A downhole power generation system is disclosed, which includes a turbine generator system. The turbine generator system includes a turbine, a generator coupled with the turbine and having an AC-DC rectifier, and an optimized power control unit. The turbine is driven by flow of a downhole fluid to rotate. The generator converts rotational energy from the turbine to electrical energy and outputting a direct current voltage. The turbine generator system is coupled to a load via the optimized power control unit. The optimized power control unit controls to regulate an output voltage of the generator and provides a regulated output voltage to the load so that the turbine generator system has an optimized power output. An optimized power control method for a downhole power generation system is also disclosed.

A downhole power generation system is disclosed, which includes a turbine generator system. The turbine generator system includes a turbine, a generator coupled with the turbine and having an AC-DC rectifier, and an optimized power control unit. The turbine is driven by flow of a downhole fluid to rotate. The generator converts rotational energy from the turbine to electrical energy and outputting a direct current voltage. The turbine generator system is coupled to a load via the optimized power control unit. The optimized power control unit controls to regulate an output voltage of the generator and provides a regulated output voltage to the load so that the turbine generator system has an optimized power output. An optimized power control method for a downhole power generation system is also disclosed.

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.

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.

The present invention is a method for controlling a wave-energy-converter system, wherein the gains of a control law having a proportional component are optimally determined in terms of the harvest of energy, and are robust with respect to uncertainties in the dynamics of the wave-energy-converter system. The harvest of energy is maximized for the worst case described by the uncertainties, by solving a semidefinite-positive optimization problem.

The present invention is a method for controlling a wave-energy-converter system, wherein the gains of a control law having a proportional component are optimally determined in terms of the harvest of energy, and are robust with respect to uncertainties in the dynamics of the wave-energy-converter system. The harvest of energy is maximized for the worst case described by the uncertainties, by solving a semidefinite-positive optimization problem.

This installation for converting a hydraulic energy into electrical energy comprises a hydraulic adapted to be operated either in a pump mode or in a turbine mode. It further comprises means (25) for applying an electric torque to the rotor to control the rotation speed of the machine during transitions between the pump mode and the turbine mode.

Disclosed is a motor which uses a hydrostatic force to generate a torque which repeats cyclically owing to a displacement of the center of gravity of a cyclic unit. Float bodies (116) are subjected to a buoyant force in a fluid (134), which buoyant force causes an upward movement (146) of the float bodies and drives these into an upper position. The upward movement drives a drive element. The upward movement furthermore causes air to be forced from upper segments (102a, 102d) of a deformable element (100) into lower segments (102b, 102c), and as a result the center of gravity of the cyclic units which comprise the float bodies (116) and the deformable element (100) is raised above an axis of rotation (106). When the float bodies (116) have passed into the upper position thereof, said elevated center of gravity position permits a rotation of the cyclic units into the initial position thereof.

Disclosed is a motor which uses a hydrostatic force to generate a torque which repeats cyclically owing to a displacement of the center of gravity of a cyclic unit. Float bodies (116) are subjected to a buoyant force in a fluid (134), which buoyant force causes an upward movement (146) of the float bodies and drives these into an upper position. The upward movement drives a drive element. The upward movement furthermore causes air to be forced from upper segments (102a, 102d) of a deformable element (100) into lower segments (102b, 102c), and as a result the center of gravity of the cyclic units which comprise the float bodies (116) and the deformable element (100) is raised above an axis of rotation (106). When the float bodies (116) have passed into the upper position thereof, said elevated center of gravity position permits a rotation of the cyclic units into the initial position thereof.

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.