1Research Assistant at Niroo Research Institute (NRI), Tehran, Iran.
2Faculty of Electrical Engineering, Shahid Beheshti University, Tehran, Iran.
The paper tries to present an improved mathematical model for distribution companies (DISCOs) in order to solve Distribution Network Expansion Planning (DNEP) problems in the presence of certain resources of Distributed Generations (DGs) entitled small scale Gas Engines in the medium voltage grids. With the aim of minimizing investment and operation costs, the recommended model combines a comprehensive multi-objective optimization model with grid designer’s experience and power transit possibility in retail trading. The proposed model determines the optimal capacity of new transformers, and the most efficient type and route of the expandable medium voltage feeders under probable power transit condition in retail markets. In addition, this model maintains system reliability along with an innovative formulation. The scenario-based results obtained after implementing this method on a typical distribution grid modeled under GAMS software platform indicate that the proposed model is really suitable for expanding distribution grids.