A system and a method for starting a rotor of an implantable blood pump are described. For example, a blood pump system includes a rotary motor having a stator and a rotor. The rotor has permanent magnetic poles for magnetic levitation of the rotor, and the stator has a plurality of pole pieces arranged circumferentially at intervals. The blood pump system includes a controller configured to control a start phase of the rotor, wherein the start phase is prior to the rotor being positioned in a predefined geometric volume for pumping blood and wherein the start phase includes performing a rotation of the rotor by an angle larger than an angle corresponding to a quarter of an angular distance between two neighboring magnetic poles of the rotor.

A state determination device for a liquid pumping apparatus includes: a casing that forms a reservoir space; a feed valve that introduces working gas into the reservoir space; an exhaust valve that releases the working gas from the reservoir space; and a valve operating mechanism having a float arranged in the reservoir space, and performing a pumping stroke in which the liquid is pumped from the reservoir space under a pressure of the working gas and an inflow stroke in which the liquid flows into the reservoir space and the working gas is released. The state determination device further includes a pressure sensor that detects a pressure of the reservoir space, and a determination unit that determines whether the liquid pumping apparatus is in an operating state of performing the pumping stroke or the inflow stroke based on the pressure detected by the pressure sensor.

An arrangement for determining an operation parameter reference for controlling a generator side converter portion coupled to a generator is provided, including: at least one arithmetic element configured to derive at least one harmonic current error by subtracting a generator output current from at least one harmonic current reference; at least one harmonic current controller configured to determine at least one harmonic reference current deviation based on the harmonic current error; another arithmetic element configured to derive a fundamental current error by subtracting the generator output current from a sum of a fundamental current reference and the at least one harmonic current reference; still another arithmetic element configured to determine a modified fundamental current error as a sum of the fundamental current error and the harmonic reference current deviation; a fundamental current controller adapted to determine the operation parameter reference based on the modified fundamental current error.

A green wind turbine system that provides continuous rotation of a propeller, to prevent stopping or critical slowing of the propeller to, which causes damage to the bearing and gear assembly, and shortens of the turbine life. The propeller includes at least two opposing hollow blades, each having a pair of reservoirs positioned with one at the tip and stem, and connected by a fluid line; a wireless hydraulic pump with a rechargeable battery, and a wireless control unit configured between the reservoirs to pump fluid that is heated and/or with anti-freeze between the reservoirs; and a nacelle with: a motion sensor, anemometer, heated reserve tank. The propeller is made with biodegradable materials; and the turbine is able to manipulate the reservoir fluids to create an imbalance within the propeller to prevent it from stopping in low or no wind conditions; and to slow down in high wind conditions.

A green wind turbine system that provides continuous rotation of a propeller, to prevent stopping or critical slowing of the propeller to, which causes damage to the bearing and gear assembly, and shortens of the turbine life. The propeller includes at least two opposing hollow blades, each having a pair of reservoirs positioned with one at the tip and stem, and connected by a fluid line; a wireless hydraulic pump with a rechargeable battery, and a wireless control unit configured between the reservoirs to pump fluid that is heated and/or with anti-freeze between the reservoirs; and a nacelle with: a motion sensor, anemometer, heated reserve tank. The propeller is made with biodegradable materials; and the turbine is able to manipulate the reservoir fluids to create an imbalance within the propeller to prevent it from stopping in low or no wind conditions; and 2) to slow down in high wind conditions.

A method for damping an oscillation of a tower of a wind turbine is disclosed, wherein a pitch angle of each of the one or more rotor blades is individually adjustable, the method comprising damping the oscillation of the tower by pitching each rotor blade individually according to tower damping pitch control signals, wherein each tower damping pitch control signal comprises a first periodic component, where a first frequency of the first periodic component corresponds to a frequency difference between a tower frequency of the oscillation of the tower and a rotor frequency of a rotation of the rotor, and where a second periodic component has been reduced or removed. A second frequency of the second periodic component corresponds to a frequency sum of the tower frequency and the rotor frequency.

Provided is a method for damping a side-side oscillation of a tower of a wind turbine having a generator connected to a converter, the method including: measuring an acceleration value of the tower; determining, based on the acceleration value, at least one frequency value of at least one tower oscillation mode, including a second tower oscillation mode; controlling the converter of the wind turbine based at least on the acceleration value and the frequency value.

An embodiment provides controllers modules that allow for an energy generation module, such as a wind turbine, to be restarted locally and remotely. To restart the energy generation module remotely, care is taken to ensure the module is not in lock down mode. Further, the adding the ability to remotely restart the module does not alter the code or logic used to locally restart the module. Other embodiments are described herein.

Provided is a control arrangement for controlling an electrical machine, including: a fundamental current controller, at least one harmonic flux controller related to a harmonic of an electrical frequency of the electrical machine, a summation system for adding voltage commands to obtain a summed voltage command based on which the electrical machine.

An arrangement for determining an operation parameter reference for controlling a generator side converter portion coupled to a generator is provided, including: at least one arithmetic element configured to derive at least one harmonic current error by subtracting a generator output current from at least one harmonic current reference; at least one harmonic current controller configured to determine at least one harmonic reference current deviation based on the harmonic current error; another arithmetic element configured to derive a fundamental current error by subtracting the generator output current from a sum of a fundamental current reference and the at least one harmonic current reference; still another arithmetic element configured to determine a modified fundamental current error as a sum of the fundamental current error and the harmonic reference current deviation; a fundamental current controller adapted to determine the operation parameter reference based on the modified fundamental current error.