Power Flow Calculation And Optimal Points Selection With UPFC

It is a worthy researching task that how to chose a estimation algorithm, which has precise estimation, excellent convergence and fast computing speed, in the algorithms of power flow concerning Unified Power Flow Controller(UPFC). The problem of power flow concerning UPFC and the allocation problem of UPFC is studied and explored deeply in this paper.Through the analysis of the basic principle and equivalent circuit of UPFC, this paper proposed a new Steady-State model and algorithm of power flow of UPFC, and the principle and the deduction process of the model and algorithm is described in detail. The model, which is visual, simple, universal and applicable to serious operation modes of UPFC, is based on power injection method and considering the admittance to ground. The algorithm is mainly combined with the fast decoupled load flow (FDLF), which can be solved in high speed and coded conveniently; Through choosing the additional power injection in the equivalent nodal as the new added state variables, it is easy to determine the better initial condition of the control parameter of UPFC and system state variables, and the convergence was improved.According to the model of DC power flow of power system, sensitivity coefficient is adopted, which is used to optimize the allocation of UPFC. The forecast allocation of UPFC in the Western grid of Inner Mongolia is given, and the significance of regulating the flow of the Western Grid of Inner Mongolia and improving the stability of power system is analyzed.