cost-effective learning tool for students or engineers in training and canserve as a supplement to a conventional laboratory based system.

Keywords: Virtual learning systems, motor drive system, simula-tion, digital signal processing, object-oriented approach.

Preprint Order Number: PE-061PRS (10-2001)Discussion Deadline: March 2002

Power System Analysis,Computing, and Economics

Marginal Pricing of Harmonic InjectionsTalacek, Pj.; Watson, N.R.

Author Affiliation: University of Canterbury, Christchurch, NewZealand

Abstract: Proper valuation of harmonic injections and distortion iscritical if an efficient solution is to be provided for any harmonic prob-lem that may exist. Indeed, without proper tools to value harmonic dis-tortion, it is not possible to quantify the extent of any problem. Thispaper demonstrates that it is possible to develop marginal prices forharmonic injections, which will accurately reflect the value of the in-jections to the rest of the network. Given an allocation of harmonic pol-lution rights these prices act to coordinate each member of the networkto act in a globally optimal manner.

Keywords: Economics, harmonics, power quality.Preprint Order Number: PE-283PRS (10-2001)Discussion Deadline: March 2002

Sensitivity of Transfer CapabilityMargins with a Fast Formula

Greene, S.; Dobson, I.; Alvarado, F.L.

Author Affiliation: L.R. Christensen Associates, Madison, WI;University of Wisconsin, Madison, WI

Abstract: Bulk power transfers in electric power systems are lim-ited by transmission network security. Transfer capability measures themaximum power transfer permissible under certain assumptions. Oncea transfer capability has been computed for one set of assumptions, it isuseful to quickly estimate the effect on the transfer capability of modi-fying those assumptions. This paper presents a computationally effi-cient formula for the first order sensitivity of the transfer capabilitywith respect to the variation of any parameters. The sensitivity formulais very fast to evaluate. The approach is consistent with the current in-dustrial practice of using dc load flow models and significantly gener-alizes that practice to more detailed ac power system models thatinclude voltage and VAR limits. The computation is illustrated andtested on a 3357 bus power system.

Keywords: Sensitivity, power system security, power system con-trol, power transmission planning, optimization.

Preprint Order Number: PE-037PRS (10-2001)Discussion Deadline: March 2002

Distribution Pricing Based on Yardstick RegulationLima, J.W.M.; Noronha, J.C.C.; Arango, H.; Steele dos Santos, P.E.

Author Affiliation: Federal School of Engineering at Itajuba,Brazil; Electrical Energy Regulatory Agency

Abstract: Transmission and distribution (T&D) pricing has beenone of the keystones of the ongoing deregulation and privatization pro-cess in the power industry. The electricity market has been establishedbased on the assumption of open access and nondiscriminatory use ofthe T&D assets. As T&D business remains as a monopoly, it is neces-sary to provide economic regulation. Many papers have dealt withtransmission pricing and certain maturity has been reached in this area,but this is not true in the case of distribution services. This paper willfocus on the distribution pricing methods and will suggest one that is

currently under development in Brazil. This method is based on incre-mental costs derived from the aggregated expansion plan of a particularutility, named model utility. This utility was obtained by comparisonsamong the real distribution companies. The method follows the funda-mentals of the yardstick regulation.

Keywords: Distribution pricing, marginal cost, utility regulation,wheeling charges, yardstick regulation.

Preprint Order Number: PE-663PRS (10-2001)Discussion Deadline: March 2002

Statistical and Dynamic Analysis ofGeneration Control Performance Standards

Sasaki, T.; Enomoto, K.

Author Affiliation: Kansia Electric Power Co., Osaka, JapanAbstract: In 1997, the North American Electric Reliability Council

(NERC) proposed new control performance standards OPSI and CPS2to evaluate the control area performance in normal interconnectedpower system operation. Though some other control performance stan-dards had been proposed, they have not been argued against these stan-dard's statistical and physical characteristics fully before. In this paper,we will conduct a statistical analysis of control performance standardsand confirm that the statistical analysis matches the results of powersystem simulations.

