The Experts below are selected from a list of 31875 Experts worldwide ranked by ideXlab platform
A Steimel - One of the best experts on this subject based on the ideXlab platform.
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dead beat control algorithm for single phase 50 kw ac railway Grid Representation
IEEE Transactions on Power Electronics, 2010Co-Authors: Martin Oettmeier, C Heising, Volker Staudt, A SteimelAbstract:The control of four-quadrant converters (4QC) of traction vehicles fed by an ac railway Grid has to meet very restrictive limitations with regard to harmonics and stability. The challenge is increased by continuously changing the position-dependent Grid impedance and voltage harmonics already contained in the Grid voltage. Testing a 4QC control in a lab, therefore, requires a railway Grid Representation that both emulates variable Grid impedance and Grid-voltage harmonics. The paper presents an innovative solution to this problem that employs a 4Q inverter with a suitably designed new control scheme. As the rated power is not high, compared to the traction vehicle fed, the control has to be effective, taking each switching event of the inverter into account. For the design of the control, a suitable simulation is needed, which is also presented in this paper. A comparison of simulation and measurement results is given, proving excellent results.
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dead beat control for a single phase 50 kw 16 7 hz railway Grid Representation inverter featuring variable Grid parameters
International Conference on Power Engineering Energy and Electrical Drives, 2009Co-Authors: Martin Oettmeier, C Heising, Volker Staudt, A SteimelAbstract:To investigate railway Grid interaction a fully controlled Grid Representation is essential in order to emulate line-current harmonics and Grid impedance. Based on a Grid Representation — realised with a four-quadrant inverter — advanced control concepts for the power train of railway traction vehicles can be developed. In this paper the focus lies on the design of a dead-beat control of the Grid inverter, including system analysis, set-point value computation, details of the control design, observer and compensation of nonlinear effects of the inverter. Measurement results for stationary and dynamic behavior at load-steps are presented, verifying proper operation.
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single phase 50 kw 16 7 hz railway Grid Representation featuring variable Grid parameters
Power Electronics Specialists Conference, 2008Co-Authors: C Heising, Volker Staudt, M Gorski, A SteimelAbstract:Railway Grid interaction is a major concern when developing the power train of a railway traction vehicle and its control. Two main areas have to be taken into account: Line current harmonics are limited - with often extremely low limit values, compared to nominal current - respecting the properties and safety issues of railway track circuits. Grid stability is influenced by the varying Grid impedance seen by the moving vehicle, in connection with varying resonances, influenced by other vehicles and the actual Grid configuration. The development of an optimized control scheme for the power train of a railway traction vehicle operating at the 15 kV,16.7Hz Grid widely used in central Europe requires advanced simulation tools as well as suitable laboratory experiments for verification. This paper describes the simulation concept, the control concept and the realization of an advanced railway-Grid Representation in the lab, featuring real-time adjustable impedance and voltage harmonics. The power-electronic basis for the Grid Representation in the lab, feed-back and feed-forward control, including compensation of nonlinear effects of the inverter, are described. Simulation and measurement results for stationary and dynamic behavior are presented, verifying excellent operation.
Martin Oettmeier - One of the best experts on this subject based on the ideXlab platform.
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dead beat control algorithm for single phase 50 kw ac railway Grid Representation
IEEE Transactions on Power Electronics, 2010Co-Authors: Martin Oettmeier, C Heising, Volker Staudt, A SteimelAbstract:The control of four-quadrant converters (4QC) of traction vehicles fed by an ac railway Grid has to meet very restrictive limitations with regard to harmonics and stability. The challenge is increased by continuously changing the position-dependent Grid impedance and voltage harmonics already contained in the Grid voltage. Testing a 4QC control in a lab, therefore, requires a railway Grid Representation that both emulates variable Grid impedance and Grid-voltage harmonics. The paper presents an innovative solution to this problem that employs a 4Q inverter with a suitably designed new control scheme. As the rated power is not high, compared to the traction vehicle fed, the control has to be effective, taking each switching event of the inverter into account. For the design of the control, a suitable simulation is needed, which is also presented in this paper. A comparison of simulation and measurement results is given, proving excellent results.
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lq optimized multivariable control for a single phase 50 kw 16 7 hz railway Grid Representation featuring variable Grid parameters
2009 Compatibility and Power Electronics, 2009Co-Authors: Martin Oettmeier, Volker Staudt, M Gorski, C Heising, A SteimelAbstract:Railway Grid interaction is a major concern when developing the power train of a railway traction vehicle and its control. Two main areas have to be taken into account: Line current harmonics and Grid stability.
