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Harald Schmidt

Other affiliations: Technische Universität Darmstadt, VDO, Volkswagen  ...read more
Bio: Harald Schmidt is an academic researcher from Siemens. The author has contributed to research in topics: Layer (electronics) & Proton exchange membrane fuel cell. The author has an hindex of 15, co-authored 82 publications receiving 772 citations. Previous affiliations of Harald Schmidt include Technische Universität Darmstadt & VDO.


Papers
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Patent
22 Sep 2004
TL;DR: In this paper, an optical module consisting of a circuit support (10), a cased semiconductor element (12) placed on the circuit support, and a lens unit (14, 16, 18, 20, 21) for projecting electromagnetic radiation onto the semiconductor elements was described.
Abstract: The invention relates to an optical module comprising: a circuit support (10); a cased semiconductor element (12) placed on the circuit support (10), and; a lens unit (14; 16, 18, 20; 21) for projecting electromagnetic radiation onto the semiconductor element (12). The lens unit preferably comprises a lens arrangement consisting of, for example, three lenses (16, 18, 20) and of a diaphragm (21). The lenses (16, 18, 20), optionally together with the diaphragm (21), are aligned in a well-defined manner due to their geometric design so that no additional optical adjustment is necessary. According to the invention, the lenses (16, 18, 20; 21) are held in a type of lens holder (14) that is an integral component of the case (13) of the semiconductor element (12).

82 citations

Journal ArticleDOI
TL;DR: In this paper, a test facility was constructed at Forschungszentrum Julich (FZJ) to evaluate the performance and dynamic behavior of a test drive system for vehicles with polymer electrolyte membrane fuel cells (PEMFC).

63 citations

Journal ArticleDOI
TL;DR: The report describes the 1-MVA transformer's detailed design, and presents the results of electrical and thermal transformer routine tests (e.g., measurement of load losses and no-load losses) that highlights the future perspective of HTS transformers for railway applications.
Abstract: We describe the high-temperature superconducting (HTS) transformer project run by Siemens. The project started in October 1996 and ended in September 2001. The aim of the project was to show the future prospects for superconducting railway transformers. To study the principle behavior of such a transformer, as a first step we designed, constructed and tested a nominal single-phase transformer of 100 kVA, 50 Hz, 5.5 kV/1.1 kV. After this was successfully tested, we started the design and construction of a single-phase transformer of 1 MVA, 50 Hz, 25 kV/1.4 kV. This unit already has the full ratings of a commercial transformer in many respects, e.g., power range, nominal voltage, 2-limb core with horizontal orientation, two secondary windings and an impedance of 25% at nominal current. Further innovative features are transposed conductor and a closed cooling cycle with sub-cooled nitrogen. The report describes the 1-MVA transformer's detailed design, and presents the results of electrical and thermal transformer routine tests (e.g., measurement of load losses and no-load losses). The conclusion highlights the future perspective of HTS transformers for railway applications.

58 citations

Journal ArticleDOI
TL;DR: In this article, the authors summarized world-wide efforts in the development of superconducting transformers and reports on the progress achieved at Siemens, where they developed a 1-MVA demonstrator transformer for laboratory testing, exhibiting innovative features like horizontal design, cabled-conductor windings and closed cooling cycle with sub-cooled nitrogen.
Abstract: Superconducting transformers are an important innovation for future power transmission and transportation systems. Powerful, lightweight, energy-saving and environmentally friendly they offer enormous benefits compared to their conventional counterparts. Siemens is developing a 1-MVA demonstrator transformer for laboratory testing, exhibiting innovative features like horizontal design, cabled-conductor windings and a closed cooling cycle with sub-cooled nitrogen. Being one of the most promising applications Siemens has started a programme towards the development of on-board transformers for electrical rail vehicles. This paper summarises world-wide efforts in the development of superconducting transformers and reports on the progress achieved at Siemens.

45 citations

PatentDOI
TL;DR: In this article, the effective interface between the electrolyte layer and an electrode layer is increased by a suitably treated surface of the electrolytes layer or by a porous and/or rough interlayer.

40 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, the advantages, challenges and progress of various cooling techniques, including cooling with heat spreaders (using high thermal conductivity materials or heat pipes), cooling with separate air flow, cooling with liquid (water or antifreeze coolant), and cooling with phase change (evaporative cooling and cooling through boiling), are systematically reviewed.

345 citations

Journal ArticleDOI
TL;DR: In this article, the authors review various reforming technologies available for the generation of such fuels from hydrocarbons and alcohols and briefly address the issue of carbon monoxide clean-up and the question of selecting the appropriate fuel(s) for small/medium scale fuel processors for stationary and automotive applications.

314 citations

Journal ArticleDOI
TL;DR: In this article, the available technologies for conversion of hydrocarbons and alcohols are described, and the integration of the fuel processing with the fuel cell represents a task with requirements depending on each type of fuel cell and application.
Abstract: Fuel conversion to hydrogen is an important part of most fuel cell systems. The paper describes the available technologies for conversion of hydrocarbons and alcohols. The endothermic steam reforming catalysts and processes as well as autothermal reforming are proven technologies. Recent developments include catalytic partial oxidation. The integration of the fuel processing with the fuel cell represents a task with requirements depending on each type of fuel cell and application. The automotive use of fuel cells is at present a special challenge. The optimum fuel for stationary plants is natural gas (if available), whereas light naphtha appears to be the choice for automotive use.

282 citations

Journal ArticleDOI
TL;DR: This paper presents a perspective on power quality issues through railway electrification development and investigates the necessity of power quality and system requirements for appropriate power quality.
Abstract: Since the beginning of railway electrification, power quality has been a main problem in railway networks because of their special characteristics. Many ways of power quality improvement have been investigated and applied to ac and dc traction systems through railway electrification history. This paper presents a perspective on power quality issues through railway electrification development and investigates the necessity of power quality and system requirements for appropriate power quality. Compensation strategies are classified and compared. This aims to provide a comprehensive perspective of the power quality issue in railway power/distribution networks for researchers and engineers working on railway electrification. Less than 100 research articles are referenced for researchers to obtain good background information.

264 citations

Journal ArticleDOI
TL;DR: In this paper, a review of commonly used Cu-based catalysts including their kinetic, compositional, and morphological characteristics in methanol reforming reactions is presented, focusing on the commonly reported surface intermediate species, which are methoxy, formaldehyde, dioxymethylene, formate and methyl formate.

213 citations