Disclosed is a deterioration determination device for a liquid pumping apparatus including: a casing that forms a reservoir space for storing liquid flowed thereto; a feed valve that introduces working gas into the reservoir space; an exhaust valve that releases the working gas from the reservoir space; and a valve operating mechanism having a float arranged in the reservoir space, and performing a pumping stroke in which the liquid is pumped from the reservoir space under a pressure of the working gas by opening the feed valve and closing the exhaust valve when the float moves up to a predetermined high level, and an inflow stroke in which the liquid flows into the reservoir space and the working gas is released from the reservoir space by closing the feed valve and opening the exhaust valve when the float moves down to a predetermined low level. The deterioration determination device includes a first pressure sensor arranged to communicate with a lower portion of the reservoir space to detect a pressure of a liquid layer in the reservoir space, and a deterioration determination unit that determines a degree of deterioration of the valve operating mechanism based on a change in the pressure detected by the first pressure sensor.

An assembly for monitoring air flow at a surface of a rotor blade of a wind turbine is provided. The assembly includes (a) a surface module adapted to be arranged at a predetermined location of the rotor blade surface, the surface module including two air inlets facing opposite directions along an axis, (b) a sensor module including two pressure sensors, wherein one of the two pressure sensors is in fluidic communication with one of the two air inlets and the other one of the two pressure sensors is in fluidic communication with the other one of the two air inlets, wherein the sensor module is adapted to output two pressure signals indicative of the pressures sensed by the two pressure sensors, and (c) a processing unit adapted to determine at least one of a flow direction and a flow speed along the axis based on the two pressure signals.

A measuring arrangement for detecting deformations, in particular bending of the outer surface, of a wind turbine structural element, includes: at least two measurement sites on the structural element spaced apart from one another toward a structural element extension, each having at least one acceleration sensor, that can be communication-connected—preferably via a wireless interface—to an evaluation device. The measuring arrangement—has at least two speed sensors, in particular angular speed sensors, on the structural element and spaced apart from one another toward a structural element extension, preferably the longitudinal extension, and/or the measuring arrangement has at least two position sensors, in particular magnetic field sensors, on the structural element and spaced apart from one another toward a structural element extension, preferably the longitudinal extension. The speed sensors and/or the position sensors can be communication-connected to the evaluation device—preferably via a wireless interface.

A method of yawing a nacelle in a wind turbine having a yawing assembly comprising a drive-ring and a plurality of drives configured to exert a torque during movement along the drive-ring and thereby move the nacelle relative to the tower. The drive-ring is made of drive-ring segments joined in intersections. The method comprises defining a location for each intersection, defining a reference torque exerted by the drives when moving along the drive-ring, defining a reduced torque being lower than the reference torque, determining when a crossing drive moves across the location of an intersection, and to increase the lifetime, exerting the reduced torque by the crossing drive.

Energy harvesters (EH) which can effectively harvest wasted vibrational/kinematic energy and convert it into electrical energy for battery-free sensor operation are described herein. The energy harvesters can be integrated with a power management circuit and a wireless sensor for monitoring wind turbine blades. The target application of the energy harvesters includes powering the wireless sensors used for wind turbine blade structural monitoring.

A method for protecting a wind turbine from extreme and fatigue loads associated with high wind speed events includes receiving, via a wind turbine condition estimator programmed in a turbine controller of the wind turbine, operating data indicative of current wind turbine operation. Further, the method includes determining, via the wind turbine condition estimator, a plurality of estimated wind turbine conditions at the wind turbine by solving a control algorithm having one or more equations using the operating data. The estimated wind turbine conditions include, at least, an estimated wind speed at the wind turbine and a loading proxy of the wind turbine. As such, the method includes implementing, via the turbine controller, a corrective action only when each of the estimated wind turbine conditions indicates that one or more loading conditions of the wind turbine exceeds a predetermined limit.

A dynamic adaptive mooring system for wave energy converters (WEC) is disclosed that has a mooring configuration that has a set of fixed mooring lines, and a set of movable mooring lines. When an incoming wave train interacts with the fixed WECs, a set of wave interference points that have higher wave amplitudes than the incoming wave train are formed downstream of the fixed WECs. The movable WECs are then positioned at the interface points to optimize wave energy transfer.

A multirotor wind turbine (1) comprising a vertical tower and at least two energy generating units (5), a load carrying structure (9, 10) extending transverse to the vertical direction and carrying the at least two energy generating units (5); and at least one escape route extending between a start and an exit. To provide a safe escape route, the load carrying structure forms at least a first section of the escape route from the start to an intermediate location, and the wind turbine comprises an escape opening in the nacelle, the escape opening leading from an interior space of a nacelle of the energy generating unit to a passage structure and the passage structure extending from the escape opening to the start of the escape route.

A wind turbine generator controller is described. The controller comprises switching circuitry, for selectively activating and deactivating one or more transducer circuits, and overcurrent detection circuitry, for detecting an overcurrent state in relation to one or more of the transducer circuits. The switching circuitry is responsive to the detection on an overcurrent state to selectively deactivate one or more of the transducer circuits.

A control system for one or more wind turbines comprising an RF receiver used as a method for adaptively controlling the noise mode of operation of a wind turbine. Preferably, this involves multilateration to determine location of RF sources near wind turbindes of a wind turbine park. The RF receivers would detect nearby RF signals in multiple spectrums, in particular mobile telecommunication signals (GSM/UMTS), to identify and localize RF sources near to the wind turbine(s). This information is then be processed to identify which RF sources are likely to be linked to a real person near the wind turbine, and this can be used to adjust the noise mode of the wind turbine accordingly. Thereby maximizing energy production from the wind turbine in absence of nearby people, while keeping noise low when people are nearby.