A new method for optimal selection of conductor sizes in radial distribution network

This paper presents a new method for optimal selection of conductor's sizes in radial distribution networks using mixed integer quadratic programming technique. The objective function to be minimized is the capital cost of conductors as well as the power and energy loss cost. The main constraints to be satisfied are the thermal limit of the selected conductors and the bus voltage limit. The method presented can deal with fixed loads and variable loads which undergo an annual growth rate. Also, the dynamic nature of the loads has been taken into consideration through deriving the load current as a linear function in bus voltage. In order to overcome the problem of large computation time required, the mathematical model has been solved in a new iterative manner, starting with an initial solution, where the overall cost is minimized from iteration to another till the least cost network is reached. Method verification has been made using two test examples.