Keywords: Power system, generation control, control performancestandards, control area.

Preprint Order Number: PE-258PRS (10-2001)Discussion Deadline: March 2002

The Economics of Electricity Hedgingand a Proposed Modification for theFutures Contract for ElectricityCollins, R.A.

Author Affiliation: Santa Clara University, Santa Clara, CAAbstract: First, this paper provides a simple explanation of the eco-

nomics of electricity hedging and shows why the unique characteristicsof electric power make risk management more complex than for othercommodities. Second, a change in the futures contract for electricpower is proposed that reflects these unique characteristics. Thesechanges would create a unique resettlement mechanism that wouldmake the futures contract more useful for hedgers on both sides of themarket. Finally, a sample of data are analyzed to evaluate the effective-ness of this proposal.

Keywords: Economics, risk analysisPreprint Order Number: PE-192PRS (10-2001)Discussion Deadline: March 2002

Economic Congestion Relief Across Multiple RegionsRequires Tradable Physical Flow-Gate Rights

Oren, S.S.; Ross, A.M.

Author Affiliation: University of California at Berkeley, Berkeley, CAAbstract: This paper is concerned with market-based protocols for

relieving congestion caused by transactions outside the control area inwhich the congestion occurred. One approach, proposed byCadwalader et al., is based on dual decomposition in which out-of-areacongestion is "priced-out" and added to the optimal power flow (OPF)objective function of the control area operator while the prices are de-termined iteratively via nodal energy adjustment bids. The paper dem-onstrates through a simple three-node example that even with "correctprices" on out-of-area congested interfaces, the augmented AC-OPFobjective function of a control area operator might not be locally con-vex at the optimal solution and, hence, the control area's optimal dis-patch may violate the thermal constraints on out-of-area interfaces.That conclusion supports the alternative "flow-based" approach thatenforces thermal limits more directly, which is consistent with NERC'sFLOWBAT proposal for interzonal transmission load relief (TLR).

IEEE Power Engineering Review, January 200268

Keywords: Duality, interconnected power systems, optimizationmethods, power distribution, power generation dispatch, power industry.

Preprint Order Number: PE-737PRS (10-2001)Discussion Deadline: March 2002

Incremental Transmission LossAllocation Under Pool Dispatch

Galiana, F.D.; Conejo, A.; Kockar, I.

Author Affiliation: McGill University, Montreal, Quebec, Can-ada; University of Castila-La Mancha, Spain

Abstract: Incremental transmission loss analysis has been used fordecades, but recent interest in its application to loss allocation calls fornew in-depth results. This paper demonstrates that, for incrementalmethods to be applied correctly in loss allocation, it is first necessary tospecify the load distribution and loss supply strategies. Incrementalloss allocation among bus power injections is shown to be arbitraryand, therefore, open to challenge as discriminatory. Loss allocation ispossible among incremental loads and/or generators, but the proportionof the total losses assigned to either one is arbitrary. Unique,nonarbitrary incremental loss allocations are, however, possible amongthe "equivalent" incremental bilateral exchanges between generatorsand loads. From these basic components it is possible then to calculatethe allocation among generators or loads in any specified proportion.The main results, although developed initially for small increments, areextended to large variations. Finally, a general incremental loss alloca-tion algorithm is developed and tested.

Keywords: Incremental transmission loss analysis, loss allocation,loss supply, pool dispatch, equivalent bilateral contracts, numerical al-gorithm.

Preprint Order Number: PE-106PRS (10-2001)Discussion Deadline: March 2002

Including Uncertainty in LOLECalculation Using Fuzzy Set TheoryKim, J.O.; Singh, C.

Author Affiliation: Hanyang University, Korea; Texas A&M Uni-versity, College Station, TX

Abstract: This paper presents a conceptual possibilistic approachusing fuzzy set theory to manage the uncertainties in the reliability in-put data of real power systems. In this paper, an algorithm is introducedto calculate the possibilistic reliability indices according to the degreeof uncertainty in the given data. The probability distribution functioncan be transformed into an appropriate possibilistic representation us-ing the probability-possibility consistency principle (PPCP) algorithm.In this algorithm, the transformation is performed by making a compro-mise between the transformation consistency and the human experi-ence. Fuzzy classification theory is applied to reduce the number ofload data points. The fuzzy classification method determines the close-ness of load data points by assigning them to various clusters and thendetermining the distance between the clusters. The IEEE-RTS with32-generating units is used to demonstrate the capability of the pro-posed algorithm.

