Direction of wind power generation (weekly topic)

Wind power generation technology is the technology that converts wind energy into electrical energy. It is achieved through wind turbines: wind power drives the blades of the turbine to rotate, and an increase gear is used to boost the rotation speed, thereby enabling the generator to produce electricity. So, what is the status of wind power generation technology and its future development trends? Basic characteristics of wind power generation: 1. High randomness of wind energy Wind energy is a form of solar energy; wind speeds vary significantly depending on factors such as atmospheric temperature and pressure. These variations make wind energy random and uncontrollable. As a result, the wind energy acting on the blades of wind turbines is also random and uncontrollable, which in turn leads to some level of uncontrollability in the mechanical power input to the generators. 　　2. Low wind energy density 　　Due to the low density of air, a large diameter is required for the wind turbine in order to generate significant power, which results in bulky wind turbine systems. 　　3. High rotational inertia of wind turbines 　　Due to the large diameter of the wind turbine blades, the massive rotor blades result in a high rotational inertia for the wind turbine. 　　4. Flexible connection between the wind turbine and the generator The rotation speed of the wind turbine rotor is generally not very high, and it differs significantly from the rotation speed of the generator; therefore, a direct connection between them is not possible. A gearbox with an appropriate speed reduction ratio must be used for transmission, which reduces the rigidity between the generator and the wind turbine. In other words, there is a flexible connection between the generator and the wind turbine. 　　5. Selection of wind turbines 　At present, domestic wind power generation systems use asynchronous generators that are connected directly to the grid. Changes in wind speed lead to variations in the active and reactive power supplied by the wind turbines to the grid, which in turn causes fluctuations in the voltage of the nearby grid buses. To overcome this issue, and thanks to the development of power electronics technology, wind power systems can employ AC-excited generators, thereby enabling these systems to exhibit better dynamic and static performance. 　　The mainstream technologies in wind power generation today Modern wind power generation systems consist of wind turbines, control devices, and monitoring and display units. A wind turbine comprises a wind rotor and a generator, which are used to convert energy. Wind turbines can operate in standalone mode, grid-connected mode, or combined mode. In terms of the methods used to control the output power of wind turbines, current wind generators primarily employ two approaches: pitch-fixed stall control and variable pitch control. The main wind power generation technologies currently in use both domestically and internationally are as follows: 1. Fixed-pitch stall-regulated wind turbine technology. Its basic principle relies on the stall characteristics of the blade airfoil itself – when the wind speed exceeds the rated value, the angle of attack of the airflow increases to the stall condition, resulting in vortices forming on the blade surface and thus reducing efficiency, thereby limiting the output power. Its advantages include reliable regulation and simple control, while the disadvantages are high stress on key components such as the blades, and a power output that varies with wind speed. This technology is mainly used in small to medium-sized wind turbines with capacities of a few hundred kilowatts. 　　2. Pitch-controlled wind turbine technology Pitch-controlled wind turbines adjust the installation angle of the turbine blades in response to changes in wind speed, by using a pitch controller, thereby controlling the amount of wind energy absorbed. Below the rated wind speed, they function like fixed-pitch wind turbines; once the wind speed exceeds the rated value, the pitch control mechanism comes into action to adjust the blade angle, ensuring that the generator’s output power remains within acceptable limits. Pitch-controlled wind turbines have a lower starting wind speed compared to fixed-pitch turbines, and the impact forces on the transmission mechanisms during shutdown are relatively less severe. 　　3. Active pitch control fan technology This technology is a combination of the previous two; its main feature is that the pitch of the blades changes accordingly, enabling the fan to operate at optimal parameters under various conditions. It achieves high power generation efficiency at the rated wind speed, and does not become overloaded when operating above this speed, thus eliminating the need for generators with high overload capacity. However, its drawback is the requirement for a relatively complex pitch control mechanism. The active pitch control fan technology incorporates some of the advantages of the previous two technologies, but compared to them, variable-speed constant-frequency wind turbine technology represents the best method of regulation. 　　The development trend of modern wind power generation technology is toward higher technology, greater complexity, and higher standards, in order to maximize the utilization of wind resources and advance wind power generation. This includes the following aspects: 1) The location of wind farms is shifting from areas with strong winds to those with weaker winds, in order to expand the available wind sources. 　　2) The location of wind farms is shifting from the mainland to coastal areas and islands. 　　3) The location of wind farms is shifting from flat areas to complex terrain. 　　4) Large-scale fan systems and small-scale fan systems will develop side by side, with their complementarity further strengthening. 　　5) It develops simultaneously in the directions of large-scale grid-connected operation and decentralized off-grid operation. 　　6) Eliminating the speed increase mechanism; brushlessization of doubly-fed motors is the main direction for future development. 　　The main development trends in current wind power generation systems include lighter weight, more flexible structures, direct drive, and variable frequency control. As for the capacity of individual turbines, requirements vary depending on the application, but there is a general pursuit of simpler structures, improved adaptability and stability, reduced costs and maintenance efforts, and higher efficiency.

