Large scale wind power machine control method based on maximum energy capture

Abstract

The present invention relates to method for controlling the output power of a wind turbine having maximum energy capture in wind power generation field. When the wind speed varies between a cut-in wind speed and a rating wind speed, a speed change control method is adopted to track the best power curve and to obtain maximum power; when the wind speed varies between the rating wind speed and a cut-out wind speed, a blade change control method is adopted to regulate the change of the blade distance angle for the blade and hold the rating power invariable. The present invention can select different control method based on the wind speed to realize the maximum power output for the wind turbine, thereby can improve the wind energy using efficiency for the generator unit and ensure the stability and reliability of running of the wind turbine.

Description

technical field [0001] The present invention relates to a control method in the technical field of wind power generation, in particular to a large-scale wind turbine control method based on maximum energy capture. Background technique [0002] Wind energy is a kind of renewable energy. In recent years, the development and utilization of wind energy has been widely and highly valued. The main purpose of wind power generation is to utilize wind energy as much as possible, but wind is a vector with randomness, whether it is wind direction or wind speed is always changing, so the energy generated is also changing all the time, which requires the wind power generation The unit is controlled to ensure that the wind turbine always outputs the maximum power, improving the utilization efficiency of wind energy and ensuring the safety and reliability of the wind turbine. [0003] In the prior art, it was proposed to adopt a stall power regulation method, in which the windward angle o...

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Problems solved by technology

This method has the advantages of simple structure and low failure probability. The disadvantage is that the performance of the wind turbine is limited by the stall performance of the blades. When the wind speed exceeds the rated value, the generated power will decrease.

Another disadvantage is that the shape and structure of the blades are complicated, and the weight is large, so that the moment of inertia of the wind rotor is large, which is not suitable for large wind turbines.

It is also proposed to use variable speed and constant frequency power regulation. Although the above shortcomings can be effectively overcome, when the wind speed exceeds the rated wind speed, the control effect is not ideal due to the limitation of the mechanical strength of the rotating parts and the power limitation of the power electronic devices.

[0004] Through literature retrieval to prior art, Perales etc. are in " Proc.of The 25th Annual Conference of the IEEE " (the 25th annual conference proceedings of the Institute of Electrical and Electronics Engineers of America) (1999, volume 2, No. 614-- 618 pages) published "Fuzzy logic control of a variable speed, variable pitch wind turbine" (variable speed variable pitch wind turbine fuzzy logic control), in which a variable speed variable pitch wind turbine fuzzy logic control method is proposed, the specific method It is: based on the principle of capturing the maximum wind energy, by detecting the rotation speed and output power of the generator, and controlling the tip speed ratio of the wind turbine according to the change of the rotation speed and output power, to find the maximum output power value point, but this method is due to the simultaneous detection of the rotation speed and output power The power is controlled, and the amount of control is large, which is difficult to apply in practice

It was also found in the search that Prats et al. published on "Proc.of The 33th Power Electronics Specialists Conference" (Proceedings of the 33rd International Power Electronics Special Annual Conference) (2002, Volume 1, Pages 101--105) "A new fuzzy logic controller to improve the captured wind energy in areal 800kW variable speed-variable pitch wind turbine" (a new type of fuzzy logic controller suitable for improving 800kw variable speed-variable pitch wind turbines to improve the capture of wind energy), the article designed A fuzzy controller, which proposes the idea of ​​using different control strategies for changes in wind speed, but the control input is still the generator speed instead of the generator power during pitch control, and the control effect is not very ideal.

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