Abstract: A fiber optic cable includes an optical fiber, strength components disposed on opposite sides of the optical fiber, and a polymeric cable jacket. The optical fiber includes a glass core, a glass cladding, and a polymer coating. The cable jacket surrounds the optical fiber and the strength components. Further, the cable jacket is tightly drawn onto the optical fiber, where excess fiber length of the optical fiber is such that positive strain is present in the optical fiber at room temperature (25° C.).

Abstract: The present subject matter is directed to apparatus and methods for producing a variable frequency output waveform from a power converter for use in a power generation system, such as a wind turbine power generation system. A voltage divider is employed to provide plural voltage levels to which a multi-level bridge circuit employing selectively activated switches in pairs of switches is coupled. The switches are operated in such a fashion as to produce a generally sinusoidal waveform that may be easily filtered by low cost filters due to the plural voltage levels to produce a generally smooth sine wave from the converter. Such converters may be used in various environments including in pairs in multi-phase power converters.

Abstract: High performance gate drives and methods for driving semiconductor switching elements, such as insulated gate bipolar transistors (IGBTs), are provided. The gate drive can control the voltage applied to the gate of the IGBT to one or more intermediate voltages near the threshold voltage of the IGBT to control dv/dt of the collector-emitter voltage during and the di/dt of the collector current turn off. For instance, a voltage level between the turn on voltage and the turn off voltage can be applied for a first time period to control dv/dt of the collector-emitter voltage and di/dt of the collector current during turn off. Another voltage level between the turn on voltage and the turn off voltage can be applied for a second time period during reverse recovery of a freewheeling diode coupled in parallel with the IGBT.

Abstract: The present disclosure is directed to a system and method for cooling or cleaning a slip ring assembly of a generator of a wind turbine. The slip ring assembly is at least partially enclosed in a slip ring compartment. In addition, the slip ring assembly includes an electrically conductive slip ring mounted to the rotatable shaft and a fixed conductive ring assembly having slip-ring contacting members mounted thereon. The conduit assembly is configured to direct fluid into the slip ring compartment so as to cool or clean the slip ring compartment. Further, the conduit assembly extends from a first end to a second end. More specifically, the first end is configured at or before an inlet of the generator assembly, whereas the second end is configured at the slip ring compartment.

Abstract: A method is provided for controlling heating of an aerosol precursor arrangement of an electronic smoking article. An average power is directed from a power source to a heating device arranged to heat the aerosol precursor arrangement and a heating time period commensurately initiated. The average power corresponds to a selected power set point associated with the power source. An actual power directed to the heating device is determined as a product of a voltage at, and a current through, the heating device. The actual power is compared to the average power, and the average power is adjusted to direct the actual power toward the selected power set point. The actual power is periodically determined and compared to the average power, and the average power adjusted toward the selected power set point, until expiration of the heating time period. An associated apparatus and computer program product are also provided.

Abstract: A wind turbine system is provided. In various embodiments, the system includes a nacelle supported by a tower. At least one rotor blade is rotatably connected with the nacelle to capture wind energy. The at least one rotor blade rotates relative to the nacelle for generating electricity. A generator is coupled to the nacelle for converting the wind energy into electrical energy. A transformer-converter assembly comprises a converter and a transformer such that the converter is integrally connected to the transformer. An electrical and control module is electronically coupled to the generator and the transformer-converter assembly.

Abstract: A modified expansion/construction joint and a method of forming the joint are disclosed, wherein all or a portion of a non-structural expansion/construction joint is widened through a sawing or other cutting process, a cable is placed in the resulting microtrench or on a bottom fill or backer material followed by top fill or backer material, and the microtrench is then sealed with a conventional crack sealer.

Abstract: A system for operating a power generation system within a battery storage/discharge mode includes a power convertor having a DC link, a switching module coupled to the DC link, a storage device, and a filter coupled between the storage device and power converter. The filter may correspond to a normal mode filter configured to limit normal mode voltage from being applied to the storage device. A common mode filter may be associated with the storage device. The storage device may correspond to one or more batteries while the power generation system may correspond to a wind-driven generator.

Abstract: In one aspect, the present subject matter discloses a method for overvoltage protection of an electrical system. The method may generally include detecting an overvoltage condition on an electrical system; and switching on, in response to the detected overvoltage condition, an impedance connected to the electrical system, wherein the impedance clamps voltage on the electrical system.

Abstract: Systems and methods for converting power are presented. The power conversion includes conducting load current through a first current path of multiple current paths in a power conversion unit using switches, diodes, or a combination thereof. The power conversion also includes blocking one or more additional current paths of the multiple current paths in the power conversion unit using one or more of the switches, one or more of the diodes, or a combination thereof. Furthermore, the power conversion includes reducing potential voltage stress on the one or more switches by using one or more voltage stress reduction switches to reduce a voltage that is blocked by the one or more blocking switches or diodes by connecting an end of each of the one or more switches opposite to a blocking edge to an intermediate voltage node.

