A new model for distribution system planning

This article presents a new and efficient simulation model for optimal expansion planning of distribution systems using separable linear programming (LP) technique. The developed model can be used to determine optimum substation sites and transformer sizes, optimum expansion of existing substation, optimal load transfer between substations and load centers, optimal routes and optimum feeder size at each selected route. The least cost expansion network is guaranteed owing to the accurate representation of cost function associated with both substations and feeders and comet simulation of load flow constraint equations and limit constraints. Also, the inherent characteristics of separable LP technique were efficiently utilized through deriving a new set of constraint equations to guarantee radial configuration as well as quality (voltage drop) constraints. The utilization of separable LP technique makes possible the determination of fast and reliable solutions for large size networks using normal size computers. The model can be easily extended for dynamic planning of distribution networks. The model verification was made using a 90-nodes test example, (C) 1999 Elsevier Science Ltd. All rights reserved.