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Abstract Alternative fuel vehicles (AFV) may help to reduce global CO2 emissions from the transport sector. One obstacle for AFV market diffusion is the lack of refueling infrastructure which prevents potential users from buying AFVs. Meanwhile infrastructure suppliers await market developments before investing in an extensive infrastructure roll-out. This mutual interaction has been a field of research for several years and a variety of modeling approaches have been applied. This paper aims at reviewing models of combined AFV and refueling infrastructure market diffusion and pointing out research gaps. We retrieve stylized facts which models should account for from empirical studies on natural gas vehicles, user acceptance analyses on AFVs and technical restraints of plug-in electric vehicles (PEVs) and fuel cell electric vehicles (FCEVs). Ten interaction models are evaluated with respect to the identified aspects. We find that simulation is the most common approach for an interaction model. Besides, the majority of the examined stylized facts is covered by the models. However, models for FCEVs could be improved by reflecting the transport of fuel to refueling infrastructure while new models on PEVs should include charging duration, frequency and charging station ownership.

The starting event of the massive air ingress into the core of the HTR module reactor, classified as hypothetical incident, is the very fast depressurization of the primary circuit. Provided that the integrity of the reactor pressure vessel is not in question, a rupture of the connecting pressure vessel between reactor pressure vessel and steam generator vessel is the maximum possible leak cross-section. In this work it is investigated whether the components of the reactor pressure vessel are exposed by the depressurization process to mechanical loads which exceed the load limits. These loads are caused by two different events, the strong momentum change of the fluid and the local pressure differences, respectively. Due to the momentum change the bottom reflector receives the maximum load, whereby only 2% of the compressive strength of the graphite quality used there are reached. However, the load by local pressure differences is between passed volumes and in normal operation, not-passed volumes lead to high load values. A maximum pressure difference of 44.5 bar was calculated at the thermal top shield.

ABSTRACTA novel design for a high temperature SOFC, based on lamellar electrode-electrolyte segments obtained by solidification of an oxidic eutectic melt on an electrolyte substrate is presented. Such “composite” electrodes contain NiO or MnO - 8Y-ZrO2 lamellae, which after reduction / oxidation yield electrode-electrolyte lamellae with 1–2 μm width and a vertical dimension of> 100 μm, depending upon the amount of eutectic melt solidified on a polycrystalline substrate. The nucleation of the eutectic on a polycrystalline substrate followed by a semi-directional crystallization of the two phases yields a gradient of 3-phase boundaries over the height of such an electrode, with the number of 3-phase boundaries increasing towards the substrate.

The fast decay in PEM fuel cells of a highly active, high performance, but unstable Fe/N/C catalyst like our NC_Ar + NH3 follows a chemical, not an electrochemical, demetallation mechanism for its ORR active FeN4 sites in the catalyst micropores.

AbstractThe future European energy supply system will have a high share of renewable energy sources (RES) to meet the greenhouse gas emission policy of the European Commission. Such a system is characterized by the need for a strongly interconnected energy transport grid as well as a high demand of energy storage capacities to compensate the time fluctuating characteristic of most RE generation technologies. With the RE generators at the location of high harvest potential, the appropriate dimension of storage and transmission system between different regions, a cost efficient system can be achieved. To find the preferred target system, the optimization tool GENESYS (Genetic Optimization of a European Energy System) was developed. The example calculations under the assumption of 100% self-supply, show a need of about 2,500 GW RES in total, a storage capacity of about 240,000 GWh, corresponding to 6% of the annual energy demand, and a HVDC transmission grid of 375,000 GWkm. The combined cost for generation, storage and transmission excluding distribution, was estimated to be 6.87 ct/kWh.

Photoconductive antennas (PCAs) are among the most conventional devices used for emission as well as detection of terahertz (THz) radiation. However, due to their low optical-to-THz conversion efficiencies, applications of these devices in out-of-laboratory conditions are limited. In this paper, we report several factors of enhancement in THz emission efficiency from conventional PCAs by coating a nano-layer of dielectric (TiO2) on the active area between the electrodes of a semi-insulating GaAs-based device. Extensive experiments were done to show the effect of thicknesses of the TiO2 layer on the THz power enhancement with different applied optical power and bias voltages. Multiphysics simulations were performed to elucidate the underlying physics behind the enhancement of efficiency of the PCA. Additionally, this layer increases the robustness of the electrode gaps of the PCAs with high electrical insulation as well as protect it from external dust particles.

In this paper the low frequency shielding behavior of shielded high voltage cables for electric vehicles is analyzed using analytical methods. First the basic theory on the operational modes and modeling of cables is presented. Measurements and numerical simulations are done to verify the models. The powertrain of an electric vehicle is investigated using the simulation models. A parametrical study determines the influence of parameters such as height and distance of the cables and gives information for an EMC compliant layout. The magnetic fields for different cable setups are calculated and compared with values from health protection standards.

With the recent advancements in power electronics for wind turbines (WTs) and increasing penetration of wind energy, wind power plants (WPP) have become necessary contributors of reactive power support for the bulk power system. Balancing reactive power support with individual WT operating requirements in a cost-effective manner is a challenge for WPP designers. In this paper, we present a methodology to optimize the WPP reactive power capability as seen from the point of common coupling (PCC), accounting for steady-state operating capabilities of the WPP equipment. Thus, the proposed methodology determines the configuration of the tap-changing transformers within the WPP that maximizes the amount of reactive power the WPP can either consume or inject to the network, considering uncertain levels of wind power generation and voltage magnitudes at the PCC. The optimized reactive power capability (ORPC) problem is initially formulated as a mixed-integer nonlinear programming (MINLP) model. Then, a set of efficient linearization techniques are used to obtain a mixed-integer linear programming (MILP) model that can be solved via off-the-shelf mathematical programming solvers. Results demonstrate that the proposed MILP model is a scalable, flexible and accurate method to maximize the reactive power capability of WPP.

AbstractIndustrial bus systems are the backbone of production control and management. Regardless of the utilised technology, industrial communication systems realise feedback loops from sensors and control values to actuators. Industrial communication is also the basis for an operative energy management system. Energy demands are metered and send to management and decision support tools to be analysed and evaluated. Present industrial bus technologies from production and building automation domains offer different functionalities to support an operative energy management. This paper aims to discuss the requirements of an advanced energy management system regarding the technical issues of appropriate data communication means. By describing the properties of various bus systems the advantages and disadvantages of each one is shown and the applicability for the described utilisation is considered. Finally, the possibilities to apply machine control mechanisms through the bus systems are analysed.