use add_costs. I would suggest using a small constant >positive cost for all of the original generators (though zero should work). >I'm not sure I've ever tested it, but I believe a polynomial cost for the >dispatchable loads should work just fine. > >-- >Ray Zimmerman >Senior Research Associate >211 Warren Hall, Cornell University, Ithaca, NY 14853 >phone: (607) 255-9645 > > > >On Dec 23, 2010, at 3:58 AM, jrwang wrote: > >> >> Dear All, >> >> I want to model load curtailment based on AC-OPF by using dispatchable load. >> And the objective is to minimize the total amount of active load(deltaPd) >> curtailed. >> >> Do I need to modify the objective using the add_costs methods? Or only set >> the cost coefficients of original generators to be zero? >> >> Another question is: can the negative generator (dispatchable load) use >> polynomial cost? >> >> Thanks! >> >> ---------------- >> Jingran Wang >> PhD candidate >> Key laboratory of Smart Grid, Ministry of Education >> Tianjin University >> Tianjin,300072 >> China >> Work: +86-022-27404221 >> E-mail: [email protected], [email protected] >> >> >> >>> From: Ray Zimmerman >>> Reply-To: "MATPOWER discussion forum" >>> To: MATPOWER discussion forum >>> Subject: Re: load shedding >>> Date:Mon, 1 Nov 2010 13:52:56 -0400 >>> >>> Yes. Either method works for AC OPF. >>> >>> -- >>> Ray Zimmerman >>> Senior Research Associate >>> 211 Warren Hall, Cornell University, Ithaca, NY 14853 >>> phone: (607) 255-9645 >>> >>> >>> >>> On Oct 31, 2010, at 2:40 AM, jrwang wrote: >>> >>>> >>>> Are the same techniques suited for load shedding in AC-OPF considering >>>> voltage constraints? >>>> >>>> Thanks! >>>> >>>>> From: Ray Zimmerman >> >>>>> Reply-To: "MATPOWER discussion forum" >> >>>>> To: MATPOWER discussion forum >> >>>>> Subject: Re: load shedding >>>>> Date:Fri, 29 Oct 2010 12:01:46 -0400 >>>>> >>>>> Both techniques work. You can do as you suggest and simply add a high >>>>> cost generator next to the load . Or you can do as Carlos suggests and >>>>> replace the load with a dispatchable load at a high price. See section >>>>> 5.4.2 in the manual for more details. >>>>> >>>>> One advantage to the latter is that as the load sheds it maintains a >>>>> constant power factor. >>>>> >>>>> -- >>>>> Ray Zimmerman >>>>> Senior Research Associate >>>>> 211 Warren Hall, Cornell University, Ithaca, NY 14853 >>>>> phone: (607) 255-9645 >>>>> >>>>> >>>>> >>>>> On Oct 29, 2010, at 12:21 AM, Mehdi wrote: >>>>> >>>>>> Hi there, >>>>>> >>>>>> Can anybody help me with how can I consider load shedding in MATPOWER's >>>>>> dc-opf ? >>>>>> >>>>>> Can I model load shedding as active power only generator (Pg=0, >>>>>> Pgmax=Load at that bus, Qg,Qgmax=0) at load buses? Then by running the >>>>>> dc-opf the output of these generator can be considered as load >>>>>> shedding!!! >>>>>> >>>>>> Regards, >>>>>> Daniel >>>>> >>>>> >>>> >>>> >>> >>> >>> > > > >
