115results about "Variable speed operation control" patented technology

A variable speed wind turbine employing a rotor connected to a multiplicity of synchronous generators with wound field or permanent magnet rotors. A passive rectifier and an inverter are used for power transfer back to the grid. A Turbine Control Unit (TCU) commands a required generator torque based on rotor speed and power output of the turbine inverters. Torque is controlled by regulating the DC current by control of the inverter. A main-shaft-damping filter is provided by measurement of the DC bus voltage. In high winds the turbine remains at a constant average output power through a constant torque command and a varying pitch command to a rotor pitch servo system. A set point is fixed at the inverter output such that output VAR load is minimized running the turbine at very nearly unity power factor. Dynamic VAR and power factor control is provided by a separate VAR apparatus.

A turbine control system for a variable speed electrical generator in a wind turbine mounted atop a support tower. The wind turbine converts wind energy into a driving torque applied to the generator. The control system includes a turbine support tower position sensor and may also include other tower acceleration and velocity sensors. A wind flow estimator uses the measured motion, generator rotation rate and blade pitch angle to predict wind flow over the swept area of the turbine's rotor, and the tower motion. The predicted wind flow and motion is used in the turbine control system to properly adjust its operating point, to tune the controller, to control the rotor rotation rate, and to damp tower oscillations.

A variable speed wind turbine is disclosed comprising a turbine rotor that drives a doubly-fed induction generator, a matrix converter which converts variable frequency output into constant frequency output, and a control unit and a protection circuit for the matrix converter. Power is circulated in the system allowing for sensorless detection of rotor position and better output ratios of power from the system.

A variable speed wind turbine having a doubly fed induction generator (DFIG), includes an exciter machine mechanically coupled to the DFIG and a power converter placed between a rotor of the DFIG and the exciter machine. Thus, the power converter is not directly connected to the grid avoiding the introduction of undesired harmonic distortion and achieving a better power quality fed into the utility grid. Moreover, the variable speed wind turbine includes a power control and a pitch regulation.

A vibration damping technique for a wind turbine system is described. The wind turbine system includes a vibration damper, which provides a variable signal to control torque produced by a generator of the wind turbine system. The variable signal is based on generator speed and has a first local peak value based on a resonant frequency of tower side-to-side oscillation.

A control system for a wind power plant that includes a damage module and a control module. The damage module compares existing stress conditions on one or more component parts of the wind power plant to current energy generating costs. The control module alters electric power generated by the wind power plant based upon the comparison.

A wind turbine generator system can regulate the rotational velocity of the wind turbine within an operation range even when the wind velocity suddenly changes and can perform continuous operation of the wind turbine. The wind turbine generator system includes a generator connected to the shaft of the wind turbine and a converter connected to the generator. When the rotational velocity of the wind turbine is within a predetermined range, power outputted from the generator is controlled so as to follow the instruction concerning the generator output given from the wind turbine to the converter. When the rotational velocity of the wind turbine is out of the predetermined range, the power outputted from the generator is controlled without following the instruction concerning generator output given from the wind turbine to the converter.

A variable speed wind turbine having a passive grid side rectifier using scalar power control and dependent pitch control is disclosed. The variable speed turbine may include an electrical generator to provide power for a power grid and a power conversion system coupled to the electrical generator. The power conversion system may include at least one passive grid side rectifier. The power conversion system may provide power to the electrical generator using the passive grid side rectifier. The variable speed wind turbine may also use scalar power control to provide more precise control of electrical quantities on the power grid. The variable speed wind turbine may further use dependent pitch control to improve responsiveness of the wind turbine.

Reduction in power output or rotor speed of a wind turbine above a defined limit value, the reduction not being implemented based on the measured wind speed, but on an input value which on one hand is easily detected physically and by control technology and on the other hand is a good indicator of mechanical stresses on the wind turbine. The invention uses the rotor-blade angle as the input value in a manner that starting at the limit value, the reduction in power output or in rotor speed is adjusted as a function of the rotor-blade angle.

A variable speed wind turbine having a passive grid side rectifier using scalar power control and dependent pitch control is disclosed. The variable speed turbine may include an electrical generator to provide power for a power grid and a power conversion system coupled to the electrical generator. The power conversion system may include at least one passive grid side rectifier. The power conversion system may provide power to the electrical generator using the passive grid side rectifier. The variable speed wind turbine may also use scaler power control to provide more precise control of electrical quantities on the power grid. The variable speed wind turbine may further use dependent pitch control to improve responsiveness of the wind turbine.

A wind turbine has multiple blades (10) that are mounted on a shaft (19) with a ring around a circumference of the blades. There are tires (18) that are arranged to be in contact or out of contact with the ring. The tires draw generators when the tires are in contact with the ring and the ring is rotating. A controller monitors the wind conditions and controls the turbine to produce electricity or other-energy output or to shut down if the wind falls below a predetermined level.

