Power System State Estimation Based On Incomplete-LU And Cholesky Preconditioned Iterative Method

In this thesis,efficient techniques with the Weighted Least Square,Conjugate Gradient and Bi-Conjugate Gradient Stabilized methods is proposed for power flow calculation.The proposed method is based on the iterative methods for solving a set of linear equations in the Newton-Raphson(N-R)method.The Bi-CGStab method is one of the variants of the extended conjugate gradient method that has good convergence characteristics.So far,the direct methods have been used to solve a set of linear equations.However,it is known in numerical analysis that the preconditioned iterative methods such as the IC(Incomplete Cholesky)and ILU(Incomplete Lower and Upper)factorization is useful for solving a set of linear equations.To speed up the power flow calculation for a large system.For the Symmetric Positive Definite(SPD)matrix,we will use the incomplete-Cholesky preconditioned CG iterative method and for the non-symmetric matrix,we use the incomplete-LU preconditioned BICGSTAB iterative method.Results generated using the Mat Lab software with C language and forecasting data of busses collect from the Mat power extension file.been used.In this thesis,the results of test direct and indirect method on IEEE 14,30 and 57-node system have been reported and Compare the Convergence time and iteration count.