An improved version of fdlf suitable for systems with large voltage variations

This paper presents a new version of Past Decoupled load flow (FDLF) which is suitable for systems with large voltage variations. This version differs from the standard one In a way the branch resistance is considered in B' and B" matrices. The branch resistances are neglected while forming the B'matrix in standard version of FDLF. This paper shows that if the resistance is considered in both B' and B" matrices the method converges faster than the standard version for systems with large voltage variations. The convergence of this new version is affected by suitable choice of convergence factor. It is found that a convergence factor of 0.9 for reactive power model makes the model still faster. The performance of this model is demonstrated by taking examples of networks of different kinds including actual utility networks with wide voltage variations. To achieve the large voltage variations in normal systems, their loads are increased by different P/sub F/ and Q/sub F/ factors. The test results reveal that the proposed version supercedes other versions for such networks.