A method for connecting a power transformer, located between an inverter of a wind turbine and an electrical grid, to the electrical grid; the method comprises the steps gradually increasing a voltage at a primary side of the transformer from a low starting voltage to a target voltage equal or close to a nominal voltage of the transformer, by means of the inverter of the wind turbine or by means of an auxiliary inverter, thereby increasing the voltage at a secondary side of the transformer, wherein the gradually increasing of the voltage uses energy of an internal energy storage device, connecting the secondary side of the transformer to the electrical grid after predefined target conditions have been reached.

Provided is a method of feeding electric reactive power using a wind farm comprising wind turbines. The wind farm feeds a wind farm active power output and the wind farm active power output includes individual plant active power outputs each generated by one of the wind turbines. The wind farm feeds a wind farm reactive power output into the electrical supply network and the wind farm reactive power output includes individual plant reactive power outputs each generated by one of the wind turbines. The method includes determining a total wind farm reactive power output to be fed in by the wind farm and calculating, for each wind turbine, an individual plant reactive power output to be generated. The individual plant reactive power output is determined depending on the individual plant active power output and depending on the wind farm reactive power output to be fed in.

An exhaust system for generating electricity is disclosed. The exhaust system for generating electricity uses a specially configured housing, a plurality of static velocity increasing devices, a turbine, and a fan to generate electricity and concurrently exhaust air from a building. In particular, the specially configured housing preferably is designed to be significantly more aerodynamic and reduces any turbulence inside the housing.

An electric driven hydraulic fracking system is disclosed. A pump configuration includes the single VFD, the single shaft electric motor, and the single hydraulic pump mounted on the single pump trailer. A controller associated with the single VFD and is mounted on the single pump trailer. The controller monitors operation parameters associated with an operation of the electric driven hydraulic fracking system as each component of the electric driven hydraulic fracking system operates to determine whether the operation parameters deviate beyond a corresponding operation parameter threshold. Each of the operation parameters provides an indicator as to an operation status of a corresponding component of the electric driven hydraulic fracking system. The controller initiates corrected actions when each operation parameter deviates beyond the corresponding operation threshold. Initiating the corrected actions when each operation parameter deviates beyond the corresponding operation threshold maintains the operation of the electric driven hydraulic fracking system.

An aero wind power generation apparatus includes: a drone unit including drone wings configured to make the aero wind power generation apparatus move and hover and a sensor unit configured to detect information for controlling the aero wind power generation apparatus; a buoyancy generation unit connected to the drone unit and including a side cover configured to open or close and a balloon provided inside the side cover, wherein the buoyancy generation unit is configured to enable injection of gas into or release of the gas from the balloon; and a power generation unit connected to the buoyancy generation unit and including a rotating unit with a plurality of blades, a blade control unit of adjusting the state of the blades, and a motor unit of converting kinetic energy transferred from the rotating unit into electrical energy.

A renewable energy generator includes a housing having the shape of a roly-poly-like capsule that floats in a sea; a main generation unit including an internal housing, a pendulum provided to be movable within the internal housing, a pendulum rotation shaft connected to the pendulum and rotatably connected to the internal housing, a main motor configured to convert the pendulum’s kinetic energy into electrical energy, and a gear set coupling the main motor and the pendulum rotation shaft and configured to transfer the kinetic energy of the pendulum to the main motor; frames fixed to the inside of the housing at predetermined intervals; a main rotation shaft rotatably connecting the main generation unit to at least one of the frames for the main generation unit to rotate with respect to the at least one of the one or more frames; and a controller configured to control the main generation unit.

A hydraulic power generation device includes a water turbine disposed in a waterway, a drive shaft that extends to one side from the water turbine a first generator, a second generator, and a conveying mechanism configured to convey rotation of the drive shaft to an input shaft of the first generator and an input shaft of the second generator. The water turbine is configured to rotate along with the water turbine.

An offshore wind turbine erected in a body of water including a generator, a base, a nacelle, a tower having a first end mounted to the base and a second end supporting the nacelle, an electrolytic unit electrically powered by the generator to produce hydrogen from an input fluid, in particular water, and a fluid supply assembly for supplying the input fluid from a fluid inlet arranged below a water level to the electrolytic unit arranged above the water level, wherein the fluid supply assembly includes a pump and a fluid connection between the fluid inlet and the electrolytic unit.

A method for in-place machining of a collector ring attached to a turbine shaft of a hydroelectric generator includes: attaching a support member to stationary portions of the hydroelectric generator, the support member being configured to support a machine tool at an angle parallel to an inclination angle of an axis of rotation of the turbine shaft; attaching an adjustable positioning device to the support member; attaching the machine tool to the adjustable positioning device, the machine tool being configured to perform a machining operation on the collector ring; controlling a rotational speed of the turbine shaft to a specified rotational speed by controlling a flow of water through the turbine; adjusting the adjustable positioning device to adjust a position of the machine tool with respect to the collector ring; and performing the machining operation on the collector ring at the specified rotational speed of the turbine shaft.

The present disclosure relates to electrical machines (100, 200) configured to be fed by pulse width modulation from a power converter (170) and comprising a stator (110), a rotor (120), a rotor shaft (130) and one or more bearings (140, 141) arranged between the rotor (120) and the stator (110). The electrical machine (100, 200) further comprising an electrical shunt (160, 161) arranged between the rotor shaft (130) and the stator (110). The present disclosure also relates to methods (500) to mitigate electrical discharge machining bearing currents in electrical machines (100, 200).