Design of Control Systems for Grid Interconnection and Power Control of a Grid Tie Inverter for Microgrid Application

College of Engineering, Pune(COEP) Microgrid, a project by the students of College of Engineering Pune aims at establishing a microgrid in the college campus serving as a living laboratory for research and development of novel grid technologies. Proposed microgrid has an AC-bus and DC-bus, interconnected together with a tie line DC -AC converter. Synchronization with AC bus requires inverter output and AC bus to have synchronism in frequency, phase sequence and voltage. Control System is required to effectively regulate power flow between the AC bus and DC bus. The AC bus synchronizing control system is composed of frequency and phase control for regulated power flow and voltage control system for reduction of reactive power flow. The control system involves automatic active power flow control. It takes the feedback of DC link capacitor and changes the power angle accordingly. Control system incorporating voltage, phase and power control is developed for grid-tie inverter. This paper discusses the design, simulation and practical implementation of control system used for grid tie inverter.