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Wyszukujesz frazę "selective elimination" wg kryterium: Temat


Wyświetlanie 1-4 z 4
Tytuł:
Synthesis, Characterization, and Application of Stabilized-Ni/Fe Bimetallic Nanoparticles for the Selective Elimination of Chlorate Impurity in Military Grade Ammonium Perchlorate
Autorzy:
Zarei, A. R.
Moloudi, A.
Hosseini, S. G.
Powiązania:
https://bibliotekanauki.pl/articles/951495.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
ammonium perchlorate
chlorate
selective elimination
stabilized-Ni/Fe bimetallic nanoparticles
solid propellants
Opis:
Ammonium perchlorate (AP) is used as the most common oxidizer in composite solid propellants. Control of chlorate impurity in military grade ammonium perchlorate is important, since it has an undesirable effect on the thermal decomposition of ammonium perchlorate. In this work stabilized Ni/Fe bimetallic nanoparticles (S-Ni/Fe NPs) were synthesized using the borohydride reduction method (BRM) in the presence of starch as a stabilizing agent, and they were characterized by field emission scanning electron microscopy (SEM), and their X-ray diffraction pattern (XRD). The results showed that the synthesized S-Ni/Fe bimetallic nanoparticles were spherical in shape and had nearly uniform distribution, with particle sizes of 20-50 nm. The prepared nanoparticles were then used for the selective elimination of chlorate impurity in ammonium perchlorate. The main factors controlling the elimination of chlorate, such as the initial pH of the solution, dosage of S-Fe/Ni NPs, initial chlorate and perchlorate concentrations, reaction temperature, and reaction time, were optimized by using an experimental design based on the Taguchi method. An L9 orthogonal array (L9-OA) was used to design experiments with four 4-level factors (34). Under the optimal conditions, i.e., pH 6.5, at 30 °C and a dosage of 50 mg S-Ni/Fe NPs, chlorate was eliminated with nearly 100% efficiency in 50 mL of a solution containing 2.0 μg·mL−1 and 100 μg·mL−1 of chlorate and perchlorate, respectively, without change in perchlorate concentration.
Źródło:
Central European Journal of Energetic Materials; 2017, 14, 1; 120-133
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
WTHD minimisation in hybrid multilevel inverter using biogeographical based optimisation
Autorzy:
Kavitha, R.
Thottungal, R.
Powiązania:
https://bibliotekanauki.pl/articles/141212.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
biogeographical based optimisation
BBO
genetic algorithm
GA
bacterial foraging algorithm
BFA
weighted total harmonics distortion
WTHD
optimal minimisation of total harmonic
OMTHD
selective harmonic elimination
SHE
Opis:
Harmonic minimisation in hybrid cascaded multilevel inverter involves complex nonlinear transcendental equation with multiple solutions. Hybrid cascaded multilevel can be implemented using reduced switch count when compared to traditional cascaded multilevel inverter topology. In this paper Biogeographical Based Optimisation (BBO) technique is applied to Hybrid multilevel inverter to determine the optimum switching angles with weighted total harmonic distortion (WTHD) as the objective function. Optimisation based on WTHD combines the advantage of both OMTHD (Optimal Minimisation of Total Harmonic Distortion) and SHE (Selective Harmonic Elimination) PWM. WTHD optimisation has the benefit of eliminating the specific lower order harmonics as in SHEPWM and minimisation of THD as in OMTHD. The simulation and experimental results for a 7 level multilevel inverter were presented. The results indicate that WTHD optimization provides both elimination of lower order harmonics and minimisation of Total Harmonic Distortion when compared to conventional OMTHD and SHE PWM. Experimental prototype of a seven level hybrid cascaded multilevel inverter is implemented to verify the simulation results.
Źródło:
Archives of Electrical Engineering; 2014, 63, 2; 187-196
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Control of open-end induction motor by multi-objective GA based selective harmonic elimination PWM to reduce zero sequence currents and torque ripples
Autorzy:
Kumar, K. Kalyan
Anuradha, K.
