In recent years, the global wind power industry has developed rapidly with the deepening understanding of environmental issues and the continuous improvement of renewable energy comprehensive utilization technology.In 2016, the global installed capacity increased to 54,642MW, with a compound growth rate of 15.25% in the past 15 years.By the end of 2016, the cumulative installed capacity of global wind power has reached 486,790MW, with a compound growth rate of 22.25% in the past 15 years.According to the global distribution of newly installed wind power capacity, in 2016, China's newly installed capacity was 23,370MW, accounting for 42.77% of the newly installed capacity in the world, ranking first in the world.The United States added 8,203MW of installed capacity, accounting for 15.01% of the world's new capacity, ranking second in the world.According to the distribution of cumulative installed capacity of global wind power, by the end of 2016, the global wind power market is mainly concentrated in the United States, Germany, Spain, China and India.Among them, China's cumulative installed capacity reached 168,732MW, ranking first in the world.The cumulative installed capacity of the United States is 82,184mw, ranking second in the world.As one of the fastest developing renewable energy sources at present, wind power accounts for an increasing proportion in the global power production structure and enjoys a broad development prospect.In the future, the cumulative installed capacity of global wind power will continue to grow at a rate of about 10% a year and reach 817.00gw in 2021.In addition, the new installed capacity of global wind power will continue to grow steadily in the future, and it is expected that the new installed capacity will reach more than 60GW every year.

　 Offshore wind power has the advantages of high power generation capacity, large installed capacity of a single machine, stable operation of the unit, suitable for large-scale development and so on. It has become a new trend of global electric power field construction.The global total installed capacity of offshore wind power is expected to reach 100GW by 2030.    

•   In 1986, China's first wind farm -- malan wind power plant was connected to the grid in rongcheng, shandong province to generate electricity. It was a milestone in China's wind power history and marked the beginning of China's wind power industry.

  1) early demonstration stage (1986-1993) : mainly used foreign grants and loans to build small demonstration wind farms. Government support was mainly in terms of funds, such as investment in wind farm projects and support for wind turbine development;2) industrialization exploration stage (1994-2003) : mandatory acquisition, debt-service electricity price and cost sharing system were established for the first time. As the interests of investors were guaranteed, loans for wind farm construction gradually increased;3) industrial development stage (2003-2007) : wind farm investors, developers and feed-in electricity prices were determined mainly through the implementation of wind power concession tendering. Through the implementation of the "renewable energy law" and its detailed rules, a stable cost-sharing system was established to rapidly improve the scale of wind power development and local equipment manufacturing capacity.4) large-scale development stage (from 2008 to now) : on the basis of bidding for wind power concession, the benchmark pricing policy for onshore wind power was issued;In line with the needs of large-scale development, the law on renewable energy was revised and a fully guaranteed purchase system for renewable energy power generation was formulated and implemented.In 2016, 154 new installations of offshore wind power were installed in China, with a capacity of 590MW and a cumulative capacity of 1,630mw.By 2020, construction of 10GW of offshore wind power will begin and 5GW will be ensured.According to this calculation, the compound growth rate from 2016 to 2020 is 43.73%.

