Masood ghodrati - Isfahan University of Technology
fereidoon kazerooni - Isfahan Regional Electric Company
hossein ali shirani - Isfahan Regional Electric Company
Mehdi Moallem - Isfahan University of Technology

Demand Response Programs (DRPs) are implemented in many countries to improve pow r system reliability and market performance. Time of Use (TOU) is one ofdemand response programs that offers different pricing tariffs during peak, off-peak and valley periods. In this paper linear and nonlinear models for responsive loadsbased on elasticity concept are extracted and the conservative model is selected. Since different load sectors like commercial, industrial and residential have differentbehaviors and prefer different demand response programs, in this paper different elasticity and different participation level is considered for each load sector. Model isimplemented on the peak load curve in 2007 of the Iranian power grid and the optimal scheme from the Independent System Operator (ISO) point of view is investigatedusing Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method

Demand response, Nonlinear economic load model, Time of Use, Optimal pricing