An axial-flux generator for fluid turbines has a continuously variable generator that is constructed of a pair of rotors that move radially across a stator resulting in varying torque and varying power output. In one embodiment the rotors are normally held proximal to the center of a stator by spring tension. The stator is larger than the normally held position of the rotors. As the angular velocity of the rotors increases, the rotors move radially toward the perimeter of the stator, thus encountering a greater stator surface area providing increased torque, increased power generation and a higher-rated output speed when used with a fluid turbine.

A passive magnetic bearing employs eddy currents in a copper core between neodymium annular magnets to support the copper core and an associated rotating shaft. The copper core has an annular flange that is coaxial with a hollow cylinder. The hollow cylinder supports a rotating shaft. An annular iron core is coaxial with and surrounds the annular flange. Annular neodymium magnets surround the upper and lower portions of the hollow cylinder. In some embodiments a touch-down bearing is made up of an upper and a lower bearing race that are spaced away from the upper surface and lower surface of the annular flange. The core rotates over the bearing race(s) until sufficient magnetic flux is generated to support the copper core and hence the shaft. Once spinning, a magnetic field is generated in the copper core.

A rotor bearing assembly for an underwater generator of a fluid flow power plant includes a hollow cylindrical bearing carrier configured to be inserted into an interior of a rotor and releasably connected to the rotor such that they rotate together and an axle journal extending into an interior of the bearing carrier and rotatably supporting the bearing carrier. The bearing the axle journal and the bearing carrier are configured as an installation unit such that a portion of the bearing carrier is insertable into the rotor interior and removable from the rotor interior while attached to the axle journal. Also a generator including the rotor bearing assembly.

A generator for a wind turbine comprising a generator stator having a mounting portion for fixing the generator stator to a machine carrier of the wind turbine, and a generator rotor mounted rotatably about a generator axis relative to the generator stator. The generator has a single-stage transmission which is adapted to non-rotatably cooperate at the drive side with a rotor blade hub and which is non-rotatably connected at the output side to the generator rotor.

An electromagnetic turbine system includes a circulation system for recirculating fluid that drives turbine impellers for electromagnetic turbine modules. The circulation system includes a fluid separator module which separates gas from liquid and circulates the liquid back to a pressure chamber. The liquid in the pressure chamber is propel by compressed gas. Multiple pressure chambers may be controlled to release pressurized fluid to drive their respective shafts on a staggered timing sequence. The turbine modules may be levitated from a supporting surface to reduce friction.

A wind turbine electrical power generating system includes a first generator configured to be mechanically coupled to a rotor, a second generator configured to be mechanically coupled to the rotor; and an electrical power conversion system including at least a first and a second power converter section. The first power converter section is electrically coupled between a rotor winding of the first generator and a coupling point and a stator winding of the first generator is electrically coupled to the coupling point such that only a fraction of electrical power generated by the first generator passes through the power conversion system. The second power converter section is electrically coupled between an electrical power output of the second generator and the coupling point such that the electrical power provided by the second generator to the coupling point passes through the power conversion system.

Systems and method for a hydrokinetic energy device. A hydrokinetic energy device includes a main body including two main wing-shaped spars mounted upon a rotating central hub, and rotatable spar tip turbines mounted at or near an end of each of the main wing-shaped spars, the main wing-shaped spars driving the rotatable spar tip turbines through water, each of the rotatable spar tip turbines including a direct-drive generator and power conversion system that transfers power from a rotating rotatable spar tip turbine to the central hub where the voltage is stepped up and amperage is reduced.

Electrical machines as provided herein can include a shaftless rotor with an annular array of permanent magnets; and a stator with an annular ferromagnetic core and a plurality of electromagnetic inductors about the ferromagnetic core. The stator is located adjacent to and substantially co-axial with the shaftless rotor; and a fluid thrust bearing located in an axially planar gap between the stator and the shaftless rotor.

An active resonance C-type buoyant flap wave energy converter includes a rigid frame, a flap, a mass center adjustment assembly and a power generation assembly. The rigid frame is connected to a marine facility, and includes a main body and a support shaft provided at a bottom thereof. The flap is swingingly arranged on the support shaft. The flap is located under water surface, and swings back and forth around the support shaft under an action of a wave. The mass center adjustment assembly is configured to adjust a mass center of the flap to make a natural period of the flap same as a wave period, so as to achieve a resonance between the flap and the wave. The power generation assembly is arranged on the support shaft and is located in the flap.

A power generator or sensor apparatus is provided. Another aspect employs a hybrid triboelectric and electromagnetic generator. In still another aspect, a power generator is used for water wave energy harvesting. A further aspect provides a power generator including an outer housing with an electrical conductor on an exterior thereof, radial overlapping electrodes located within the housing with a dielectric layer between the electrodes, a plate linearly moveable within the housing, at least one magnet affixed to the plate, and at least one spring biasing the plate within the housing. Moreover, an aspect of the present power generator includes a modularized connection configuration to linearly secure together multiples of the housing.