Market-based transmission congestion management using extended optimal power flow techniques

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 5/9/2001This thesis describes research into the problem of transmission congestion management. The causes, remedies, pricing methods, and other issues of transmission congestion are briefly reviewed. This research is to develop market-based approaches to cope with transmission congestion in real-time, short-run and long-run efficiently, economically and fairly. Extended OPF techniques have been playing key roles in many aspects of electricity markets. The Primal-Dual Interior Point Linear Programming and Quadratic Programming are applied to solve various optimization problems of congestion management proposed in the thesis. A coordinated real-time optimal dispatch method for unbundled electricity markets is proposed for system balancing and congestion management. With this method, almost all the possible resources in different electricity markets, including operating reserves and bilateral transactions, can be used to eliminate the real-time congestion according to their bids into the balancing market. Spot pricing theory is applied to real-time congestion pricing. Under the same framework, a Lagrangian Relaxation based region decomposition OPF algorithm is presented to deal with the problems of real-time active power congestion management across multiple regions. The inter/intra-regional congestion can be relieved without exchanging any information between regional ISOs but the Lagrangian Multipliers. In day-ahead spot market, a new optimal dispatch method is proposed for congestion and price risk management, particularly for bilateral transaction curtailment. Individual revenue adequacy constraints, which include payments from financial instruments, are involved in the original dispatch problem. An iterative procedure is applied to solve this special optimization problem with both primal and dual variables involved in its constraints. An optimal Financial Transmission Rights (FTR) auction model is presented as an approach to the long-term congestion management. Two types of series F ACTS devices are incorporated into this auction problem using the Power Injection Model to maximize the auction revenue. Some new treatment has been done on TCSC's operating limits to keep the auction problem linear

Bi-Level Optimization Considering Uncertainties of Wind Power and Demand Response

Recently, world-wide power systems have been undergone a paradigm change with increasing penetration of renewable energy. The renewable energy is clean with low operation cost while subject to significant variability and uncertainty. Therefore, integration of renewables presents various challenges in power systems. Meanwhile, to offset the uncertainty from renewables, demand response (DR) has gained considerable research interests because of DR’s flexibility to mitigate the uncertainty from renewables. In this dissertation, various power system problems using bi-level optimization are investigated considering the uncertainties from wind power and demand response. In power system planning, reactive power planning (RPP) under high-penetration wind power is studied in this dissertation. To properly model wind power uncertainty, a multi-scenario framework based on alternating current optimal power flow (ACOPF) considering the voltage stability constraint under the worst wind scenario and transmission N-1 contingency is developed. The objective of RPP in this work is to minimize the VAR investment and the expected generation cost. Benders decomposition is used to solve this model with an upper level problem for VAR allocation optimization and generation cost minimization as a lower problem. Then, several problems related wind power and demand response uncertainties under power market operation are investigated. These include: an efficient and effective method to calculate the LMP intervals under wind uncertainty is proposed; the load serving entities’ strategic bidding through a coupon-based demand response (CBDR) with which a load serving entity (LSE) may participate in the electricity market as strategic bidders by offering CBDR programs to customers; the impact of financial transmission right (FTR) with CBDR programs is also studied from the perspective of LSEs; and the stragegic scheduling of energy storages owned by LSEs considering the impact of charging and discharging on the bus LMP. In these problems, a bi-level optimization framework is presented with various objective functions representing different problems as the upper level problems and the ISO’s economic dispatch (ED) as the lower level problem. The bi-level model is addressed with mathematic program with equilibrium constraints (MPEC) model and mixed-integer linear programming (MILP), which can be easily solved with the available optimization software tool

Fabrication of mixed matrix membrane containing chlorophyll extracted from spinach for humic acid removal

The implementation of the pore-forming agent in the polymeric membrane has been applied for ages in enhancing the characteristics and performance of mixed matrix membrane. In this work, chlorophyll extracted from spinach has been used as an additional pore-forming agent alongside polyethylene glycol (PEG) to improve the polysulfone’s pore structure (PSf) mixed matrix membrane. The effect of chlorophyll was investigated in terms of characteristics and performance of the mixed matrix membrane. As a result, the cross-section morphologies show that the pore structure was enhanced significantly inside the mem�brane structure for 0.25 wt% chlorophyll concentration, thus resulted in better hydrophilicity, surface roughness, and membrane porosity value. Plus, the permeation and rejection performance was increased drastically due to the pore formation inside the mixed matrix membrane structure. These results prove that the addition of chlorophyll with low concentration managed to improve the characteristics and per�formance of the fabricated mixed matrix membrane