Keywords: Loss of load expectation, forced outage rate, probabil-ity-possibility consistency principle, fuzzy clustering

Preprint Order Number: PE-030PRS (10-2001)Discussion Deadline: March 2002

An Empirical Study of Applied Game Theory:Transmission Constrained Cournot Behavior

Cunningham, L.B.; Baldick, R.; Baughman, M.L.

Author Affiliation: University of TexasAbstract: Restructured energy markets present opportunities for the

exercise of market power, meaning market players can potentially main-tain prices in excess of competitive prices. In this paper, we investigateCoumot equilibrium in a simple example network. We analyze three mar-

ket players in a transmission-constrained system and consider nonconstantmarginal cost. Several scenarios are evaluated that show a pure strategyequilibrium can break down even when a transmission constraint exceedsthe value of the unconstrained Coumot equilibrium line flow.

Keywords: Game theory, Coumot, transmission constraints, pric-ing of power, market models

Preprint Order Number: PE-761PRS (10-2001)Discussion Deadline: March 2002

Genetic Algorithms Based Economic Dispatchfor Cogeneration Units Considering MultiplantMultibuyer Wheeling

Hong, Y.Y.; Li, C.

Author Affiliation: Chung Yuan UniversityAbstract: A new method based on genetic algorithms (GA) is pro-

posed for optimal dispatch among multi-plant (cogeneration systems)with multi-cogenerators, which transmit MW to designated buyers(load buses) via wheeling. The operation constraints in thecogeneration systems and security constraints in the third party (trans-mission system owner) were considered. Varying weighting coeffi-cients for penalty functions and determination of gene variables for GAwere discussed. The IEEE 30- and 118-bus systems were used as testsystems to illustrate the applicability of the proposed method.

Keywords: Cogeneration, genetic algorithms, wheelingPreprint Order Number: PE-612PRS (10-2001)Discussion Deadline: March 2002

Production Cost Minimization Versus ConsumerPayment Minimization in Electricity Pools

Vasquez, C.; Rivier, M.; Perez-Arriaga, IJ.P.

Author Affiliation: Universidad Pontificia Comillas, Madrid, SpainAbstract: Algorithms that involve some kind of optimization have

been adopted by several electricity pools as a tool to clear the market.Traditionally, this kind of model was used on a cost-minimizing basis,but recent papers have pointed out that alternative dispatches may beobtained that, even with higher production costs, result in lower elec-tricity prices for consumers. This paper studies this new pay-ment-minimization approach, including the long-term economicsignals that it provides and their impact on future investments. Our re-sults show that minimizing consumer payment results in discrimina-tory scheduling for certain generation resources and may cause, in thelong run, higher prices for consumers.

Keywords: Electricity auctions, market design, unit commitment,marginal pricing, power generation dispatch, deregulation.

Preprint Order Number: PE-482PRS (10-2001)Discussion Deadline: March 2002

Power System Instrumentation Measurement

Pattern Recognition Applications forPower System Disturbance Classification

Gaouda, A.M.; Kanoun, S.H.; Salama, M.M.A.; Chikhani, A.Y.

Author Affiliation: University of Waterloo, Waterloo, Ontario,Canada; Royal Military College, Kingston, Ontario, Canada

Abstract: This paper presents an automated on-line disturbanceclassification technique. This technique is based on waveletmultiresolution analysis and pattem recognition techniques. The wave-let-multiresolution transform is introduced as a powerful tool for fea-ture extraction in order to classify different disturbances. MinimumEuclidean distance, k-nearest neighbor, and neural network classifiersare used to evaluate the efficiency of the extracted features.

IEEE Power Engineering Review, January 2002 69