     Market supply and demand condition and fluctuant reason

    (1) market demand: in 2016, China's economy entered a new normal, with the growth rate of national economy stabilizing and the demand for electricity recovering.On January 16, 2017, itu announced that electricity consumption in 2016 was 5919.8 billion KWH, up 5.01% year on year, 4.5 percentage points higher than that in 2015, and a new high in nearly three years.Based on the overall environment of increasing the demand for electricity and adjusting the energy structure, the demand for wind power is also gradually increasing.On April 25, 2017, the national development and reform commission and the national energy administration issued the revolutionary strategy for energy production and consumption (2016-2030).According to the document, by 2030, non-fossil energy will account for 50% of the total power generation, and wind and solar power will be vigorously developed to continuously improve the efficiency of power generation, reduce the cost of power generation and achieve the same competition with conventional power.On July 28, 2017, the state energy administration issued the guiding opinions on the implementation of the 13th five-year plan for the development of renewable energy to achieve sustainable, healthy and orderly development of the renewable energy industry.The document requires provincial (district, municipal) energy authorities to take the delivery and absorption of renewable energy power as the basic prerequisite for the scale and distribution of renewable energy power construction in their regions, and give full play to the role of trans-provincial and trans-regional uhv transmission channels in absorbing renewable energy.At the same time, the state energy administration issued the "new scale plan for wind power construction in 2017-2020", proposing that the new scale of construction in the country from 2017 to 2020 is 30.65gw, 28.84gw, 26.6gw and 24.31gw respectively, with a total of 110.41gw of new wind power installed.According to the 13th five-year plan for wind power development, by the end of 2020, the installed capacity of offshore wind power connected to the grid will reach more than 5GW, and the starting capacity will exceed 10GW.By the end of 2016, the cumulative installed capacity of offshore wind power in China was only 1.63GW, and it is expected that the offshore wind power will enter a period of rapid development after 2017.In the first half of 2017, China's offshore wind power construction activities accelerated, and the demand for project bidding was strong. Guangdong, jiangsu, shandong and other provinces actively deployed offshore wind power development.The offshore wind power market is expected to accelerate during the 13th five-year plan period.      

　 Market supply

Before 2008, megawatt wind turbine sets have not yet fully entered the mass production period, so the temporary market shortage situation has been formed.During the period from 2008 to 2012, due to the obvious increase of policy support for the wind power industry, China's wind turbine equipment enterprises rushed forward one by one, and the technology level was uneven.After 2012, with the continuous optimization and adjustment of industrial structure, the concentration degree of wind power industry has been significantly improved.In the past two years, wind conditions have put forward higher requirements on the technical level of wind turbine manufacturing enterprises, the market concentration has been further improved, and the number of wind turbine manufacturers has been reduced from more than 60 in the peak to more than 20.At present, there are 8 fan manufacturing enterprises in China whose annual sales volume exceeds 1GW, all of which are domestic manufacturers.In the future, the market share of leading enterprises with scale, technology and management advantages will be further expanded.

    Development trend of wind power industry in China

   (1) the eastern and the southern region onshore wind energy resources development speed: according to the principle of "nearby local given access,", will use the wind energy resource distribution in China's wind power industry and the characteristics of the application of flexible, in environmental protection, water and soil conservation and vegetation restoration work, on the basis of to accelerate the development of eastern and southern region scale onshore wind energy resources.Recently, national policies have actively guided the transfer of domestic wind power installation to the central and eastern and southern regions, which are shown as follows: 1) project approval is mainly concentrated in the central and eastern and southern regions;2) the feedin tariff in the central, eastern and southern regions is lowered by a relatively low margin to attract regional wind power investment;3) according to the 13th five-year plan for wind power development, by 2020, over 42 million kilowatts of new onshore wind power grid connection capacity will be added in the central, eastern and southern regions, and the cumulative installed grid connection capacity will reach over 70 million kilowatts.

  (2) accelerated construction of offshore wind power: offshore wind power has the characteristics of stable wind power, high hours of power generation, and easy absorption near the load center.China's offshore wind power technology has a large amount of exploitable capacity, which is about 200 million kilowatts in depth of 5-25 meters and height of 50 meters, and about 500 million kilowatts in depth of 5-50 meters and height of 70 meters.

