风力发电技术外文文献翻译

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毕业设计风力发电外文文献

Abstract--The purpose of this paper is to find an innovative, high efficiency, practical and low cost control system structure with an optimized control strategy for small-scale grid-connected wind turbine with direct-driven permanent magnet synchronous generator (PMSG). This research adopts the sensorless vector control strategy based on phase-locked loop (PLL) for PMSG control, and the grid-side inverter control strategy is based on the single-phase PLL. The simulation demonstrates that the sensorless control strategy and single-phase grid-side inverter control strategy are practical solutions for grid-connected PMSG wind turbines, and they can provide both generator speed control for optimized wind power tracking and good power quality control for electricity delivered to the grid. The designed system offers many unique advantages, including simple topology, optimized control strategy, cost-effective and fast respond to grid failures.Index Terms--Maximum power point tracking (MPPT), PMSG, pulse-width modulation (PWM) converter, speed control, variable-speed wind turbine.I. I NTRODUCTIONn recent years, great attention has been paid on renewable energy sources, such as wind and solar energy. Wind energy is the most popular renewable energy source due to its relatively low cost. The overall system cost can be further reduced by optimal control of high efficiency power electronic converters to extract maximum power in accordance with atmospheric conditions [11].The wind energy conversion system based on permanent magnet synchronous generator (PMSG) is one of the most favorable and reliable methods of power generation. Reliability of variable-speed direct-driven PMSG wind turbines can be improved significantly comparing to doubly-fed induction generator (DFIG) wind turbines with gearboxes. Noise, power loss, additional cost, and potential mechanical failure are typical problems for a DFIG wind turbine because of the existence of a gearbox. The use of direct-driven PMSG could solve these problems. Moreover, low voltage ride through (LVRT) is also a big issue for DFIG because the This work was supported in part by the special funds from Beijing Municipal Education Commission.Chunxue Wen, Guojie Lu, Peng Wang and Zhengxi Li are with the Power Electronics and Motor Drivers Engineering Research Centre, North China University of Technology,Beijing,China(e-mail: wenchx1980@, lugod307@, catdapeng2008@, lzx@).Xiongwei Liu and Zaiming Fan are with the School of Computing, Engineering and Physical Sciences, University of Central Lancashire, Preston, PR1 2HE, UK (e-mail: xliu9@, zmfan@) electromagnetic relationship between the stator and the rotor is more complex than PMSG. Therefore, it’s more difficult for DFIG to solve LVRT problem safely and reliably.In a variable-speed PMSG system, vector control approach is often used to achieve nearly decoupled active and reactive power control on the grid-side inverter which is a current regulated voltage source inverter. In this way, the power converter maintains the DC-link voltage and improves the power factor of the system [1], [7], [10]. Different control methods for maximum power point tracking (MPPT) in variable-speed wind turbine generators have been discussed in [2], [4], [7].This research adopts the sensorless vector control strategy based on phase-locked loop (PLL) for PMSG control [2]. The method requires only one active switching device, i.e. insulated-gate bipolar transistor (IGBT), which is used to control the generator torque and speed so as to extract maximum wind power. It is a simple topology and low cost solution for a small-scale wind turbine because of the sensorless vector control strategy. The grid-side inverter control strategy is based on the single-phase PLL, which applies a control method in Direct-Quadrature (DQ) rotating frame to single-phase inverter and achieves superior steady state and dynamic performance [6].For small-scale wind turbine, single-phase power supply to consumers is popular. There are many control methods for single-phase inverter, such as PI controller, quasi-PR controller, etc. [5]. However, these methods can’t decouple the active power and reactive power so as to have good power control performance. Single-phase PLL method based on DQ rotating frame can well solve this problem. On the other hand, encoders are vulnerable components for wind turbines, particularly for small wind turbines, because small wind turbines experience severer vibrations than their large counterparts. The sensorless vector control opts out the encoders, and therefore the reliability of wind turbines is much improved. For these reasons, the sensorless vector control and single-phase PLL method have their unique advantages for small-scale wind turbines.This paper is structured further in following three sections. In section II, the principle of the full power back-to-back PWM converter is introduced. Then the vector control of small-scale grid-connected wind power system including sensorless control, vector control of PMSG, single-phase PLL, vector control of grid-side inverter are described in section III. Finally, in section IV, the simulation results and conclusion are given.Vector control strategy for small-scale grid-connected PMSG wind turbine converter Chunxue Wen, Guojie Lu, Peng Wang, Zhengxi Li Member IEEE, Xiongwei Liu Member IEEE,Zaiming Fan Student Member IEEEIII. T HE PRINCIPLE OF FULL POWER BACK-TO-BACK PWMCONVERTERTypical topology model of direct-driven PMSG wind turbine is shown in Fig. 1. Converters of the system adopt back-to-back pairs of pulse-width modulation (PWM) architecture. The generator-side converter controls the generator speed in order to achieve maximum capture of wind power, and the grid-side inverter controls the stability of DC-bus voltage and the power factor of the system. This topology can be a good way to improve performance, and the control method is flexible. Converters have four-quadrant operation function, which can fulfill the generator speed control anddeliver the fine quality of electricity to the grid [7], [8].Fig. 1. Topology of permanent magnet direct-driven wind power systemIII. T HE VECTOR CONTROL OF SMALL-SCALE GRID-CONNECTEDDIRECT-DRIVEN WIND POWER SYSTEM CONVERTERFig. 2 shows the back-to-back PWM voltage convertervector control block diagram. The machine-side PWMconverter controls the electromagnetic torque and statorreactive power (reactive power is often be set to 0) byadjusting the current of the d-axis and q-axis of the machine-side converter. This control mechanism helps the PMSG tooperate in variable speed, so that the wind turbine can workwith maximum power point tracking (MPPT) under the ratedwind speed. The grid-side PWM inverter stabilizes the DC-busvoltage and accomplishes active and reactive decouplingcontrol by adjusting the current of the d-axis and q-axis of thegrid-side. The grid-side PWM inverter also controls thereactive power flow to the grid, usually at unity power factorcondition.A. Sensorless control based on PLLThe speed and position control is achieved throughsensorless vector control of the machine-side converter basedon all-digital phase-locked loop. The phase-locked loop isdesigned to control the frequency of the D-Q axis voltagethrough minimizing the difference of the output voltage phaseangle and the given voltage phase angle, until the outputvoltage phase angle tracks the given voltage phase angle. Asthe phase-locked loop has frequency closed-loop trackingmechanism, the generator voltage frequency and the anglebetween d-axis voltage and rotor flux can be measured withthis characteristic, then the generator speed and rotor positionangle can be derived [2]. The control accuracy is generallygood using this method, however some problems may occurwhen the generator operates at very low speed. The windpower system often works above the cut-in wind speed, so thismethod can be applied to wind power generation system.Fig. 2.The back-to-back PWM voltage converter vector control block diagramThe actual rotor position of PMSG is indicated in the D-Q coordinate system. The estimated location for ∧θ is the d q ∧∧− coordinate system, αβ is the stationary coordinate system, as shown in Fig. 3. As the rotor position of PMSG is estimated rather than measured in the sensorless vector control system, there exists an error θΔ between the actual rotor position θ and the estimated location ∧θ. At the same time, the back-EMF (electromotive force) generated by the rotor permanent magnets generates two d-axis and q-axis components in the estimated rotor position orientation coordinates, which are expressed as sd e ∧and sq e ∧respectively. Conventional PI controller can achieve zero error control, i.e. sd e ∧or θΔ can be adjusted to zero value. The PLL sensorless vector control schematic diagram is shown in Fig. 4, and the value of sd e ∧and sq e ∧can be obtained from (1).sd sd s sd dq sq sd sq sq s sq q d sd sq di u R i L L i e dt di u R i L L i e dt ωω∧∧∧∧∧∧⎧=+−−⎪⎪⎨⎪=+++⎪⎩(1)Fig. 3. Presumed rotating coordinate systemFig. 