Showing papers by "Harald Schmidt published in 2003"

Development of high-temperature superconducting 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.

System test of a 1-MVA-HTS-transformer connected to a converter-fed drive for rail vehicles

Abstract: Railway companies aim to realize environmentally friendly revenue operations with high efficiency. High Temperature Superconducting (HTS)-transformers offer advantages regarding less mass and volume and considerably higher efficiency in drive systems. Siemens has developed a 1-MVA-HTS-transformer with typical characteristics for railway applications. For a successful introduction in the market, it is essential to guarantee the operational behavior of drive systems in well-known manner. So, Siemens realized the 1st operation of an AC-converter fed by a HTS-transformer. System test measurements of losses, tests of cooling redundancy as well as drive cycle operation were performed to compare the converter operation to sinusoidal operation, to analyze the losses depending on the harmonics of nonsinusoidal current and to investigate the behavior of the whole system under realistic drive cycles of a current rail vehicle.

Optisches Modul mit federndem Element zwischen Linsenhalter und Schaltungsträger und optisches System

Abstract: Ein optisches Modul weist einen Linsenhalter (14) auf, in den eine Linsenanordnung aus beispielsweise drei Linsen (16, 18, 20) und einer Blende (21) eingesetzt ist. Vorzugsweise sind die Linsen (16, 18, 20) und die Blende (21) durch ihre geometrische Gestaltung eindeutig ausgerichtet, so dass keine weitere optische Justierung erforderlich ist. Daruber hinaus erfolgt die Justierung von Schaltungstrager (10) und Linseneinheit (14; 16, 18, 20; 21) erfindungsgemas uber wenigstens ein zwischen Linsenhalter (14) und Schaltungstrager (10) angeordnetes dauerelastisches oder federndes Element (22), welches die Bestuckflache (10a) des Schaltungstragers (10) vom Linsenhalter (14) weg gegen wenigstens ein Anschlagselement (13; 35) presst, welches formschlussig zur Linseneinheit (14; 16, 18, 20; 21) in Beziehung steht. Mit dem erfindungsgemasen Aufbau eines optischen Moduls bzw. Systems fliest vorteilhaft erstmals die Dickentolerenz des Schaltungstragers (10) und etwaiger Klebstoffe nicht in die Toleranzkette gattungsgemaser optischer Modulen bzw. Systeme ein. Die Erfindung eignet sich insbesondere bei Anwendungen im Innen- oder Ausenbereich eines Kraftfahrzeugs.

Method and apparatus for controlling a valve and method and apparatus for controlling a pump-nozzle apparatus with the valve

Abstract: A valve has a piezoelectric actuator with a valve element, a valve body and a valve seat. In order to control the valve, the valve element is moved into the valve seat from a position remote from the valve seat by means of a charging process at a prescribable first time. A first value is determined being characteristic of the electrical power supplied to the piezoelectric actuator when the valve element meets the valve seat. A second value is determined being characteristic of the electrical power supplied to the piezoelectric actuator when the charging process of the piezoelectric actuator is concluded. An actual difference value between the second value and the first value is determined. A difference between a setpoint difference value and the actual difference value is supplied to a controller. An actuating signal for charging the piezoelectric actuator is determined as a function of the actuating variable.

Force measurement arrangement, comprises a compact arrangement of force application bolt, force receiving base part, meander spring for force transfer between the two and a linear displacement sensor for the force application bolt

Abstract: Force measurement arrangement comprises means (3) for applying a force and fixed counter means (4) that receive the applied force. A spring element (1) elastically transfers the force between the two parts, while a deflection sensor measures the movement of the force applying means. The spring element is mounted in a rotationally symmetric manner about the central axis of the force applying means and the deflection sensor is arranged radially within the spring means.

Method for operating a fuel cell, polymer electrolyte membrane fuel cell which works with the method and process for producing the fuel cell

Abstract: When operating known polymer electrolyte membrane fuel cells it has to be made sure that the phosphoric acid does not directly contact the metal bipolar plate of the fuel cell at high temperatures. In order to avoid such a contact, a sufficiently electroconducting intermediate layer is interposed between the membrane electrode unit and the bipolar plate of the fuel cell, which prevents the phosphoric acid or a mixture of phosphoric acid and water that may escape from the membrane-electrode unit from reaching the bipolar plate. For producing the fuel cell, at least a two-layer stratified structure is introduced which becomes more hydrophobic and more finely pored with increasing proximity to the bipolar plate.

