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Blondel B.,LAboratoire PLAsma et Conversion dEnergie | Blondel B.,CNRS Coordination Chemistry | Colin A.,LAboratoire PLAsma et Conversion dEnergie | Lopes M.,LAboratoire PLAsma et Conversion dEnergie | And 3 more authors.
Nanotechnology Materials and Devices Conference, NMDC 2016 - Conference Proceedings | Year: 2016

Studies on [Pt(II)(di-tert-butylSalophen)] which is thermally stable (Td = 390°C) and displays a deep-red emission (Imax = 660 nm) are presented. Based on efficient energy transfer, this Pt(II) complex was used as a probe for exciton formation in organic light-emitting diodes (OLEDs). Electrical characterisation of host-guest system based devices showed that the presence of the Pt(II) complex within Tris-(8-hydroxyquinoline)aluminium matrix emissive layer, led to electrically active states. Upon electrical driving stress, modulation of the charge transport properties in devices was highlighted. Negative Differential Resistance (NDR) was observed and interpreted in terms of space charge effect. A figure of merit higher than 103 was achieved. Aging investigations showed a reversible electrical degradation and suggested that the Pt(II) complex would stabilise OLEDs performance. Moreover, internal electric field model was proposed to explain the observed polarisation/depolarisation phenomena. © 2016 IEEE.

Floricau D.,Polytechnic University of Bucharest | Richardeau F.,Toulouse 1 University Capitole | Richardeau F.,Ecole Polytechnique - Palaiseau | Richardeau F.,University Paul Sabatier | And 2 more authors.
IEEE Transactions on Industrial Electronics | Year: 2011

In this paper, a new three-level (3L) converter is presented. It is called 3L Vienna neutral-point-clamped (3L-VNPC) converter and consists of two stacked high-frequency (HF) commutation cells working with a shared power device. The HF cells are connected to a single-phase switched bridge controlled at low frequency. The 3L-VNPC topology is extended to 3L active VNPC (3L-AVNPC) concept, which is generalized for five levels (5L) and N odd voltage levels (N L). The proposed multilevel converters can be seen as two cascaded voltage stages. The high-voltage stage is specific to the single-phase switched bridge, while the low-voltage (LV) stage corresponds to the stacked HF cells with shared power devices. The new concept AVNPC is a useful and suitable solution for medium-voltage applications, where small modulation index (M) is as crucial as large M. The analyses of the new converters are verified by simulations both for 3L and for 5L topologies, and their features are generalized for NL. Experimental results for single-phase 3L-AVNPC converter on an LV test bench are also provided to validate the proper operation of the new concept. © 2011 IEEE.

Ben Abdelmlek K.,Unite dEtude des Milieux Ionises et Reactifs | Araoud Z.,Unite dEtude des Milieux Ionises et Reactifs | Ghnay R.,Unite dEtude des Milieux Ionises et Reactifs | Abderrazak K.,Unite de Thermique et Thermodynamique des Procedes Industriels | And 2 more authors.
Applied Thermal Engineering | Year: 2016

This paper presents the details of a numerical study of the LEDs thermal conduction path deficiency. A three-dimensional numerical modeling using COMSOL Multiphysics® simulation software has been developed. The model was then validated by the literature, showed a good agreement. The effect of the number of LED-chips put on substrate was studied since it can affect the junction temperature and participate severely on the LED degradation. In addition, when there is trouble in the LED package, junction temperature can increase widely with no indication from the heat sink temperature, even with an efficient heat sink design. To justify this fact, a study of the effect of a deficient thermal conduction path between the heat sink and the thermal grease was performed by two methods: adding an air layer between the TIM and the heat sink, and modifying the effective thermal conductivity of the TIM. Its effects on the junction temperature, the heat sink average temperature, the total thermal resistance and the luminous flux was also investigated and it was found that a deficient thermal path affects severely the thermal properties of LED package even with an efficient heat sink. © 2016 Elsevier Ltd. All rights reserved.

