Thank you Prof !! On Mon, Mar 25, 2013 at 7:51 AM, Ray Zimmerman <[email protected]> wrote:
> The total cost for a dispatchable load is negative … the marginal cost is > positive. But, yes, the overall cost of "generation" at a bus could be > negative if you are adding together the costs of actual generators and > dispatchable loads. In fact, the total "cost" is now the negative of the > net benefit, so it could be a very large negative number. > > -- > Ray Zimmerman > Senior Research Associate > 419A Warren Hall, Cornell University, Ithaca, NY 14853 > phone: (607) 255-9645 > > > > > On Mar 22, 2013, at 12:30 AM, Aman Bansal <[email protected]> > wrote: > > Dear Prof. > > Last question, like we have represented dispatchable loads as negative > generation, what about their cost functions? > > I mean a & b for dispatchable loads will also be considered as negative? > > if yes this may result in overall negative cost function for the > generation at a particular bus... > > thanks sir > > > On Thu, Mar 21, 2013 at 1:35 PM, Ray Zimmerman <[email protected]> wrote: > >> For multiple generators and dispatchable loads at a bus, you simply have >> multiple injections, let's call them p1, p2, …, pn, and each has a cost >> f1(p1), f2(p2), … fn(pn). To get the aggregate cost function you simply add >> everything together. Let p = p1+ p2 + … + pn be the aggregate injection and >> f(p) = f1(p1) + f2(p2) + ... + fn(pn) be the total cost function. >> >> -- >> Ray Zimmerman >> Senior Research Associate >> 419A Warren Hall, Cornell University, Ithaca, NY 14853 >> phone: (607) 255-9645 >> >> >> >> >> On Mar 21, 2013, at 3:20 AM, Aman Bansal <[email protected]> >> wrote: >> >> Prof. Zimmerman >> >> But in case when a generator and a price sensitive load lie on same bus, >> then if we denote price sensitive load as negative of generation, then what >> is the effective cost function at that bus is both generator and >> dispatchable load have different cost functions..... >> >> On Wed, Mar 20, 2013 at 8:16 PM, Ray Zimmerman <[email protected]> wrote: >> >>> You can still easily create a matrix that corresponds to only the real >>> generators (dimension 6 in your example). There is a lot of internal code >>> that does something like … >>> >>> ig = find(~isload(mpc.gen)); >>> >>> … and then uses ig to index the generator and gencost matrices to get >>> info only for the real generators. >>> >>> -- >>> Ray Zimmerman >>> Senior Research Associate >>> 419A Warren Hall, Cornell University, Ithaca, NY 14853 >>> phone: (607) 255-9645 >>> >>> >>> >>> >>> On Mar 20, 2013, at 2:54 AM, Aman Bansal <[email protected]> >>> wrote: >>> >>> Hello Prof. Zimmerman >>> >>> I just realized from the manual that dispatchable or price-sensitive >>> loads are modelled as negative real power injections with associated costs. >>> But if we represent them as generators instead of loads (which they are >>> actually), the flow participation matrix (that is obtained from power >>> tracing) get affected. Like consider we have 6 gencos in problem and there >>> are 5 price sensitive loads, then generator participation matrix would >>> become 11*x instead of 6*x. >>> >>> How to deal with this?? >>> >>> please enlighten me >>> >>> -- >>> Aman Bansal, >>> M.Tech. Student (Power Systems) >>> Indian Institute of Technology (BHU) >>> Varanasi >>> Cell No. +91-841-799-9350 >>> >>> **The smallest good deed is better than the grandest good intention** >>> >>> >>> >> >> >> -- >> Aman Bansal, >> M.Tech. Student (Power Systems) >> Indian Institute of Technology (BHU) >> Varanasi >> Cell No. +91-912-569-8850, 841-799-9350 >> >> **The smallest good deed is better than the grandest good intention** >> >> >> > > > -- > Aman Bansal, > M.Tech. Student (Power Systems) > Indian Institute of Technology (BHU) > Varanasi > Cell No. +91-912-569-8850, 841-799-9350 > > **The smallest good deed is better than the grandest good intention** > > > -- Aman Bansal, M.Tech. Student (Power Systems) Indian Institute of Technology (BHU) Varanasi Cell No. +91-912-569-8850, 841-799-9350 **The smallest good deed is better than the grandest good intention**
