37 results about "Variable speed wind generator" patented technology

A variable speed system for use in systems, such as, for example, wind turbines, is described. The system comprises a wound rotor induction generator, a torque controller and a proportional integral derivative (PID) pitch controller. The torque controller controls generator torque using field oriented control, and the PID controller performs pitch regulation based on generator rotor speed.

Provided is a power generator, including a plurality of wind power generators generating electrical power using wind power energy, and variable-speed wind power generators (020a, 20b) connected between the power generator and an electrical power system. The variable-speed wind power generators (20a, 20b) equalize an output of the entire power generating system by outputting power for correcting for a drop in output of the power generator.

A wind farm (10) may include a plurality of variable speed wind turbines (12, 14,16). A centralized controller (50) may be configured to selectively adjust a respective electrical output power from each of the wind turbines at least during an underfrequency condition. The controller may include a monitor (52) configured to monitor a grid frequency value relative to at least a first threshold value. A deviation of the grid frequency value beyond the first threshold value is indicative of the underfrequency condition. The controller further includes a control unit (54) configured to effect a step response to the electrical output power of the wind turbine in a direction selected to counteract the underfrequency condition.

A method of controlling inertia response of variable-speed wind turbine generator includes following steps. A maximum wind power of the wind turbine is gotten through a wind speed ν_w and a rotation speed ω_r at the hub of the wind turbine based on a maximum wind power tracking control strategy. The maximum wind power is set as an active power control reference value P₀ of the wind turbine. A grid frequency f is obtained via a frequency measurement equipment. An additional active power control reference value ΔP of the wind turbine is generated based on the grid frequency f via an additional control block, and the additional active power control reference value ΔP is added on the active power control reference value P₀, wherein a total of active power control reference value of the wind turbine is P₀+ΔP.

The invention discloses a variable-speed wind generating set maximum wind energy capturing method based on effective wind speed estimation. The method comprises an effective wind speed estimating model and a maximum wind energy capturing controller. In order to acquire an effective wind speed estimated value, a training set of an SVR model is formed by normalized unit historical output data and historical wind speed measured values, penalty parameters and kernel function parameters are selected by a GA algorithm to obtain the trained SVR model, and the model gives out the wind speed estimatedvalue in an online manner; and when the maximum wind energy capturing controller is design, the real-time optimal wind wheel rotating speed estimated value is obtained according to effective wind speed which is given out by the effective wind speed estimating model, nonlinear characteristics and parameter uncertainty of the system are responded by robust factors and a neural network, and therefore, boundedness of rotating speed tracking errors and stability of a wind generating set system are realized. By the method, a mathematical model and parameters of the unit do not require to be used, adesign process is simple, an implementing cost is low, and the capacity of the unit and the economic benefit of a wind power plant can be improved.

A variable rotational speed wind turbine includes a doubly-fed induction generator, a rotor current controller for controlling the rotor currents of the generator, a compensation mechanism having a computation mechanism, and an input mechanism for providing input to the compensation mechanism, the input being representative of at least the instantaneous angular speed of the rotor of the generator. The computation mechanism is arranged to compute an instantaneous compensation control output in dependency of the instantaneous angular speed of the rotor of the generator and feed the compensation control output to the rotor, and to compute the compensation control output during operation of the wind turbine to compensate at least partly for dependencies on the rotor angular speed of the locations of poles of a generator transfer function, thus making a resulting generator transfer function substantially independent of variations in the rotor angular speed during operation of the wind turbine.

The invention discloses a pitch change and torque change combined control method of a variable-speed wind turbine generator system. Unmodeled dynamics and disturbance are considered to build a simplified dynamic model of the wind turbine generator system. Power adjustment error dynamic characteristics are calculated. A sliding mode surface and switching functions are selected to design a self-adaption updating mechanism of sliding mode gaining to obtain sliding mode variable structure electromagnetic torque control signals. Wind wheel rotating speed anticipant error dynamic characteristics aredefined. The simplified dynamic model of the wind turbine generator system is rewritten to obtain a pitch angle initial expression. Approach results of a low-pass filter to non-affine uncertain itemsand disturbance items are substituted into the pitch angle initial expression to obtain a pitch angle final expression. The combined control method can preferably deal with non-affine uncertain characteristics of the wind turbine generator system, is simple in structure and excellent in robustness, can provide more stable wind wheel rotating speed and power generation power, reduces mechanical load of the wind turbine generator system, prolongs the service life, and provides high-quality electric energy to a power grid.

The invention discloses a self-adaptive maximum power tracing control method for a wind turbine generator set. The self-adaptive maximum power tracing control method comprises the steps of establishing a variable speed wind turbine generator set model, converting system errors into new errors through an error scaling function to obtain a performance index adjustable self-adaptive maximum power tracing control strategy, designing an electromagnetic torque controller and controlling the wind turbine generator set through the designed electromagnetic torque controller. According to the self-adaptive maximum power tracing control method, the problem of stable control cover a wind turbine generator set system under the conditions of parameter uncertainty and perturbation is solved, the dynamicperformance index of MPPT operation is ensured, the purpose of designing the MPPT speed of the set as required is achieved, and the operation efficiency and overall performance of the variable speed wind turbine generation system are improved.

