ORCID Profile
0000-0002-4785-7736
Current Organisations
RMIT University
,
UNSW Australia
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Publisher: MDPI AG
Date: 06-03-2021
Abstract: This paper presents a novel thermopile chip in which the resonant cavity structure was fully utilized as an absorber by an optical design. The resonant cavity absorber structure was designed using Al as anthe bottom reflective metal layer, air as the intermediate dielectric layer, and SiO2/TiN/Si3N4 sandwich layers as the top absorption layer, while the bottom reflective metal (Al) was deposited on the cold junctions of the thermopile. The simulation and calculation results show that the thermopile chip with resonant cavity absorber structure not only has great infrared absorption in the wide infrared absorption range but also can effectively prevent the cold junctions from absorbing infrared radiation and inhibit the rise of temperature. As a result, the temperature difference between the hot junctions and the cold junctions is increased, and the responsivity of the thermopile chip is further improved. Moreover, the duty cycle of the thermopile chip is greatly improved due to the double-layer suspension structure. Compared with the traditional thermopile chip structure, the sizes of the thermopile chip with the resonant cavity absorber structure can be further reduced while maintaining responsivity and specific detectivity.
Publisher: Power System Technology Press
Date: 2022
Publisher: Elsevier BV
Date: 12-2022
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2021
Publisher: Trans Tech Publications, Ltd.
Date: 08-2012
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.562-564.1772
Abstract: Due to the complex design and high costs of production, solar thermal systems have fallen behind in the world of alternative energy systems. Different mechanisms are applied to increase the efficiency of the solar collectors and to reduce the cost. Solar tracking system is the most appropriate technology to increase the efficiency of solar collectors as well as solar power plants by tracking the sun timely. In order to maximize the efficiency of collectors, one needs to keep the reflecting surface of parabolic trough collectors perpendicular to the sun rays. For this purpose microcontroller based real time sun tracker is designed which is controlled by an intelligent algorithm using shadow technique. The aim of the research project is to test the solar-to-thermal energy efficiency by tracking parabolic trough collector (PTC). The energy efficiency is determined by measuring the temperature rise of working fluid as it flows through the receiver of the collector when it is properly focused. The design tracker is also simulated to check its accuracy. The main purpose to design this embedded system is to increase the efficiency and reliability of solar plants by reducing size, complexity and cost of product.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2018
Publisher: Institution of Engineering and Technology (IET)
Date: 02-2019
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2018
Publisher: Elsevier BV
Date: 12-2017
Publisher: IEEE
Date: 09-2017
Publisher: Springer Science and Business Media LLC
Date: 25-02-2019
Publisher: IEEE
Date: 09-2016
Publisher: Elsevier BV
Date: 11-2020
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2022
Publisher: Power System Technology Press
Date: 06-2020
Publisher: IOP Publishing
Date: 05-12-2019
Publisher: IEEE
Date: 10-2019
Publisher: IEEE
Date: 10-2017
Publisher: MDPI AG
Date: 05-03-2020
Abstract: Ethylene propylene diene monomer (EPDM) is broadly employed as an insulating material for high voltage applications. Surface discharge-induced thermal depolymerization and carbon tracking adversely affect its performance. This work reports the electrical field modeling, carbon tracking lifetime, infrared thermal distribution, and leakage current development on EPDM-based insulation with the addition of nano-BN (boron nitride) contents. Melt mixing and compression molding techniques were used for the fabrication of nanocomposites. An electrical tracking resistance test was carried out as per IEC-60587. Simulation results show that contamination significantly distorted the electrical field distribution and induced dry band arcing. Experimental results indicate that electric field stress was noticed significantly higher at the intersection of insulation and edges of the area of contamination. Moreover, the field substantially intensified with the increasing voltage levels. Experimental results show improved carbonized tracking lifetime with the addition of nano-BN contents. Furthermore, surface temperature was reduced in the critical contamination flow path. The third harmonic component in the leakage current declined with the increase of the nano-BN contents. It is concluded that addition of nano-BN imparts a better tracking failure time, and this is attributed to better thermal conductivity and thermal stability, as well as an improved shielding effect to electrical discharges on the surface of nanocomposite insulators.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2019
Publisher: Wiley
Date: 15-08-2020
DOI: 10.1002/APP.49715
Publisher: Springer Science and Business Media LLC
Date: 28-04-2020
Publisher: Springer Science and Business Media LLC
Date: 07-2019
Publisher: Informa UK Limited
Date: 07-08-2020
Publisher: Elsevier BV
Date: 11-2023
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 04-2021
Publisher: IEEE
Date: 05-2018
Publisher: Springer Science and Business Media LLC
Date: 20-08-2020
Publisher: Elsevier BV
Date: 10-2020
Publisher: MDPI AG
Date: 25-08-2021
Abstract: Room temperature vulcanized (RTV) silicone rubber filled with aluminum trihydrate (ATH) is substantially engaged in electrical outdoor insulation applications. The pristine silicone rubber is highly combustible. ATH filled silicone rubber offers excellent electrical insulation but lacks in providing adequate flame retardancy. This short communication reports the novel results on improved flame retardancy of pristine and ATH filled silicone rubber whilst retaining the electrical insulation properties to a great extent. Results suggest that the presence of only one percent of graphene nanoplatelets with ATH sharply reduces the heat release rate and rate of smoke release. A minor reduction in dielectric breakdown strength and volume resistivity is noticed. Furthermore, permittivity and dielectric loss at power frequency suggest that a marginal 1% concentration of nanoplatelet with ATH is an excellent approach to fabricate flame retardant silicone rubber with an acceptable electrical insulation level.
