Wittstock
Arne Wittstock, Bremen DE
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20090101241 | ACTUATION VIA SURFACE CHEMISTRY INDUCED SURFACE STRESS - A method of controlling macroscopic strain of a porous structure includes contacting a porous structure with a modifying agent which chemically adsorbs to a surface of the porous structure and modifies an existing surface stress of the porous structure. A device in one embodiment includes a porous metal structure, which when contacted with a modifying agent which chemically adsorbs to a surface of the porous metal structure, exhibits a volumetric change due to modification of an existing surface stress of the porous metal structure; and a mechanism for detecting the volumetric change. Additional methods and systems are also presented. | 04-23-2009 |
Arne Wittstock, Livermore, CA US
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20130337995 | HIGHLY ACTIVE THERMALLY STABLE NANOPOROUS GOLD CATALYST - In one embodiment, a system includes a nanoporous gold structure and a plurality of oxide particles deposited on the nanoporous gold structure; the oxide particles are characterized by a crystalline phase. In another embodiment, a method includes depositing oxide nanoparticles on a nanoporous gold support to form an active structure and functionalizing the deposited oxide nanoparticles. | 12-19-2013 |
Carsten Wittstock, Nürnberg DE
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20100127769 | ACTIVE FILTER HAVING A MULTILEVEL TOPOLOGY - A cost-effective device for influencing the transmission of electrical energy of an alternating voltage line with a plurality of phases has phase modules, which each have an alternating voltage terminal for connecting to a phase of the alternating voltage line and two connecting terminals. A phase module branch extends between each connecting terminal and each alternating voltage terminal. The phase module branch is formed of a series connection of sub-modules, each having a power semiconductor circuit and an energy accumulator connected in parallel to the power semiconductor circuit. The connecting terminals are connected to one another. The power semiconductor circuit is equipped with power semiconductors that can be switched off and are connected to each other in a half bridge. | 05-27-2010 |
20110205771 | CLOSED-LOOP CONTROL METHOD FOR AN HVDC TRANSFER INSTALLATION HAVING A DC VOLTAGE INTERMEDIATE CIRCUIT AND SELF-COMMUTATED CONVERTERS - A closed-loop control method for at least two converters in an energy transmission and/or distribution system. The converters may be controlled either as rectifier or inverter and they are connected to each other by a DC link. A measured DC voltage and a measured DC current is measured at each converter and transmitted to a rectifier regulator for regulating the corresponding rectifier or to an inverter regulator for regulating the corresponding inverter. Each rectifier regulator and each inverter regulator gives the difference between a given set DC voltage and the relevant received measured DC voltage to give a differential DC voltage and the difference between a set DC current and the corresponding received measured DC current to give a differential DC current. The measured DC current, the measured DC voltage, the set DC current and the set DC voltage are normalized with which a regulation of inverters formed of switchable power semiconductors connected by a DC link can be carried out, wherein the proviso of set currents being zero is possible. Each converter is a self-commutated converter with power semiconductors and the rectifier regulation of the provided converter is regulated such that the sum of the product of the differential voltages and the value of given set DC current at the corresponding rectifier and the differential current is a minimum and the inverter regulation regulates the corresponding inverter such that the sum between the differential voltage and the differential current is a minimum. | 08-25-2011 |
20110235375 | APPARATUS HAVING A CONVERTER - A device has a converter which is connected to a direct voltage circuit through a short-circuit protection unit. The short-circuit protection unit is arranged at least partially in the direct voltage circuit and is provided in the direct voltage circuit to suppress short-circuit current flowing through the converter. The device contains one or more controllable power semiconductors, wherein a protection element is arranged in parallel to at least one of the controllable power semiconductors. The device prevents the negative effects of a short circuit occurring in the direct voltage network in a particularly reliable manner. For this purpose, the protection element is an energy store. | 09-29-2011 |
Carsten Wittstock, Nürnberg DE
Patent application number | Description | Published |
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20100127769 | ACTIVE FILTER HAVING A MULTILEVEL TOPOLOGY - A cost-effective device for influencing the transmission of electrical energy of an alternating voltage line with a plurality of phases has phase modules, which each have an alternating voltage terminal for connecting to a phase of the alternating voltage line and two connecting terminals. A phase module branch extends between each connecting terminal and each alternating voltage terminal. The phase module branch is formed of a series connection of sub-modules, each having a power semiconductor circuit and an energy accumulator connected in parallel to the power semiconductor circuit. The connecting terminals are connected to one another. The power semiconductor circuit is equipped with power semiconductors that can be switched off and are connected to each other in a half bridge. | 05-27-2010 |
Carsten Wittstock, Nuernberg DE
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20110163702 | CONVERTER WITH DISTRIBUTED BRAKE RESISTANCES - A device converts electrical energy into heat in the field of drive voltage technology and/or high voltage technology. The device contains a brake resistance and at least one controllable brake power semiconductor for controlling the conversion, enabling a rapid and economical transformation of effective power into heat as required. To this end, the brake resistance contains a plurality of individual brake resistances that are each part of a bipolar submodule. The submodules are connected in series, form a submodule series connection, and at least partially contain an energy accumulator respectively connected in parallel to an associated individual brake resistance and a controllable brake power semiconductor, which allows the current flow over the respectively associated individual brake resistance in a brake position, and interrupts the current flow over the brake resistance in a normal operating position. | 07-07-2011 |
Volker Wittstock, Dresden DE
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20090046348 | Imaging Apparatus for Influencing Impinging Light - An imaging apparatus for influencing impinging light comprising an optical element and an actuator for deforming the optical element is proposed. The optical element has a surface facing the impinging light and the actuator ( | 02-19-2009 |
20100060973 | Imaging Device for Influencing Incident Light - Disclosed is an imaging device for influencing incident light, comprising an optical element in the form of a mirror and an actuator for deforming the optical element. The optical element has a surface facing the incident light. The actuator laterally grips the optical surface of the optical element in order to deform the optical element. | 03-11-2010 |