Discussion of "A new preconditioned conjugate gradient power flow"

The author comments on the paper by H. Dag et al (see ibid., vol.18, no.4, p.1248-55, 2003). The author commends Dag et al for their interesting contribution to the power flow solution via iterative methods. The availability of a good preconditioner is perhaps the decisive factor influencing whether or not iterative solvers would have an impact in the future of power flow calculations in power systems. The paper contributes in this direction. The author brings to the attention of the readers a publication on the subject by F. de Leon et al. (see Proc. Inst. Elect. Eng.-Gen., Transm. Dist., vol. 149, no. 4, p. 479-484, 2002). In this work the use of the (full) Newton power flow (NPF) method is preferred over the fast decoupled (FD) approach as the basis for the implementation of iterative solvers. The author asks Dag et al. for their comments on preconditioners development focusing on the NPF method.