4. Principle of PLL based sensorless vector controlIf we ignore the current differential items in (1), then wehavesd s sd q sq sd sq sq s sq d sd ˆˆˆˆˆarctan(arctan(ˆˆˆˆˆu R i L i ee uR i L i ωθω−+Δ=−=−−− (2)where sd u , sq u , sd i and sq i are the d, q-axis components of the output voltage and current of the generator stator; d L q L and s R are the inductance and resistance of the stator; ω is thegenerator electrical angular velocity of the generator; "∧" indicates estimated value.Block diagram of sensorless vector control based on digital PLL is shown in Fig. 5. The back-EMF (electromotive force) value of the estimated rotating coordinates can be obtained by calculating the three-phase voltages and currents of the PMSGstator. The calculated angle difference θΔcan be used to estimate the angular velocity through the PI controller. Then the value of the estimated angle can be obtained by integral element. Generally, the speed has considerable fluctuations using this method. Therefore it will achieve a better estimation by adding a low-pass filter (LPF), as shown in Fig. 5.∧Fig. 5. Block diagram of sensorless vector control based on digital PLLB. Vector control of PMSGIn order to study the torque control of PMSG, it is necessary to establish a mathematical model. Because q-axis leads d-axis 90° in the D-Q coordinate system, the generator voltage equation can be expressed as [8]: sd sd s sd d sq sq sq sq sq q d sd di u R i L L i dt di u Ri L L i dt ωωωψ⎧=+−⎪⎪⎨⎪=+++⎪⎩(3) The significance of various physical quantities in (3) is the same as in (1).The generator electromagnetic torque equation can be expressed as:33()22e sq d q sd sq T p i p L L i i ψ=+− (4) where p is the number of generator pole pairs, and ψ is the magnetic flux.Based on the above mathematical model, the sensorless vector control program of PMSG is established, and its controlblock diagram is shown in Fig. 6.sa i sbi Fig. 6. Sensorless vector control block diagram of PMSGGenerator rotor position and speed which are estimated by sensorless algorithm can be used in vector control. Thereference value of motor torque can be obtained by the speedcontroller. The voltage reference of generator can also be gotby current controller, and then the control signals of rectifier switching device can be obtained by a set of PWM modulation algorithms. The position and speed of generator rotor which is necessary to vector control is obtained by sensorless algorithm.C. Single-phase grid-connected PLLFig. 7 shows the block diagram of the single-phase gird-connected PLL. In order to ensure that the converter outputvoltage is in the same phase with the output current, the PLLis used to achieve unity power factor control. At the sametime, the converter also provides the angle of the referencecurrent transformation [5].Fig. 7. The block diagram of the single-phase PLLThe transformation between orthogonal a-b and D-Q reference frames can be described by trigonometric relations, which are given in (5) and (6), and the rotating reference frame is shown in Fig. 8.Fig. 8. Definition of rotating reference frame⎥⎦⎤⎢⎣⎡⎥⎦⎤⎢⎣⎡−=⎥⎦⎤⎢⎣⎡b a q d f f f f θθθθcos sin sin cos (5) ⎥⎦⎤⎢⎣⎡⎥⎦⎤⎢⎣⎡−=⎥⎦⎤⎢⎣⎡q d b a f f f f θθθθcos sin sin cos (6)Active power and reactive power equations can beexpressed as:⎩⎨⎧−=+=d q q d qq d d i v i v Q i v i v P (7) If the phase voltage and q-axis coincide, then 0=d v andv v q =, active power and reactive power equations can besimplified as:||||q dP v i Q v i =⎧⎪⎨=−⎪⎩ (8) D. The vector control strategy of the grid-side inverterFor a three phase converter, simple PI compensators designed in a D-Q synchronous frame can achieve zero steady state error at the fundamental frequency, but this method is not applicable to single-phase power converter because there is only one phase variable available in a single-phase power converter, while the D-Q transformation needs at least two orthogonal variables.In order to construct the additional orthogonal phaseinformation from the original single-phase power converter,the imaginary orthogonal circuit is developed, as shown inFig. 9. The imaginary orthogonal circuit has exactly the samecircuit components and parameters, but the current b i and the voltage b e , maintain 90D phase shift with respect to their counterparts in the real circuit- a i and a e [6].Fig. 9. Real circuit and its imaginary orthogonal circuitFrom Fig. 9, the voltage equation can be expressed as:⎥⎦⎤⎢⎣⎡−−+⎥⎦⎤⎢⎣⎡⎥⎦⎤⎢⎣⎡−=⎥⎦⎤⎢⎣⎡b b a a b a b a v e v e L i i L R i i p 11001 (9) Transforming the voltage equations into the synchronousreference frame using (5) and (6), and considering 0=d v and v v q =, we have: ⎥⎦⎤⎢⎣⎡−+⎥⎦⎤⎢⎣⎡⎥⎦⎤⎢⎣⎡−−−=⎥⎦⎤⎢⎣⎡||1//v e e L i i L R L R i i p qd q d q d ωω (10) To achieve decoupled control of active power and reactive power, the output voltage of the inverter in the synchronousreference frame can be expressed as:||)(1v i x L e d q +−=ω (11))(2q d i x L e ω+= (12)Substituting (11) and (12) into (10), system equations canbe rewritten as follows:⎥⎦⎤⎢⎣⎡+⎥⎦⎤⎢⎣⎡⎥⎦⎤⎢⎣⎡−=⎥⎦⎤⎢⎣⎡211001x x i i L R i i p q d q d (13) The active power and reactive power could be controlled by d i and q i respectively. Therefore, system control can be completed by current feedback loops as follows:))((211q q i i s k k x −+=∗(14)))((212d d i i sk k x −+=∗(15) Fig. 10 shows the control block diagram of the grid-sideinverter. It should be noted that the given active and reactive power should be set at two times of the desired values, because the imaginary circuit will not deliver any active andreactive power to the grid.θωFig. 10. The vector control block diagram of the grid-side inverterIV. S IMULATION RESULTSA simulation model in Matlab/Simulink is developed based on above theoretical analysis, and the system simulation block diagram is shown in Fig. 11.Fig. 11. The system simulation block diagramA. The simulation results of the machine-side converterIn the simulation model, the Reference speed represents the wind speed. At the beginning of the simulation (i.e. 0s), the generator speed is 4rpm and its input torque is -50Nm. At the time of 0.5s, the generator speed is 17 rpm and the input torque maintains at the value of -50Nm. At 1s, the generator speed maintains at 17 rpm and the input torque is -80Nm. The simulated waveforms are shown in Fig. 12, Fig. 13, Fig. 14, Fig. 15, respectively.It can be seen from Fig. 12 and Fig. 13, the error between the estimated rotor position angle and the actual measurement of the rotor position angle is very small in the steady state, there are some fluctuations in the dynamic response, but the rotor position angle is stabilized quickly.It can be seen from Fig. 14 and Fig. 15, there is a small error between the estimated and measured generator rotor speed at low speed. At high speed, however, the error is very small and can be ignored, and the transient response is very short. At the time 1s, the input torque increase affects thegenerator rotor speed slightly, and soon the transientdisappears.