Over the last century, there has been no significant change in the centrally controlled structure of electrical power grids. The economic and population growth throughout the planet increases the pressure on the power sector. Power electrical grid, as the main structure for power transmission has to reconsider its concepts. The flexible controlling of DER (Distributed Energy Resources) such as wind power, solar power, hydropower, wave power, geo-thermal power and biomass power has to be considered to overcome these challenges. The demand for electricity is steadily increasing and current centrally controlled structure is ill-suited to fulfill the modern complex power requirements. As a result the concepts like micro grids, smart grids, multi-energy systems, virtual power plants are emerging combined with new concepts like MAS (Multi-Agent Systems) and IoT (Internet of Things). They move our electrical power grid to a more decentralized, highly efficient energy management system. The objective of this paper is to discuss how multi-agent concept based energy management systems will behave for micro grids. The paper contributes a description of smart micro grids, MAS based Energy management systems and controlling of DER in micro grids, and future of power electrical grid structure with MAS.