http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Harmonics Mitigation of Stand-Alone Photovoltaic System Using LC Passive Filter
Adak Suleyman 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.5
This article investigates modeling and simulation of the off -grid photovoltaic (PV) system, and elimination of harmonic components using an LC passive fi lter. Pulse width modulation (PWM) inverter is used to convert the direct current to alternating current. It is very important in terms of energy quality that the inverter output current total harmonic distortion (THD I ) is below the value given by standards. Harmonic components have negatively eff ect on off -grid PV power system. THD I should be kept below a certain level in order to prevent damage to the equipment in the off -grid system and to ensure a higher quality energy fl ow to reduce the total harmonic distortion (THD) of the solar inverter output current; LC passive fi lter must be connected to the output of the PWM inverter. There are many types of passive fi lters for solar inverters. One of the most widely used fi lter types is the LC fi lter. LC fi lters are used in off -grid systems. LC fi lter is smaller in size and lower cost than other fi lters. But it is more complicated to determine the parameters of the LC fi lter. Therefore, in order for the system to remain in a steady state, the parameters must be accurately calculated and analyzed. In this study, the output power of the solar inverter, switching frequency, bus voltage etc. values were determined and LC fi lter parameters were calculated. Since high inductance values are used in LC fi lters, the voltage drop increases in these fi lters. To reduce the voltage drop, the DC bus voltage must be increased, which increases the switching losses. LC fi lter is connected between the inverter and the nonlinear load to fi lter the harmonic components produced by the DC/DC boost converter, DC/AC inverter and non-linear load. Matlab/Simulink program was used in Simulation and analysis of off -grid solar system. Solar inverter output current THD was measured as 91.55%. After the LC fi lter is connected to the system, this value has dropped to 2.62%.
Adak, Nitai Chandra,Chhetri, Suman,Kuila, Tapas,Murmu, Naresh Chandra,Samanta, Pranab,Lee, Joong Hee Elsevier 2018 Composites. Part B, Engineering Vol.149 No.-
<P><B>Abstract</B></P> <P>In this work, the hybridization effects of hydrazine reduced graphene oxide (rGO) on the inter-laminar shear strength (ILSS), impact strength, and in-plane fracture toughness of symmetric type carbon fiber/epoxy composite (CF/epoxy) laminates were investigated. The composite laminates were fabricated through the vacuum-assisted resin transfer molding (VARTM) process. At 0.2 wt% of rGO loading, the CF/epoxy composites showed the best load carrying capacity among the developed laminates. ILSS, impact strength, and critical stress intensity factor (<I>K</I> <SUB> <I>IC</I> </SUB>) were enhanced by ∼ (84, 100, and 33) %, respectively, in the case of rGO (0.2 wt%) filled CF/epoxy composite specimens, as compared to CF/epoxy composite. The consumed fracture energy of rGO (0.2 wt%)/CF/epoxy increased, as compared to the rGO (0.4 wt%)/CF/epoxy composite. The fracture surfaces obtained from field emission scanning electron microscopy of the developed composites showed compatible dispersion of rGO in the epoxy matrix, and branched fracture of the specimens. This study suggests that the rGO nanofiller might be used as a matrix modifier to resist matrix fracture, as well as fiber fracture.</P>
Adak, Nitai Chandra,Chhetri, Suman,Kim, Nam Hoon,Murmu, Naresh Chandra,Samanta, Pranab,Kuila, Tapas Springer-Verlag 2018 Journal of materials engineering and performance Vol.27 No.3
<P>This study investigates the synergistic effects of graphene oxide (GO) on the woven carbon fiber (CF)-reinforced epoxy composites. The GO nanofiller was incorporated into the epoxy resin with variations in the content, and the CF/epoxy composites were manufactured using a vacuum-assisted resin transfer molding process and then cured at 70 and 120 A degrees C. An analysis of the mechanical properties of the GO (0.2 wt.%)/CF/epoxy composites showed an improvement in the tensile strength, Young's modulus, toughness, flexural strength and flexural modulus by similar to 34, 20, 83, 55 and 31%, respectively, when compared to the CF/epoxy composite. The dynamic mechanical analysis of the composites exhibited an enhancement of similar to 56, 114 and 22% in the storage modulus, loss modulus and damping capacity (tan delta), respectively, at its glass transition temperature. The fiber-matrix interaction was studied using a Cole-Cole plot analysis.</P>
Effect of Barrier Thickness on Linearity of Underlap AlInN/GaN DG-MOSHEMTs
Sarosij Adak,Sanjit Kumar Swain,Hemant Pardeshi,Ha¯zur Rahaman,Chandan Kumar Sarkar 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.1
In this proposed work, an extensive study on the linearity performance of underlap AlInN/GaN double gate metal oxide semiconductor high electron mobility transistors (MOS-HEMT) has been analyzed using 2D Sentaurus TCAD simulation. Specifically a brief comparison is made on the linearity and intermodulation distortion characteristics of the proposed device due to variation of barrierlayer thickness from 2 nm to 6 nm. Various parameters such as transconductance (gm), second-order transconductance (gm2), third-order transconductance (gm3), second-order voltage intercept point (VIP2), third-order voltage intercept point (VIP3), third-order input intercept point (IIP3) and third-order intermodulation distortion (IMD3) of underlap AlInN/GaN double gate metal oxide semiconductor high electron mobility transistors (MOS-HEMT) are discussed. The simulated results obtained confirms that by careful optimization of barrier layer thickness linearity characteristics of this proposed device can be improved, which can be suitable for analog and circuit applications.