Transmission congestion management by optimal placement of FACTS devices

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 13/09/2010.This thesis describes the implementation of the Flexible AC Transmission Systems (FACTS) devices to develop a market-based approach to the problem of transmission congestion management in a Balancing Market. The causes, remedies and pricing methods of transmission congestion are briefly reviewed. Balancing Market exists in markets in which most of the trading is done via decentralized bilateral contracts. In these markets only final adjustments necessary to ensure secure system operation is carried out at a centralized Balancing Market. Each market player can participate in the Balancing Market by submitting offers and bids to increase and decrease its initially submitted active generation output. In this research a method is proposed to reduce costs associated with congestion re-dispatch in a Balancing Market by optimal placement of FACTS devices, and in particular Thyristor Controlled Phase Shifter Transformers (TCPST). The proposed technique is applicable to both Mixed Integer Linear Programming (MILP) and Mixed Integer Non-Linear Programming (MINLP). In the MILP a power system network is represented by a simplified DC power flow under a MILP structure and the Market participants' offers and bids are also represented by linear models. Results show that applications of FACTS devices can significantly reduce costs of congestion re-dispatch. The application of the method based on the MINLP creates a nonlinear and non-convex AC OPF problem that might be trapped in local sub-optima solutions. The reliability of the solution that determines the optimal placement of FACTS devices is an important issue and is carried out by investigation of alternative solvers. The behavior of the MINLP solvers is presented and finally the best solvers for this particular optimization problem are introduced. The application of DC OPF is very common in industry. The accuracy of the DC OPF results is investigated and a comparison between the DC and AC OPF is presented

Congestion Management in Hybrid Electricity Markets with FACTS Devices with Loadability Limits

Congestion management (CM) is one of the most important challenging tasks of the Independent System Operator (ISO) in the deregulated environment. In this paper, generators’ rescheduling based CM approach to manage transmission line congestion considering loadability limit has been presented for hybrid based electricity market model. The main contribution of the paper is (i) to obtain secure transactions for hybrid market model, (ii) optimal rescheduling of generators with loadability limits taken into account with secure transactions, (iii) and impact of FACTS devices on transmission line congestion management. The ISO ensures secure bilateral transactions in a hybrid market model and CM is managed with minimum preferred schedule to obtain minimum congestion cost. The results have been obtained for IEEE 24 bus test system.  Keywords: Generator re-dispatch, congestion management, pool electricity market, bid function, loadability limit.DOI:http://dx.doi.org/10.11591/ijece.v2i1.11

Transmissionmanagementforcongestedpowersystem:Areviewof concepts,technicalchallengesanddevelopmentofanewmethodology

Transmissionnetworkshavesomeconstraintsthatshouldbeaddressedinordertoensuresufficient\ud control tomaintainthesecuritylevelofapowersystemwhilemaximisingmarketefficiency.Themost\ud obviousdrawbackoftransmissionconstraintsisacongestionproblemthatbecomesanobstacleto\ud perfect competitionamongthemarketparticipantssinceitcaninfluence spotmarketpricing.Asthe\ud power flow violatestransmissionconstraints,redispatchinggeneratingunitsisrequiredandthiswill\ud cause thepriceateverynodetovary.Thismanuscriptpresentsconcepts,technicalchallengesand\ud methodology forinvestigatinganalternativesolutiontotheredispatchmechanismandthenformulates\ud LMP schemeusinganoptimisationtechniquethatmaywellcontrolcongestionasthemainissue.The\ud LMP schemearevariedandimprovedtotakeintoaccounttheenergyprice,congestionrevenue,costof\ud losses, aswellasthetransmissionusagetariffbyutilisingshiftfactor-basedoptimalpower flow\ud (SF-OPF), whichisderivedfromthewell-knownDCoptimalpower flow(DC-OPF)mode