ˆ,(d e g )θθ()t sFig. 12. The estimated and measured rotor position angle(rad/s)θθ∧−(s)tFig. 13. The error of estimated and measured rotor position anglet(s)()nrpmFig. 14. The measured generator rotor speedt(s)t()esirpmnFig. 15. The estimated generator rotor speedThe simulation waveforms of the machine-side converterdemonstrate that the sensorless vector control algorithm canestimate the rotor angular position accurately, and the vectorcontrol strategy of the machine-side converter can realizegenerator speed control for the wind turbine to follow theoptimized power curve, i.e. MPPT when the wind speed isbelow rated wind speed.B. The simulation results of the grid-side inverterThe simulation results of the grid-side inverter is shown inFig. 16, Fig. 17 and Fig. 18 respectively.It can be seen from Fig. 16, when the generator outputtorque increases, the DC bus voltage is maintained constant.Fig. 17 shows that θu followsavvery well, and Fig. 18shows thatai followsavvery well.Fig. 16. The simulated DC voltageavuθuθFig. 17. The generator output A phase voltage and the grid voltage vectorangleFig. 18. The output voltage and current of the grid-side inverterFrom the simulation results of the grid-side inverter, it canbe seen that the single-phase PLL algorithm can accuratelytrack the grid-side voltage, and the vector control strategy ofthe grid-side inverter can stabilize the DC bus voltage, andcontrol the grid power factor.V. C ONCLUSIONThis research developed a power electronic converter for asmall direct-driven PMSG wind turbine using the back-to-back pulse-width modulation (PWM) topology. Thesimulation results demonstrate that1) The machine-side converter can control the generatorspeed and torque for the wind turbine to follow the optimizedpower curve, i.e. maximum power point tracking (MPPT)when the wind speed is below rated wind speed.2) The sensorless phase-locked loop (PLL) controlalgorithm can realize the vector control of the generator.3) The grid-side inverter control algorithm based on single-phase PLL can stabilize the DC bus voltage of the converter and control the grid power factor.VI. R EFERENCESPeriodicals:[1]De Tian, “The wind power technology status and development trend inthe world,” New Energy Industry, in press.[2]Ruzhen Dou, Lingyun Gu, Baotao Ning, “Sensorless control of thePMSM based on the PLL,” Electric Machines & Control Application, vol. 32, pp. 53-57, 2005.Books:[3]Qingding Guo, Yibiao Sun, Limei Wang, Modern permanent magnet ACservo motor system. China Electric Power Press, Beijing. In press.Papers from Conference Proceedings (Published):[4]S. Song, S. Kang, and N. Hahm, “Implementation and control of gridconnected AC-DC-AC power converter for variable speed wind energy conversion system,” in Proc. 2003 IEEE Applied Power Electronics Conference and Exposition, vol.1, pp.154 – 158.[5]M. Ciobotaru, R. Teodorescu and F. Blaabjerg, “A new single-phasePLL structure based on second order generalized integrator,” Record of IEEE PESC 2006, Korea, pp.1511-1516.[6]R. Zhang, M. Cardinal, P. Szczesny, M. Dame, “A grid simulator withcontrol of single-phase power converters in D-Q rotating frame,” Power Electronics Specialists Conference, vol.3, pp.1431 – 1436, 23-27 June 2002.[7]R. Esmail, L. Xu, D.K. Nichols, “A new control method of permanentmagnet generator for maximum power tracking in wind turbine application,” IEEE Power Engineering Society Meeting, vol.3, pp. 2090-2095, August 2005.[8]Yang Zhenkun, Liang Hui, “A DSP control system for the gridconnected inverter in wind energy conversion system,” IEEE ICEMS 2005 Electrical Machines and Systems, vol. 2, 2005, pp. 1050-1053, June 2005.[9]N V Suresh Kumar Srighakollapu, Partha Sarathi Sensarma, “Sensorlessmaximum power point tracking control in wind energy generation using permanent magnet synchronous generator,” Industrial Electronics 2008, 34th Annual Conference Of IEEE, Iecon , pp.2225-2230.Dissertations:[10]Cheng Lu, “The coordination control of dual PWM converter for VSCFwind power generation system,” MSc thesis, Graduate School of Chinese Academy of Sciences, Beijing, 2004.[11]Shenbing Wu, “Research on CSC-based small-scale grid-connectedwind power generation system”, MSc thesis, Hefei University of Technology, Hefei, 2009.VII. B IOGRAPHIESChunxue Wen received his BSc degree from Inner Mongolia University of Technology in 2001, MSc degree from Wuhan University in 2006, and PhD degree from the Institute of Electrical Engineering, Chinese Academy of Sciences in 2009. In 2010 he joined the Wind Energy Engineering Research Group at the University of Central Lancashire as a visiting researcher. He is currently working as a Lecturer at the Power Electronics and Motor Drivers Engineering Research Center, North China University of Technology, Beijing, China. His research interests include power electronics, wind turbine control system, converters for wind turbines.Guojie Lu received his BSc degree from North China Electric Power University in 2006. He worked in Beijing Xinhuadu Special Transformer Company from 2007 to 2009, and was responsible for the technical service transformer. At present, he is registered as a postgraduate research student at the Power Electronics and Motor Drivers Engineering Research Center, North China University of Technology, Beijing, China. His research area is wind turbine control system.The project aims to develop maximum power point tracking control algorithm for grid-connected small wind turbines.Peng Wang received his BSc degree from Taiyuan University of Technology in 2003, MSc degree from North China University of Technology in 2011. Since 2008, he has been working as a research assistant in Electrical Engineering at the Power Electronics and Motor Drivers Engineering Research Center, North China University of Technology, Beijing, China. In 2010 he joined the Wind Energy Engineering Research Group at the University of Central Lancashire as a visiting student. His research areas are permanent-magnet synchronous generator control and wind energy engineering.Zhengxi Li received his PhD degree from the University of Science and Technology, Beijing. He is the Chair Professor in Power Electronics and Motor Drivers and Head of the Power Electronics and Motor Drivers Engineering Research Center, North China University of Technology, Beijing, China. He is also Vice President of North China University of Technology. His research interests include power electronics, high voltage power transmission and distribution, intelligent transportation and renewable energy. Xiongwei Liu was born in Xiangtan, China, in 1965. He received his BEng (Hons) degree from National University of Defense Technology, Changsha, in 1985, and his MSc (Distinction) and PhD degrees from Harbin Institute of Technology in 1988 and 1991 respectively.His employment experience included Northwestern Polytechnical University, Huaqiao University, Leeds Met University, University of Hertforshire and University of Central Lancashire. His research interests include wind energy engineering, renewable energy technologies, smart grid and microgrid, and intelligent energy management system.He received a research fellowship from Alexander-von-Humboldt Foundation of Germany, which allowed him to visit Ruhr University Bochum, as a research fellow for 18 months from 1993. In 1999 he was awarded a Bronze Medal by Huo Yingdong Education Funding Council and a Model Worker Medal by the Mayor of Quanzhou, China, due to his excellent contributions in higher education when he served as a professor at Huaqiao University. He received a research fellowship from Chinese Scholarship Council, which allowed him to visit Technical University Berlin as a senior research fellow for 6 months in 2000.Xiongwei Liu is currently working as Chair Professor of Energy and Power Management and Head of Wind Energy Engineering Research Group at the University of Central Lancashire.。