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dead beat control for a single phase 50 kw 16 7 hz railway Grid Representation inverter featuring variable Grid parameters
International Conference on Power Engineering Energy and Electrical Drives, 2009Co-Authors: Martin Oettmeier, C Heising, Volker Staudt, A SteimelAbstract:To investigate railway Grid interaction a fully controlled Grid Representation is essential in order to emulate line-current harmonics and Grid impedance. Based on a Grid Representation — realised with a four-quadrant inverter — advanced control concepts for the power train of railway traction vehicles can be developed. In this paper the focus lies on the design of a dead-beat control of the Grid inverter, including system analysis, set-point value computation, details of the control design, observer and compensation of nonlinear effects of the inverter. Measurement results for stationary and dynamic behavior at load-steps are presented, verifying proper operation.
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advanced simulation concept for interaction of railway Grid Representation and model power train of ac locomotive
International Conference on Power Engineering Energy and Electrical Drives, 2009Co-Authors: Roman Bartelt, Martin Oettmeier, Volker Staudt, C Heising, A SteimelAbstract:Grid interaction and stability is an important issue for 16.7-Hz single-phase railway applications. A project is set up which aims to develop an overall control scheme for traction vehicles which stabilizes the Grid and avoids generating disturbances and excitation. To analyse the full dynamic behaviour on the firm footing of experimental results, a test bench is built. On the one hand the 16.7-Hz single-phase railway Grid is modelled — featuring impedance, Grid voltage harmonics and pantograph arcing. On the other hand the full power chain of a traction vehicle is modelled. To simulate such complex structures consisting of networks and components described by high-order differential equations and several power-electronic devices with high accuracy and efficiency as well, an advanced simulation concept is needed. One which fulfils the requirements and convincing simulation results of the interaction between modelled Grid and loco are presented. The verification is done by measurements.
Volker Staudt - One of the best experts on this subject based on the ideXlab platform.
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dead beat control algorithm for single phase 50 kw ac railway Grid Representation
IEEE Transactions on Power Electronics, 2010Co-Authors: Martin Oettmeier, C Heising, Volker Staudt, A SteimelAbstract:The control of four-quadrant converters (4QC) of traction vehicles fed by an ac railway Grid has to meet very restrictive limitations with regard to harmonics and stability. The challenge is increased by continuously changing the position-dependent Grid impedance and voltage harmonics already contained in the Grid voltage. Testing a 4QC control in a lab, therefore, requires a railway Grid Representation that both emulates variable Grid impedance and Grid-voltage harmonics. The paper presents an innovative solution to this problem that employs a 4Q inverter with a suitably designed new control scheme. As the rated power is not high, compared to the traction vehicle fed, the control has to be effective, taking each switching event of the inverter into account. For the design of the control, a suitable simulation is needed, which is also presented in this paper. A comparison of simulation and measurement results is given, proving excellent results.
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lq optimized multivariable control for a single phase 50 kw 16 7 hz railway Grid Representation featuring variable Grid parameters
2009 Compatibility and Power Electronics, 2009Co-Authors: Martin Oettmeier, Volker Staudt, M Gorski, C Heising, A SteimelAbstract:Railway Grid interaction is a major concern when developing the power train of a railway traction vehicle and its control. Two main areas have to be taken into account: Line current harmonics and Grid stability.
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dead beat control for a single phase 50 kw 16 7 hz railway Grid Representation inverter featuring variable Grid parameters
International Conference on Power Engineering Energy and Electrical Drives, 2009Co-Authors: Martin Oettmeier, C Heising, Volker Staudt, A SteimelAbstract:To investigate railway Grid interaction a fully controlled Grid Representation is essential in order to emulate line-current harmonics and Grid impedance. Based on a Grid Representation — realised with a four-quadrant inverter — advanced control concepts for the power train of railway traction vehicles can be developed. In this paper the focus lies on the design of a dead-beat control of the Grid inverter, including system analysis, set-point value computation, details of the control design, observer and compensation of nonlinear effects of the inverter. Measurement results for stationary and dynamic behavior at load-steps are presented, verifying proper operation.
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advanced simulation concept for interaction of railway Grid Representation and model power train of ac locomotive
International Conference on Power Engineering Energy and Electrical Drives, 2009Co-Authors: Roman Bartelt, Martin Oettmeier, Volker Staudt, C Heising, A SteimelAbstract:Grid interaction and stability is an important issue for 16.7-Hz single-phase railway applications. A project is set up which aims to develop an overall control scheme for traction vehicles which stabilizes the Grid and avoids generating disturbances and excitation. To analyse the full dynamic behaviour on the firm footing of experimental results, a test bench is built. On the one hand the 16.7-Hz single-phase railway Grid is modelled — featuring impedance, Grid voltage harmonics and pantograph arcing. On the other hand the full power chain of a traction vehicle is modelled. To simulate such complex structures consisting of networks and components described by high-order differential equations and several power-electronic devices with high accuracy and efficiency as well, an advanced simulation concept is needed. One which fulfils the requirements and convincing simulation results of the interaction between modelled Grid and loco are presented. The verification is done by measurements.
