Abstract: An apparatus comprises an array of vertical-cavity surface-emitting lasers. Each of the vertical-cavity surface-emitting lasers is configured to be a source of light. The apparatus also comprises an optical arrangement configured to receive light from a plurality of the vertical-cavity surface-emitting lasers and to output a plurality of light beams.

Abstract: Various embodiments provide an optical element having a high or large refractive index. The optical element is able to maintain its beam shaping function or output when it is immersed in air or water. Accordingly, the optical element may be used for a variety of different devices or applications, including optical telecommunication devices, cameras, tablets, computers, mobile telephones, and optical sensors, that may be immersed in multiple environments, such as air or water.

Abstract: Structural health monitoring and protection systems and methods are provided. System and methods utilize structural information and/or enhanced built in testing capabilities for detecting failure modes that may cause damage to a structure. Systems and methods herein may protect a structure by mitigating one or more incorrect forces. The structure may be an aircraft, a rotary wing aircraft, or any other physical structure subject to vibrations and receptive to canceling of those vibrations.

Abstract: A sensor package may include a source configured to emit a signal, a detector configured to receive a first reflection of the signal, and an isolator disposed between the source and the detector, where a surface of the isolator has one or more grooves configured to direct a second reflection of the signal away from the detector.

Abstract: A converter arrangement for an AC system includes a phase leg including a first sub-converter, a second sub-converter, an IPT interface configured for connecting the first and second sub-converters with a phase line A, and at least one DC bus connected to the first and second sub-converters. The first sub-converter is connected in parallel with the second sub-converter between the DC bus and the IPT interface. Each of the first and second sub-converters includes a chain-link converter connected to the IPT interface and including a plurality of converter cells connected in series with each other, and a common DC link multilevel converter connected to the DC bus and in series with the chain-link converter.

Abstract: A sensor package may include a source configured to emit a signal, a detector configured to receive a first reflection of the signal, and an isolator disposed between the source and the detector, where a surface of the isolator has one or more grooves configured to direct a second reflection of the signal away from the detector.

Abstract: Structural health monitoring and protection systems and methods are provided. System and methods utilize structural information and/or enhanced built in testing capabilities for detecting failure modes that may cause damage to a structure. Systems and methods herein may protect a structure by mitigating one or more incorrect forces. The structure may be an aircraft, a rotary wing aircraft, or any other physical structure subject to vibrations and receptive to canceling of those vibrations.

Abstract: Various embodiments provide an optical element having a high or large refractive index. The optical element is able to maintain its beam shaping function or output when it is immersed in air or water. Accordingly, the optical element may be used for a variety of different devices or applications, including optical telecommunication devices, cameras, tablets, computers, mobile telephones, and optical sensors, that may be immersed in multiple environments, such as air or water.

Abstract: An energy storage system (ESS) for an electrical system includes an energy storage, and a converter interface arranged for connecting the energy storage to the electrical system. The converter interface includes a modular multilevel converter in which each phase leg includes a plurality of series connected cells of which at least one is a half-bridge cell and at least one is a full-bridge cell.

Abstract: A time of flight detector includes an electromagnetic radiation emitter configured to emit a beam of radiation. A first optical element receives the beam of radiation and generates a collimated beam of radiation. A second optical element defines a narrow imaging field of view sufficient to capture reflected electromagnetic radiation from the collimated beam. An electromagnetic radiation sensor then senses the captured reflected electromagnetic radiation from the collimated beam in the narrow imaging field of view. Further narrowing of the imaging field of view is accomplished by selective enabling a sub-array of photosensitive elements with the electromagnetic radiation sensor.

Abstract: A switching cell for a chain link includes a first side including a first terminal and a second terminal, a second side including a third terminal and a fourth terminal, a first switching unit, a second switching unit, and a first and a second capacitor unit. The first terminal is connected to the second terminal via the first capacitor unit. The first capacitor unit has its positive side facing the first terminal. The third terminal is connected to the fourth terminal via the second capacitor unit. The second capacitor has its positive side facing the fourth terminal. The second terminal is connected to the fourth terminal via the second switching unit. The switching cell also includes a third capacitor unit, and the first terminal is connected to the third terminal via a first series connection including the first switching unit and the third capacitor unit. The third capacitor unit has its positive side facing the third terminal. A switching module includes at least one such switching cell.