风力发电英文作文

风力发电英文作文Wind power generation is a clean and renewable energy source that harnesses the power of the wind to generate electricity. It is a sustainable alternative to traditional fossil fuels and has the potential to reduce greenhouse gas emissions and combat climate change.The use of wind turbines to capture the kinetic energyof the wind and convert it into electricity has beengrowing rapidly in recent years. Wind power generation has the advantage of being able to produce electricity without the release of harmful pollutants or greenhouse gases, making it an environmentally friendly energy source.One of the key benefits of wind power generation is its ability to provide electricity to remote and off-grid areas. Wind turbines can be installed in locations wheretraditional power infrastructure is not available, bringing electricity to communities that would otherwise havelimited access to energy.In addition to its environmental benefits, wind power generation also has the potential to create jobs and stimulate economic growth. The development, installation, and maintenance of wind turbines require skilled labor, creating employment opportunities in the renewable energy sector.Despite its many advantages, wind power generation also faces challenges. One of the main challenges is the intermittent nature of wind energy, as the wind does not blow consistently. This variability in wind speed can make it difficult to rely solely on wind power generation for electricity supply.In conclusion, wind power generation is a promising and sustainable energy source that has the potential to play a significant role in the transition to a low-carbon economy. With ongoing technological advancements and investment in wind energy infrastructure, it is likely to become an increasingly important part of the global energy mix.。

