Load flow solution by applying hybrid algorithm to the Newton-Raphson method

Abstract

The purpose of the HYBRID algorithm, discussed in this thesis, is to improve the efficiency of the convergence of the existing NEWTON-RAPHSON method in solving the system of nonlinear power flow equations, when its close initial estimates are not available. The algorithm is based on the interpolation between the fast convergence standard NEWTON-RAPHSON iteration and the method of steepest descent applied to the sum of the square of mismatch fi(x). The balance between these two methods is governed by introducing the concept of the trust region to restrict the step predicted by the classical method to be in the quadratic region and to switch to the steepest decent method that is better when the initial values are far from the solution. Digital computer results and their comparisons of the 10 bus test system, with different initial values, by the proposed algorithm and by the standard method are also discussed in this thesis.