Working Principle

     The principle of wind power generation is to use wind power to drive the rotation of windmill blades, and then increase the speed of rotation through the growth machine to promote the generator generation.Based on current windmill technology, wind speeds of about three meters per second (the degree to which a breeze blows) can be used to generate electricity.Wind power generation is very popular in Finland, Denmark and other countries.China's wind power industry has made rapid progress in recent years.Small wind power systems are highly efficient, but they don't consist of just one generator head. They are small systems with a certain amount of technology: wind turbines + chargers + digital inverters.Wind turbine is composed of head, rotor, tail and blade.Each part is very important. The functions of each part are: the blades are used to receive wind power and convert it into electricity through the nose;The tail fin keeps the blade facing the direction of the incoming wind so as to obtain the maximum wind energy;The rotating body can make the head rotate flexibly to realize the function of adjusting the direction of the tail fin.The rotor of the head is a permanent magnet, and the stator winding cuts the magnetic force line to generate electric energy.Wind turbine output is 13~25V alternating current due to the unstable air volume, which must be rectified by the charger, and then charged on the storage battery, so that the electric energy generated by the wind turbine becomes chemical energy.Then with the protection circuit of the inverter power supply, the battery chemical energy into ac 220V city power, to ensure stable use.Fan blade mechanical connection and the level of power transmission shaft through the gear box and the high speed shaft is connected with the universal elastic coupling, transfer torque to the generator shaft, the shaft coupling should press has very good damping and vibration absorption characteristics, absorb right amount the radial, axial and Angle offset, and the mechanism of coupling prevents overload.The other is a direct drive fan impeller blade is not directly connected to the motor through the gearbox fan motor type.

   Generator structure: engine room: the engine room contains key equipment of wind turbine, including gearbox and generator.Maintenance personnel can enter the cabin through the wind turbine tower.The left end of the engine room is the rotor of the wind turbine, namely rotor blade and shaft.Rotor blade: captures the wind and transmits it to the rotor shaft.On a modern 600 kilowatt wind turbine, each rotor blade measures about 20 meters in length and is designed to resemble an airplane wing.Shaft: the shaft of a rotor is attached to the low-speed shaft of a wind turbine.Low-speed shaft: the low-speed shaft of a wind turbine connects the shaft of the rotor to the gearbox.On a modern 600 kilowatt wind turbine, the rotor speed is fairly slow, about 19 to 30 revolutions per minute.The shaft has a conduit for the hydraulic system to activate the aerodynamic brake.Gearbox: the left side of the gearbox is the low speed shaft, which can increase the speed of the high speed shaft to 50 times the speed of the low speed shaft.High speed shaft and its mechanical brake: the high speed shaft runs at 1500 RPM and drives the generator.It is equipped with emergency mechanical gates for use when the aerodynamic gates fail or when the wind turbines are repaired.Generator: often referred to as an induction or asynchronous generator.On modern wind turbines, the maximum power output is usually 500 to 1,500 kilowatts.Yaw gear: the engine room is rotated by means of an electric motor so that the rotor is facing the wind.The yaw device is operated by an electronic controller that senses the direction of the wind through a vane.The wind turbine yaw is shown.Typically, wind turbines deflect only a few degrees at a time when the wind changes direction.Electronic controller: contains a computer that continuously monitors the state of the wind turbine and controls the yaw device.To prevent any malfunctions (i.e., overheating of the gearbox or generator), the controller automatically stops the wind turbine and calls the wind turbine operator through a telephone modem.Hydraulic system: used to reset the aerodynamic brake of a wind turbine.Cooling element: contains a fan for cooling the generator.In addition, it contains an oil cooling element for cooling oil in the gearbox.Some wind turbines have water-cooled generators.Tower: the wind turbine tower carries the engine room and rotor.Tall towers usually have an advantage because the higher away from the ground, the greater the wind speed.Modern 600 kilowatt wind turbines have towers 40 to 60 meters high.It can be a tubular tower or a lattice tower.Tubular towers are safer for maintenance workers because they can reach the top through internal ladders.The advantage of a lattice tower is that it is cheaper.Anemometer and vane: used for measuring wind speed and direction.

   Wind power USES natural energy.Compared with thermal power, nuclear power generation to be more green, environmental protection.