风力发电外文文献翻译中英文

风力发电外文翻译中英文英文Wind power in China – Dream or reality?HubacekAbstractAfter tremendous growth of wind power generation capacity in recent years, China now has 44.7 GW of wind-derived power. Despite the recent growth rates and promises of a bright future, two important issues - the capability of the grid infrastructure and the availability of backup systems - must be critically discussed and tackled in the medium term.The study shows that only a relatively small share of investment goes towards improving and extending the electricity infrastructure which is a precondition for transmitting clean wind energy to the end users. In addition, the backup systems are either geographically too remote from the potential wind power sites or currently financially infeasible. Finally, the introduction of wind power to the coal-dominated energy production system is not problem-free. Frequent ramp ups and downs of coal-fired plants lead to lower energy efficiency and higher emissions, which are likely to negate some of the emission savings from wind power.The current power system is heavily reliant on independentlyacting but state-owned energy companies optimizing their part of the system, and this is partly incompatible with building a robust system supporting renewable energy technologies. Hence, strategic, top-down co-ordination and incentives to improve the overall electricity infrastructure is recommended.Keywords: Wind power, China, Power grids, Back-up systems1. IntroductionChina 'wsi nd energy industry has experienced a rapid growth over the last decade. Since the promulgation of the first Renewable Energy Law in 2006, the cumulative installed capacity of wind energy amounted to 44.7 GW by the end of 2010 [1]. The newly installed capacity in 2010 reached 18.9 GW which accounted for about 49.5% of new windmills globally. The wind energy potential in China is considerable, though with differing estimates from different sources. According to He et al. [2], the exploitable wind energy potential is 600–1000 GW onshore and 100–200 GW offshore. Without considering the limitations of wind energy such as variable power outputs and seasonal variations, McElroy et al. [3] concluded that if the Chinese government commits to an aggressive low carbon energy future, wind energy is capable of generating 6.96 million GWh of electricity by 2030, which is sufficient to satisfy China ' selectricity demand in 2030.The existing literature of wind energy development in China focuses on several discussion themes. The majority of the studies emphasize the importance of government policy on the promotion of wind energy industry in China [4], [5], [6], [7]. For instance, Lema and Ruby [8] compared the growth of wind generation capacity between 1986 and 2006, and addressed the importance of a coordinated government policy and corresponding incentives. Several studies assessed other issues such as the current status of wind energy development in China [9]; the potential of wind power [10]; the significance of wind turbine manufacturing [11]; wind resource assessment [5]; theapplication of small-scale wind power in rural areas [12]; clean development mechanism in the promotion of wind energy in China [4], social, economic and technical performance of wind turbines [13] etc.There are few studies which assess the challenge of grid infrastructure in the integration of wind power. For instance, Wang [14] studied grid investment, grid security, long-distance transmission and the difficulties of wind power integration at present. Liao et al. [15] criticised the inadequacy of transmission lines in the wind energy development. However, webelieve that there is a need to further investigate these issues since they are critical to the development of wind power in China. Furthermore, wind power is not a stand-alone energy source; it needs to be complemented by other energy sources when wind does not blow. Although the viability and feasibility of the combination of wind power with other power generation technologies have been discussed widely in other countries, none of the papers reviewed the situation in the Chinese context. In this paper, we discuss and clarify two major issues in light of the Chinese wind energy distribution process: 1) the capability of the grid infrastructure to absorb and transmit large amounts of wind powered electricity, especially when these wind farms are built in remote areas; 2) the choices and viability of the backup systems to cope with the fluctuations of wind electricity output.2. Is the existing power grid infrastructure sufficient?Wind power has to be generated at specific locations with sufficient wind speed and other favourable conditions. In China, most of the wind energy potential is located in remote areas with sparse populations and less developed economies. It means that less wind powered electricity would be consumed close to the source. A large amount of electricity has to be transmittedbetween supply and demand centres leading to several problems associated with the integration with the national power grid system, including grid investment, grid safety and grid interconnection.2.1.P ower grid investmentAlthough the two state grid companies-(SGCC) State Grid Corporation of China and (CSG) China Southern Grid - have invested heavily in grid construction, China 'pso wer grid is still insufficient to cope with increasing demand. For example, some coal-fired plants in Jiangsu, which is one of the largest electricity consumers in China, had to drop the load ratio to 60 percent against the international standard of 80 percent due to the limited transmission capacity [16]. This situation is a result of an imbalanced investment between power grid construction and power generation capacity. For example, during the Eighth Five-Year Plan, Ninth Five-Year Plan and Tenth Five-Year Plan,1 power grid investments accounted for 13.7%, 37.3% and 30% of total investment in the electricity sector, respectively. The ratio further increased from 31.1% in 2005 to 45.94% in 2008, the cumulative investment in the power grid is still significantly lower than the investments in power generation [17]. Fig. 1 gives a comparison of the ratios ofaccumulative investments in power grid and power generation in China, the US, Japan, the UK and France since 1978. In most of these countries, more than half of the electric power investment has been made on grid construction. By contrast, the ratio is less than 40% in China.According to the Articles 14 and 21 of the Chinese Renewable Energy Law, the power grid operators are responsible for thegrid connection of renewable energy projects. Subsidies are given subject to the length of the grid extension with standard rates. However, Mo [18] found that the subsidies were only sufficient to compensate for capital investment and corresponding interest but excluding operational and maintenance costs.Again, similar to grid connection, grid reinforcement requires significant amounts of capital investment. The Three Gorges power plant has provided an example of large-scale and long-distance electricity transmission in China. Similar to wind power, hydropower is usually situated in less developed areas. As a result, electricity transmission lines are necessaryt o deliver the electricity to the demand centres where the majority are located; these are the eastern coastal areas and the southern part of China. According to SGCC [19], the gridreinforcement investment of the Three Gorges power plants amounted to 34.4 billion yuan (about 5 billion US dollars). This could be a lot higher in the case of wind power due to a number of reasons. First, the total generating capacity of Three Gorges project is approximately 18.2 GW at this moment and will reach 22.4 GW when fully operating [20], whilst the total generating capacity of the massive wind farms amount to over 100 GW. Hence, more transmission capacities are absolutely necessary. Second, the Three Gorges hydropower plant is located in central China. A number of transmission paths are available, such as the 500 kV DC transmission lines to Shanghai (with a length of 1100 km), Guangzhou (located in Guangdong province, with a length of 1000 km) and Changzhou (located in Jiangsu province, with a length of 1000 km) with a transmission capacity of 3 GW each and the 500 kV AC transmission lines to central China with transmission capacity of 12 GW. By contrast, the majority of wind farm bases, which are located in the northern part of China, are far away from the load centres. For example, Jiuquan located in Gansu has a planned generation capacity of 20 GW. The distances from Jiuquan to the demand centres of the Central China grid and the Eastern China grid are 1500 km and 2500 km, respectively. For Xinjiang, the distances are even longer at 2500 km and 4000 km,respectively. As a result, longer transmission lines are required. Fig. 2 depicts the demand centres and wind farms in detail.2.2.Grid safetyThe second problem is related to grid safety. The large-scale penetration of wind electricity leads to voltage instability, flickers and voltage asymmetry which are likely to cause severe damage to the stability of the power grid [21]. For example, voltage stability is a key issue in the grid impact studies of wind power integration. During the continuous operation of wind turbines, a large amount of reactive power is absorbed, which lead to voltage stability deterioration [22]. Furthermore, the significant changes in power supply from wind might damage the power quality [23]. Hence, additional regulation capacity would be needed. However, in a power system with the majority of its power from base load provider, the requirements cannot be met easily [24]. In addition, the possible expansion of existing transmission lines would be necessary since integration of large-scale wind would cause congestion and other grid safety problems in the existing transmission system. For example, Holttinen [23] summarized the majorimpacts of wind power integration on the power grid at the temporal level (the impacts of power outputs at second, minute to year level on the power grid operation) and the spatial level (the impact on local, regional and national power grid). Besides the impacts mentioned above, the authors highlight other impacts such as distribution efficiency, voltage management and adequacy of power on the integration of wind power [23].One of the grid safety problems caused by wind power is reported by the (SERC) State Electricity Regulatory Commission [25]. In February and April of 2011, three large-scale wind power drop-off accidents in Gansu (twice) and Hebei caused power losses of 840.43 MW, 1006.223 MW and 854 MW, respectively, which accounted for 54.4%, 54.17% and 48.5% of the total wind powered outputs. The massive shutdown of wind turbines resulted in serious operational difficulties as frequency dropped to 49.854 Hz, 49.815 Hz and 49.95 Hz in the corresponding regional power grids.The Chinese Renewable Energy Law requires the power grid operators to coordinate the integration of windmills and accept all of the wind powered electricity. However, the power grid companies have been reluctant to do so due to the above mentioned problems as well as technical and economic reasons. For instance, more than one third of the wind turbines in China, amounting to 4 GW capacity, were not connected to the power grid by the end of 2008 [17]. Given that the national grid in China is exclusively controlled by the power companies – SGCC and CSG - the willingness ofthese companies to integrate wind energy into the electricity generation systems is critical.2.3.T he interconnection of provincial and regional power gridsThe interconnection of trans-regional power grids started at the end of 1980s. A (HVDC) high voltage direct current transmission line was established to link the Gezhouba2 dam with Shanghai which signifies the beginning of regional power grids interconnection. In 2001, two regional power grids, the North China Power Grid and Northeast China Power Grid were interconnected. This was followed by the interconnection of the Central China Power Grid and the North China Power Grid in 2003. In 2005, two other interconnection agreements were made between the South China Power Grid with North, Northeast and Central China Power Grid, and the Northwest China Power Grid and the Central China Power Grid. Finally, in 2009, the interconnection of Central China Power Grid and the East China Power Grid was made. In today ' s China, the Chinesepower transmission systems are composed of 330 kV and 500 kV transmission lines as the backbone and six interconnected regional power grids and one Tibet power grid [26].It seems that the interconnectivity of regional power grids would help the delivery of wind powered outputs from wind-rich regions todemand centres. However, administrative and technical barriers stillexist. First, the interconnectivity among regions is always considered as a backup to contingencies, and could not support the large-scale, long-distance electricity transmission [27]. In addition, the construction of transmission systems is far behind the expansion of wind power. The delivery of large amounts of wind power would be difficult due to limited transmission capacity. Furthermore, the quantity of inter-regional electricity transmission is fixed [27]. Additional wind power in theinter-regional transmission might have to go through complexadministrative procedures and may result in profit reductions of conventional power plants.3. Are the backup systems geographically available and technically feasible?Power system operators maintain the security of power supply by holding power reserve capacities in operation. Although terminologies used in the classification of power reserves vary among countries [28], power reserves are always used to keep the production and generation in balance under a range of circumstances, including power plant outages, uncertain variations in load and fluctuations in power generations (such as wind) [29]. As wind speed varies on all time scales (e.g. from seconds to minutes and from months to years), the integration of fluctuating wind power generation induces additional system balancing requirements on the operational timescale [29].A number of studies have examined the approaches to stabilize the electricity output from wind power plants. For example, Belanger and Gagnon [30] conducted a study on the compensation of wind power fluctuations by using hydropower in Canada. Nema et al. [31] discussed the application of wind combined solar PV power generation systems and concluded that the hybrid energy system was a viable alternative to current power supply systems in remote areas. In China, He et al. [2]investigated the choices of combined power generation systems. The combinations of wind-hydro, wind-diesel, wind-solar and wind-gas power were evaluated respectively. They found that, for instance, the wind-diesel hybrid systems were used at remote areas and isolated islands. This is because the wind-diesel hybrid systems have lower generation efficiency and higher generation costs compared to other generation systems. Currently, the wind-solar hybrid systems are not economically viable for large-scale application; thus, these systems have either been used at remote areas with limited electricity demand (e.g. Gansu Subei and Qinghai Tiansuo) or for lighting in some coastal cities [2]. Liu et al. [32] adopted the EnergyPLAN model to investigate the maximum wind power penetration level in the Chinese power system. The authors derived a conclusion that approximately 26% of national power demand could be supplied by wind power by the end of 2007. However, theauthors fail to explain the provision of power reserves at different time scales due to wind power integration.Because of the smoothing effects of dispersing wind turbines at different locations (as exemplified by Drake and Hubacek [33] for theU.K., Roques [34] for the E.U. and Kempton et al. [35] for the U.S.), the integration of wind power has a very small impact on the primary reserves which are available from seconds to minutes [36]. However, the increased reserve requirements are considerable on secondary reserves (available within 10 –15 min) which mainly consist of hydropower plants and gas turbine power plants [29]. Besides, the long-term reserves, which are used to restore secondary reserves after a major power deficit, will be in operation to keep power production and consumption in balance for a longer timescale (from several minutes to several hours). In the following subsection, we examine the availability of power plants providing secondary and long-term reserves and investigate the viability of energy storage system in China.中文中国的风力发电–梦想还是现实？胡巴切克摘要经过近几年风力发电能力的巨大增长，中国现在拥有 44.7 吉瓦的风力发电。

风力发电机英语作文加翻译

风力发电机英语作文加翻译Use of wind turbines, wind energy is continuously put into power for our household use. This article uses the low-speed rated at 5KW wind turbine permanent magnet, such a small amount of instability due to wind turbines, it began to turn from their work, to convert wind energy into mechanical energy, and then the mechanical energy into electrical energy, it outputs voltage and current is constantly changing, the controller must be rectified by the regulator, into DC and then to the battery charging, wind turbines will generate electricity into chemical energy. Then there is the power protection circuit of the inverter, the battery in the chemical energy into AC 220V power. If it is only required to output DC electrical voltage to the corresponding electrical voltage and can be used. This ensures stable use. This article is complete with a thyristor trigger circuit to the rectifier circuit; inverter power supply selection switch controller SG3524 integrated inverter to achieve the conversion process使用风力涡轮机，风力发电将持续用于我们的家庭使用。

