Published in IET Generation, Transmission & Distribution Received on 7th June 2011 Revised on 5th March 2012 doi: 10.1049/iet-gtd.2011.0806 ISSN 1751-8687 Simultanous emergency demand response programming and unit commitment programming in comparison with interruptible load contracts M.M. Sahebi E.A. Duki M. Kia A. Soroudi M. Ehsan Center of Excellence in Power System Management & Control, Sharif University of Technology E-mail: sahebi@ee.sharif.edu Abstract: Different reasons such as power system restructuring, electricity price variation in some hours of a day and growth in the fuel price, have led to more attention to demand response (DR) programmes for consumers. Two important issues in DR programmes are emergency demand response programming (EDRP) and Interruptible/Curtail able (I/C) programme that is utilised as interruptible load contracts (ILC). The EDDR is utilised to decrease the consumption in peak load or critical hours of the day. This occurs by means of customer’s behaviour in response to the incentives. However, the curtailment of voluntarily loads in the critical hours considering the consumer requirements is an action that can be performed in DR. A model has been proposed for EDRP and ILC implementation in the unit commitment (UC) programme. Then, the effect of these two DR programmes have been compared in long-term UC problem with fuel constraints. The proposed methodology has been formulated as a mixed integer linear problem and implemented in GAMS environment. The proposed model is applied to a 6-bus test system and a modified IEEE 118-bus system to demonstrate its effectiveness. Nomenclature TC Total cost of unit commitment programming ($) F C,i (P itp , I itp ) Running cost of unit i at time t at weekly interval p P itp Real power generation of unit i at time t at weekly interval p (MW) I itp Binary variable of generation unit commitment equals 1 if generator is online at time t at weekly interval p, 0 otherwise) SU itp Startup cost of unit i at time t at weekly interval p SD itp Shutdown cost of unit i at time t at weekly interval p F f,i (P itp , I itp ) Fuel usage of unit i running during time t in week p F i min Minimum permissible fuel usage of unit i F i max Maximum permissible fuel usage of unit i F Gj min Minimum permissible fuel usage of generation group Gj F Gj max Maximum permissible fuel usage of generation group Gj SU f,itp Startup fuel usage of unit i during time t in week p SD f,itp Shutdown fuel usage of unit i during time t in week C EDRP Cost of EDRP participation ($) GCS Gross consumer surplus NCS Net consumer surplus E(t, tz) Price elasticity of the time t against period tz a(tz) Incentive price paid to the costumer in load period tz for voluntary load reduction ($/MWh) p(tz) Price of electricity in period tz ($/MWh) q 0 (t ) Initial demand of costumer (MW) q(t ) New demand of costumer after participation in EDRP C IL Cost of interruptible load programming participation ($) IL btp Load shedding in bus b at time t (MW) ILP b Bidding price for interruptible load in bus b ($/MWh) IIL btp Binary variable of interruptible load participation (equals 1 if load curtailment occurs during time t and week p, 0 otherwise). P btp D Demand at bus b during time t in week p (MW) IL b Max Maximum amount of reduction that has been mentioned at bus b (MW) f ltp Electricity flow in line l at time t in week p ILH b fix Desired value of Interrupted Load Hours (ILH) for each bus tz Time period of consumption (included peak, off-peak, low) i Index of generation units from 1 to N G IET Gener. Transm. Distrib., 2012, Vol. 6, Iss. 7, pp. 605–611 605 doi: 10.1049/iet-gtd.2011.0806 & The Institution of Engineering and Technology 2012 www.ietdl.org