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single phase 50 kw 16 7 hz railway Grid Representation featuring variable Grid parameters
Power Electronics Specialists Conference, 2008Co-Authors: C Heising, Volker Staudt, M Gorski, A SteimelAbstract:Railway Grid interaction is a major concern when developing the power train of a railway traction vehicle and its control. Two main areas have to be taken into account: Line current harmonics are limited - with often extremely low limit values, compared to nominal current - respecting the properties and safety issues of railway track circuits. Grid stability is influenced by the varying Grid impedance seen by the moving vehicle, in connection with varying resonances, influenced by other vehicles and the actual Grid configuration. The development of an optimized control scheme for the power train of a railway traction vehicle operating at the 15 kV,16.7Hz Grid widely used in central Europe requires advanced simulation tools as well as suitable laboratory experiments for verification. This paper describes the simulation concept, the control concept and the realization of an advanced railway-Grid Representation in the lab, featuring real-time adjustable impedance and voltage harmonics. The power-electronic basis for the Grid Representation in the lab, feed-back and feed-forward control, including compensation of nonlinear effects of the inverter, are described. Simulation and measurement results for stationary and dynamic behavior are presented, verifying excellent operation.
C Heising - One of the best experts on this subject based on the ideXlab platform.
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dead beat control algorithm for single phase 50 kw ac railway Grid Representation
IEEE Transactions on Power Electronics, 2010Co-Authors: Martin Oettmeier, C Heising, Volker Staudt, A SteimelAbstract:The control of four-quadrant converters (4QC) of traction vehicles fed by an ac railway Grid has to meet very restrictive limitations with regard to harmonics and stability. The challenge is increased by continuously changing the position-dependent Grid impedance and voltage harmonics already contained in the Grid voltage. Testing a 4QC control in a lab, therefore, requires a railway Grid Representation that both emulates variable Grid impedance and Grid-voltage harmonics. The paper presents an innovative solution to this problem that employs a 4Q inverter with a suitably designed new control scheme. As the rated power is not high, compared to the traction vehicle fed, the control has to be effective, taking each switching event of the inverter into account. For the design of the control, a suitable simulation is needed, which is also presented in this paper. A comparison of simulation and measurement results is given, proving excellent results.
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dead beat control for a single phase 50 kw 16 7 hz railway Grid Representation inverter featuring variable Grid parameters
International Conference on Power Engineering Energy and Electrical Drives, 2009Co-Authors: Martin Oettmeier, C Heising, Volker Staudt, A SteimelAbstract:To investigate railway Grid interaction a fully controlled Grid Representation is essential in order to emulate line-current harmonics and Grid impedance. Based on a Grid Representation — realised with a four-quadrant inverter — advanced control concepts for the power train of railway traction vehicles can be developed. In this paper the focus lies on the design of a dead-beat control of the Grid inverter, including system analysis, set-point value computation, details of the control design, observer and compensation of nonlinear effects of the inverter. Measurement results for stationary and dynamic behavior at load-steps are presented, verifying proper operation.
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single phase 50 kw 16 7 hz railway Grid Representation featuring variable Grid parameters
Power Electronics Specialists Conference, 2008Co-Authors: C Heising, Volker Staudt, M Gorski, A SteimelAbstract:Railway Grid interaction is a major concern when developing the power train of a railway traction vehicle and its control. Two main areas have to be taken into account: Line current harmonics are limited - with often extremely low limit values, compared to nominal current - respecting the properties and safety issues of railway track circuits. Grid stability is influenced by the varying Grid impedance seen by the moving vehicle, in connection with varying resonances, influenced by other vehicles and the actual Grid configuration. The development of an optimized control scheme for the power train of a railway traction vehicle operating at the 15 kV,16.7Hz Grid widely used in central Europe requires advanced simulation tools as well as suitable laboratory experiments for verification. This paper describes the simulation concept, the control concept and the realization of an advanced railway-Grid Representation in the lab, featuring real-time adjustable impedance and voltage harmonics. The power-electronic basis for the Grid Representation in the lab, feed-back and feed-forward control, including compensation of nonlinear effects of the inverter, are described. Simulation and measurement results for stationary and dynamic behavior are presented, verifying excellent operation.
Edvard I. Moser - One of the best experts on this subject based on the ideXlab platform.
