The invention relates to a method for controlling the operation of a submersible power plant (1) and a submersible power plant (1). The submersible power plant (1) comprises a structure (2) and a vehicle (3). The vehicle (3) comprises at least one wing (4). The vehicle (3) is arranged to be secured to the structure (2) by means of at least one tether (5). The vehicle (3) is arranged to move in a predetermined trajectory by means of a fluid stream passing the vehicle (3). The vehicle (3) is arranged to change the angle of attack of the at least one wing (4). The method comprises: I: determining if the speed of the fluid passing the vehicle (3) is higher than a predetermined value; or II: determining if the speed of the fluid passing the vehicle (3) is lower than the predetermined value. The vehicle (3) changes the angle of attack for different situations depending on if the speed is higher or lower than the predetermined trajectory.

An example method includes: determining a period of natural oscillation of a floating ground station in an airborne wind turbine with an aerial vehicle coupled to the ground station via a tether, and wherein each natural-oscillation period comprises forward and backward displacement of the floating ground station with respect to the aerial vehicle; and operating the aerial vehicle to fly in a substantially circular path with a looping period that matches the natural-oscillation period of the floating ground station, and a looping phase that aligns with the oscillation phase of the floating ground station such that movement of the aerial vehicle on a downstroke portion the circular path corresponds to forward displacement of the floating ground station, and movement of the aerial vehicle on an upstroke portion the circular path corresponds to reverse displacement of the floating ground station.

This underwater device is twin-motor underwater floating-type power generation device that is provided with: a device main body that is equipped with a pair of pods that have a turbine, and with a connecting beam that connects these pods together in parallel with each other; a sinker; and tether cables that tether the device main body to the seabed via this sinker. The respective turbines of the pods are each provided with variable pitch turbine blades. This device is also provided with a depth meter that detects deviation in posture in the roll direction that is generated in the pair of pods, and a posture controller that controls the pitch of the variable pitch turbine blades of the respective turbines so as to nullify any deviation in posture in the roll direction that has been generated in the pair of pods and has been detected by the depth meter.

The invention relates to a method for controlling the operation of a submersible power plant (1) and a submersible power plant (1). The submersible power plant (1) comprises a structure (2) and a vehicle (3). The vehicle (3) comprises at least one wing (4). The vehicle (3) is arranged to be secured to the structure (2) by means of at least one tether (5). The vehicle (3) is arranged to move in a predetermined trajectory by means of a fluid stream passing the vehicle (3). The vehicle (3) is arranged to change the angle of attack of the at least one wing (4). The method comprises: I: determining if the speed of the fluid passing the vehicle (3) is higher than a predetermined value; or II: determining if the speed of the fluid passing the vehicle (3) is lower than the predetermined value. The vehicle (3) changes the angle of attack for different situations depending on if the speed is higher or lower than the predetermined trajectory.

The invention relates to a submersible power plant for producing electrical power. The submersible power plant comprises a structure and a vehicle comprising at least one wing. The vehicle is arranged to be secured to the structure by means of at least one tether and the vehicle is arranged to move in a predetermined trajectory by means of a fluid stream passing the wing during operation of the submersible power plant. The submersible power plant further comprises at least one turbine connected to a generator, where the at least one turbine is connected to a rear edge rear edge of the wing and wherein the generator is arranged inside the wing of the vehicle.