Verfahren und vorrichtung zum messen und regeln der schliess- und öffnungszeit eines piezo-steuerventils

Abstract: Die Erfindung betrifft ein Verfahren und eine Vorrichtung zum Messen der Zeitdauer, die die Ventilnadel (50) eines Steuerventils (21) einer Piezo-Pumpe-Duse-Einheit benotigt, um von einer ersten Endposition (64) in eine zweite Endposition (65) zu gelangen. Wobei die Zeitdauer in Abhangigkeit von der am Steuerventil (21) angelegten Spannung (u (t)) und/oder des angelegten Stromes (i (t)) ermittelt wird, und das Stellsignal zu einem Zeitpunkt erzeugt wird, in dem gewahrleistet ist, dass der Druck im Steuerventil (21) wahrend der Messung weitgehend dem Druck des Kraftstoff-Niederdruckbereiches (31) entspricht.

Method for working the edge of a high pressure-resistant part, especially for the hydro-erosive rounding of an edge and corresponding device

Abstract: The invention relates to a method for working the edge of a high pressure-resistant part, according to which the edge is hydro-erosively rounded off in a working step. The invention also relates to a method and a device for the hydro-erosive rounding of the edge of a high pressure-resistant part, especially the edge of a bore intersection of a high pressure-resistant part of a fuel injection system. According to said method, a liquid to which abrasives are added is directed across the edge that is to be rounded in the area of a first continued bore to a branching second bore. In order to optimize the result of the rounding process and thus in order to optimize the high pressure-resistance of the part, the edge (5) and the surfaces (4, 6) of the high pressure-resistant part (1) adjacent to the edge (5), before the step of hydro-erosive rounding, are subjected to compressive strains in the area of their surfaces by means of a grinding and/or honing method. The method and the device for the hydro-erosive rounding are improved by inserting an obturating element (9) in the continued first bore (2) behind the branching second bore (3), when seen from the main direction of flow (S) of the liquid (8) to which abrasives (7) are added, to deflect the liquid (8) to which abrasives (7) are added from the first bore (2) to the second bore (3).

Verfahren zum bearbeiten einer kante eines hochdruckfesten bauteils, insbesondere zum hydro-erosiven verrunden einer kante sowie und vorrichtung hierzu

Abstract: Die Erfindung betrifft Verfahren zum Bearbeiten einer Kante eines hochdruckfesten Bauteils, bei dem in einem Bearbeitungsschritt die Kante hydro-erosiv verrundet wird, sowie ein Verfahren und eine Vorrichtung zum hydro-erosiven Verrunden einer Kante eines hochdruckfesten Bauteils, insbesondere einer Kante einer Bohrungsverschneidung eines hochdruckfesten Bauteils einer Kraftstoffeinspritzanlage, bei dem eine mit Schleifkorpern versetzte Flussigkeit quer uber die zu verrundende Kante im Bereich einer von einer ersten weiterfuhrenden Bohrung zu einer abzweigenden zweiten Bohrung gefuhrt wird.Um ein eine Optimierung des Verrundungsergebnisses und somit eine Optimierung der Hochdruckfestigkeit des Bauteils zu erreichen, wird einerseits vorgeschlagen, dass vor dem Bearbeitungsschritt des hydro-erosiven Verrundens die Kante (5) und die an die Kante (5) angrenzenden Flachen (4, 6) des hochdruckfesten Bauteiles (1) jeweils im Bereich ihrer Oberflache mittels eines Schleif- und/oder Honverfahrens unter Druckspannungen gesetzt werden. Auch in Bezug auf das Verfahren und eine Vorrichtung zum hydro-erosiven Verrunden wird vorgeschlagen, dass zur Umlenkung der mit Schleifkorpern (7) versetzten Flussigkeit (8) von der ersten Bohrung (2) in die zweite Bohrung (3) in die weiterfuhrende erste Bohrung (2) in Haupt-Stromungsrichtung (S) der mit Schleifkorpern (7) versetzten Flussigkeit (8) gesehen hinter der abzweigenden zweiten Bohrung (3) ein Verschlusselement (9) eingesetzt ist.