Abstract: A submersible hydraulic assembly for an energy storage plant is provided that includes at least one hydraulic machine and at least one first buoyancy chamber filled with at least one first buoyancy element. The at least one first buoyancy chamber is generally configured in such a way that the hydraulic machine is substantially neutrally buoyant when submerged in an environmental liquid. An energy storage plant is also provided as well as a method for performing maintenance operations on an energy storage plant and a method for assembling/disassembling an energy storage plant.

Abstract: A flexible floating reservoir for storing liquids denser than the environmental body of water, such as sea salt brine, is provided. The flexible floating reservoir is adaptable to environmental body waves, such as sea waves. A method for operating the flexible floating reservoir and an underwater energy storage system that uses the flexible floating reservoir are also provided.

Abstract: A power production system is provided that includes: a hydraulic turbine, installable in a penstock and being rotatable in a first rotation direction by effect of a flow of fluid flowing in the penstock in a downward direction; an energy converter group; an accumulator; a control unit, configured to operate the system in a power generation mode, in which the energy converter group receives an input mechanical power from the hydraulic turbine rotating in the first rotation direction, generates an output electric power and supplies said output electrical power to an external grid and/or to the accumulator, and in a downward pushing mode, in which the energy converter group absorbs an input electrical power from the accumulator and generates an output mechanical power to move the hydraulic turbine.

Abstract: An hydroelectric unit extends along a longitudinal axis and includes a least one rim-driven hydraulic machine comprising an impeller provided with at least two blades, and at least one motor/generator configured to selectively supply mechanical energy to the impeller or convert mechanical energy produced by the impeller into electricity. The motor/generator includes an annular rotor arranged about the impeller and an annular stator arranged, at a distance, about the annular rotor; the annular rotor being coupled to the impeller and including a plurality of rotor poles, which are distributed along an annular surface, are arranged parallel one to another and extend transversal to a plane containing the longitudinal axis forming a first angle with the plane containing the longitudinal axis. The annular stator includes a plurality of stator windings and a plurality of stator slots configured to guide the magnetic flux and to house respective stator windings.

Abstract: A submersible hydraulic assembly for an energy storage plant is provided that includes at least one hydraulic machine and at least one first buoyancy chamber filled with at least one first buoyancy element. The at least one first buoyancy chamber is generally configured in such a way that the hydraulic machine is substantially neutrally buoyant when submerged in an environmental liquid. An energy storage plant is also provided as well as a method for performing maintenance operations on an energy storage plant and a method for assembling/disassembling an energy storage plant.

Abstract: The system for offsetting the input voltage unbalance in multilevel inverters or the like comprises a control unit operatively associated with a multilevel inverter for converting direct current into alternate current, the control unit being suitable for piloting the multilevel inverter for generating an output current depending on a reference current, and an equalisation unit for equalising the input voltages of the multilevel inverter having first generation means of a harmonic component of order equal to the reference current, out of phase with respect to the fundamental component of the reference current, detection means of the unbalance of the input voltages to the multilevel inverter, regulation means of the amplitude of the harmonic component depending on the detected unbalance, for offsetting the unbalance.

Abstract: A jewelry ornamental article including a plurality of links (2, 2?, . . . ) connected to each other by connecting means (5a, 5b, 6a, 6b, 5a?, 5b?,6a?, 6b?, 7, . . . ) so as to form a chain. Each link (2, 2?, . . . ) includes a frame (3, 3?, . . . ) that extends in a vertical direction (V) and supports at one of its ends a mounting (4, 4?, . . . ) suitable to house a decorative member. The links (2, 2?, . . . ) are linked together so that the mountings (4, 4?, . . . ) of adjacent links (2, 2?, . . . ) face opposite surfaces of said chain in the vertical direction (V). This arrangement minimizes the size of the gaps that are formed between the links when the chain is closed in a ring-like manner, thus obtaining a remarkably higher continuity of color, design and brightness than the reversible chains known in the field.