Suryakalvathi, M.
Powiązania:
https://bibliotekanauki.pl/articles/41179745.pdf
Data publikacji:
2023
Wydawca:
Politechnika Warszawska, Instytut Techniki Cieplnej
Tematy:
open-end winding induction machine
zero sequence currents
torque ripple
selective harmonic elimination
triplen harmonics
maszyna indukcyjna
uzwojenie otwarte
tętnienie momentu obrotowego
selektywna eliminacja harmonicznych
potrójne harmoniczne
Opis:
A double inverter powered induction motor with open stator winding has few benefits, including excessive error forbearance functionality, great flexibility and lesser rating of DC input voltage etc. For this Configuration, two types of Modules can be implemented: they are Non-Isolated DC link and Isolated DC link. In these two, Non-Isolated DC link is a good choice due to effective DC-link utilization and ruggedness, which is very beneficial in many applications. However, this module produces more zero sequence currents (Z-SC) by means of common mode (CMMD) voltage, which flows through DC bus. The circulation of Z-SC must be as little as possible since it merely rises the amplitude of currents in all phases. High ripple frequency of currents and torque, in addition results in extra loss, which not only reduces the efficiency, but influences loading ability and quickens the aging of drive. The Triplen harmonics can be defined as harmonics with integer of three times the frequency at fundamental, when they are in Phase in all Phases forms the Z-SC. In this paper, a novel SHE method is chosen to target Triplen harmonics in Single DC Source Module (Non- Isolated) and holding preferred fundamental quantity, which aids in improving the torque handling ability of the motor. In addition, the investigation of dual inverter fed OEW-IM with both common DC source as well as separate DC sources is also explored in the SHE for different number of switching angles and variable Modulation Index (MI) towards the torque ripples and Z-SC reduction given. The foremost challenge related to the SHE method is resolving a set of higher order nonlinear equations with a number of variables. A Multi-objective GA method is provided for that challenge which effects the reduction in Z-SC so that torque ripples will be minimized. Moreover, the novel SHE method reduces the number of harmonics better than the conventional SHE, which further decreases TH-D with decent fundamental quantity. For validation, the essential mathematical formulations and simulation results are presented.
Źródło:
Journal of Power Technologies; 2023, 103, 1; 72-87
1425-1353
Pojawia się w:
Journal of Power Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An approach to suppress high-frequency resonance using model predictive and selective harmonic elimination combined strategy
Autorzy:
Chen, Sitong
Chen, Xiaoqiang
Wang, Ying
Xiong, Ye
Powiązania:
https://bibliotekanauki.pl/articles/1841300.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
CRH5 EMUs and traction power supply coupled system
high-frequency oscillation
high speed railway
model predictive control (MPC)
selective harmonic elimination pulse-width modulation (SHEPWM)
CRH5 EMU i system sprzężony z zasilaniem trakcyjnym
oscylacja wysokiej częstotliwości
kolej dużych prędkości
kontrola predykcyjna modelu (MPC)
selektywna eliminacja harmoniczna modulacja szerokości impulsu (SHEPWM)
Opis:
High-frequency resonance is a prominent phenomenon which affects the normal operation of the high-speed railway in China. Aiming at this problem, the resonance mechanism is analyzed first. Then, model predictive control and selective harmonic elimination pulse-width modulation (MPC-SHEPWM) combined control strategy is proposed, where the harmonics which cause the resonance can be eliminated at the harmonic source. Besides, the MPC is combined to make the current track the reference in transients. The proposed control has the ability to suppress the resonance while has a faster dynamic performance comparing with SHEPWM. Finally, the proposed MPC-SHEPWM is tested in a simulation model of CRH5 (Chinese Railway High-speed), EMUs (electric multiple units) and a traction power supply coupled system, which shows that the proposed MPC-SHEPWM approach can achieve the resonance suppression and shows a better dynamic performance.
Źródło:
Archives of Electrical Engineering; 2021, 70, 2; 415-430
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

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