Announcing the Final Examination of Sahin Gullu for the degree of Doctor of Philosophy
The traditional grid structure has large power plant generation stations, high voltage transmission lines, and distribution stations. This electric power system can be considered one of the greatest engineering achievements of mankind. However, the traditional grid is insufficient to supply energy demand due to increasing energy consumption worldwide. Secondly, the traditional grid has mainly utilized fossil fuel for power generation that increases CO2 emission. Last but not least, today, three billion people are in lack of energy, and more than one billion people are not able to access electricity. Therefore, the photovoltaic (PV) and battery integration will play a key role. However, battery management systems, grid-forming (GFM) inverters, state-of-the-art systems integration for microgrids are not mature yet. Another main challenge is to send that energy to the traditional electric grid by using GFM inverters. In this dissertation, three major contributions are presented. The first contribution is to design and to optimize AC-PV module that is the integration of a GFM microinverter and a lithium-ion battery pack at the back of PV panel. The technoeconomic analysis, battery capacity optimization, PV panel size optimization, electrical and thermal model of batteries, battery heat generation model, battery management system and thermal management strategy are discussed by using stochastic analysis and battery test results. The second contribution is to design an enhanced droop control algorithm for this AC-PV module in order to ensure that the frequency and voltage is the range of continuous operation for grid-tied and off-grid scenarios. Lastly, a three-phase 540 KVA bidirectional inverter and a 1.86 MWh lithium-ion battery energy storage system were integrated at the Florida Solar Energy Center. A case study is performed for this system by acquiring the energy consumption of the building, the reduced energy consumption, the battery testing, the load shifting, and the peak shaving.
Committee in Charge:
Issa Batarseh, Chair, Electrical and computer Engineering
Aleksandar Dimitrovski, University of Central Florida
Wasfy Mikhael, University of Central Florida
Wei Sun , University of Central Florida
Nasser Kutkut, Smart Charging Technologies (SCT)