Publisher: Elsevier BV
Date: 11-2022
Publisher: Elsevier BV
Date: 10-2022
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2023
Publisher: IEEE
Date: 05-2017
Publisher: Institution of Engineering and Technology (IET)
Date: 28-07-2023
DOI: 10.1049/HVE2.12352
Abstract: The flashover strength of epoxy (EP) insulations in the High voltage direct current applications of future energy grids can be improved by tailoring their surface condition. This work aims to improve the DC surface flashover characteristics of EP after being treated with sandpaper of different gradings. S les with virgin EP and homogenously modified EP considering varying surface roughness ( R a = 0.54, 3.16, 5.24, and 8.35 μm) are prepared. Different experimental characterisations, such as water contact angle, surface intrinsic conductivity, surface voltages, flashover strength, and trap distributions are conducted and evaluated to analyse the difference between virgin and treated EP. Moreover, based on the obtained experimental results of homogenously treated EP and theoretical analysis, the concept of surface functionally graded materials (SFGMs) is put forward. The flashover voltages of homogenously treated EP are augmented significantly compared to virgin EP regardless of the voltage polarity and enhanced by enhancing the surface roughness. The s le T Model‐C with SFGM design shows a 45.02% and 43.75% improvement in the negative and positive flashover voltages than that of the virgin EP. In the end, COMSOL simulations are conducted to justify the experimental findings and to analyse the difference between virgin and modified s les in terms of electric field distribution.
Publisher: Institution of Engineering and Technology (IET)
Date: 06-11-2018
Publisher: Elsevier BV
Date: 04-2021
Publisher: Springer Science and Business Media LLC
Date: 12-10-2020
Publisher: Institution of Engineering and Technology (IET)
Date: 2011
Publisher: Springer Science and Business Media LLC
Date: 09-09-2019
Publisher: Elsevier BV
Date: 10-2023
Publisher: IEEE
Date: 07-2015
Publisher: Elsevier BV
Date: 02-2021
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2020
Publisher: IEEE
Date: 09-2016
Publisher: Elsevier BV
Date: 02-2023
Publisher: Elsevier BV
Date: 10-2020
Publisher: IEEE
Date: 07-2016
Publisher: MDPI AG
Date: 21-02-2021
Abstract: The steady-state electrical conduction current for single and multilayer polyimide (PI) nanocomposite films was observed at the low and high electric field for different temperatures. Experimental data were fitted to conduction models to investigate the dominant conduction mechanism in these films. In most films, space charge limited current (SCLC) and Poole–Frenkel current displayed dominant conduction. At a high electric field, the ohmic conduction was replaced by current–voltage dependency. Higher conduction current was observed for nanocomposite films at a lower temperature, but it declined at a higher temperature. PI nanocomposite multilayer films showed a huge reduction in the conduction current at higher electric fields and temperatures. The conclusions derived in this study would provide the empirical basis and early breakdown phenomenon explanation when performing dielectric strength and partial discharge measurements of PI-based nanocomposite insulation systems of electric motors.
