Maximum wind energy capturing method for double-feed type wind generating set

Abstract

The invention discloses a maximum wind energy capturing method for a double-feed type wind generating set in the field of wind power generation. A BP neural network model with the air speed value, the air direction value and the wind wheel rotating speed value as the input quantity and the electromagnetic torque value as the output quantity is constructed, the expected theoretical optimal air wheel rotating speed value is calculated according to a tip speed ratio point formula, the expected theoretical optimal air wheel rotating speed value is substituted into the BP neural network model to determine the initial control quantity of the electromagnetic torque value initial control quantity, a step-length-changing climbing search method is adopted, the changed step length of the electromagnetic torque value is reduced along with rising of the control period number, the electromagnetic torque value is changed in a small range so that the maximum power value point can be found, the real-time generator rotating speed value is measured in real time before each time of search, when the changed value of the generator rotating speed value exceeds the limiting value compared with the initial generator rotating speed value generated when the whole search is started, the search is started again, and when the absolute value of the difference value of the generator rotating speed values or the power generating power values in two adjacent control periods is smaller than the limiting value, the search is over. The maximum wind energy capturing method has the advantages that overlong periods or oscillation is avoided in the climbing search, and the maximum power capturing is ensured.

Description

technical field [0001] The invention relates to a method for capturing maximum wind energy of a doubly-fed wind power generating set in the field of wind power generation. Background technique [0002] In order to achieve the maximum wind energy capture below the rated wind speed, the wind turbine usually needs to control the speed of the wind rotor to match the real-time wind speed, so that the wind turbine runs at the best tip speed ratio point. For double-fed wind turbines, the speed value of the wind rotor is determined by the dynamic torque value generated by wind energy and the electromagnetic torque value generated by the double-fed motor, so the electromagnetic torque generated by the double-fed motor can be actively changed through the inverter. The magnitude of the torque value is used to adjust the rotational speed value of the wind rotor to achieve a predetermined rotational speed value of the wind rotor. However, the rapid fluctuation of the wind speed value an...

AI Technical Summary

Problems solved by technology

The conventional hill-climbing search method has some disadvantages, such as a long control period, and there may be oscillations near the maximum power value point, especially when the wind speed value changes rapidly, the hill-climbing search method may fail, resulting in a decrease in wind energy capture efficiency

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