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development of the spatial Representation system in the rat
Science, 2010Co-Authors: Rosamund F Langston, Edvard I. Moser, Menno P. Witter, James A Ainge, Jonathan J Couey, Cathrin B Canto, Tale Litlere Bjerknes, Maybritt MoserAbstract:In the adult brain, space and orientation are represented by an elaborate hippocampal-parahippocampal circuit consisting of head-direction cells, place cells, and Grid cells. We report that a rudimentary map of space is already present when 2½-week-old rat pups explore an open environment outside the nest for the first time. Head-direction cells in the pre- and parasubiculum have adultlike properties from the beginning. Place and Grid cells are also present but evolve more gradually. Grid cells show the slowest development. The gradual refinement of the spatial Representation is accompanied by an increase in network synchrony among entorhinal stellate cells. The presence of adultlike directional signals at the onset of navigation raises the possibility that such signals are instrumental in setting up networks for place and Grid Representation.
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fragmentation of Grid cell maps in a multicompartment environment
Nature Neuroscience, 2009Co-Authors: Dori Derdikman, Maybritt Moser, Marianne Fyhn, Jonathan R Whitlock, Albert Tsao, Torkel Hafting, Edvard I. MoserAbstract:To determine whether entorhinal spatial Representations are continuous or fragmented, we recorded neural activity in Grid cells while rats ran through a stack of interconnected, zig-zagged compartments of equal shape and orientation (a hairpin maze). The distribution of spatial firing fields was markedly similar across all compartments in which running occurred in the same direction, implying that the Grid Representation was fragmented into repeating submaps. Activity at neighboring positions was least correlated at the transitions between different arms, indicating that the map split regularly at the turning points. We saw similar discontinuities among place cells in the hippocampus. No fragmentation was observed when the rats followed similar trajectories in the absence of internal walls, implying that stereotypic behavior alone cannot explain the compartmentalization. These results indicate that spatial environments are represented in entorhinal cortex and hippocampus as a mosaic of discrete submaps that correspond to the geometric structure of the space.
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fragmentation of Grid cell maps in a multicompartment environment
Nature Neuroscience, 2009Co-Authors: Dori Derdikman, Maybritt Moser, Marianne Fyhn, Jonathan R Whitlock, Albert Tsao, Torkel Hafting, Edvard I. MoserAbstract:The authors recorded neural activity in Grid cells while rats ran through a hairpin maze. Their results demonstrate that spatial environments are represented in the entorhinal cortex and hippocampus as a mosaic of discrete submaps corresponding to the geometric structure of the space. To determine whether entorhinal spatial Representations are continuous or fragmented, we recorded neural activity in Grid cells while rats ran through a stack of interconnected, zig-zagged compartments of equal shape and orientation (a hairpin maze). The distribution of spatial firing fields was markedly similar across all compartments in which running occurred in the same direction, implying that the Grid Representation was fragmented into repeating submaps. Activity at neighboring positions was least correlated at the transitions between different arms, indicating that the map split regularly at the turning points. We saw similar discontinuities among place cells in the hippocampus. No fragmentation was observed when the rats followed similar trajectories in the absence of internal walls, implying that stereotypic behavior alone cannot explain the compartmentalization. These results indicate that spatial environments are represented in entorhinal cortex and hippocampus as a mosaic of discrete submaps that correspond to the geometric structure of the space.
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Progressive increase in Grid scale from dorsal to ventral medial entorhinal cortex
Hippocampus, 2008Co-Authors: Vegard Heimly Brun, Edvard I. Moser, Trygve Solstad, Kirsten Brun Kjelstrup, Marianne Fyhn, Menno P. Witter, Maybritt MoserAbstract:Grid cells are topographically organized in the sense that, within the dorsal part of the medial entorhinal cortex, the scale of the Grid increases systematically with anatomical distance from the dor- sal border of this brain area. The ventral limit of the spatial map is cur- rently not known. To determine if the Grid map extends into the inter- mediate and ventral parts of the medial entorhinal cortex, we recorded activity from entorhinal principal cells at multiple dorsoventral levels while rats shuttled back and forth on an 18 m long linear track. The recordings spanned a range of more than 3 mm, covering approximately three quarters of the dorsoventral extent of the medial entorhinal cor- tex. Distinct periodic firing fields were observed at all recording levels. The average interpeak distance between the fields increased from � 50 cm in the most dorsal part to � 3 m at the most ventral recording posi- tions. The increase in Grid scale was accompanied by a decrease in the frequency of theta modulation and the rate of phase precession. The increase in average spacing and field size was approximately linear but this relationship coincided with a substantial increase in the variability of each measure. Taken together, the observations suggest that the spa- tial scale of the Grid Representation increases progressively along most of the dorsoventral axis of the medial entorhinal cortex, mirroring the topographical scale expansion observed in place cells in the hippocam- pus. V C 2008 Wiley-Liss, Inc.
