The Experts below are selected from a list of 168 Experts worldwide ranked by ideXlab platform
Frederik C Krebs - One of the best experts on this subject based on the ideXlab platform.
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life cycle analysis of product integrated polymer solar cells
Energy and Environmental Science, 2011Co-Authors: Nieves Espinosa, Rafael Garciavalverde, Frederik C KrebsAbstract:A life cycle analysis (LCA) on a product integrated polymer solar module is carried out in this study. These assessments are well-known to be useful in developmental stages of a product in order to identify the bottlenecks for the up-scaling in its production phase for several aspects spanning from economics through design to functionality. An LCA study was performed to quantify the energy use and greenhouse gas (GHG) emissions from electricity use in the manufacture of a light-weight lamp based on a plastic foil, a lithium-polymer battery, a polymer solar cell, printed circuitry, Blocking Diode, switch and a white light emitting semiconductor Diode. The polymer solar cell employed in this prototype presents a power conversion efficiency in the range of 2 to 3% yielding energy payback times (EPBT) in the range of 1.3–2 years. Based on this it is worthwhile to undertake a life-cycle study on the complete product integrated polymer solar cell. We have compared this portable lighting system with other lighting solutions, namely: a kerosene lamp in a remote rural area in Africa (Ethiopia), as a replacement of a silicon PV based lamp, in place of a torch with non-rechargeable lead-acid battery and instead of a battery charging station. The analysis reveals that the OPV lamp has a significant advantage provided that some of the challenges facing this novel technology are efficiently met such that it can enter the market of portable lighting devices.
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Product integration of compact roll-to-roll processed polymer solar cell modules: methods and manufacture using flexographic printing, slot-die coating and rotary screen printing
Journal of Materials Chemistry, 2010Co-Authors: Frederik C Krebs, Jan Fyenbo, Mikkel JorgensenAbstract:The improvement of the performance of roll-to-roll processed polymer solar cell modules through miniaturization of the device outline is described. The devices were prepared using full roll-to-roll processing comprising flexographic printing, slot-die coating and rotary screen printing to create 5 mm wide lines of ZnO, P3HT:[60/70]PCBM, PEDOT:PSS and silver on an ITO-PET substrate. The lines were spaced by 1 mm and the devices were completed by encapsulation using roll-to-roll lamination on both sides using a pressure sensitive adhesive and a multilayered barrier material having a UV-filter with a cut-off at 390 nm, oxygen and water vapor transmission rates of respectively 0.01 cm3 m-2 bar-1 day-1 and 0.04 g m-2 day-1. The final modules comprised 16 serially connected cells. The technical yield was 89% based on the criterion that the Voc had to be larger than 7.2 V. This set of modules gave respectively a voltage, current, fill factor and power conversion efficiency of 8.47 +/- 0.41 V, -23.20 +/- 4.10 mA, 35.4 +/- 2.8% and 1.96 +/- 0.34% in the case of modules based on P3HT:[60]PCBM. A total of 1960 modules were prepared for each run and the best power conversion reached was 2.75% for devices based on P3HT:[70]PCBM. The solar cell modules were used to demonstrate the complete manufacture of a small lamp entirely using techniques of flexible electronics. The solar cell module was used to charge a polymer lithium ion battery through a Blocking Diode. The entire process was fully automated and demonstrates the capacity of polymer solar cells in the context of flexible and printed electronics. Finally a comparison was made between the learning curve for OPV and crystalline silicon solar cells in terms of the cost per watt peak and the cumulative watt peak. OPV as a technology was found to have a significantly steeper learning curve.
Mikkel Jorgensen - One of the best experts on this subject based on the ideXlab platform.
