1) I suppose you could model each area as a single node with both a generator and dispatchable load, with a fully connected network, but I'm not sure how you would come up with meaningful network parameters. It sounds like you don't particularly care about modeling the underlying physical network with the transmission limitations it imposes, correct? If that's the case, then using a DC OPF on such a system without line flow constraints is probably fine.
2) Optimal from the point of view of maximum earnings of the area 5 market participant (gen owner and load). Offering all available generation at marginal cost will ensure that any power that can be generated at a profit will be. Likewise for the load, any benefit that can be derived by consuming electricity will be. Putting in a higher offer (for the gen) or a lower bid (for the load) would only result in a reduced quantity being sold or bought. This is basic auction theory in a last accepted offer/bid style of auction (which I've been assuming). 3) This is clearly a bi-lateral type market, where each transaction is between a specific buyer and a specific seller. MATPOWER's smartmarket does not include this type of market. As I mentioned in my previous e-mail, it only handles a single centralized market, where all transactions are between a buyer or seller and the ISO itself, never between a specific buyer and a specific seller. That is, all power sold by generators is bought by the ISO and all power bought by the loads is sold to them by the ISO. So, my comments about the optimal bid/offer strategy probably do not apply to the kind of market you are envisioning, which, by the way, only makes sense IF you can justify the use of a linear network model. The difficulty with real world electricity markets is that every physical transaction affects the cost of every other physical transaction, because of network losses and congestion. -- Ray Zimmerman Senior Research Associate 211 Warren Hall, Cornell University, Ithaca, NY 14853 phone: (607) 255-9645 On May 21, 2010, at 9:31 AM, Anirudh Raghavan wrote: > Thanks for your response. I still have a couple of doubts: > > 1) Can't interconnected areas be modeled as interconnected generators, > with each area having one buy-bids-negative-generator and one > sell-bids-generator, assuming all generators except those > corresponding to the same area, are connected? > > 2) I did not quite follow what you meant by "the optimal offer from > area 5 would be the marginal cost of generation and the optimal bid to > buy would be the marginal benefit of consumption". To clarify, the > areas are completely interconnected and can exchange power with each > other, based on some non-area-specific inter-area transaction limit. > > 3) For a particular buy bid of the entering area, with qty Q and price > P, this area would pay (P-P')*Q/2 to the broker and (P+P')*Q/2 to the > seller,(assuming sell bid of P') and hence a total of PQ would be > paid. Hence, to maximize the benefit of recording a bid earlier than > an existing one, but minimizing the cost, which depends only on P, not > P', shouldn't the optimal buy bid prices for the new area be some > epsilon higher than existing buy bids(with some zero and some non-zero > quantities) and the sell bids as some epsilon lower than existing sell > bid prices? > > Thanks in advance. > > Anirudh > > On Fri, May 21, 2010 at 5:01 PM, Ray Zimmerman <[email protected]> wrote: >> Anirudh, >> First of all, MATPOWER's smartmarket code is based on nodal bids/offers, not >> zonal. That is, the offers to sell are from individual generators, and the >> bids to buy are from individual dispatchable loads. Second, it treats the >> bids and offers as inputs to an optimization problem that an ISO/RTO would >> run to compute the optimal dispatch and corresponding prices. It does not >> compute any optimal bids or offers and it does not arrange bi-lateral >> transactions between buyers and sellers. All buy/sell transactions are with >> the ISO itself. >> Having said that, it sounds to me like the optimal offer from area 5 would >> be the marginal cost of generation and the optimal bid to buy would be the >> marginal benefit of consumption, UNLESS there is some market power provided >> by the network that isolates area 5 from competing generation and demand >> response OR there is some non-competitive collusive behavior going on among >> the market participants. >> I suppose, if you have the network set up with all of your bids and offers >> associated with specific dispatchable loads and generators, then you could >> use some brute force approach, where you modify offer/bid prices over a >> range for a fixed quantity, and modify offer/bid quantity over a range for a >> fixed price in search of the point that yields maximum earnings/minimum >> cost. >> Regarding (2), it sounds like you may be thinking of bi-lateral >> transactions. MATPOWER assumes everything is cleared through a central >> market, so the only limits are physical flow limits between areas, which can >> be handled by individual line flow limits or by using the interface limits >> implemented in MATPOWER 4 (see toggle_iflims.m). >> Hope this helps, >> -- >> Ray Zimmerman >> Senior Research Associate >> 211 Warren Hall, Cornell University, Ithaca, NY 14853 >> phone: (607) 255-9645 >> >> >> On May 21, 2010, at 3:43 AM, Anirudh Raghavan wrote: >> >> Hello >> >> I am new to Matpower and in need of some help with the smart_market >> auction clearing code that comes with Matpower. My aim is the >> following: >> >> 1) Given a set of buy and sell bids from 4 areas, and given >> c0,c1,c2,Pmin,Pmax,Pdemand for a 5th area, I would like to get the >> optimum buy/sell bids(their quantities and prices) that a 5th area >> should bid at, to minimize its total cost of meeting its demand. >> >> I guess the buy bids of area 5 could be modeled as a negative >> generator with piecewise continuous price function, with each of its >> prices marginally above each of the existing buy bids. Similarly, the >> sell bids could be modeled as a generator with prices marginally below >> each of the existing sell bids. However, I do not know what quantities >> to assign to these buy/sell bids. >> >> 2) Further, I would like to incorporate transaction limits between areas. >> >> Any help regarding 1 and 2 would be greatly appreciated. >> >> Many thanks, and sorry for initially posting this as a reply to the >> battery question :p >> >> Anirudh >> >> >> >
