dc.description.abstract | Economy and reliability of service are important considerations in power system operation and planning. These two aspects of a power system can be adequately satisfied by formulating a suitable optimal power flow problem and finding an appropriate solution methodology. The solution to an optimal power flow problem locates a feasible operating point that gives the least value of a desired objective parameter (e.g. fuel cost, real power loss) subject to satisfying system constraints like voltage levels, real and reactive power flow on transmission lines and transformer tap settings. A suitable optimal power flow solution thus ensures an economical and secure operating point. The solution can be obtained using several nonlinear programming techniques which include the steepest descent method, quadratic programming method (QPM) and the gradient projection method (GPM) among others. In this paper, the optimization problem is solved using the steepest descent method and targets the Kenya Power System | en |