A variable speed wind turbine having a doubly fed induction generator (DFIG), includes an exciter machine mechanically coupled to the DFIG and a power converter placed between a rotor of the DFIG and the exciter machine. Thus, the power converter is not directly connected to the grid avoiding the introduction of undesired harmonic distortion and achieving a better power quality fed into the utility grid. Moreover, the variable speed wind turbine includes a power control and a pitch regulation.

A variable speed power generator system, includes a primary power induction generator (12), a secondary control induction (14), each of the induction generators having a rotor (22, 24) mounted so as to be rotated by a common shaft (16) of a variable speed prime mover (20), an inverter (50) connected to the stator (15) of the secondary control induction generator, a controller (30) connected to the inverter controls the output of the inverter, output of the primary induction generator is connected to the grid (51), controller provides output signal to the inverter based on selected inputs to the controller so that the output of the primary induction generator matches the active and reactive power requirements of the grid. An induction machine which includes a rotor having laminations and insulated cage bars, the bars being electrically isolated from on another as well as electrically insulated from the laminations.

A variable speed wind turbine is provided. The wind turbine comprises a generator, a power converter for converting at least a portion of electrical power generated by the generator, an energy management arrangement coupled to the power converter, the energy management arrangement comprises an energy storage unit, and a controller. The controller is adapted to detect a power imbalance event and to transfer at least a portion of excess electrical energy generated by the generator to the energy storage unit to be stored therein when the power imbalance event is detected.

Control features for a wind turbine that control the turbine over a range of wind speeds and under triggering conditions with reduced noise, cost, and reliability issues associated with other such controls. Control is accomplished via control electronics, which adjust the torque produced by the electrical output generation device (e.g., alternator) within the wind turbine. During normal operation, torque is adjusted for optimum aerodynamic performance and maximum output of power. In winds above rated power, the control circuit regulates torque to lower aerodynamic performance, as necessary to maintain desired power level output. In triggering conditions, such as during simultaneous control circuit failure and loss of some portion of the electrical output generation device in extreme winds, wind turbine control is accomplished by increasing torque (e.g., via a separate controller) from the electrical output generation device via shorting of windings, so as to cause retardation of blade rotation.

Reduction in power output or rotor speed of a wind turbine above a defined limit value, the reduction not being implemented based on the measured wind speed, but on an input value which on one hand is easily detected physically and by control technology and on the other hand is a good indicator of mechanical stresses on the wind turbine. The invention uses the rotor-blade angle as the input value in a manner that starting at the limit value, the reduction in power output or in rotor speed is adjusted as a function of the rotor-blade angle.

A wind turbine comprising a wind turbine blade with high lift and / or low solidity is provided. The blade is directed towards pitch regulated wind turbines, which are operated at variable rotor speed and have blades longer than about 30 meters. The blade is for example advantageous in that it may provide reduced extreme and fatigue loads at the same or near the same power production.

The invention relates to a wind energy system having a rotor that can be driven by the wind, preferably having one or more rotor blades that can be adjusted in angle, a generator directly or indirectly connected with the rotor, to generate electric energy, which is configured as an asynchronous generator having a super-synchronous converter cascade in the rotor circuit, for slip-variable generator operation, so that power output of the generator is possible at variable speeds of rotation of the rotor, and an operation guide system that is configured to regulate the speed of rotation of the rotor, within a predetermined wind speed range. To improve the energy yield, it is provided that the super-synchronous rectifier cascade is configured in the rotor circuit for feeding the slip power into the network. For this purpose, the super-synchronous converter cascade has a DC voltage intermediate circuit having a high-set element. These are configured to switch, as IGBT switches, with a 180 degree phase shift relative to the rotor voltage.Furthermore, the invention relates to a method for regulating the power output of the wind energy system, in that the slip is regulated, whereby the slip power is fed into the network.

A method of controlling the operation of a variable speed wind turbine (11), tracking a power curve (25, 27) including a nominal operational region (3) and sub-nominal operational regions (2, 1, 0), comprising steps of: a) implementing a control strategy to follow said power curve in said nominal operational region (3) based on the use of demanded torque Td for controlling power P and on the use of demanded pitch θd for controlling demanded torque Td; b) implementing a control strategy to follow said power curve in sub-nominal operational regions (2, 1, 0) based on the use of demanded torque Td for controlling power P and on the setting of a constant optimum value for demanded pitch θd in each sub-nominal operational region (2, 1, 0). The invention also refers to a control system comprising one or more Adaptive Predictive Controllers (51, 53, 55, 59).

The power of wind energy or the revolution rate drive down to the prescribed limit value has been carried based on easily measured in physical and control technique aspect and reflect the input variable of machine utilization but not based on the metrical wind speed. For the assume of this invention, use rotor blade angle as input variable, then when arrive in the limit value adjust power and the drive down of revolution rate based on the rotor blade angle.