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排序方式: 共有677条查询结果,搜索用时 15 毫秒
81.
Buddhadeva Sahoo Sangram Keshari Routray Pravat Kumar Rout Mohammed M. Alhaider 《计算机、材料和连续体(英文)》2021,69(2):1851-1875
This paper suggests a combined novel control strategy for DFIG based wind power systems (WPS) under both nonlinear and unbalanced load conditions. The combined control approach is designed by coordinating the machine side converter (MSC) and the load side converter (LSC) control approaches. The proposed MSC control approach is designed by using a model predictive control (MPC) approach to generate appropriate real and reactive power. The MSC controller selects an appropriate rotor voltage vector by using a minimized optimization cost function for the converter operation. It shows its superiority by eliminating the requirement of transformation, switching table, and the PWM techniques. The proposed MSC reduces the cost, complexity, and computational burden of the WPS. On the other hand, the LSC control approach is designed by using a mathematical morphological technique (MMT) for appropriate DC component extraction. Due to the appropriate DC-component extraction, the WPS can compensate the harmonics during both steady and dynamic states. Further, the LSC controller also provides active power filter operation even under the shutdown of WPS condition. To verify the applicability of coordinated control operation, the WPS-based microgrid system is tested under various test conditions. The proposed WPS is designed by using a MATLAB/Simulink software. 相似文献
82.
Buddhadeva Sahoo Sangram Keshari Routray Pravat Kumar Rout Mohammed M. Alhaider 《计算机、材料和连续体(英文)》2022,70(2):2319-2346
This paper presents a combined control and modulation technique to enhance the power quality (PQ) and power reliability (PR) of a hybrid energy system (HES) through a single-phase 11-level cascaded H-bridge inverter (11-CHBI). The controller and inverter specifically regulate the HES and meet the load demand. To track optimum power, a Modified Perturb and Observe (MP&O) technique is used for HES. Ultra-capacitor (UCAP) based energy storage device and a novel current control strategy are proposed to provide additional active power support during both voltage sag and swell conditions. For an improved PQ and PR, a two-way current control strategy such as the main controller (MC) and auxiliary controller (AC) is suggested for the 11-CHBI operation. MC is used to regulate the active current component through the fuzzy controller (FC), and AC is used to regulate the dc-link voltage of CHBI through a neural network-based PI controller (ANN-PI). By tracking the reference signals from MC and AC, a novel hybrid pulse width modulation (HPWM) technique is proposed for the 11-CHBI operation. To justify and analyze the MATLAB/Simulink software-based designed model, the robust controller performance is tested through numerous steady-state and dynamic state case studies. 相似文献
83.
Wireless Personal Communications - The proposed beamforming model exploits the underlying sparseness of the adaptive filter as impulse response of wireless channel shows some extent of sparse... 相似文献
84.
Krishna Vaibhav Deb Senorita Sahoo Bibhu Datta 《Analog Integrated Circuits and Signal Processing》2021,109(1):225-239
Analog Integrated Circuits and Signal Processing - Electronic circuits operating in the radiation intensive environment like space, are subject to a barrage of cosmic particles like neutrons,... 相似文献
85.
Delineation of Groundwater Potential Zones of Coastal Groundwater Basin Using Multi-Criteria Decision Making Technique 总被引:3,自引:0,他引:3
Uday Mandal Satiprasad Sahoo Selva Balaji Munusamy Anirban Dhar Sudhindra N. Panda Amlanjyoti Kar Prasanta K. Mishra 《Water Resources Management》2016,30(12):4293-4310
Delineation of groundwater potential zones (GWPZ) has been performed for a coastal groundwater basin of eastern India. The groundwater potential zone index (GWPZI) map is generated by using Analytic Hierarchy Process (AHP) from different influencing features, e.g., Land Use/Land Cover (LU/LC), soil (S), geomorphology (GM), hydrogeology (HG), surface geology (SG), recharge rate (RR), drainage density (DD), rainfall (RF), slope (Sl), surface water bodies (SW), lineament density (LD), and Normalized Difference Vegetative Index (NDVI). Recharge rate values are estimated from hydrological water balance model. Overlay weighted sum method is used to integrate all thematic feature maps to generate GWPZ map of the study area. Four zones have been identified for the coastal groundwater basin [very good: 36.39 % (273.53 km2, good: 43.57 % (327.47 km2), moderate: 18.27 % (137.30 km2), and poor: 1.77 % (13.27 km2)]. Areas in north to south-west and south-east direction show very good GWPZ due to the presence of low drainage density. GWPZ map and well yield values show good agreement. Sensitivity analysis reveals that exclusion/absence of rainfall and lineament density increases the poor groundwater potential zones. Omission of hydrogeology, soils, surface geology, and NDVI show maximum increase in good GWPZ. Obtained GWPZ map can be utilized effectively for planning of sustainable agriculture. This analysis demonstrates the potential applicability of the methodology for a general coastal groundwater basin. 相似文献
86.
