Transient Frequency Drift Compensation on Weak 3-phase AC Microgrids using an Energy Storage System

Abstract

Micro-grids are without any doubt the future of electrical grids, advocating for a sustainable and efficient exploitation of the energy sources and the integration of re- newable energies. However, these grids are by nature weak grids, exhibiting a low inertia and high impedance which makes them prone to contingencies that compro- mised the grid quality and stability. The scope of this master thesis is to cover one of these contingencies consisting on the transient frequency drift that occurs when changes in the active power takes place. The low inertia of the generators that com- pose a micro-grid could cause a fluctuation in their rotor speed, which is directly related to the grid frequency due to the applied transient torque. Thus, the present Thesis is focused on the study of a solution based on Energy Storage System (ESS) for transient frequency drift compensation in micro-grids. Such study covers the design and implementation of a power topology and different control alternatives in both, simulations and in an experimental setup, demonstrating the validity of the proposed system.