Abstract: The present disclosure is directed to a lift system for a rotor blade of a wind turbine. The lift system includes a lifting device having at least one cradle. The cradle has a profile that corresponds to at least one of the exterior surfaces of the rotor blade so as to support at least a portion of the rotor blade. Further, the lift system includes a positioning assembly having at least one distance sensor mounted to the hub and at least one visual sensor mounted to the lifting device. Thus, the distance sensor is configured to identify a distance from the hub to the lifting device and the visual sensor is configured to identify a position of the rotor blade in the cradle.

Abstract: The present disclosure is directed to a system for controlling a yaw drive of a wind turbine when a native yaw drive control system is non-operational. The system includes an external sensor configured to detect a parameter indicative of a wind condition experienced by the wind turbine. The system also includes an external controller communicatively coupled to the external sensor. The external controller is configured to control the yaw drive based on measurement signals received from the external sensor. The external sensor and the external controller are electrically isolated from the native yaw drive control system.

Abstract: The present disclosure is directed to a system for controlling a yaw drive of a wind turbine when a native yaw drive control system is non-operational. The system includes an external sensor configured to detect a parameter indicative of a wind condition experienced by the wind turbine. The system also includes an external controller communicatively coupled to the external sensor. The external controller is configured to control the yaw drive based on measurement signals received from the external sensor. The external sensor and the external controller are electrically isolated from the native yaw drive control system.

Abstract: The present disclosure is directed to a lift system for a rotor blade of a wind turbine. The lift system includes a lifting device having at least one cradle. The cradle has a profile that corresponds to at least one of the exterior surfaces of the rotor blade so as to support at least a portion of the rotor blade. Further, the lift system includes a positioning assembly having at least one distance sensor mounted to the hub and at least one visual sensor mounted to the lifting device. Thus, the distance sensor is configured to identify a distance from the hub to the lifting device and the visual sensor is configured to identify a position of the rotor blade in the cradle.

Abstract: The present disclosure is directed to systems and methods for removing or installing a pitch bearing of a wind turbine. The method includes installing a first pulley block at an up-tower location of the wind turbine and configuring a second pulley block with the pitch bearing. A pulley cable is routed from a ground location over the first pulley block to the second pulley block such that the second pulley block is configured to slide along the pulley cable. The method also includes rotating the pitch bearing to a tilted position. Thus, the method further includes lowering or lifting the pitch bearing in the tilted position so as to prevent the pitch bearing from colliding with the tower.

Abstract: The present disclosure is directed to a lifting device for a rotor blade of a wind turbine. The lifting device includes at least one cradle and a vacuum sealing system configured with the cradle. The cradle has a profile that corresponds to at least one of the exterior surfaces of the rotor blade so as to support at least a portion of the rotor blade. The vacuum sealing system is configured to secure the rotor blade to the cradle as the rotor blade is lifted and/or lowered from a hub mounted atop a tower of the wind turbine.

Abstract: An electric power system for a wind turbine includes at least one auxiliary load bus configured to transmit electric power to auxiliary equipment. The auxiliary load bus is further configured to receive electric power having a voltage within a first predetermined tolerance range. The system also includes at least one motor-generator set coupled to the auxiliary load bus. The motor-generator set is configured to receive electric power having a voltage within a second predetermined tolerance range and transmit electric power to the auxiliary load bus in the first predetermined tolerance range.

Abstract: The present disclosure is directed to systems and methods for removing or installing a pitch bearing of a wind turbine. The method includes installing a first pulley block at an up-tower location of the wind turbine and configuring a second pulley block with the pitch bearing. A pulley cable is routed from a ground location over the first pulley block to the second pulley block such that the second pulley block is configured to slide along the pulley cable. The method also includes rotating the pitch bearing to a tilted position. Thus, the method further includes lowering or lifting the pitch bearing in the tilted position so as to prevent the pitch bearing from colliding with the tower.

Abstract: An electric power system for a wind turbine includes at least one auxiliary load bus configured to transmit electric power to auxiliary equipment. The auxiliary load bus is further configured to receive electric power having a voltage within a first predetermined tolerance range. The system also includes at least one motor-generator set coupled to the auxiliary load bus. The motor-generator set is configured to receive electric power having a voltage within a second predetermined tolerance range and transmit electric power to the auxiliary load bus in the first predetermined tolerance range.

Abstract: In one aspect, a method for over-voltage protection is provided. The method includes connecting a first winding of a saturable reactor to a direct current (DC) source; connecting at least one phase of an alternating current (AC) electrical system to ground through a second winding of the saturable reactor; and controlling DC current flow from the DC source to the first winding of the saturable reactor in response to an over-voltage event, wherein energy is shunted to ground from the at least one phase of the alternating current electrical system through the second winding of the saturable reactor.

Abstract: In one aspect, a method for over-voltage protection is provided. The method includes connecting a first winding of a saturable reactor to a direct current (DC) source; connecting at least one phase of an alternating current (AC) electrical system to ground through a second winding of the saturable reactor; and controlling DC current flow from the DC source to the first winding of the saturable reactor in response to an over-voltage event, wherein energy is shunted to ground from the at least one phase of the alternating current electrical system through the second winding of the saturable reactor.

Abstract: An air cooled core mounted ignition system for gas turbine engine applications is provided. The ignition system includes an ignition exciter component directly mechanically and electrically connected to an igniter component. The housing member of the exciter component includes an air plenum configured to receive bleed air from the engine fan or compressor sections of the turbine engine, or other source. The bleed air provides a relatively low temperature air source for the purpose of cooling the exciter. As such, the exciter component can be directly secured to the igniter, thereby eliminating the need for an ignition lead.

Abstract: An air cooled core mounted ignition system for gas turbine engine applications is provided. The ignition system includes an ignition exciter component directly mechanically and electrically connected to an igniter component. The housing member of the exciter component includes an air plenum configured to receive bleed air from the engine fan or compressor sections of the turbine engine, or other source. The bleed air provides a relatively low temperature air source for the purpose of cooling of the exciter. As such, the exciter component can be directly secured to the igniter, thereby eliminating the need for an ignition lead.

Abstract: An improved turbine engine ignition exciter circuit. Energy stored in an exciter tank capacitor is subsequently switched to the load (igniter plug) through a novel thyristor switching device specifically designed for pulse power applications. The switching device is designed and constructed to include, for example, a highly interdigitated cathode/gate structure. The semiconductor switching device is periodically activated by a trigger circuit which may be comprised of either electromagnetic or optoelectronic triggering circuitry to initiate discharge of energy stored in exciter tank capacitor to mating ignition lead and igniter plug. Likewise, the present invention allows new flexibility in the output PFN (Pulse Forming Network) stage, eliminating need for specialized protective output devices such as saturable output inductors. Due to considerably higher di/dt performance of the device, true high voltage output pulse networks may be utilized without damage to the semiconductor switching device.

Abstract: An improved turbine engine ignition exciter circuit. Energy stored in an exciter tank capacitor is subsequently switched to the load (igniter plug) through a novel thyristor switching device specifically designed for pulse power applications. The switching device is designed and constructed to include, for example, a highly interdigitated cathode/gate structure. The semiconductor switching device is periodically activated by a trigger circuit which may be comprised of either electromagnetic or optoelectronic triggering circuitry to initiate discharge of energy stored in exciter tank capacitor to mating ignition lead and igniter plug. Likewise, the present invention allows new flexibility in the output PFN (Pulse Forming Network) stage, eliminating need for specialized protective output devices such as saturable output inductors. Due to considerably higher di/dt performance of the device, true high voltage output pulse networks may be utilized without damage to the semiconductor switching device.