Banca de QUALIFICAÇÃO: PEDRO AQUINO DE ALCÂNTARA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE: PEDRO AQUINO DE ALCÂNTARA
DATA: 05/08/2022
HORA: 08:30
LOCAL: Videoconferência
TÍTULO: PERFORMANCE ANALYSIS OF PHOTOVOLTAIC/BATTERY-BASEDISLANDED MICROGRID REGULATION UNDER UNBALANCED CONDITIONS
PALAVRAS-CHAVES: Islanded Microgrid. Photovoltaic-Battery unit. Grid-Forming Control. Droop Control. Unbalanced load.
PÁGINAS: 69
RESUMO: The huge development of distributed generation (DG) systems and its insertion in main grid, made the concept of microgrids (MG) target of many literature works and researches. Most of DG units of MG are formed by renewable energy sources (RES), such as wind and solar photovoltaic (PV) systems. This kind of electrical generators have been widely studied and developed in order to replace non-clean energy sources. However, it has been quite a challenge to make possible MG operation when it is not connected to the main grid. Many problems have been faced, ranging from voltage and frequency deviations, power sharing between units and load unbalances. This work studies a three-phase PV/battery-based MG operating mainly in islanded mode, perform control strategies in power/load sharing, and analyse MG behavior under several load unbalances. For this, many control strategies has been implemented in order to overcome several problems. First, it is important to note that once MG is formed only by PV generators, no rotational inertia is provided to MG, making it lose frequency reference. Therefore, droop control method attached to Proportional-Resonant (PR) loops has been implemented aiming to simulate synchronous generators behavior through a grid-forming control strategy. Furthermore, Battery Energy Storage Systems (BESS) has been attached to DG units to provide power support due to its fast response to MG needs. Thus, a power sharing strategy aims to provide MG power balance through a decentralized method taking in consideration several operation scenarios. When power required by load is lower than power provided by PV units, BESS absorbs the surplus power to keep MG balance, once its power and state-of-charge limits are respected. However, once BESS limits are achieved, it operates in with a current limit control or it is disconnected from the system, so PV units perform generation curtailment. On the other hand, once load power is larger than PV power, BESS operates in discharging mode to compensate power lack, again, until its limits are achieved. Partial results were obtained from a reduced MG structure used to analyze system behavior under several levels of load unbalance. It was observed that for a high load scenario, unbalance degrees above 40% makes MG not to work properly, since DC-link voltage drops and, consequently, the power delivered to load. In addition, for a low load scenario, 20% of load unbalance is enough to make BESS, working not properly, discharging instead charging. The work modelling has been performed using Matlab/Simulink environment.
MEMBROS DA BANCA:
Presidente - 1652514 - CAMILA MARA VITAL BARROS
Interno - 1636976 - FABIANO SALVADORI
Externo à Instituição - FLÁVIO BEZERRA COSTA
Externo ao Programa - 1597497 - LUCIANO SALES BARROS