Matpower Ill-conditioned systems v1

According to the definition of [1], an ill-conditioned power system can be described as this system which, despite its solution does exists, it is not reachable using the standard Newton-Raphson technique and a flat start. They are ill-conditioned systems building by combining some available cases from Matpower's database (see file MATPOWER_Ill-conditioned_systems.txt for information). These systems have been used in some papers for validating novel Power-Flow techniques. [1] F. Milano, "Continuous Newton's Method for Power Flow Analysis," in IEEE Transactions on Power Systems, vol. 24, no. 1, pp. 50-57, Feb. 2009