A comprehensive long-term power distribution system expansion planning model

A new long-term power distribution system expansion planning model is devel oped. The model includes accurate representation of the different nonlinear planning cost functions. The cost of expanding an existing substation by a dding transformer units is also included in the planning cost formulation. Moreover, power-conservation, voltage-drop and equipment-capacity constrain ts are explicitly included in the planning problem formulation. The develop ed model is illustrated using a numerical example and is rested for both ef ficiency and accuracy.