Publisher: Elsevier BV
Date: 10-2022
Publisher: Elsevier BV
Date: 09-2018
Publisher: IEEE
Date: 04-2019
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2022
Publisher: MDPI AG
Date: 27-09-2020
Abstract: The application of wide band-gap power electronic devices brings more challenges to insulating packaging technology. Knowing the influence of applied voltage parameters on insulation performance is helpful to evaluate the insulation condition of electric power equipment. In this paper, the effect of repetitive square wave voltage duty cycle on the growth characteristics of electrical trees in epoxy resin was studied. The experimental results show that the square wave voltage duty cycle has a significant influence on treeing features. The electrical tree proportion initiation has shown a decreasing trend, and the shape of the electrical tree changes from pine-like to branch-like by increasing the duty cycles. The length and damaged area of electrical tree increased with the increase in the duty cycle up to 10% and then decrease by increasing the duty cycle higher than 30%. It indicates that a low duty cycle will enhance the electron injection and accumulate space charges and thus accelerate electrical tree development. Under short duty cycles, the electric field due to the shielding effect near the needle tip suppresses the electrical tree growth, which results in treeing growth stagnation. The obtained results are helpful to keep these parameters in mind during the design of epoxy-based insulation such high-voltage rotating machines and power electronic device packaging.
Publisher: Elsevier BV
Date: 03-2021
Publisher: Power System Technology Press
Date: 2019
Publisher: Institution of Engineering and Technology (IET)
Date: 12-2018
Publisher: Elsevier BV
Date: 03-2020
Publisher: American Chemical Society (ACS)
Date: 06-08-2020
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 10-2016
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2020
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2020
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2023
Publisher: Trans Tech Publications, Ltd.
Date: 08-2012
DOI: 10.4028/WWW.SCIENTIFIC.NET/AMR.562-564.60
Abstract: Outdoor electrical insulators form an important link in an electric power system. Along with the traditional insulators like glass and porcelain, presently the polymeric insulators are also used world widely. These polymeric insulating materials are very sensitive to various environmental parameters such temperature, raining, pollution, UV-radiations and icing etc. which seriously effect their electrical, chemical and hydrophobic properties. This paper shows a dynamic change of hydrophobicity on the surface of polymeric insulator under different environmental and contamination stresses. The hydrophobicity decrease of polymeric insulating surface due to rain and icing, hydrophobicity transfer status though different pollution layers and hydrophobicity recovery at different temperatures, humidity and wind speed are carried out in this paper. The hydrophobic characteristics are studied by measuring static contact angle on the surface on polymeric insulating material.
Publisher: Institution of Engineering and Technology (IET)
Date: 02-05-2022
DOI: 10.1049/HVE2.12213
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2023
Publisher: MDPI AG
Date: 29-06-2023
DOI: 10.3390/MOLECULES28135100
Abstract: The effect of varying the weight percentage composition (wt.%) of low-cost expandable graphite (EG), ammonium polyphosphate (APP), fibreglass (FG), and vermiculite (VMT) in polyurethane (PU) polymer was studied using a traditional intumescent flame retardant (IFR) system. The synergistic effect between EG, APP, FG, and VMT on the flame retardant properties of the PU composites was investigated using SEM, TGA, tensile strength tests, and cone calorimetry. The IFR that contained PU composites with 40 wt.% EG displayed superior flame retardant performance compared with the composites containing only 20 w.t.% or 10 w.t.% EG. The peak heat release rate, total smoke release, and carbon dioxide production from the 40 wt.% EG s le along with APP, FG, and VMT in the PU composite were 88%, 93%, and 92% less than the PU control s le, respectively. As a result, the synergistic effect was greatly influenced by the compactness of the united protective layer. The PU composite suppressed smoke emission and inhibited air penetrating the composite, thus reducing reactions with the gas volatiles of the material. SEM images and TGA results provided positive evidence for the combustion tests. Further, the mechanical properties of PU composites were also investigated. As expected, compared with control PU, the addition of flame-retardant additives decreased the tensile strength, but this was ameliorated with the addition of FG. These new PU composite materials provide a promising strategy for producing polymer composites with flame retardation and smoke suppression for construction materials.
Publisher: Elsevier BV
Date: 2022
Publisher: Royal Society of Chemistry (RSC)
Date: 2020
DOI: 10.1039/C9QI01105F
Abstract: We designed a cost-effective and novel strategy for the construction of hard carbon spheres enveloped with graphene networks as a high performance anode material for sodium-ion batteries.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 06-2019
Publisher: IEEE
Date: 08-2015
Publisher: Elsevier BV
Date: 09-2019
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2018
Publisher: Elsevier BV
Date: 06-2021
Publisher: IEEE
Date: 05-07-2020
Start Date: 2019
End Date: 2021
Funder: National Natural Science Foundation of China
View Funded ActivityStart Date: 2012
End Date: 2012
Funder: Chongqing University, College of Electrical Engineering
View Funded ActivityStart Date: 2016
End Date: 2017
Funder: State Key Laboratory of Electrical Insulation and Power Equipment
View Funded ActivityStart Date: 2016
End Date: 2016
Funder: IEEE NSW
View Funded Activity