Florida Polytechnic University

About: Florida Polytechnic University is a education organization based out in Lakeland, Florida, United States. It is known for research contribution in the topics: Computer science & Catalysis. The organization has 302 authors who have published 538 publications receiving 6549 citations. The organization is also known as: Florida Poly.

Unipolar Single Reference Multicarrier Sinusoidal Pulse Width Modulation Based 7-level Inverter with Reduced Number of Semiconductor Switches for Renewable Energy Applications

Abstract: In the present scenario of increasing power demand and depletion of fossil fuel results in the research advancements in the field of renewable energy sources. Among various types of renewable energy sources, photovoltaic related applications are gaining importance. DC-AC converters play a very prominent role in photovoltaic system in efficient power delivering for various applications. This paper proposed a 7-level inverter with reduced number of switches for photovoltaic applications. Unipolar Single Reference Multicarrier Sinusoidal Pulse Width Modulation (U-SR-MC-SPWM) technique is used for the purpose of gate pulse generation for the proposed multilevel inverter. A comparative study of seven-level cascaded multilevel inverter and a proposed multilevel inverter is carried out. Simulation and power quality analyses of both multilevel inverters are performed in MATLAB/Simulink platform version 2016(a). It is noticed that the total harmonic distortion is slightly more of the proposed multilevel inverter when compared with cascaded h-bridge inverter. But, with the reduction in the number of power semiconductor switches in proposed multilevel inverter overall switching power losses, circuit complexity, gate driver requirements and cost of the system can be reduced. The simulation results always show a good agreement with the proposed approach.

Active and reactive power control method for three-phase PV module-integrated converter based on a single-stage inverter

Abstract: The concept of the module-integrated converters (MICs) incorporated in photovoltaic (PV) has recently imbibed a significant attention due to advantages such as low cost of mass production, high efficiency, easier installation, and improved energy harvest. This paper presents the current-source inverter (CSI) with dc voltage boost capability, called single-stage power conversion system, for grid-tied three-phase PV MIC systems. A reliable control system is adopted to modulate the proposed topology in such a way that provides both active and reactive power in order to meet power system needs. To reduce the number of actives switches, the topology utilizes the modified switching pattern based on conventional space vector pulse width modulation (SVPWM) method. It is demonstrated that the injected active and reactive power can be controlled through two modulation indices introduced in the modified SVPWM switching algorithm. The proposed structure is implemented in hardware and experimentally tested with 300-W laboratory prototype. The results verify the desired performance and robustness of the proposed control scheme for exchanging of both active and reactive powers between the PV MIC and the grid within different operating conditions.

Highly Birefringent, Low-Loss, and Near-Zero Flat Dispersion ENZ Based THz Photonic Crystal Fibers

Abstract: In this paper, we present and compare two experimentally feasible photonic crystal fiber (PCF) designs ( $\textit{Type-I}$ and $\textit{Type-II}$ ) which ensure near-zero flattened dispersion with ultra-high phase and group birefringence at THz frequencies. Both structures are based on a subset of a triangular array of circular air-holes, which define the cladding of the PCF and a central elliptical air-hole which breaks the symmetry of the structure, thus introducing high levels of birefringence. Additionally, we investigate the possibility of further enhancing the birefringence properties of $\textit{Type-II}$ structure by selectively filling the air-holes with Potassium Chloride (KCl) as strong Epsilon-Near-Zero (ENZ) material. Our investigation reveals that significant enhancement of birefringence can be achieved than its original counterpart with birefringence to be as high as 0.0627 at 6.2 THz and near-zero flat dispersion of $-$ 0.54 $\pm$ 0.04 ps/THz/cm over the frequency range of 6.2 $-$ 6.3 THz.