Abstract: A gas turbine engine combustor conical-flat heat shield includes an annular conical section extending upstream from and being integral with a flat section with a flat downstream facing surface which may be generally perpendicular to or canted with respect to a centerline. The flat section includes radially outer and inner edges at least one of which is circular and circumscribed about a centerline and circumferentially spaced apart clockwise and counter-clockwise radial edges having an origin on the centerline. A gas turbine engine combustor includes conical-flat heat shields in one or more circular rows arranged in a non-symmetrical or asymmetrical pattern. Two or more groups (A, B, C) of the conical-flat heat shields in the circular rows may be mounted on a domeplate and one or more of the conical-flat heat shields is different in one or more of the groups (A, B, C).

Abstract: A system and method for estimating a remaining life period for a device. The system includes a sensor coupled to the device, wherein the sensor is configured to facilitate measuring an operating parameter of the device and generate a measurement signal that is representative of the operating parameter. The system includes a database comprising an upper limit value, a lower limit value and a reference parameter. A processor of system includes circuitry coupled to the sensor and coupled to the database The processor is configured to correlate measurements of the operating parameter with the reference parameter to facilitate estimating a remaining life period of the device.

Abstract: In one aspect, a method for protecting one or more electrical machines during a grid fault on an electrical system connected with the one or more electrical machines is provided. The method includes detecting a grid fault on an electrical system; taking one or more first actions from a first set of actions based on detected grid fault on the electrical system; detecting at least one operating condition of the electrical system after taking one or more first actions from the first set of actions based on the detected grid fault on the electrical system; and taking one or more second actions from a second set of actions based on the detected at least one operating condition of the electrical system.

Abstract: The present subject matter is directed to a system and method for controlling an electrical component, e.g. a power bridge, of a wind turbine using contingency communications. In one embodiment, the method includes receiving, by the electrical component, a standard set of commands for a first time frame. A next step includes receiving, by the electrical component, one or more contingency sets of commands for time frames beyond the first time frame. The method also includes determining if the standard set of commands is received within a start window of the first time frame. A further step includes implementing, by the electrical component, the standard set of commands during the first time frame if the standard set of commands is received within the start window. The method also includes implementing, by the electrical component, one of the contingency sets of commands received during a previous time frame if the standard set of commands is not received within the start window.

Abstract: A fiber optic cable includes an optical fiber, strength components disposed on opposite sides of the optical fiber, and a polymeric cable jacket. The optical fiber includes a glass core, a glass cladding, and a polymer coating. The cable jacket surrounds the optical fiber and the strength components. Further, the cable jacket is tightly drawn onto the optical fiber, where excess fiber length of the optical fiber is such that positive strain is present in the optical fiber at room temperature (25° C.).

Abstract: The present subject matter is directed to a system and method for controlling an electrical component, e.g. a power bridge, of a wind turbine using contingency communications. In one embodiment, the method includes receiving, by the electrical component, a standard set of commands for a first time frame. A next step includes receiving, by the electrical component, one or more contingency sets of commands for time frames beyond the first time frame. The method also includes determining if the standard set of commands is received within a start window of the first time frame. A further step includes implementing, by the electrical component, the standard set of commands during the first time frame if the standard set of commands is received within the start window. The method also includes implementing, by the electrical component, one of the contingency sets of commands received during a previous time frame if the standard set of commands is not received within the start window.

Abstract: In one aspect, a method for protecting one or more electrical machines during an islanding event is provided. The method includes connecting one or more electrical machines to an alternating current (AC) electric power system, wherein the AC electric power system is configured to transmit at least one phase of electrical power to the one or more electrical machines or to receive at least on phase of electrical power from the one or more electrical machines; electrically coupling at least a portion of a control system to at least a portion of the AC electric power system; coupling at least a portion of the control system in electronic data communication with at least a portion of the one or more electrical machines; and detecting an islanding of the one or more electrical machines based on one or more conditions monitored by the control system.

Abstract: A power converter includes a plurality of power conversion modules. At least one power conversion module includes a plurality of power conversion devices defining a three-level bridge. A first power conversion module includes four terminals including one of a positive terminal and a negative terminal, an output terminal, a first neutral terminal, and a second neutral terminal. The first neutral terminal is coupled to a direct current (DC) link and the second neutral terminal is coupled to a second power conversion module.

Abstract: Systems and methods for power conversion are disclosed. The systems and methods use generation of a plurality of power levels approximately equal to multiples of one or more power supply voltage levels along with generation of one or more intermediate power levels between levels of the plurality of power levels via spanning reactor inductors. Furthermore, the method includes generating an output signal using the generated plurality of power levels and the one or more intermediate levels.

Abstract: Systems and methods for converting power are presented. The power conversion includes conducting load current through a first current path of multiple current paths in a power conversion unit using switches, diodes, or a combination thereof. The power conversion also includes blocking one or more additional current paths of the multiple current paths in the power conversion unit using one or more of the switches, one or more of the diodes, or a combination thereof. Furthermore, the power conversion includes reducing potential voltage stress on the one or more switches by using one or more voltage stress reduction switches to reduce a voltage that is blocked by the one or more blocking switches or diodes by connecting an end of each of the one or more switches opposite to a blocking edge to an intermediate voltage node.