Design and implementation of STATCOM for reactive power compensation and voltage fluctuation mitigation in microgrid

COEP-Microgrid, a project by the students of College of Engineering, Pune (COEP) aims at establishing a microgrid in the college campus. Proposed microgrid has a AC-bus and DC-bus, interconnected together with a tie line DC-AC converter. AC-bus of the microgrid can operate in synchronism with the utility grid. In islanded mode of operation, i.e. in the absence of the utility grid, voltage on AC bus is observed to show drastic fluctuations with changing reactive power load on the Microgrid. This provokes the need of a dynamic reactive power supplying and consuming element on AC bus. Furthermore, compensation of reactive power maximizes utilization of capacity of power converters and generators. The proposed solution for compensation of reactive power and minimize voltage fluctuations is a static synchronous compensator (STATCOM) on AC bus of the microgrid. It includes a 2-level voltage source inverter(VSI) with a capacitor bank in DC link. It is embedded with grid synchronizing control system and DC link capacitor voltage regulating control system. The STATCOM is simulated with the existing architecture of COEP-microgrid and results of the same are discussed. This paper also describes implementation of the designed STATCOM and its response in various microgrid scenarios.