Transmission Policy in the United States

This paper provides an overview of the development of electric power transmission access, pricing and investment policies in the U.S. over the last 15 years and evaluates the current state of those policies. It includes a discussion of pre-liberalisation transmission access and pricing policies, the prevailing basic transmission access and pricing rules contained in Orders 888 and 889, FERC’s policies regarding Regional Transmission Organizations (RTO) as reflected in Order 2000, and FERC’s subsequent Standard Market Design (SMD) proposal. PJM’s market rules and transmission pricing, planning and investment policies are reviewed as an articulation of FERC’s RTO and SMD visions

Kaedah megawatt mile menggunakan pendekatan berasaskan faktor kuasa untuk caj perkhidmatan penghantaran

Deregulation of the electricity energy market has changed many aspects of utility industry, including transmission pricing. The main problem in transmission pricing is the determination of transmission cost according to actual power flow and the load power factor. In fact, poor power factor will cause a decrease in electrical power delivery capability. Therefore, it needs an accurate method to determine the transmission cost according to the actual power flow ang load characteristic that can satisfy costumer of transmission line. This thesis proposes a novel method through an improved Megawatt Mile (MW-Mile) method using the power factor-based approach for pricing the transmission services. In the proposed method, the power factor correction coefficient is introduced as a price parameter to determine the additional or reduction of transmission cost due to the difference between the average load power factor and the reference power factor set by a regulator. This method is incorporated with the distribution factor method to trace the power flow in the network. The proposed method as tested on the IEEE-14 bus system and the IEEE 30-bus system to illustrate the effectiveness of the proposed method in allocating the transmission pricing to a user in a fair manner. The results have indicated that there were differences in the cost of transmission utilization which in reality, depends on the power factor of the load. For power factor reference is 0.9, the user with an average power factor of 0.85 will be charged at 5.88% higher, while the user with power factor of 0.95, the payment will be decrease by 5.2% as compared to the existing methods. The advantage of the proposed method lies in the incentive given to the users due to power factor improvement. This method is also able to solve the problem of the reactive power charges and the transmission loss share for the users

Power transmission cost calculation in deregulated electricity market

The restructuring of electricity industry towards a competitive market has resulted in essential changes at the operation of power market. This book illustrates the results of research work made as intersection between technique and economy. Cornerstones of this work are carried out in the fields of congestion and power system fixed costs. A contribution to the study of power losses cost is also included in this book. Considering the system congestions as a main reason for price volatility the book presents a method for the allocation of congestion component of nodal prices for energy to the market participants. Furthermore, a new method for the simulation of zonal pricing using nodal pricing algorithm, in order to assess the Norwegian market, is given. The last part of the book deals with the task of power system fixed cost allocation. For this purpose, game theoretical methods are used. Die Dissertation erscheint parallel im Logos-Verlag, Berlin <br

Transmission congestion management by optimal placement of FACTS devices

This thesis describes the implementation of the Flexible AC Transmission Systems (FACTS) devices to develop a market-based approach to the problem of transmission congestion management in a Balancing Market. The causes, remedies and pricing methods of transmission congestion are briefly reviewed. Balancing Market exists in markets in which most of the trading is done via decentralized bilateral contracts. In these markets only final adjustments necessary to ensure secure system operation is carried out at a centralized Balancing Market. Each market player can participate in the Balancing Market by submitting offers and bids to increase and decrease its initially submitted active generation output. In this research a method is proposed to reduce costs associated with congestion re-dispatch in a Balancing Market by optimal placement of FACTS devices, and in particular Thyristor Controlled Phase Shifter Transformers (TCPST). The proposed technique is applicable to both Mixed Integer Linear Programming (MILP) and Mixed Integer Non-Linear Programming (MINLP). In the MILP a power system network is represented by a simplified DC power flow under a MILP structure and the Market participants' offers and bids are also represented by linear models. Results show that applications of FACTS devices can significantly reduce costs of congestion re-dispatch. The application of the method based on the MINLP creates a nonlinear and non-convex AC OPF problem that might be trapped in local sub-optima solutions. The reliability of the solution that determines the optimal placement of FACTS devices is an important issue and is carried out by investigation of alternative solvers. The behavior of the MINLP solvers is presented and finally the best solvers for this particular optimization problem are introduced. The application of DC OPF is very common in industry. The accuracy of the DC OPF results is investigated and a comparison between the DC and AC OPF is presented.EThOS - Electronic Theses Online ServiceGBUnited Kingdo