Development of Wind Power Generation
Development of Wind Power Generation
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Development of Wind Power Generation
1. Introduction
Withthegrowing consumption of non-renewable resources such asoil and theserious problems ofenvironmental pollutioncaused by fossil fuels, Countries around the world compete to invest a large amount of manpower and money in research and application of renewable resources.Wind energy has a strong competitive edge in renewable energy use.Wind power not only technically mature, business operations level is also rising.As one of the most important alternative energy sources, wind power is being large-scale development and utilization. Wind power generation technology also has made significant progress at the same time.In recent years, China's wind power industry has also developed rapidly, becoming one of the world's major markets after Europe and the United States.With the scale of wind power accounted for a substantial increase in the proportion of network capacity. Due to a substantial increase in wind power in the grid scale,the existing regular power adjustment and control of power grid operation ability is weakened.And wind power is difficult to perform the same as the conventional power executionsystem of frequency modulation, regulating tasks, and inhibition of power oscillation of the system. SoProblems about wind farms connected to the grid technology and the impact of the wind farm grid operation have become increasingly prominent.
It is well known that renewable energy sources include hydro, wind, solar, biomass, tidal energy, geothermal energy in the form of six.With the increasing scarcity of conventional fossil energy, renewable energy as a solution to the global energy crisis green program, it has received wide attention around the world. Among them, the wind comes from solar radiation to the Earth's surface to heat unevenly, leading to uneven distribution of atmospheric pressure and allowing air movement in the horizontal direction the kinetic energy gained. It is estimated that the development and utilization of wind energy on the planet is about 2x107MW, which is 10 times the hydro. We only use 1% of wind energy to meet the world's energy needs.
According to the Chinese Academy of Meteorological Sciences estimated that China's wind resources are very rich. The actual land available for development of wind energy resources in the total reserves of 253 million kilowatts and wind power has become an important development direction of energy policy support in China. While wind power and network operation is the most important mode of operation. China's
total installed capacity reached 96.37 million kilowatts in 2014. By 2020, the total installed capacity will reach 20 millionkilowatts, which will account for 1% of the national power generation capacity.
Wind power is the renewable energy technology with most mature technology, largest commercial development conditions and prospects in new energy technologies. Its rational use and development of wind energy can effectively alleviate the current shortage of energy and environmental pollution problems caused by fuel resources. In the long term wind energy is likely to become the most important alternative energy sources. With the maturity of power generation technology, wind power generation industry is increasing continuously on a global scale, and it maintains a sustained growth momentum.
2. Operating principle
Wind generator works by converting wind energy into mechanical work of power machinery, also known as the windmill. Broadly speaking, Wind generatoris a kind of sun as a heat source, to take advantage of air as the working medium of heat engine.Wind power is the use of natural energy. Relative to diesel power generation is much better. But if it is an emergency to use, which is not as good as diesel generators. Wind power is as a standby power supply, but it can use for a long time.
Wind generator works by using a wind driven windmill blade rotation. Then through the growth machine rotational speed boostto induce generators. According to the current windmill technology, which is about three meters per second wind speed. Then it can begin to generate electricity.
Wind power is forming a boom in the world, because wind power is no fuel problem andit does not produce radiation or air pollution.Wind power is very popular in Finland, Denmark and other countries. China is also a strong proponent of the western region. Small wind power system efficiency is high.But it is not composed of only one generator head. It is a certain scientific and technological content of small systems. It consists of wind generators, chargers and digital inverter. Wind turbines by the head, swivel, tail, leaf composition. Each part is very important for the function of each part. Leaves used to accept wind power into electrical energy through the nose. The tail is always facing the blade to the wind direction so as to obtain the largest wind energy,Swivel head allows the flexibility to rotate to achieve function to adjust the direction of the tail,The head of the rotor is a permanent magnet and the stator winding cutting magnetic field lines to produce electricity.
