Global wind power manufacturing technology presents twelve characteristics (3)

9. Development trend of blade technology As the size of the wind turbine increases, the length of the blade also becomes longer. In order to make the tip of the blade not collide with the tower, the main idea of ​​the design is to increase the stiffness of the blade. In order to reduce gravity and maintain frequency, the weight of the blade needs to be reduced. Good fatigue characteristics and good damping structure help to ensure long-term working life of the blade.

Additional blade condition detection equipment will be developed and installed on the wind turbine to warn the operator before the cracks in the blade structure develop into fatal damage or before the entire wind turbine unit is damaged. For onshore wind turbines, this type of testing equipment will soon become a must.

In order to increase the stiffness of the blade and prevent it from hitting the tower due to bending, reinforced carbon fiber material will be widely used on blades longer than 50 meters.

In order to facilitate the road transport of megawatt blades, some companies have made the blades into two sections. For example, the blades of the E126 6MW wind turbine unit of the Enercon Company in Germany are composed of two segments of the inner and outer blades. The inner segment near the root of the blade is made of steel. The outer shell of the FRP shell forms an aerodynamically shaped surface.

Intellectual materials, such as piezoelectric materials, will be used to enable rapid changes in the aerodynamic shape of the blade.

In order to reduce the fatigue load on the blade and the complete machine, the controllable trailing edge leaflets may be gradually introduced into the blade market.

Thermoplastic applications: LM Glasfibre is carrying out a research project worth 8 million Euros to manufacture blades from a blend of glass-fibre, carbon and thermoplastic materials. Once this yarn is laid into the mold and the mold is heated to a certain temperature, the plastic melts and turns the yarn into a synthetic material, which may reduce blade production time by 50%.

10. The technical level of wind farm construction and operation is increasing day by day With the increasing requirements of investors for the evaluation of the early stage of wind farm construction and the quality of the operation after completion, many foreign countries have developed many tests and assessments for wind resources. Advanced test equipment and evaluation software. Commercial application software has been developed in the site selection of wind farms, especially site selection. Mature software has also been developed in the layout of wind turbines and the design of power transmission and distribution systems. Foreign countries have also done a lot of research on short-term and long-term power generation forecast of wind turbines and wind farms, and made significant progress, with an accuracy of over 90%.

11. The reliability of wind turbines under severe climate conditions has received attention.

Since China’s northern region has sandstorms, low temperatures, ice, thunderstorms, typhoons and salt fog on the southeast coast, and severe climate features such as high altitudes in the southwest, adverse weather conditions have caused a great impact on wind turbines, including increased maintenance workload. Reducing the amount of power generated will also result in damage to wind turbines in severe cases. Therefore, when designing and operating a wind turbine, certain precautions must be taken to improve the wind turbine's ability to withstand adverse weather conditions and reduce losses. Therefore, this year, China's wind turbine research and development unit has carried out research in areas such as sand prevention, low-temperature resistance, lightning protection, typhoon resistance, and salt spray prevention to ensure reliable operation of wind turbines under adverse weather conditions and increase power generation. .

12. Application of low-voltage ride-through technology With the continuous increase of single-machine capacity of wind turbines and the continuous expansion of wind farms, the mutual influence between wind turbines and power grids has become increasingly serious. Once the grid fails to force large-scale wind turbines off the net due to their own protection, it will seriously affect the operational stability of the power system. Therefore, as the capacity of wind turbines connected to the power grid increases, the power grid requires more and more power. Generally, the generator set is required to be fault-through without a voltage drop in the power grid fault. , And can help the power system to return to stable operation as soon as possible after the fault is removed, that is to say, the wind turbine has a certain low voltage ride-through capability. As the installed capacity of wind power continues to increase, the guidelines for power system operation in many countries have stipulated the low voltage ride through (LVRT) capability of wind turbines. China's wind turbines must also take corresponding measures to ensure the safe operation of the wind power system and realize the LVRT function under the condition of grid voltage drop. At present, wind turbine products from many companies in China have passed low-voltage ride-through performance tests.