Optimization for Microgrid with Considerations of Oversupply in National Grid based on Lagrange Multiplier

While the traditional energy sources are harmful to environment, together with the continuous growth of power demand, renewable energy is currently an efficient solution. In this study, a system implemented with energy management system which consists of the national power grid, renewable energy sources, battery, electric vehicle (EV), diesel engine and loads is considered. A method based on Lagrange multiplier theorem is presented for the objectives of optimizing the use of energy in the system and minimizing the cost of using electricity of the system. Two test cases, with and without limits of the grid, are considered in this paper to verify the proposed method.