Small wind power system efficiency is high, but it is not only the first component consists of a generator. It is a certain scientific and technological content of small systemsconsist of wind generators, chargers and digital inverter. Wind generators consist of the nose, swivel, tail, leaf. Each part is very important for the function of each part. Leaves used to accept wind power into electrical energy through the nose. The tail is always facing the blade to the wind direction so as to obtain the largest wind energy. Swivel head allows the flexibility to rotate to achieve function to adjust the direction of the tail. The head of the rotor is a permanent magnet and the stator winding cutting magnetic field lines to produce electricity.
Fig. 1 Schematic diagram of the principle of wind power
With the gradual development of science and technology, a variety of new wind turbines have also been invented. But the wind generator still works as described above. The new wind turbines just do a lot of improvements.
3. Distribution and Characteristics of wind energy resources
According to the World Meteorological Organization estimates that the global wind energy resources available about 20 billion kW. Wind resources available water resources on the planet 10 times. After estimating the global wind reserves of approximately 3x107 kW, which can make use of wind energy for the 2x1010kW. Because wind energy is derived from solar energy, it was assumed that When solar energy into the Earth's atmosphere, each square meter of power 1.35kW.About 60% of
the energy is assumed to remain in the atmosphere, Then the total energy is about 1.04x1014 kW. If you imagine the wind is 1 percent to 2 percent of the value, the wind is 1.04x1012 ~ 2.08x1012kW. While various estimates would be different, but in general has tremendous global wind energy resources. Wind energy is inexhaustible, inexhaustible, clean energy and renewable.
4.Research status at home and abroad
Wind power is widely used in Europe, China, and the United States. From 2004 to 2014, worldwide installed capacity of wind power has been growing from 47 GW to 369 GW—a more than sevenfold increase within 10 years with 2014 breaking a new record in global installations (51 GW). As of the end of 2014, China, the United States and Germany combined accounted for half of total global capacity. Several other countries have achieved relatively high levels of wind power penetration, such as 21% of stationary electricity production in Denmark, 18% in Portugal, 16% in Spain, and 14% in Ireland in 2010 and have since continued to expand their installed capacity. More than 80 countries around the world are using wind power on a commercial basis.
As of 2014, offshore wind power amounted to 8,771 megawatt of global installed capacity. Although offshore capacity doubled within three years (from 4,117 MW in 2011), it accounted for only 2.3% of the total wind power capacity. TheUnited Kingdom is the undisputed leader of offshore power with half of the world's installed capacity ahead of Denmark, Germany, Belgium and China.
Fig. 2 Global Wind Power Cumulative Capacity
Wind power industry in our country started earlier, but slow to develop. In the 1990 s, under the strong support of national policy, wind power business has made considerable progress, gradually formed an emerging market. FigureFig. 3 shows in the past 10 years, China's wind power installed capacity growth trend.
Fig. 3Wind power installed capacity in China (2004-2014)
Power project investment in 2014, the scale of hydropower investment is 96 billion yuan, the scale of investment in wind power is 56.9 billion yuan, nuclear power investment is 99.3 billion yuan. We can see that clean energy investment has accounted for more than 70%. It is worth noting that the wind power investment scale beyond the thermal power for the first time.
Since the "11th five-year plan", the scale of wind power development was accelerated. Investment is a peak in 2010 was $2010. Enthusiasm appears to reduce investment, investment fell to 65 billion yuan in 2013. Investment is back up to $99.3 billion in 2014.
5.Types of wind turbine generator system
Wind turbine consists of two parts. Part of the power to provide the driving force of the wind turbine, the wind turbine, the other part is to convert it to electrical energy. Wind power wind turbine used in general can be divided into two types of conventional and novel type. Conventional namely conventional propeller wind turbine, according to the different forms of exercise can be divided into a vibrating, translational, fixed and rotary. If you press a different style can be divided into the propeller, the Netherlands, multi-wing, turbine, wing sail windy wheeled and so on.