Abstract: A method of controlling a multilevel converter, a computer program and a controller for a converter is provided. The method includes determining a transition voltage from a control period to a following control period, analyzing the switching cells of each phase leg, selecting capacitors to provide the transition voltage and synthesize the output voltage for the following control period, and connecting the selected capacitors during the following control period. The analyzing of each switching cell includes analyzing a first switching leg and a second switching leg of the switching cell. The method includes determining whether a change of state of the first switching leg would contribute to the direction of the transition voltage, and determining whether a change of state of the second switching leg would contribute to the direction of the transition voltage, and determining the internal conditions of each of the first and the second switching leg that are determined as contributing to the transition.

Abstract: A converter arrangement and a method of controlling a three-phase converter arrangement connected to a transmission grid are provided. The converter arrangement includes three phase legs and an energy transfer circuit. The method includes providing a varying respective output phase voltage to the transmission grid by selecting energy storage elements of both the phase legs and the energy transfer circuit and connecting the selected energy storage elements to the transmission grid output. The method further includes selecting energy storage elements for performing a transfer of energy between the energy storage elements during the control period.

Abstract: A multi-level power converter includes switching cells, each comprising switching devices and an energy storage element. The switching cells include switching cells of a first type and switching cells of a second type. The converter includes, for each phase, a first arm of serial connected switching cells and a second arm of serial connected switching cells, which first arm and second arm are connected in parallel. The first arm includes more switching cells of the first type than switching cells of the second type and the second arm includes more switching cells of the second type than switching cells of the first type. The switching cells of the first type have lower conduction loss than the switching cells of the second type. The converter is arranged so that a larger current flows through the first arm than the second arm.

Abstract: A converter arrangement for an AC system includes a phase leg including a first sub-converter, a second sub-converter, an IPT interface configured for connecting the first and second sub-converters with a phase line A, and at least one DC bus connected to the first and second sub-converters. The first sub-converter is connected in parallel with the second sub-converter between the DC bus and the IPT interface. Each of the first and second sub-converters includes a chain-link converter connected to the IPT interface and including a plurality of converter cells connected in series with each other, and a common DC link multilevel converter connected to the DC bus and in series with the chain-link converter.

Abstract: A method of controlling a multilevel converter, a computer program and a controller for a converter is provided. The method includes determining a transition voltage from a control period to a following control period, analyzing the switching cells of each phase leg, selecting capacitors to provide the transition voltage and synthesize the output voltage for the following control period, and connecting the selected capacitors during the following control period. The analyzing of each switching cell includes analyzing a first switching leg and a second switching leg of the switching cell. The method includes determining whether a change of state of the first switching leg would contribute to the direction of the transition voltage, and determining whether a change of state of the second switching leg would contribute to the direction of the transition voltage, and determining the internal conditions of each of the first and the second switching leg that are determined as contributing to the transition.

Abstract: A switching cell for a chain link includes a first side including a first terminal and a second terminal, a second side including a third terminal and a fourth terminal, a first switching unit, a second switching unit, and a first and a second capacitor unit. The first terminal is connected to the second terminal via the first capacitor unit. The first capacitor unit has its positive side facing the first terminal. The third terminal is connected to the fourth terminal via the second capacitor unit. The second capacitor has its positive side facing the fourth terminal. The second terminal is connected to the fourth terminal via the second switching unit. The switching cell also includes a third capacitor unit, and the first terminal is connected to the third terminal via a first series connection including the first switching unit and the third capacitor unit. The third capacitor unit has its positive side facing the third terminal. A switching module includes at least one such switching cell.

Abstract: A multi-level power converter includes switching cells, each comprising switching devices and an energy storage element. The switching cells include switching cells of a first type and switching cells of a second type. The converter includes, for each phase, a first arm of serial connected switching cells and a second arm of serial connected switching cells, which first arm and second arm are connected in parallel. The first arm includes more switching cells of the first type than switching cells of the second type and the second arm includes more switching cells of the second type than switching cells of the first type. The switching cells of the first type have lower conduction loss than the switching cells of the second type. The converter is arranged so that a larger current flows through the first arm than the second arm.

Abstract: An energy storage system (ESS) for an electrical system includes an energy storage, and a converter interface arranged for connecting the energy storage to the electrical system. The converter interface includes a modular multilevel converter in which each phase leg includes a plurality of series connected cells of which at least one is a half-bridge cell and at least one is a full-bridge cell.

Abstract: A time of flight detector includes an electromagnetic radiation emitter configured to emit a beam of radiation. A first optical element receives the beam of radiation and generates a collimated beam of radiation. A second optical element defines a narrow imaging field of view sufficient to capture reflected electromagnetic radiation from the collimated beam. An electromagnetic radiation sensor then senses the captured reflected electromagnetic radiation from the collimated beam in the narrow imaging field of view. Further narrowing of the imaging field of view is accomplished by selective enabling a sub-array of photosensitive elements with the electromagnetic radiation sensor.