This analysis is important for the delineation of the power systems, as well as in the definition of the best conditions of operation, control and supervision of the existing systems. For this to be possible some analysis of the system is required, among them Power Flow Analysis. The basic function of the Electric Power System is to supply electrical energy with quality and when requested. Power flow, Numerical methods, C language Abstract Universidade Federal de Santa Maria - UFSM, Campus Cachoeira do Sul, Cachoeira do Sul, RS.