Structurally, power grids are composed of the generation (power), transport and consumption. For the mean transport, the transfer of all energy generated in the plants to where the consumers, so it is necessary to create networks that are capable of carrying large amounts of energy over long distances. To this end, we transport networks that connect high voltage power transformer substations with and through networks of medium voltage substations are connected to the processing centers. Depending on the voltage level employee can be considered two types of distribution networks, "networks of medium voltage-low voltage networks. Medium voltage networks are used primarily for supplying energy to customers of industrial and energy to bring even more customers to low, to be distributed by the second, low-voltage from the centers processing. Clearly, the design and operation of the entire power system requires careful planning to ensure proper operation at all times and in the future. The distribution network planning involves the procurement program of future actions to perform on the network, so to achieve certain targets, to have a proper functioning of the network.
The main objective is to provide a quality supply of optimizing costs. In general, planning models are based on models of optimizing a cost function that reflects the network costs (investment, losses, …) and costs associated with the quality of supply, so that both terms can be evaluated together. Basically, or costs can be classified into: Investment costs: for the material, labor, project implementation, etc. You can treat the investment is made at the time of entry into service or are amortized over the lifetime of the installation.