Announcing the Final Examination of Reza Rezaii for the degree of Doctor of Philosophy
The widespread adoption of photovoltaic (PV) and electric vehicle (EV) technologies is crucial for mitigating greenhouse gas emissions. A Multi-Port Converter (MPC) connects multiple PV panels, improving efficiency and reducing costs. In EVs, MPCs extend battery lifespan by adding energy sources, enhancing system quality beyond reliance on Li-ion batteries. This dissertation proposes a Quad-input LLC topology for PV microinverters. It utilizes a single LLC resonant tank and two Y switches configurations. An MPPT control strategy based on Perturb and Observe (P&O) method ensures independent MPPT for each panel. The zero-voltage switching (ZVS) is achieved across all switches for wide input range and load variations. A 500W prototype validates the operation, achieving peak efficiency of 94.3% with individual MPP tracking. Also, a high gain DC-DC converter for hybrid inverter is proposed. The proposed converter can be used in the PV panel level for hybrid inverter where the low voltage of PV must be increased to DC-link voltage. The proposed converter uses two inductors connected either in series or parallel during discharge or charge mode. The designed hybrid system based on this high gain converter has three ports that can be connected to PV, battery, and grid/ac load. In addition, a bidirectional hybrid DC-DC converter (BHDC) is proposed for hybrid energy storage systems in electric vehicles. The converter can connect both batteries and supercapacitors to the DC-link. With a wide voltage-gain range, low voltage stress on power switches, and common ground between low and high voltage ports, the converter achieves zero-voltage switching (ZVS) via synchronous rectification, improving efficiency. A 300W prototype with a 94.8% maximum efficiency in step-up mode and 94.2% in step-down mode was built to validate the wide voltage gain range and voltage control scheme.
Committee in Charge:
Issa Batarseh, Chair, Electrical & Computer Engineering
Chinwendu Enyioha, University of Central Florida
Aleksandar Dimitrovski, University of Central Florida
Wei Sun, University of Central Florida
Nasser Kutkut, Smart Charging Technologies (SCT)