An experimental study was carried out to investigate the dry sliding friction and wear characteristics of woven glass epoxy composites filled with Al particulates sliding against steel using a pin-on-disc tribometer. The glass fiber weight fraction was kept constant at 60 wt% and Al wt% varied as 0, 5, 10, and 15%. The composite was fabricated by a hand lay-up technique followed by light compression molding. Friction and wear behavior under dry sliding condition are presented as a function of sliding speed varying between 1–5 m/s and normal load ranging between 10–40 N. Friction characteristics of composites depend strongly on a combination of filler content, sliding speed and load. Wear loss increases with both sliding speed and load. Incorporation of a smaller amount of Al filler reduces wear loss compared to un-filled glass epoxy composites. An attempt has also been made to observe the distribution of fiber and Al particles in the composite, and to correlate the wear behavior using Scanning Electron Microscopy (SEM) observations. 相似文献
87.
Nanogold-imprinted starch bionanocomposites of various compositions were synthesized by “one-pot reaction” with in situ generation of nanogold. Bionanocomposites were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscope and high-resolution transmission electron microscope. The electrical conductivity of nanocomposites was enhanced because of dispersion of nanogold in the starch. Antimicrobial activity of starch was increased due to incorporation of nanogold. The bionanocomposites were resistant towards dilute acid and alkali with little scarification in biodegradable properties. The enhanced thermal, gas barrier and antimicrobial properties may enable the synthesized materials for packaging applications. 相似文献
88.
Built-up members with battens designed for typical 2–2.5% of axial load may not behave satisfactorily in the presence of lateral seismic loads. Analytical evaluation of double-channel battened cantilever members designed as per the current practice, and subjected to constant axial compressive load and gradually increasing lateral load showed that the members failed to reach their expected flexural capacity due to lateral instability. The design of members was modified by changing the configuration of battens in the expected plastic-hinge region, i.e., reducing the spacing of battens in end panel by half, and designing battens for a shear demand due to moment capacity of section. The members with battens designed for moment capacity could able to reach the expected flexural strength. Five half-scale test specimens of battened members designed as per the current practice and improved design method were subjected to axial load and gradually increasing cyclic load. The specimens designed as per improved design method showed excellent performance in terms of lateral strength, lateral stiffness, moment rotation characteristics and energy dissipation capacity. 相似文献
89.
P. K. Sahoo S. Tripathy M. K. Panigrahi Sk. Md. Equeenuddin 《Bulletin of Engineering Geology and the Environment》2017,76(2):537-552
The total concentrations and chemical partitioning of heavy metals in streambed sediments, collected around the Jaintia Hills coal deposit of northeast India, were studied using pollution indices and multivariate techniques to evaluate the risk and contamination levels from heavy metals and their possible origins. Results show that sediments close to mining sites have low pH (<4), high organic carbon, and contain significant amounts of Fe-oxyhydroxide phases (mainly, goethite and schwertmannite), which implies direct impact of coal mine drainage. The average concentrations of Fe, Cu, Co, Cd, Cr, and Zn exceeded the World average, and in some cases, Cd, Cu, Ni, and Cr concentrations exceeded the threshold effects level, which suggests they will be toxic to aquatic biota. Contamination factors (CF) show that the sediments are low to highly contaminated with Cd, Cu, Mn, Pb, Fe, and Zn and low to moderately contaminated with Co, Cr and Ni. The pollution load index (PLI), degree of contamination index (C deg) and Nemerow integrated pollution index (NIPI) show that the sediments are moderately to highly contaminated, with the extent of pollution greatest nearest to the collieries. The potential ecological risk index (RI) shows low to considerable ecological risk from heavy metals in the sediments, with Cd having the high potential of risk, which also agrees with the risk assessment code (RAC). Multivariate statistical analysis suggests that the concentrations of the heavy metals in stream sediments are strongly influenced by Fe-oxyhydroxide phases and organic carbon derived from anthropogenic sources, mainly coal mining activities. Although a significant proportion of the Cd, Mn, and Ni in the sediments are partitioned into exchangeable and organic fractions, a sizable amount of metals are also found in the Fe–Mn fraction, suggesting that Fe-oxyhydroxides play a dominant role in controlling metal mobility in these stream sediments. 相似文献
90.
Satyabrata Sahoo 《国际自然能源杂志》2016,37(4):372-383
A transient heat and mass transfer model is developed to simulate the performance of an adsorbed natural gas (ANG) storage system subjected to variable charge and discharge conditions. The obtained results are applicable for internal combustion engines with natural gas as the fuel. The ANG system performance is presented in terms of delivery capacity. Results are obtained for the cases of (i) constant pressure charging with a constant flow discharging and (ii) constant flow charging and discharging. Results show the importance of improving the heat transfer performance of the reactor, particularly at high specific gas flow rates. From the second law analysis of the system, it is seen that significant internal entropy generation occurs at high specific flow rate and low heating fluid temperatures. Based on the minimum specific entropy generation criterion, the optimum heating fluid temperatures for different ranges of specific flow rate of the adsorbate are found. 相似文献