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Product integration of compact roll-to-roll processed polymer solar cell modules: methods and manufacture using flexographic printing, slot-die coating and rotary screen printing
Journal of Materials Chemistry, 2010Co-Authors: Frederik C Krebs, Jan Fyenbo, Mikkel JorgensenAbstract:The improvement of the performance of roll-to-roll processed polymer solar cell modules through miniaturization of the device outline is described. The devices were prepared using full roll-to-roll processing comprising flexographic printing, slot-die coating and rotary screen printing to create 5 mm wide lines of ZnO, P3HT:[60/70]PCBM, PEDOT:PSS and silver on an ITO-PET substrate. The lines were spaced by 1 mm and the devices were completed by encapsulation using roll-to-roll lamination on both sides using a pressure sensitive adhesive and a multilayered barrier material having a UV-filter with a cut-off at 390 nm, oxygen and water vapor transmission rates of respectively 0.01 cm3 m-2 bar-1 day-1 and 0.04 g m-2 day-1. The final modules comprised 16 serially connected cells. The technical yield was 89% based on the criterion that the Voc had to be larger than 7.2 V. This set of modules gave respectively a voltage, current, fill factor and power conversion efficiency of 8.47 +/- 0.41 V, -23.20 +/- 4.10 mA, 35.4 +/- 2.8% and 1.96 +/- 0.34% in the case of modules based on P3HT:[60]PCBM. A total of 1960 modules were prepared for each run and the best power conversion reached was 2.75% for devices based on P3HT:[70]PCBM. The solar cell modules were used to demonstrate the complete manufacture of a small lamp entirely using techniques of flexible electronics. The solar cell module was used to charge a polymer lithium ion battery through a Blocking Diode. The entire process was fully automated and demonstrates the capacity of polymer solar cells in the context of flexible and printed electronics. Finally a comparison was made between the learning curve for OPV and crystalline silicon solar cells in terms of the cost per watt peak and the cumulative watt peak. OPV as a technology was found to have a significantly steeper learning curve.
Nieves Espinosa - One of the best experts on this subject based on the ideXlab platform.
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life cycle analysis of product integrated polymer solar cells
Energy and Environmental Science, 2011Co-Authors: Nieves Espinosa, Rafael Garciavalverde, Frederik C KrebsAbstract:A life cycle analysis (LCA) on a product integrated polymer solar module is carried out in this study. These assessments are well-known to be useful in developmental stages of a product in order to identify the bottlenecks for the up-scaling in its production phase for several aspects spanning from economics through design to functionality. An LCA study was performed to quantify the energy use and greenhouse gas (GHG) emissions from electricity use in the manufacture of a light-weight lamp based on a plastic foil, a lithium-polymer battery, a polymer solar cell, printed circuitry, Blocking Diode, switch and a white light emitting semiconductor Diode. The polymer solar cell employed in this prototype presents a power conversion efficiency in the range of 2 to 3% yielding energy payback times (EPBT) in the range of 1.3–2 years. Based on this it is worthwhile to undertake a life-cycle study on the complete product integrated polymer solar cell. We have compared this portable lighting system with other lighting solutions, namely: a kerosene lamp in a remote rural area in Africa (Ethiopia), as a replacement of a silicon PV based lamp, in place of a torch with non-rechargeable lead-acid battery and instead of a battery charging station. The analysis reveals that the OPV lamp has a significant advantage provided that some of the challenges facing this novel technology are efficiently met such that it can enter the market of portable lighting devices.
Ke-horng Chen - One of the best experts on this subject based on the ideXlab platform.
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Delay-Lock-Loop-Based Inductorless and Electrolytic Capacitorless Pseudo-Sine-Current Controller in LED Lighting Systems
IEEE Transactions on Very Large Scale Integration Systems, 2015Co-Authors: Shao-wei Chiu, Yi-ping Su, Ke-horng ChenAbstract:Light-emitting Diode lighting system with the proposed pseudo-sine-current controller removes most of the external passive components, which include inductor, electrolytic capacitor, freewheel Diode, Blocking Diode, and the bleeding circuit for Triac dimming control, for low cost and small volume. Delay-lock loop control can ensure the in-phase operation of ac input voltage and current for high power factor (PF) and low total harmonic distortion (THD). In addition, redundant power loss in Triac dimming control is eliminated to get a high efficiency of 85%. Furthermore, a high PF of 0.997 and a low THD of 7.74% are also achieved owing to in-phase line voltage and current.
