Abstract: Generation and transmission systems are two important parts of power systems which are mainly considered for expansion. GEP is related to the investment on energy production and determines size, place, technology and the time of installing new plants to satisfy the forecasted load within the given reliability criteria over a planning horizon. TEP is the other important planning in power systems and denotes when, where and how many lines should be installed to ensure an adequate level of energy supply to customers, taking into account the load growth and reliability. In recent years, integration of renewable into main grid and ongoing deregulated environment take many challenges to power system expansion planning. In recent years, integration of renewable into main grid and ongoing deregulated environment take many challenges to power system expansion planning.

Keywords: Graverís 6-Bus System (Thermal, Thermal and Thermal) GRAV_TTT, Renewable integration, deregulated, solar, wind.