The work presented in this paper is to study the impact of FACTS (flexible alternating current transmission system) on the power flow and power losses of a multi-machine electrical system. In this work, we have calculated the power flow and the active and reactive power losses for a 6-bus 3-machine network system, in the first case where there are no FACTS, and in the second case where there are FACTS (SVC). So, and in the second case we used an SVC ((Static Var Compensator) because it is one of the elements of FACTS, to see their influence on power flow and power losses in electrical systems using MATLAB software (we used the Newton-Raphson method) and using PSAT software (Power System Analysis Toolbox), we calculated the power flow and the active and reactive power losses in the lines, respectively. Finally, we compare the results obtained by the simulation programs MATLAB and PSAT, and see what effect FACTS (SVC) has on the power flow and power loss in our electrical system that we are studying.