Optimal Power Flow Program Development And OPF-based Available Transfer Capacity Computation Research

With the development of large-scale interconnected network and power market, the importance of Optimal Power Flow (OPF) issues of interconnected systems and the computation for Available Transfer Capacity (ATC) between them rises dramatically. This paper is focus on the development of OPF program and the research for OPF-based ATC computation with consideration of voltage stability. The major works of this article are as follows.First of all, a major algorithm in optimization field, interior point method, is introduced in this article, including its developing history, catalogue, and basic theory. The principles, calculating approaches and process of primal-dual interior point method (PDIPM), one of interior method adopted in our work, are discussed in details. This part of work is the base stones for optimal power flow (OPF) software development and ATC computation.Then, starting with its development, the mathematic module and algorithm of OPF are summarized, as well as the expanding applications of OPF in modern power system. In this article, major efforts are put on several OPF related issues: application of OPF in power market, OPF with consideration of voltage and transient safety constraints, dynamic OPF, and OPF with FACTS components, etc. The expanding application of OPF is clarified.Thirdly, an OPF software is accomplished in this article, including main program debugging, I/O and man-machine conversation interface development. The program flow, functions and characters of this software are amply introduced. Furthermore, an assistant file OPF.chm is established using HTML Help Workshop, which could provide intuitionistic and visual assists for software operators. The rapidity of convergence, reduction of system loss and operation cost, improvement of system economical efficiency are proved IEEE standard case study. With nice interface and easy operation, in general, this software has significant practical meaning on power system computation and analysis.Finally, the definition of ATC between interconnection systems is discussed. The ATC computation methods are summarized. With the consideration of voltage stability constraints, the ATC computation module based on OPF is presented in this article, and the corresponding ATC values are gained through this PDIPM method. The correctness of this module and advantages of OPF method for ATC calculation are confirmed by case study and simulation.