The invention concerns a method for coupling to the grid a hydraulic unit having a synchronous generator, a runner, and wicket gates. The method includes a step of increasing the flow of water into the runner from a time t.sub.0 to a time t.sub.1 so that the rotation frequency of the rotor of the synchronous generator is, at time t.sub.1 equal to the frequency of the grid, and closing the circuit breaker at time t.sub.1. A sub-interval from a time t2 to time t1 is defined, with t0<=t2<t3<=t1, wherein a sub-step is executed to apply an adjustment torque to the shaft line via a first actuator that controls the flow of water into the runner and a second actuator coupled to a stator of the synchronous generator.

An energy conversion device for converting water energy, in some cases water energy from waves and/or a flow such as an ocean current, into electric energy, comprises at least one rotor having a rotor rotational axis, the alignment of which is in some cases fixed by a supporting frame, and a flow housing which comprises a rotor shell which surrounds the rotor radially to the rotor rotational axis.

An air injection device for a hydraulic turbine includes: a body having a first end and a second end; an air injection passage extending through the body from the second end to the first end; a protrusion disposed at the first end of the body; and one or more air injection holes disposed in the protrusion.

According to an embodiment, the vane 13 has a thick root portion 16P formed on the band 12 side of a pressure surface to be joined to the band 12, with a thickness of the thick root portion 16P being gradually increased toward the band 12, and a thick root portion 16N formed on the band 12 side of a negative pressure surface to be joined to the band 12, with a thickness of the thick root portion 16N being gradually increased toward the band 12. The outlet end 15 has a first curved portion 151 and a second curved portion 152. An extreme point 15B forming a bottom end of the second curved portion 152 is positioned closer to the band 12 than an end of the thick root portion 16P, 16N on the crown 11 side.

A startup method of a Francis turbine according to an embodiment includes: a first rotation-speed increasing step in which a rotation speed of the runner is increased by opening the guide vane at a first opening; a second rotation-speed increasing step in which the increase in the rotation speed of the runner is accelerated by opening the guide vane at a second opening that is larger than the first opening after the first rotation-speed increasing step; and a rotation-speed regulating step in which the rotation speed of the runner is regulated to a rated rotation speed by opening the guide vane at a no-load opening after the second rotation-speed increasing step. The first opening is an opening that is half or less than the no-load opening.

The present invention provides a hydraulic turbine cavitation acoustic signal identification method based on big data machine learning. According to the method, time sequence clustering based on multiple operating conditions under the multi-output condition of the hydraulic turbine set is performed by utilizing an neural network, characteristic quantities of the hydraulic turbine set under a steady condition in a healthy state is screened; a random forest algorithm is introduced to perform feature screening of multiple measuring points under steady-state operation of the hydraulic turbine set, optimal feature measuring points and optimal feature subsets are extracted, finally a health state prediction model is constructed by using gated recurrent units; whether incipient cavitation is present in the equipment is judged. The present invention can effectively identify the occurrence of incipient cavitation in the hydraulic turbine set, reducing unnecessary shutdown of the equipment and prolonging the service life.

Described is an oscillating device for generating electricity from a fluid flow, comprising at least one oscillating part, at least one support, fixed to a reference surface and connected to the oscillating part at an oscillation axis, at least one counter-balancing system connected to, and/or acting on the oscillating part, at least one adjustable profile configured to be at least partially immersed in the fluid flow and movably connected to the oscillating part. The oscillating device comprises an adjustment system configured to change the position of the adjustable profile with respect to the fluid flow between at least one position of greatest resistance and at least one position of least resistance. The invention also relates to an adjustment method for oscillating devices designed to generate electricity, according to which adjustments to the position of the adjustable profile are made as a function of certain parameters, such as the speed and/or the change in direction of the oscillation of the oscillating part, detected by a series of sensors.

A hydrokinetic energy interface device includes a hydrokinetic wheel and a moveable support structure with an angled frame. The angled frame mounted upon the moveable support structure connects between a hydrokinetic wheel and a counterbalance. A bearing is mounted at a vertex between a first end and a second end of the angled frame. The angled frame pivots to move the hydrokinetic wheel and the counterbalance in opposite vertical direction. The hydrokinetic wheel maintains vertical alignment as the angled frame pivots. The hydrokinetic wheel can be formed with interconnectable rim sections. The hydrokinetic wheel may be cantilevered out away from a riverbank by the counterbalance. The hydrokinetic wheel may be raised or lowered by actuation. The movable support structure supporting the hydrokinetic wheel may be rolled away from a free-flowing river for maintenance, repairs, or modification.

The telescopic hydrokinetic turbine system is a device meant for lifting the burden of manufacturing, installing, and maintaining hydrokinetic systems in the water. The device attempts to overcome the issues faced by present day hydrokinetic systems. To accomplish this, the device includes a light weight and easy to carry and install design, a telescopic pillar to align itself with the tide direction or even to leave the body of water for maintenance. Electrical parts are not submerged but instead remain onshore in a small cabin or housing. Further, by adding the use of multiple diffusers, the water flowing into the turbine is made smoother and the overload of water is able to be evacuated and swiped by the fins. The diffusers increase the blades working capacity while homogenizing the water flow and avoiding the phenomena of vibrations and cavitation, thereby increasing efficiency.

An example system comprises an enclosure configured to be submerged in a body of water. The system also comprises a capture device coupled to the enclosure. The capture device includes a rotor shaft and a plurality of blades coupled to the rotor shaft. The plurality of blades are arranged to receive a flow of water when the enclosure is submerged in the body of water. The flow of water causes the plurality of blades to rotate the rotor shaft. The system also comprises a transfer device extending lengthwise from a first end to a second end of the transfer device. The transfer device is mechanically coupled to the capture device at the first end and configured to transfer a torque of the rotating rotor shaft from the first end to the second end. The second end is located outside the enclosure.