When it is not possible for a power generation device to operate coupled to an electric power system, an autonomous operation of connection and disconnection of a load of the power generation device is performed along an efficiency-characteristics curve within a speed range from a rated speed to a maximum speed in the efficiency-characteristics curve of an energy source. During the autonomous operation, an aperture command is outputted to an inlet valve of a water turbine and a first converter is operated in a converter mode when an operation preparation command is outputted by a control unit, a second converter is operated in an inverter mode when a voltage is established by of a DC linkage unit, and the load is connected when the operation preparation is completed.

This method for stabilizing the rotation speed of a hydraulic machine having S-characteristic and comprising a distributor (9) is adapted to modify a water flow, so that the machine can be coupled to a grid. The method comprises the steps of calculating an orientation of the distributor (9); and orienting the distributor according to the calculated orientation. The method further comprises the steps of providing an electric torque to the machine so as to reach a target speed.

In accordance with the present invention a start/stop system is provided for a machine that drives an electric generator by moving buoyant modules on a duty-cycle pathway through a bi-level water tank. Included is a valve mechanism that maintains different water surface levels in the bi-level tank, and also establishes different spaces within the bi-level tank. Additionally, grips are included for selectively holding individual modules in respective spaces. To stop the machine, water is drained from the bi-level tank, and grips are activated, to hold modules in their respective spaces. To restart, water is introduced into the spaces and the grips are deactivated to release the modules for operation.

An ocean current electric power generator includes a mechanical brake that restricts a rotation of a rotor shaft of a rotatable wing, and a power transmission mechanism that is disposed between the rotor shaft and an electric power generator. The power transmission mechanism includes a switching section that switches between a power transmission state and a power disconnection state, a load application section that applies a rotation load on the rotor shaft during the power disconnection state, and a speed varying section that varies a revolution speed of the rotor shaft, and transmits the revolution to the electric power generator during the power transmission state.

The method allows stabilizing the rotation speed of a hydraulic machine with S-characteristics. It is implemented by means of a control loop feedback system having a controller for calculating an orientation to affect guide vanes of the machine. It includes steps of calculating a set of internal states associated with the operating point of the machine, establishing a linearized transfer function in function of the set of internal states, calculating characteristics parameters of the controller in function of the established transfer function so that the control loop feedback system is stable, measuring the rotation speed of the hydraulic machine, comparing the measured rotation speed with a target rotation speed, and adjusting the orientation affected to the guide vanes so as to reduce the speed difference between the calculated rotation speed and the target rotation speed.

Utility Scale Hydro Pump (USHP) uses a vehicle in a uniquely configured water tower to generate hydro potential energy and electricity. The vehicle operates in the lower chamber of the water tower. The upper chamber has two distinct compartments: the body chamber just above the lower chamber to hold water for the vehicle to pump, and a tall and slender head chamber for the head. As the vehicle is lifted from the lower chamber to pump water in the upper chamber into an upper reservoir, a void in the lower chamber is produced simultaneously. The void is the reduced vehicle volume in the lower chamber and gets filled with recycled water from the lower reservoir. USHP releases water from the upper reservoir to generate electricity, and hydro discharge from a hydro turbine generator is collected and recycled in the lower reservoir.

A mass activated generator to generate torque, including a power drop device to receive liquid to drive a continuous loop device to generate the torque; a mass activated pump to receive the liquid from the continuous loop device and to pump the liquid to the continuous loop device. The continuous loop device includes a pair of torque shafts to drive an electric generator and a plurality of power drop containers connected to the torque shafts to receive the liquid and to transfer the liquid to the mass activated pump.

A gentle start-up device includes: a rotational type hollow pipe body, including an inlet and an outlet, and having an inner wall provided with a plurality of bar-shaped fins; a transmission unit, physically connected to the rotational type hollow pipe body; and a driving unit, physically connected to the transmission unit for driving the transmission unit to rotate the rotational type hollow pipe body in a rotational direction and to achieve a predetermined rotational speed according to a water supply flow value of a water turbine of a hydraulic generator set, whereby water flow which passes through the rotational type hollow pipe body generates rotational flow.

An energy generating device for generating energy from a flowing fluid, especially from a wind flow and/or from a water flow, comprises: a rotation body, the rotation body extending along an axis of rotation between a first point and a second point and the rotation body being adapted to rotate about the axis of rotation and the rotation body being formed from at least a first, a second, and a third rotation segment, wherein the rotation segments are joined together and arranged along the axis of rotation, and they form a region at least partly surrounded by fluid, wherein the second rotation segment is situated between the first and the third rotation segment and has a different diameter than the first and third rotation segment; and a generator device mechanically connected to the rotation body, wherein the generator device is adapted to generate energy which is produced from the rotation of the rotation body.

The present invention provides a hydraulic drive train including a check valve provided in a return oil passage disposed between a branching position of a first branching oil passage and a branching position of a second branching oil passage, wherein at the time of starting of startup of the hydraulic drive train, the switching valve is closed, the opening degree of the flow rate adjusting valve is set to the initial opening degree, the on-off valve is opened, the boost pump is driven by the drive motor, and the hydraulic oil is supplied to the hydraulic pump, thereby assisting the rotational speed of the vanes by the hydraulic oil.