Browsing by Author "Uzmus, Hasan"

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Design and Application of Pem Fuel Cell-Based Cascade Boost Converter
(Springer, 2019) Kocaarslan, Ilhan; Kart, Sude; Genc, Naci; Uzmus, Hasan
This paper presents average sliding current controller (ASCC) for the proton membrane exchange fuel cell (PEMFC)-based DC-DC cascade boost converter under different source and load conditions. PEMFC which has variable voltage and current can be used in a lot of applications with a wide operating range in low temperatures. However, as the PEMFC produces low nonlinear voltage, this lower nonlinear voltage value needs to be increased as a linear voltage with an appropriate power electronics converter. Therefore, this paper proposes DC-DC cascade boost converter which has a higher voltage gain for PEMFC stack. First, a classical PI controller was applied to regulate the output voltage. Then, the current of the PEMFC-based DC-DC cascade boost converter was controlled via ASCC by using output of the voltage controller. After analyzing the dynamic model of the PEMFC-based DC-DC cascade boost converter via MATLAB/Simulink program, the experimental results of the controlled PEMFC-based DC-DC cascade boost converter are observed and discussed.
Dsp Based Hybrid Control Method for Pv Systems
(Gazi Univ, Fac Engineering Architecture, 2023) Uzmus, Hasan; Genc, Naci; Celik, Mehmet Ali
Purpose: In this study, it is aimed to control the output voltage and current of the DC/DC boost converter faster with PI and ASM controllers, respectively, while PV panels are forced to harvest maximum power with the P&O MPPT control method. Theory and Methods: In this study, perturb and observation maximum power point tracking (P&O MPPT) control method was used to harvest maximum power from solar energy with PV panel. Conventional PI and average sliding mode (ASM) controllers were utilized for voltage and current control, respectively. The proposed hybrid control method was obtained by cascading P&O MPPT, PI, ASM controllers. MPPT and conventional PI controllers were cascaded in order to obtain an output voltage that does not change according to irradiation and load. A reference voltage was generated with MPPT for PI controller to control the output voltage. The reference current for ASMC was generated by cascaded MPPT-PI controllers. ASM controller was utilized for increasing the speed of the controller and controlling current. The process was depicted in Figure A. Results: The simulation and experimental results were compatible. There was no oscillation and chattering at output of the system. The proposed hybrid control method is quite fast. Conclusion: The simulation and experimental results clearly indicate that the proposed hybrid control method is quite satisfactory. This hybrid control method can be used for on-grid, off-grid and hybrid PV systems.
Experimental Verification of Interleaved Hybrid Dc/Dc Boost Converter
(Springer Heidelberg, 2022) Celik, M. Ali; Genc, Naci; Uzmus, Hasan
In this study, an improved interleaved hybrid DC/DC boost converter used for high-power applications with high voltage gain was proposed. The proposed DC/DC boost converter increases low-input voltage to the desired high-output voltage with a wide duty cycle range through the hybrid structure, thereby prolonging the lifetime of the proposed converter by decreasing the current on circuit components. An extra filter for input current ripples is unnecessary. The proposed converter is less complex and has easier control than the converters used for high voltage gain. The proposed converter was operated when the duty cycle (d) was larger and smaller than 0.5. It was also analyzed theoretically, and the average- and small-signal circuits were obtained to show its stability. The proposed converter was controlled with the conventional control method by using a modern digital signal processor TMS320F28379D board. The proposed converter and its controller were operated under different conditions.
The Modified Mppt for Pv System With Interleaved Hybrid Dc-To Boost Converter
(Taylor & Francis inc, 2023) Uzmus, Hasan; Genc, Naci; Celik, M. Ali
A modified maximum power point tracking control technic for an off-grid photovoltaic system which include the interleaved hybrid DC-to-DC boost converter was presented in this paper. The input voltage was predicted by measured one branch current of the proposed hybrid DC-to-DC boost converter. The proposed control technic consists of maximum power point tracking with the predicted input voltage and PI controller. Thanks to the proposed control technic, the photovoltaic panel was forced to operate at maximum power point and the output voltage of the proposed converter ensured the desired value despite the varying input power. In addition, the interleaved hybrid DC-to-DC boost converter was increased the low output DC voltage of photovoltaic panel to the desired high voltage value and the stresses on the circuit elements was decreased by reducing the input current ripples. As a conclusion, the total cost of the proposed system is reduced by eliminating the sensing of the input voltage and the service lifespan of the proposed system is extended by using the interleave hybrid DC-to-DC boost converter. The simulation and experimental results of the proposed system were obtained by using MATLAB/Simulink and 400 W DSP TMS320F28379D based porotype, respectively.
Mosfet ve Igbt Tabanlı Hibrit Dc-dc Boost Dönüştürücü için Yumuşak Anahtarlama
(2023) Dilber, Ibrahim Halil; Uzmus, Hasan; Çelik, Mehmet Ali; Genç, Nacı
Bu çalışmada, yüksek voltaj kazancına sahip MOSFET ve IGBT tabanlı hibrit DC-DC yükseltici dönüştürücü için aktif yumuşak anahtarlama yöntemleri önerilmiştir. MOSFET ve IGBT ana anahtarlı hibrit DC-DC yükseltici dönüştürücüye sırasıyla sıfır voltaj geçişli ve sıfır akım geçişli aktif yumuşak anahtarlama yöntemleri uygulandı. Böylece MOSFET ve IGBT tabanlı hibrit DC-DC yükseltici dönüştürücünün sert anahtarlama kaynaklı güç kayıpları azaltılmıştır. Değişken yüklere sahip MOSFET ve IGBT tabanlı hibrit DC-DC yükselten dönüştürücü, yumuşak anahtarlama yöntemleri ve sert anahtarlama için OrCAD-PSpice ortamında benzetim çalışmaları yapılmıştır. Benzetim çalışmalarından elde edilen sonuçlar, yumuşak anahtarlama yöntemlerinin hibrit DC-DC yükseltici dönüştürücünün verimini %1 kadar arttırdığını göstermektedir.