Abouda K.,Freescale Semiconductor | Aulagnier G.,Freescale Semiconductor | Rolland E.,Freescale Semiconductor | Cousineau M.,Laboratoire Plasma et Conversion dEnergie
EMC Compo 2015 - 2015 10th International Workshop on the Electromagnetic Compatibility of Integrated Circuits | Year: 2015

inside the car, all integrated circuits IC have to be optimized to survive against severe external aggressions. The noise generated by each activity inside each IC must be low enough, to not disturb the environment. As known nowadays, DC-DC converters can significantly impact the Electromagnetic Compatibility EMC performances, and mainly the emission ones. Unfortunately, simulation with linear models like ICEM or IBIS models [1, 2] remains very challenging for integrated analogue products due to the high number of parameters, plenty of possible applications and the extent of the frequency domain where the integrated circuit must be compliant. A paper describes an analytical approach to highlight the main contributors to the high frequency noise generated by switching activity in Buck converters [3]. This approach is then employed to reduce Conducted Emission CE performance using multiphase interleaved Buck converters and to highlight benefits of increasing the number of phases in improving the emission profile. © 2015 IEEE.

Zissis G.,Laboratoire Plasma et Conversion DEnergie | Aizenberg J.B.,Russian Lighting Research Institute VNISI | Shevchenko A.C.,Nizhny Novgorod State Technical University
Light and Engineering | Year: 2010

Lighting accounts for 14% of all electricity demand in Russia and consumes approximately 137 billion kWh year. The largest energy saving potential in lighting systems exists within Russia's industrial buildings, residential sector and public buildings. The total lighting energy savings potential in Russia is enormous: 56 TWh/annum which is equivalent to approx. 39 Mt CO2 per annum, and this project aims to tap 60% of that potential. While the energy saving potential in this sector is enormous, there is a number of barriers to energy effi ciency investments and market transformation. Among those barriers are the absence of mandatory energy effi ciency standards and labeling schemes for lighting equipment; regulatory constrains hampering investment infl ow into public and residential sectors; lack of state support for technological innovations in lighting; non-competitive local industry; and profound lack of awareness among consumers. Supply is dominated by cheap and low quality equipment. In order to address these barriers and support the Russian Federation in market transformation towards energy effi cient lighting, a new initiative has been developed with the Global Environment Facility (GEF) and United Nations Development Programme (UNDP) in partnership with the Russian Government - the Ministry of Energy of the Russian Federation. The project is coordinated with a UNEP/UNDP/GEF initiative 'Global Market Transformation for Effi cient Lighting?. The objective of the GEF project is to transform the Russian market towards effi cient lighting technologies and the phase-out of ineffi cient lighting, thereby reducing national GHG emissions. The project will focus on phasing out outdated technologies for residential, public and street lighting.

Ladoux P.,Laboratoire Plasma et Conversion dEnergie | Serbia N.,Laboratoire Plasma et Conversion dEnergie | Carroll E.I.,E.I.C Consultancy
IEEE Journal of Emerging and Selected Topics in Power Electronics | Year: 2015

In today's voltage source converter HVDC solutions, insulated-gate bipolar transistors (IGBTs) are used exclusively, generally in module form where the modular multilevel converter is concerned; this entails a number of protective measures that increase complexity and cost. As we move to higher transmitted powers, the use of integrated gate-commutated thyristors (IGCTs) would allow both higher voltages and currents while simultaneously reducing losses, failure rates, and costs, as this paper tries to demonstrate by comparing current production IGCTs with both current module and press-pack IGBTs. © 2013 IEEE.