风力发电技术英语翻译

Wind Power Generation TechnologyWind is very important and reserves of energy, it is safe, clean, and can provide abundant energy, stabilityof the stream. Now, use wind power has become the main form of wind, the world's attention, and the fastest. Wind energy technology is a high-tech; it relates more than a dozen of subjects, including meteorology,aerodynamics, structural mechanics, computer technology, electronic control technology, material science,chemistry, electrical engineering, electrical engineering, so the difficulty of a system technology may beyondthe difficulty of space technology.First, The division of wind energy technologies:Wind energy technology is divided into large-scale wind power technology and small and medium sizedwind power technology, although both are wind energy technology, working principles are the same, the twoindustries are completely different: specific performance of the "policy orientation is different in differentmarkets, different applications, applied technology is different, totally belong to the same kinds of industries inthe two sectors. Therefore, in China machinery industry meeting on the wind to large wind power and windpower to distinguish between small and medium treated separately. In addition, to meet different market needs,extending from the wind and solar technology has not only promoted the development of small wind powertechnology, but also for the small wind power opens up new markets.1. Large-scale wind power technology:The technology of large-scale wind power in China still has a certain gap between international.The technology of large-scale wind power technology originated in Denmark and some other Europeancountries, the wind power industry propelled by the government, because of the local wind resource-rich,large-scale wind power technology and equipment ahead of the international development. Our governmenthas also started to boost the development of large-scale wind power technology, and a range of policies toguide industry development. Large-scale wind power technology are for the large-scale wind turbine design,wind turbine applications for large area on the very strict environmental requirements are applied to limitedresources, wind energy resource-rich wind field, to accept a variety of perennial bad environment thatsomething was the complex nature of the environment, high demands on the technology up on the line.Currently large-scale wind power technology in general is not yet ripe, the core technology of large-scale windpower still rely on foreign, national policy guidance to the domestic wind power project launched in variousplaces, like crazy, all over look forward to slice.Worthy of the name "mad electricity" through the wind beganto Negative effect and Precaution policy. Although wind power projects have been started, but more ascomplementary type, complete with independent intellectual property rights of large-scale wind powersystems technology and core technology few. The test environment needs to have been a large-scale windpower technology to mature. In addition, the large-scale wind power generation technology and networktechnology has also improved a number of issues still restrict the development of large-scale wind powertechnology.2. The technology of small wind power:The technology of small wind power in China could compare with the international technology.In 1970s, the small wind power technology in China had been developed which has wind resources for abetter situation, including Inner Mongolia, Xinjiang areas, the first small wind power technology is widelyused in power transmission project to the Township for a one of farmers and herdsmen household powersupply, continuously updated as the technology improvement and development, not only alone but also withthe combination of complementary optical has been widely used in distributed independent power supply.These years as Chinese exports of small and medium wind steadily. Internationally, China's small and mediumsized wind power technology and wind and solar technology have leapt to international leadership.Small wind power technology is mature and relatively small by natural resource constraints, distributedindependent power as a significant effect not only connected, but also the formation of more stable andreliable combination of optical complementary technologies scenery Moreover, technology is completelyself-localization. Both from a technical or price in the international arena are very competitive; withinternational has now started a small wind power in China brand; "wall flower wall Hong" has intensified. Inthe country's most technical advantages and competitiveness of small and medium wind power has alwaysbeen forgotten by the government and policy in a corner of reasons, in the early states has been to locate thesmall and medium sized wind power in Inner Mongolia, Xinjiang, farmers and herdsmen in remote areas touse and return into the agricultural class, low cost, shoddy, low-performance reliability, security, no security ofland mostly sparsely populated areas, most of the domestic market are subject to loss of reliability of largeprice war; in people subconsciously form a poor understanding of So get national attention and development.Domestic small wind power technology in the "low wind start, low wind speed generation, pitch moment,multiple protection, and a series of technical attention by the international market and international clientsunanimously approved, has a leading position. Moreover, the smalland medium Wind power technology isultimately distributed independent power supply to meet end-market, rather than large-scale wind powergeneration and network technologies to meet the domestic monopoly market, technology, update rate must beadapted to a broad and rapidly growing market.3. wind and solar technology:Wind is the integration of technical skills and the Small and Medium Wind Energy Solar EnergyTechnology, combines a variety of applications of new technology, and it covers many areas, the wide rangeof applications, technical differentiation is so great that a variety of techniques which can separate match.Wind and solar power is currently the world in the use of new energy technology the most mature, mostlarge-scale and industrial development of the industry, separate and individual solar wind has its drawbacks ofdevelopment, but both wind and solar power complementary combined to realize the two new configurationof energy in natural resources, the technical programs of integration, performance and price compared toaspects of the new energy source for the most reasonable, not only reduces the demand to meet under the sameunit cost and expand the scope of application of the market, also increases the reliability of the product.In addition: solar and wind power are both new energy, solar energy than the wind started to be late morethan 30 per solar PV / W by the general public about the price of recognition can be converted to a 15% rate;while the price of small wind power conversion rate is only 1/5-1/6 of the same 60% -80%, only the low priceWorse still suppressed, photoelectric production of pollution on the environment greater than wind power,than substantial development in wind energy, this comparison contrast twist of meditation ......, if people usethe energy from the point of view, our goal is to meet the electricity from wind power generating capacity tomeasure the cost of solar energy economy than many .Wind, solar and wind power integration advantages, not only for the "energy saving, emission reduction,"opened up new horizons for the application of science to meet human needs, for the world to open a fourthrevolution.Second，Wind power has three kinds of operation mode:one is independent operation mode, usually a small wind generators to one or a few families to providepower, storage battery energy, to ensure the electricity without wind, Second is the wind turbines and otherpower mode (such as engine power), combining to a unit or an village or an island power supply, Three iswind power into conventional power operate and to provide electric power grid, is often a wind tens orhundreds of sets installed wind generators, this is the main development direction of windpower.Wind power system in the two main parts is wind machine and generators. Wind turbines to change fromadjusting technique, plasma generator toward VSCF technology, this is the development trend of wind powertechnology is the core technology nowadays wind turbines. The following simple introduction of this tworespects.1 the change of wind plasma from regulationWind turbines impeller, will capture the wind by converting wind effects on the mechanical wheeltorque.Change is the change from adjustment with vertical axis wind leaf surface of Angle, thus affecting theforce and the blade, when the wind resistance increases, the output power of the fan is kept constant poweroutput. By regulating mode, fan from the output power curve is smooth. In the rated wind leaf Angle of attack,controller will be placed near zero, do not change, approximate distance equal to adjust for pulp. In the ratedwind above, variable structure control function from pulp, adjust the blade Angle of attack, the output powercontrol in near ratings. Change from the wind plasma starting from wind speed is set slurry machinedowntime at low impact stress relative ease. The normal work, is mainly adopts power control, in practicalapplications, power and speed is directly proportional to the set. Small changes will cause the wind changes ofwind. Due to the change of wind from pulp by adjusting the impact than other wind from small, can reducematerial utilization rate, reduce overall weight. And the change of wind fromaccommodation type at lowspeed, can make the blades, keep good Angle of attack than accommodation type stall wind turbines havebetter energy output, therefore is suitable for low average speed of the region.Change from another advantage of regulation, when the winds reach a certain value, stall type of windand downtime, must from type machine can gradually changes to the wind load without a blades of openmode, avoid wing, increase of wind turbine.Change is to adjust the defect is sensitive response requires gusts. Because the wind accommodation typestall fan vibration power pulse are small, and accommodation type from wind turbines is bigger, especially forthe change from the constant speed windmills way, this kind of circumstance, this does not require moreobvious change in the fan is the response speed of wind system to fast enough, can reduce this phenomenon.Third, the development of wind energy technology requires constantinnovation:At present, China's wind energy development in technological innovation is still very weak, the lack ofcore technologies with independent intellectual property. Thus, much would import technology fromabroad.Although the arrival of knowledge economy era, all countries take full advantage of global resources andinternational cooperation through the introduction of technology to bridge the gap and improvecompetitiveness. But if there is no capability of independent innovation, not know what the introduction ofadvanced technologies, are not able to absorb the future, can not carry out another record, which is on the onehand; on the other hand, the core technology is the introduction of foreign countries cannot, and must be relyon innovation to master the core technology; Moreover, the domestic policy of independent innovation oftechnology needs to supporting, guiding, supporting, with the core technology of wind energy products to beincreasing support, such a "wall flower wall incense" situation can be change, innovation and power can comefrom constant innovation.In short: the wind power industry continuing to creating in a single generation from wind energytechnology to power the various areas of need ,its additional products have emerged such as: street, landscape,traffic control, communication, irrigation, planting, breeding, sea water desalination , fire, alarm, islands,mountains and so on. Shows the development of wind energy in this new industry can be brought aboutnumerous development and transformation of traditional industries, but the application of wind energytechnology in various fields has become the industry's benchmark. World revolution will be caused by windenergy technology from the New Energy and Industrial revolution.风力发电技术风能是非常重要并储量巨大的能源，它安全、清洁、充裕，能提供源源不绝，稳定的能源。