Sarosij Adak,Sanjit Kumar Swain 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.5
This work systematically investigated the effect of high-K oxide materials on the performance of InAlN/GaN heterostructure underlap double gate (DG) MOS-HEMTs by considering 2D Sentaurus TCAD simulation. During the course of simulation, hydrodynamic mobility model was implemented and the obtained results were used for validating the model with the previously published experimental results. Different device performance parameters are thoroughly studied for different high-K oxide materials by performing extensive simulations. It is verified that short channel effects (SCEs), key analog and RF figures of merits parameters and V th improved with an increase in the value of high-K oxide material. Moreover, it is also revealed that there is a significant growth in the values of key analog and RF figures of merits with respect to high-K values. This analysis suggested that use of a suitable value of high-K-valued oxide material in InAlN/GaN heterostructure underlap DG MOS-HEMTs can be one of the alternatives for future high speed and microwave applications.
Sarosij Adak,Sanjit Kumar Swain,Arka Dutta 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.9
Comparative assessment of graded channel gate stack (GCGS) DG MOSFET structure is done by using two-dimensional (2D) Sentrausu TCAD simulator for different high K oxide thickness. This novel device includes gate stack (GS) engineering (high K) and nonuniformly channel engineering (GC) to suppress the short channel effects and improve the device performance. This novel device can be a better alternative for the future high speed switching and low power circuit applications. It has the advantage of improved breakdown voltage, reduced leakage current, low output conductance and reduced bipolar parasitic effects. The given device must be properly investigated with respect to the variation of different high K oxide thickness on different parameters such as drain induced barrier lowering (DIBL), subthreshold slope (SS), Ion/Ioff, Vth roll off before fabrication to have better reliability. The 2D Sentrausu TCAD simulator using driftdiffusion model was used to simulate the developed structure and good agreement is obtained with respect to already published result in the sub-threshold regime. The result indicates that there is a need to be optimize the DC parameters for specific circuit applications.
Experimental and analytical research on geopolymer concrete beams reinforced with GFRP bars
Suleyman Anil Adakli,Serkan Tokgoz,Sedat Karaahmetli,Cengiz Dundar 국제구조공학회 2024 Structural Engineering and Mechanics, An Int'l Jou Vol.91 No.4
This paper presents the behavior of geopolymer concrete beams reinforced with glass fiber reinforced polymer (GFRP) bars. In the study, ordinary Portland cement concrete and geopolymer concrete beams having GFRP bars were prepared and tested under four-point loading. The load-deflection diagrams and load capacities of the tested beams were obtained. It was observed that the tested beams exhibited good ductility and significant deflection capacity. The results showed that increasing the tension GFRP reinforcement ratio caused enhancement in the strength capacity of geopolymer concrete beams. In addition, the tested beams were analyzed to obtain the load capacity and the load-deflection responses. The theoretical load‒deflection curves and load bearing capacities have been predicted well with the test results. Parametric study has been performed to determine the influences of concrete strength, shear span to depth ratio (a/d) and reinforcement ratio on the behavior of geopolymer concrete beams longitudinally reinforced with GFRP bars. It was concluded that increasing concrete strength led to an increase in load capacity. Besides, the ultimate load increased as the reinforcement ratio increased. On the other hand, increasing a/d ratio reduced the ultimate load value of GFRP reinforced geopolymer concrete beams.