The invention relates to a wind generating set, in particular to a pitch angle detecting device of a variable-pitch variable-speed wind generating set. An incremental coder is arranged on an output shaft of a variable-pitch motor, the output of the incremental coder is connected with a variable-pitch control system; a maximum pitch angle position correcting switch, a minimum pitch angle position correcting switch, a maximum pitch angle position limit switch and a minimum pitch angle position limit switch are arranged aside a variable-pitch rotating shaft; output signals of all correcting switches and limit switches are connected with the variable-pitch control system so that the installation is simple and the cost of the pitch angle detecting device is reduced by 50 percent; and the minimum pitch angle position limit switch is added so as to improve reliability and authenticity of pitch angle detection of the wind generating set and security of set operation. The invention provides correct pitch angle information of vanes for a control system of the wind generating set, thereby improving efficiency for capturing the wind energy by the set and obtaining optimal electric energy output.

The invention discloses a nonlinear predictive control method for acquiring the maximum wind energy of variable-speed wind turbine generator system. The method includes: introducing a dynamic area toconstrain the allowed range of generator torque; determining the finite control set of candidate generator torque; searching for optimal generator torque sequence; using the first element of the optimal generator torque sequence as the controller output. The method has the advantages that the optimal generator torque sequence is directly searched on the basis of a variable-speed wind turbine generator system nonlinear prediction model, so that the provided controller can sufficiently utilize a large prediction range; the method has high efficiency and excellent performance in maximum wind energy acquiring.

The invention relates to a clean production method for preparing hydrogen energy by using natural wind, and a device used in the method, which belong to the field of regenerative energy utilization. The method is characterized by comprising the following steps: adopting a direct current constant frequency variable speed aerogenerator to generate electricity; transmitting the electricity generated by the direct current constant frequency variable speed aerogenerator into a rated distribution system, performing electrolysis of water after rated electricity distribution, and introducing hydrogen and oxygen prepared by the electrolysis of the water into a storage tank to be stored; and processing wastewater in a storage pool. In the device, the input end of the rated distribution system is connected with the output end of the direct current constant frequency variable speed aerogenerator, and the output end of the rated distribution system is connected with an electrode terminal in an electrolysis small room. The method and the device use wind energy to produce hydrogen and consume no energy resource, the electric power generated by the aerogenerator needs not to be stored and converted and is used for direct electrolysis after generation, and the capability of a production device changes along with the voltage of the electricity generated by wind power, thus about one third of electric energy loss is reduced to process wastewater so as to reduce the environmental pollution.

The invention provides a small fixed-pitch permanent magnet synchronous wind turbine generator system controller. The wind turbine generator system controller comprises a main controller, a signal acquisition module and a PWM driving module, wherein a main controller built-in algorithm is used for carrying out wind turbine generator system control according to signals; the control strategy is characterized in that when a wind turbine generator system is in a low wind speed area, a maximum power tracking MPPT control is carried out, the wind energy utilization coefficient is maximum so as to obtain the maximum wind energy, when the wind turbine generator system is in a high wind speed area, the wind turbine generator system is maintained to run below the rated rotating speed, the wind energy utilization coefficient is changed, the constant-power control of the wind turbine generator system is realized, and the rated power operation of the wind turbine generator system is guaranteed; andon the basis of the above control strategy, the main controller controls the wind turbine generator system to run at a variable speed according to the wind speed signal through the PWM driving module. According to the wind turbine generator system controller, the small wind turbine generator system controller can stably run at the full wind speed, so that the small wind turbine generator system controller can be smoothly transited at all operation stages, the reliability and the safety of the fixed-pitch variable-speed wind turbine generator system controller are improved, and the instant overload phenomenon in the high-wind-speed region can be effectively inhibited.

The invention discloses a control method and system for increasing the generating capacity of a high-capacity variable-speed wind generating set. The method comprises the steps that (1) wind speed information of a sensor is read; 2) calculating a minimum rotating speed limit value; 3) carrying out amplitude limiting processing on the minimum rotating speed limit value omega Min obtained by calculation; and 4) modifying an actual minimum rotating speed limiting parameter. According to the invention, the generating capacity can be improved without additionally arranging hardware or sensor equipment, and higher benefits can be obtained on the premise of not additionally arranging cost.

The invention discloses a method for controlling the power of a variable-speed wind generating set based on slip frequency, which comprises the following steps of: creating a slip frequency control curve by a main controller of the wind generating set, and controlling the power of the wind generating set by the slip frequency controller based on the slip frequency control curve, the two-dimensional coordinate corresponding relation of the rotating speed and the power of the wind generating set is determined through the slip frequency control curve; according to the method, the control effect of the wind generating set on rotating speed stable adjustment and power stable output can be improved, meanwhile, the slip frequency control curve is automatically and dynamically adjusted through slip frequency limited power control, and the limited power control requirement of the wind generating set is met.

The invention discloses a rotating speed power control method of a wind generating set and a variable speed wind generating set, a nonlinear gain control module used for calculating an output gain value is added in a speed control mode, and the rotating speed characteristic of a fan is adjusted based on the gain value. The variable-pitch rotating speed controller outputs a variable-pitch angle rotating speed control value according to the rotating speed characteristic of the fan; and/or, a first nonlinear gain control module and a second nonlinear gain control module which are used for calculating and outputting a first gain value and a second gain value respectively are added in the power control mode, and the fan power characteristics are controlled and adjusted based on the first gain value and the second gain value. The variable pitch power controller calculates and outputs a variable pitch angle power control value according to the fan power characteristics; according to the invention, the rotating speed of the wind generating set is stably adjusted, the wind generating set realizes stable starting and grid-connected operation, and the power output control of the wind generating set is more stable and reliable.