wind power generation作文及翻译风力发电

wind power generation作文及翻译风力发电In recent years, as a renewable clean energy, wind energy has been paid more and more attention all over the world. In recent years, the world wind power has been taking the wind turbine as the core to develop the key equipment of wind turbine power generation system. In the past few years, the localization of design and manufacturing problems has been the bottleneck of China's wind power generation.With the development of localization of wind power equipment in China The research and design of Zhanhe asynchronous generator has always been an urgent problem to be solved in the power industry. With the support and pro motion of the relevant preferential policies of the state, the rapid development of wind power industry in China has reached. With the expansion of the total installed capacity of wind power in kilowatt scale, due to the contingency a nd randomness of wind power, the impact of wind power on the stability of power grid can not be ignored, so the wind turbine was established The asynchronous model of group variable capacity makes the stability of wind turbine i n the wind power generation system can be analyzed and treated by the method similar to synchronous motor.The asynchronous wind generator is an important model of wind power generation. The simulation of asynchronous generator based on SPS module is of great significance because of its simple structure, lowprice and no strict control and control network equipment It is easier to connect with the power grid, but its speed can be changed to a certain extent, which will be able to absorb the transient process of wind energy. However, Xu Jizhu asynchronous generator grid is exciting and increases the demand for reactive power.Based on the requirements of asynchronous wind turbine control system, according to the actual operation model of wind turbine, and using Matlab/Simulink The simulation results are basically consistent with the actual operation of wind turbines.翻译：近年来，风能作为一种可再生的清洁能源日益受到世界各国的广泛关注，使得近几年世界风电一直以风电机组为核心发展风电机组发电系统的关键设备，在过去的几年里，设计和制造问题的本地化一直是中国风力发电的瓶颈，随着我国风力发电设备国产化工作的开展和异步发电机的研究与设计一直是电力行业迫切需要解决的问题，在国家相关优惠政策的支持和推动下，我国风电事业的快速发展已经达到了随着风电总装机容量千瓦规模的扩大，由于风电的偶然性和随机性，风电对电网稳定性的影响已不容忽视，建立了风电机组变容量异步模型，使风电机组在风力发电系统中的稳定性可以用类似于同步电机来分析处理它们的异步风力发电机是风力发电的一个重要模型，基于SPS模块的异步发电机仿真具有重要意义，因为其结构简单、价格低廉，而且不需要严格的控制和控制网络设备，可以更容易地与电网连接，但其转速可以在一定程度上改变，将能够吸收风能的暂态过程然而，许继柱异步发电机电网令人振奋，增加了电网对无功功率的需求，基于异步风电机组控制系统的要求开发了，根据建立的风力发电机组实际运行模型，并利用MATLAB/SIMULINK对其过程进行了仿真，仿真结果与实际运行的风电机组基本一致。

风力发电英文作文

风力发电英文作文英文：Wind power is a renewable energy source that has gained popularity in recent years. It involves the use of wind turbines to generate electricity, which can then be used to power homes, businesses, and even entire cities. One of the benefits of wind power is that it is clean and does not produce any harmful emissions, unlike fossil fuels.Another advantage of wind power is that it is cost-effective. While the initial investment in wind turbines can be high, the cost of producing electricity from wind power is much lower than that of traditional power sources. This is because wind is a free and abundant resource, and once the turbines are installed, the cost of producing electricity is relatively low.In addition to being a clean and cost-effective energy source, wind power also has the potential to create jobsand stimulate economic growth. The construction and maintenance of wind turbines require skilled workers, and the development of wind farms can create new opportunities for businesses and entrepreneurs.However, there are also some challenges associated with wind power. One of the biggest challenges is that wind is an intermittent energy source, meaning that it is not always available. This can make it difficult to rely solely on wind power to meet energy needs. Additionally, wind turbines can be noisy and can have negative impacts on wildlife and their habitats.Despite these challenges, wind power is still a promising energy source that has the potential to play a significant role in our transition to a more sustainable future.中文：风力发电是一种可再生能源，近年来受到了广泛的关注。