Ibrahim M.,Laboratoire Plasma et Conversion dEnergie | Bernard L.,Laboratoire Of Genie Electrique Et Electronique Of Paris | Pichon L.,Laboratoire Of Genie Electrique Et Electronique Of Paris | Laboure E.,Laboratoire Of Genie Electrique Et Electronique Of Paris | And 4 more authors.
IEEE Transactions on Power Electronics | Year: 2016

This paper focuses on the interoperability analysis of a resonating contactless charging system for electric vehicles (EVs). The design uses different inductive loops realized by industrial partners. It highlights an advanced electromagnetic modeling (EM) concerning the geometrical characteristics, the resonant topologies, and the control loop. It is shown that the EV chassis plays a major role in the calculation of the electrical parameters and the radiation of the interoperable system. Furthermore, the position of the interoperable magnetic couplers with respect to the EV (middle or backend) has an important effect on the values of the coupling factor and also for the radiation of the system. Finally, an efficiency of 90% is realized in the experimental test with the interoperability which gives flexibility for the driver to use charging stations with different technologies. © 2016 IEEE.

Wormeester G.,Centrum Wiskunde and Informatica CWI | Pancheshnyi S.,Laboratoire Plasma et Conversion dEnergie | Luque A.,Institute Astrofisica Of Andalucia | Nijdam S.,TU Eindhoven | And 2 more authors.
Journal of Physics D: Applied Physics | Year: 2010

Photo-ionization is the accepted mechanism for the propagation of positive streamers in air though the parameters are not very well known; the efficiency of this mechanism largely depends on the presence of both nitrogen and oxygen. But experiments show that streamer propagation is amazingly robust against changes of the gas composition; even for pure nitrogen with impurity levels below 1 ppm streamers propagate essentially with the same velocity as in air, but their minimal diameter is smaller, and they branch more frequently. Additionally, they move more in a zigzag fashion and sometimes exhibit a feathery structure. In our simulations, we test the relative importance of photo-ionization and of the background ionization from pulsed repetitive discharges, in air as well as in nitrogen with 1 ppm O2. We also test reasonable parameter changes of the photo-ionization model. We find that photo-ionization dominates streamer propagation in air for repetition frequencies of at least 1 kHz, while in nitrogen with 1 ppm O2 the effect of the repetition frequency has to be included above 1 Hz. Finally, we explain the feather-like structures around streamer channels that are observed in experiments in high purity nitrogen, but not in air. © 2010 IOP Publishing Ltd.

Toure B.,Grenoble Institute of Technology | Schanen J.-L.,Liebherr - Aerospace | Gerbaud L.,Liebherr - Aerospace | Meynard T.,Laboratoire Plasma et Conversion dEnergie | And 2 more authors.
IEEE Transactions on Power Electronics | Year: 2013

A new approach for easy and fast modeling of EMI filter in aircraft application is proposed, in order to be used in an optimization process. A modular description in a user friendly environment allows describing the model and taking into account all the technological parameters of the system, i.e., the control strategy, the inverter model (semiconductors, layout, etc.), the filter, the cables, and the ac machine. The frequency model is automatically built from this description, as well as its gradients according to its inputs. In a second step, by using this model, an optimization of the filter values can be carried out, using various algorithms, to reach the smallest volume. This early design methodology can also be used to investigate the impact of some technological choices of the electrical drive (control strategy or cable characteristics for instance) on the filter volume. © 2012 IEEE.

Pham T.T.L.,Laboratoire Plasma et Conversion dEnergie | Richardeau F.,Laboratoire Plasma et Conversion dEnergie | Gateau G.,Laboratoire Plasma et Conversion dEnergie
IEEE Transactions on Industrial Electronics | Year: 2013

A five-level power factor correction topology with fault-diagnosis and fault-tolerant capabilities is proposed and analyzed. This structure is derived from the well-known three-level one-pole double-boost including double-stacked redundant and low-storage-energy flying capacitor cells. Two fault-diagnosis strategies are presented. The first one directly operates the monitoring of the voltages across the flying capacitors, detecting and localizing the faulty switch by means of two sensors. The second one is based on indirect voltage vector detection through only one sensor. Both of these strategies are analyzed and simulated with the efficient phase disposition pulsewidth modulation technique. The design and the most important features are highlighted owing to a digital control frame and a single-phase mock-up rated at 115 V/400 V,-4 kW, and 2 × 31 kHz. The presented results also offer a dedicated strategy permitting an optimized real-time reconfiguration in postfault operation. © 1982-2012 IEEE.

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