Basic and extended planning models, based on a pseudodynamic methodology, for solving the global expansion problem (sizing, locating, and timing) of distribution substations and feeders throughout the planning time period are presented. The objective functions that represent the expansion costs are minimized by successive concatenated optimizations subject to the Kirchhoff's current law, power capacity limits, and logical constraints in the basic model. Also presented is an extended model that is obtained by including the voltage drop constraints in the basic model. >