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ESSCIRC - Inductorless and electrolytic capacitorless pseudo-sine current controller in LED lighting system with 1.1W/2.2W power reduction
2012 Proceedings of the ESSCIRC (ESSCIRC), 2012Co-Authors: Chiu Shao-wei, Ke-horng Chen, Chun-chieh Kuo, Yu-huei Lee, Ying-hsi Lin, Chen-chih Huang, Chao-cheng Lee, Yu-wen ChenAbstract:LED lighting system with the proposed pseudo-sine-current (PSC) controller removes most of the external passive components, which include inductor, electrolytic capacitor (E-cap), freewheel Diode, Blocking Diode, and the bleeding circuit for Triac dimming control, for low cost and small volume. Besides, 1.1W and 2.2W power loss are reduced in Triac dimming control to get high efficiency of 85% at 110Vrms and 87% at 220Vrms, respectively. Furthermore, High PF of 0.98 at 110Vrms and 0.96 at 220Vrms, and low THD of 18% at 110Vrms and 19% at 220Vrms are also achieved owing to in-phase line voltage and current.
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P‐43: LED Backlight Driver Implemented by Single‐stage Linear Regulation Control (LRC) Technique for High Efficiency and Low Cost
SID Symposium Digest of Technical Papers, 2012Co-Authors: Po-hsien Huang, Shao-wei Chiu, Ke-horng Chen, Chun-chieh Kuo, Yu-huei Lee, Chih Jen Chen, Chao Chiun Liang, Sheng Fa Liu, Pao Hsien ChiuAbstract:LCD panel with the LED backlight can be controlled by the proposed linear regulation control (LRC) technique for high efficiency and low cost. The LRC technique removes most of the external passive components, which include inductor, E-cap, freewheel Diode, and Blocking Diode. Due to single-stage operation without two-stage power consumption, small volume and high efficiency can be simultaneously ensured. Furthermore, the PLL function can guarantee the line voltage and current to be in phase so as to realize the high power factor (PF) for green power. High efficiency of 85% at 110Vrms and 87% at 220Vrms, high PF of 0.98 at 110Vrms and 0.96 at 220Vrms, and low THD of 18% at 110Vrms and 19% at 220Vrms are achieved.
Subhashish Bhattacharya - One of the best experts on this subject based on the ideXlab platform.
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high switching performance of 1700 v 50 a sic power mosfet over si igbt bimosfet for advanced power conversion applications
IEEE Transactions on Power Electronics, 2016Co-Authors: Samir Hazra, Ankan De, Lin Cheng, John W Palmour, Marcelo Schupbach, Brett Hull, Scott Allen, Subhashish BhattacharyaAbstract:Due to wider band gap of silicon carbide (SiC) compared to silicon (Si), MOSFET made in SiC has considerably lower drift region resistance, which is a significant resistive component in high-voltage power devices. With low on-state resistance and its inherently low switching loss, SiC MOSFETs can offer much improved efficiency and compact size for the converter compared to those using Si devices. In this paper, we report switching performance of a new 1700-V, 50-A SiC MOSFET designed and developed by Cree, Inc. Hard-switching losses of the SiC MOSFETs with different circuit parameters and operating conditions are measured and compared with the 1700-V Si BiMOSFET and 1700-V Si IGBT, using same test set-up. Based on switching and conduction losses, the operating boundary of output power and switching frequency of these devices are found out in a dc–dc boost converter and compared. The switching $dv/dts$ and $di/dts$ of SiC MOSFET are captured and discussed in the perspective of converter design. To validate the continuous operation, three dc–dc boost converters using these devices, are designed and tested at 10 kW of power with 1 kV of output voltage and 10 kHz of switching frequency. 1700-V SiC Schottky Diode is used as the Blocking Diode in each case. Corresponding converter efficiencies are evaluated and the junction temperature of each device is estimated. To demonstrate high switching frequency operation, the SiC MOSFET is switched upto 150 kHz within permissible junction temperature rise. A switch combination of the 1700-V SiC MOSFET and 1700-V SiC Schottky Diode connected in series is also evaluated for zero voltage switching turn-ON behavior and compared with those of bipolar Si devices. Results show substantial power loss saving with the use of SiC MOSFET.