Real-time energy management automation in microgrid can improve energy security, reliability, efficiency and power quality but is a challenging issue as it requires a robust, deterministic and interoperable communication architecture. IEC 61850 based communication architecture has the potential to be the promising solution for microgrid automation. Hence, this paper addresses this challenge by proposing IEC 61850 based design and modeling of IEDs for different types of Distributed Energy Resources (DERs) and a new Logical Node (LN) for controllable loads along with the design of structure and size of communication messages required for energy management automation in microgrid for the first time. The paper demonstrates the validation and implementation of the proposed design and modeling through a real-time system-in-the-loop (SITL) simulation for a test microgrid. Finally, to justify the feasibility of the proposed design and modeling, dynamic performance of the microgrid communication architecture is evaluated in terms of End-to-End (ETE) delay and throughput for different network topological configurations. This work intends to provide a platform to model, configure and evaluate a promising future standards based communication for microgrid automation.