Novel type of conventional type of innovation is generally divided into two kinds
of vertical axis wind turbine and energizing the horizontal axis wind turbine. Vertical axis wind turbine can be divided into four kinds of ∮vertical axis wind machines, rotary wing wind turbine, circulation control type and S-type wind turbine wind turbine. Energizing the horizontal axis wind turbine can be divided into dynamic diversion wind turbine and wind turbine Tornado.
For wind power generatorscan be divided into two types of DC generators and alternators. Among them, the alternator can be divided into two kinds of synchronous and asynchronous alternator. If the wind turbine and generator system as a whole to consider, wind turbines can be divided into constant speed constant frequency, nearly constant speed constant frequency, variable speed frequency and variable speed constant frequency four kinds of systems.
6. China's wind power development problem to be solved
(1)economic issues
China's current wind power still faces many challenges, mainly the high construction cost and high tariff. At present, China is in the stage of development of wind power and policy support provided by the country is also not perfect. Limitations of national policy, economic factors and other aspects are also difficult to make wind power into commercial and industrial development track. To accelerate the development of wind power, our countryshould not only need to tack protection policies, but also to encourage competition and development process should give strong supportin the industrial.
(2) power grid access issues
As an intermittent cutting andchangeable power, large-scale wind power development is bound to be faced with the challenge of how to successfully connected to the grid. China's wind farms are mainly located in areas far from the load centers, and the local power grid facilities are relatively poor. So the current grid design for wind power development constitutes a restriction. This has become the biggest problem facing China's future development of wind power.
(3) the sharpening contradictions between the system balance
Wind power has a part-time anti-peaking characteristics, increasing the difficulty of power peaking. According to the statistics and Jilin Northeast power grid, wind power anti-peaking probability of 60% and 56%. Jilin grid access due to wind power, a larger difference in peak time to reach 210 days. Wind power peaking problems after significant investment has become a prominent problem of grid operation. In addition,
wind power intermittent and random FM increase the burden on the power grid.
(4)Lack of ability to accept local power grid
Many wind farms are in the grid tip. After large-scale wind power connected to the grid, power transmission flow is increased,then increases overloading operation line. They leadto thermal stability problem increasingly prominent
(5)Increasing the probability of a hit in the grid
The fan itself is not strong anti-jamming capability, which will increase the frequency of the grid a hit and even lead to expansion of the accident.
7. Wind power in the future
(1) Gradually increase the capacity of a single the generator
Currently, megawatt-class wind turbine wind power has become mainstream products on the market. Its market share from less than 10 percent in 1997 soared to 95% in 2010. The maximum capacity of the fan to run stand-alone wind turbines in the world has reached a 5MW and 6MW has developed into.
(2) Wind farms near the coast gradually shift from land
It is estimated that China Wind Energy Association and the World Wide Fund for Nature, 100 km away from the coastline, within the scope of the center height of 100 meters, 7 meters per second wind average duration is three to four times than the land. In addition, offshore wind power close to the traditional load centers, to facilitate power consumptive, can reduce long-distance transmission troubles. The many advantages of offshore wind trend destined to offshore wind farms will certainly transfer.
(3)High-altitude wind power
The height of the wind power equipment now is slow and wind energy is limited. The motive of the wind speed is low. It is difficult to realize the direct drive generator problems. At an altitude of over 1000 meters, wind power density of up to 10 kW or more. The use of high-altitude wind resources will become an urgent task in the field of wind power technology and it is also a major trend in the future development of wind power.
8.Conclusion
In recent years, the energy crisis has put on the agenda, so new energy development is imminent. Wind power is the most used new energy. Within a few years, wind power at home and abroad have gained great development. China's wind power installed capacity has increased year by year, it has surpassed the United States as the world. Nevertheless, the wind power development still exist many problems. For
example, wind power technology is not yet mature.The future large-scale development of wind power needs to the government and people work together. We improve the science and technology as well as reform policy, which will make great progress in wind power development.More important is to work through the wind power technology innovation, which makes our country's wind power get long-term development and makes the wind get more extensive application in our country.