Reply to 1#: Standing in the East, first and foremost, we must acknowledge the great significance of wind power as a clean energy generation technology, which has seen rapid development in recent years. As everyone should be aware, the huge order signed by Dongfang Electric with India shows that China’s wind power technology is continuously improving, and several of the country’s leading enterprises are also entering the wind power industry. Moreover, the development of direct-drive technology is also becoming increasingly sophisticated. However, the wind power industry is still in its infancy, and the time required to achieve returns will undoubtedly be extremely long. Wind turbines have a small capacity, they require specific natural conditions, and the imperfections in certain technologies will also pose challenges to this industry. From a **policy perspective, this technology holds great potential for development. However, compared to coal or nuclear power, the time required to see returns on investment is much longer, and the immaturity of the associated technologies will inevitably pose various unknown challenges to its further development. Moreover, regarding the requirements for materials and such, I personally believe that China’s current technology is not yet capable of producing wind power generation equipment of larger size; therefore, the scale can only be increased by increasing the number of such devices. It’s all just empty talk, but currently wind power enjoys better conditions than other industries. Since several power companies have substantial operations in foreign markets, there are opportunities for projects based abroad, which can result in higher earnings; however, one has to stay in places like India and Bangladesh. .

Following the nuclear disaster caused by the accident in Japan, safety has become the top priority in the development of energy projects, and more and more countries are investing more funds in clean energy sources such as solar and wind power. The world’s largest offshore wind farm, located in the Irish Sea near Barrow and Furness, has recently come online. The project will provide sufficient electricity for 320,000 residents; the 102 wind turbines, each 118 meters tall, will generate a total of 367 million watts of power, which is connected to the inland areas via nearly 20,000 meters of optical cables buried underground. There are three operating modes for wind power generation: the first is standalone operation, in which a small wind turbine supplies electricity to one or several households; it uses batteries to store energy in order to ensure power supply during periods of no wind ； Secondly, wind power is combined with other power generation methods (such as diesel generator power) to supply electricity to a unit, a village, or an island ； Thirdly, wind power is integrated into the conventional power grid to supply electricity to it; often, a wind farm consists of dozens or even hundreds of wind turbines, and this represents the main direction of development for wind power generation. The two main components in a wind power generation system are the wind turbine and the generator. Wind turbines are moving toward pitch control technology, while generators are advancing toward variable-speed constant-frequency power generation technology – these represent the trends in the development of wind power generation technology and are also the core technologies in modern wind power generation.

This post was last edited by Standing in the East on 2012-3-30 08:27. Currently, we are also considering the issue of wind power capacity; too large a wind power capacity imposes too much strain on the power grid. At present, a hybrid approach combining wind and solar energy is encouraged. Another idea is to use wind power for heating or cooling, and research is underway on this, though there is considerable debate, as some do not support electric heating methods. However, wind power has its particularities, so what will happen in the future will depend on policies!

Recently, **there is a need to vigorously develop smart grids; if this is achieved, it might solve the problem.

This post was last edited by Standing in the East on 2012-3-31 at 14:33. There are not many locations available for construction, the investment required is high, and the power supply is unstable; however, wind power generation is indeed clean

This post was last edited by Standing in the East on 2012-3-31 at 14:34. At present, China does not have the capability to develop smart grids on a large scale; smart grids require sophisticated detection methods and strong connections between various provincial power grids, as well as guidance for end-users – all of which are very difficult to implement at the moment.

Some time ago, I saw that **intelligent grids were to be developed vigorously during the 12th Five-Year Plan period. Perhaps this is also an opportunity.

This post was last edited by Standing in the East on 2012-3-31 15:55. The problem of wind energy waste in our country is becoming increasingly severe. Preliminary statistics show that in 2011, wind power waste in certain provinces and cities in China was around 20%, while in some areas with abundant wind resources in the \"Three Norths\" regions, it exceeded 30%. Therefore, in this year’s **work report**, the phrase \"stop the uncontrolled expansion of industries such as solar and wind power\" was changed to \"prevent the uncontrolled expansion of manufacturing capacity for solar and wind power equipment\". But for now, a non-supportive approach should be taken toward the manufacturing of wind power equipment. It can therefore be said that there are significant problems in both the manufacturing of wind power equipment and the operation of wind power facilities in China at present. Although the development of wind power is seen as promising, it should be planned carefully so as to guide its development through demand.

Please explain what \"wind energy curtailment\" means