| 1. |
- Becerra, Marley, et al.
(författare)
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On the optical radiation of ablation dominated arcs in air
- 2011
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Ingår i: 19th Symposium on Physics of Switching Arc 2011, FSO 2011. - : Brno University of Technology. - 9781632660060 ; , s. 113-116
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Konferensbidrag (refereegranskat)abstract
- The optical emission of high current electric arcs confined between polymeric (PA6 - C6H11ON- and PMMA -C5H8O2-) and ceramic (Al2O 3) walls has been investigated experimentally in air. Arcs standing between copper electrodes with a separation of 8 mm under AC currents with peak values of 2 kA are studied here. The arc optical emission in the range between 250 and 700 nm is measured with a fast spectrometer at the mid-section of the arc column, while the spatial variations of the radiation is recorded with high speed photography. It is found that the ablation of the polymeric walls strongly reduce the intensity of emitted copper peaks as well as the arc column radius. Furthermore, a strong hydrogen Balmer-alpha peak is detected, which indicates the strong injection of hydrogen in the arc atmosphere by the ablation of the polymeric walls.
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| 2. |
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| 3. |
- Doddapaneni, Venkatesh, 1984-, et al.
(författare)
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Engineered PMMA-CuO nanocomposites for improving the electric arc interruption process in electrical switching applications
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Polymer-based nanocomposites (PNCs) display fascinating functionalities to be useful in electrical switching applications like circuit breakers, switch gears, etc. These PNCs are fabricated by incorporating nanoparticles (NPs) into a polymer by in-situ polymerization. When the PNCs interrupt the high energetic fault currents generate between the two contacts in a circuit breaker, they outgas (ablation) chemical species and cooling gases, which change the thermodynamic properties of the arcing environment leading to quench the electrical arcs quickly. Two PNCs are fabricated with different wt% of oleic acid modified CuO NPs and a polymer matrix i.e. poly methyl methacrylate (PMMA). These PNCs are tested with the electrical arcs of a prospective current of 1.6 kA generated in the test-setup. The electrical signals (arc current and voltage) and computed dissipated enegy i.e., ∫?(?)?(?)?? help to understand the effect of PNCs on the electrical arcs. In addition to that, the computed joule integral and mass loss of the PNCs due to outgassing is reported. The re-depositions of the chemical species are analyzed by using Fourier transform infrared spectroscopy (FTIR) and the morphological changes on the surface of outgassed PNCs are analyzed by using scanning electron microscopy (SEM). These results help to understand the effect of PNCs on the arc interruption process in circuit breakers.
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| 4. |
- Doddapaneni, Venkatesh, et al.
(författare)
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New experimental insights for controlling the electrical arcs in electrical switching applications : a comparative study on PMMA nanocomposites of Au and ZnO
- 2017
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Ingår i: Composites Science And Technology. - : Elsevier. - 0266-3538 .- 1879-1050.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Polymer inorganic nanocomposites (PINCs) are developed, not only due to scientific interest but also improving theelectric arc interruption process in the electrical switching applications like circuit breakers. The novelty of this work isin integrating the current developments in PINCs into electrical switching application in order to extend the limits of thepower switching devices. Several PINCs are fabricated by using pre-synthesized Au nanoparticles (NPs) of size 2.75 ±0.4 nm and poly (methyl methacrylate) (PMMA) matrix via in-situ polymerization method. Six homogeneous PINCsamples with ultra-low wt% of Au NPs varying from 0.0003 to 0.005 wt% have been fabricated. We find that thepresence of Au NPs improved the convective heat transfer and visible optical radiation absorption of PMMA. Thefabricated PINCs are tested for their arc interruption performance and the results are compared with ZnO PINCs in ourearlier work. The results of the experiments insights demonstrate the impact of PINCs on the electrical arcs and theirpotential advantages of having PINCs for the electric arc interruption process in high power switching devices.
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| 5. |
- Doddapaneni, Venkatesh
(författare)
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On the polymer-based nanocomposites for electrical switching applications
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Recent research demonstrated that polymer based nanocomposites (PNCs) have been engineered in order to improve the arc interruption capability of the circuit breakers. PNCs are the combination of nano-sized inorganic nanoparticles (NPs) and polymers, opened up new developments in materials science and engineering applications. Inorganic NPs are selected based on their physical and chemical properties which could make multifunctional PNCs in order to interrupt the electrical arcs effectively. In particular, we presented the PNCs fabricated by using CuO, Fe3O4, ZnO and Au NPs in a poly (methyl methacrylate) (PMMA) matrix via in-situ polymerization method, recently developed method to avoid NPs agglomeration, leading to good spatial distribution in the polymer matrix. Thus, several samples with various wt% of NPs in PMMA matrix have been fabricated. These PNCs have been characterized in detail for the morphology of NPs, interaction between NPs and polymer matrix, and radiative/thermal energy absorption properties. In the next stage, PNCs are tested to determine their arc interruption performance and impact on the electrical arcs of current 1.6 kA generated using a specially designed test set-up. When PNCs interact with the electrical arcs, they generate ablation of chemical species towards core of the electrical arc, resulting in cooling-down the arc due to strong temperature and pressure gradient in the arc quenching domain. This thesis demonstrates for the first time that these engineered PNCs are easily processed, reproducible, and can be used to improve the arc interruption process in electrical switching applications.
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