Modos de operação de uma microrrede de baixa tensão baseada em inversores de potência

Abstract

A microgrid is a cluster of distributed generations, loads and energy storages that work in a coordinate way to be treated by the main grid as a generator or a controllable load. Typically, a microgrid operates in parallel with the main grid. However, eventual energy quality issues may force the microgrid to disconnect from the main grid and operate in autonomous mode, with load shedding ability in case internal generation is not enough. When grid service returns, the microgrid can change its operational mode in order to synchronize with the main grid and, later, reconnect to the grid, returning to its initial state. For such, it is necessary that grid and microgrid differences in voltage, frequency and phase are minimum. Only when these conditions are satisfied, the microgrid will be able to reconect. This dissertation proposes the modeling and simulation of a microgrid connected to the distribution grid of the Federal University of Espírito Santo (UFES) to verify its behavior when connected to the main grid, during islanding and at synchronization and reconnection. The microgrid proposed in this work is composed of a photovoltaic system, a battery and loads. From the results obtained through simulation in MATLAB/Simulink®, it is proven that the control strategies provides to the microgrid stability and reliability in power supply to associated loads