Studies On Transmission Management In Deregulated Environment

The function and role of transmission networks are changed fundamentally with electric power industry deregulation and restructuring. In Transmission Open Access environment, how to manage transmission networks efficiently is crucial both in theory significance and practical value. In this dissertation, the kernel engineering and economic problems in transmission management are studied thoroughly using mathematical methodologies and economic theories.The optimization methodologies for solving general power system optimization problems are studied. As the basic foundation of this thesis's algorithm study, a novel class optimal power flow (OPF) algorithm named Global Semi-Smooth Newton (GSSN) algorithm based on nonlinear complementarity problem (NCP) function is presented. The new algorithm avoids entirely the identification of active constraint sets in traditional OPF algorithms and possesses the advantages of high efficiency, good convergence, strong robustness and simple implementation. A global Newton decomposition OPF algorithm is constructed using the weak coupling property of power systems. Local and global projective Newton OPF algorithms are also constructed to solve the high dimension problem caused by boundary constraints. The convergence properties of the above algorithms are proved strictly using mathematical theories.The calculations of available transfer capability (ATC) of transmission networks are studied. A new algorithm based on OPF to calculate ATC considering both reactive power and voltage is presented. The higher precision and rationality of the new method are demonstrated in comparison with computation mechanism and numerical examples of the traditional methods. The management issues of forward bilateral markets are studied. The forward markets' influence on transmission security is analyzed. A curtailment model for bilateral contracts considering economic target is presented and solved by Sequential Quadratic Programming (SQP) method. The new model satisfies market principles and is flexible for bilateral energy trading. The combined distribution factors for group-to-group transactions are defined and deduced. The efficiency of new model is validated using 2005 China 500KV power girds composing four regions. Transmission congestion management in spot market is studied. The congestion management mechanisms in day-ahead market and real-time market are analyzed. A new congestion elimination method is proposed and validated by the comparison with traditional sensitivity based method and linear programming method. Based on market equilibrium theory, the definitions of congestion cost and congestion rent are given. The financial cash flows of congestion cost in various pricing modes are studied and the allocation mechanisms for congestion cost using tradable transmission rights are also analyzed.The economic influences of transmission congestion on market efficiency and equilibrium in incomplete competition environment are studied. The identification and government of local market power are analyzed. The countermeasures to eliminate the network externality effects are also studied from the viewpoint of regulation theory and property theory.