风力发电外文文献翻译中英文

风力发电外文翻译中英文英文Wind power in China – Dream or reality?HubacekAbstractAfter tremendous growth of wind power generation capacity in recent years, China now has 44.7 GW of wind-derived power. Despite the recent growth rates and promises of a bright future, two important issues - the capability of the grid infrastructure and the availability of backup systems - must be critically discussed and tackled in the medium term.The study shows that only a relatively small share of investment goes towards improving and extending the electricity infrastructure which is a precondition for transmitting clean wind energy to the end users. In addition, the backup systems are either geographically too remote from the potential wind power sites or currently financially infeasible. Finally, the introduction of wind power to the coal-dominated energy production system is not problem-free. Frequent ramp ups and downs of coal-fired plants lead to lower energy efficiency and higher emissions, which are likely to negate some of the emission savings from wind power.The current power system is heavily reliant on independently acting but state-owned energy companies optimizing their part of the system, and this is partly incompatible with building a robust system supportingrenewable energy technologies. Hence, strategic, top-down co-ordination and incentives to improve the overall electricity infrastructure is recommended.Keywords: Wind power, China, Power grids, Back-up systems1. IntroductionChina’s wind energy industry has exper ienced a rapid growth over the last decade. Since the promulgation of the first Renewable Energy Law in 2006, the cumulative installed capacity of wind energy amounted to 44.7 GW by the end of 2010 [1]. The newly installed capacity in 2010 reached 18.9 GW which accounted for about 49.5% of new windmills globally. The wind energy potential in China is considerable, though with differing estimates from different sources. According to He et al. [2], the exploitable wind energy potential is 600–1000 GW onshore and 100–200 GW offshore. Without considering the limitations of wind energy such as variable power outputs and seasonal variations, McElroy et al. [3] concluded that if the Chinese government commits to an aggressive low carbon energy future, wind energy is capable of generating 6.96 million GWh of electricity by 2030, which is sufficient to satisfy China’s electricity demand in 2030.The existing literature of wind energy development in China focuses on several discussion themes. The majority of the studies emphasize the importance of government policy on the promotion of wind energyindustry in China [4], [5], [6], [7]. For instance, Lema and Ruby [8] compared the growth of wind generation capacity between 1986 and 2006, and addressed the importance of a coordinated government policy and corresponding incentives. Several studies assessed other issues such as the current status of wind energy development in China [9]; the potential of wind power [10]; the significance of wind turbine manufacturing [11]; wind resource assessment [5]; the application of small-scale wind power in rural areas [12]; clean development mechanism in the promotion of wind energy in China [4], social, economic and technical performance of wind turbines [13] etc.There are few studies which assess the challenge of grid infrastructure in the integration of wind power. For instance, Wang [14] studied grid investment, grid security, long-distance transmission and the difficulties of wind power integration at present. Liao et al. [15] criticised the inadequacy of transmission lines in the wind energy development. However, we believe that there is a need to further investigate these issues since they are critical to the development of wind power in China. Furthermore, wind power is not a stand-alone energy source; it needs to be complemented by other energy sources when wind does not blow. Although the viability and feasibility of the combination of wind power with other power generation technologies have been discussed widely in other countries, none of the papers reviewed thesituation in the Chinese context. In this paper, we discuss and clarify two major issues in light of the Chinese wind energy distribution process: 1) the capability of the grid infrastructure to absorb and transmit large amounts of wind powered electricity, especially when these wind farms are built in remote areas; 2) the choices and viability of the backup systems to cope with the fluctuations of wind electricity output.2. Is the existing power grid infrastructure sufficient?Wind power has to be generated at specific locations with sufficient wind speed and other favourable conditions. In China, most of the wind energy potential is located in remote areas with sparse populations and less developed economies. It means that less wind powered electricity would be consumed close to the source. A large amount of electricity has to be transmitted between supply and demand centres leading to several problems associated with the integration with the national power grid system, including grid investment, grid safety and grid interconnection.2.1. Power grid investmentAlthough the two state grid companies-(SGCC) State Grid Corporation of China and (CSG) China Southern Grid - have invested heavily in grid construction, China’s powe r grid is still insufficient to cope with increasing demand. For example, some coal-fired plants in Jiangsu, which is one of the largest electricity consumers in China, had to drop the load ratio to 60 percent against the international standard of 80percent due to the limited transmission capacity [16]. This situation is a result of an imbalanced investment between power grid construction and power generation capacity. For example, during the Eighth Five-Year Plan, Ninth Five-Year Plan and Tenth Five-Year Plan,1 power grid investments accounted for 13.7%, 37.3% and 30% of total investment in the electricity sector, respectively. The ratio further increased from 31.1% in 2005 to 45.94% in 2008, the cumulative investment in the power grid is still significantly lower than the investments in power generation [17]. Fig. 1 gives a comparison of the ratios of accumulative investments in power grid and power generation in China, the US, Japan, the UK and France since 1978. In most of these countries, more than half of the electric power investment has been made on grid construction. By contrast, the ratio is less than 40% in China.According to the Articles 14 and 21 of the Chinese Renewable Energy Law, the power grid operators are responsible for the grid connection of renewable energy projects. Subsidies are given subject to the length of the grid extension with standard rates. However, Mo [18] found that the subsidies were only sufficient to compensate for capital investment and corresponding interest but excluding operational and maintenance costs.Again, similar to grid connection, grid reinforcement requires significant amounts of capital investment. The Three Gorges power planthas provided an example of large-scale and long-distance electricity transmission in China. Similar to wind power, hydropower is usually situated in less developed areas. As a result, electricity transmission lines are necessary to deliver the electricity to the demand centres where the majority are located; these are the eastern coastal areas and the southern part of China. According to SGCC [19], the grid reinforcement investment of the Three Gorges power plants amounted to 34.4 billion yuan (about 5 billion US dollars). This could be a lot higher in the case of wind power due to a number of reasons. First, the total generating capacity of Three Gorges project is approximately 18.2 GW at this moment and will reach 22.4 GW when fully operating [20], whilst the total generating capacity of the massive wind farms amount to over 100 GW. Hence, more transmission capacities are absolutely necessary. Second, the Three Gorges hydropower plant is located in central China. A number of transmission paths are available, such as the 500 kV DC transmission lines to Shanghai (with a length of 1100 km), Guangzhou (located in Guangdong province, with a length of 1000 km) and Changzhou (located in Jiangsu province, with a length of 1000 km) with a transmission capacity of 3 GW each and the 500 kV AC transmission lines to central China with transmission capacity of 12 GW. By contrast, the majority of wind farm bases, which are located in the northern part of China, are far away from the load centres. For example, Jiuquan locatedin Gansu has a planned generation capacity of 20 GW. The distances from Jiuquan to the demand centres of the Central China grid and the Eastern China grid are 1500 km and 2500 km, respectively. For Xinjiang, the distances are even longer at 2500 km and 4000 km, respectively. As a result, longer transmission lines are required. Fig. 2 depicts the demand centres and wind farms in detail.2.2. Grid safetyThe second problem is related to grid safety. The large-scale penetration of wind electricity leads to voltage instability, flickers and voltage asymmetry which are likely to cause severe damage to the stability of the power grid [21]. For example, voltage stability is a key issue in the grid impact studies of wind power integration. During the continuous operation of wind turbines, a large amount of reactive power is absorbed, which lead to voltage stability deterioration [22]. Furthermore, the significant changes in power supply from wind might damage the power quality [23]. Hence, additional regulation capacity would be needed. However, in a power system with the majority of its power from base load provider, the requirements cannot be met easily [24]. In addition, the possible expansion of existing transmission lines would be necessary since integration of large-scale wind would cause congestion and other grid safety problems in the existing transmission system. For example, Holttinen [23] summarized the majorimpacts of wind power integration on the power grid at the temporal level (the impacts of power outputs at second, minute to year level on the power grid operation) and the spatial level (the impact on local, regional and national power grid). Besides the impacts mentioned above, the authors highlight other impacts such as distribution efficiency, voltage management and adequacy of power on the integration of wind power [23].One of the grid safety problems caused by wind power is reported by the (SERC) State Electricity Regulatory Commission [25]. In February and April of 2011, three large-scale wind power drop-off accidents in Gansu (twice) and Hebei caused power losses of 840.43 MW, 1006.223 MW and 854 MW, respectively, which accounted for 54.4%, 54.17% and 48.5% of the total wind powered outputs. The massive shutdown of wind turbines resulted in serious operational difficulties as frequency dropped to 49.854 Hz, 49.815 Hz and 49.95 Hz in the corresponding regional power grids.The Chinese Renewable Energy Law requires the power grid operators to coordinate the integration of windmills and accept all of the wind powered electricity. However, the power grid companies have been reluctant to do so due to the above mentioned problems as well as technical and economic reasons. For instance, more than one third of the wind turbines in China, amounting to 4 GW capacity, were not connectedto the power grid by the end of 2008 [17]. Given that the national grid in China is exclusively controlled by the power companies –SGCC and CSG - the willingness of these companies to integrate wind energy into the electricity generation systems is critical.2.3. The interconnection of provincial and regional power gridsThe interconnection of trans-regional power grids started at the end of 1980s. A (HVDC) high voltage direct current transmission line was established to link the Gezhouba2 dam with Shanghai which signifies the beginning of regional power grids interconnection. In 2001, two regional power grids, the North China Power Grid and Northeast China Power Grid were interconnected. This was followed by the interconnection of the Central China Power Grid and the North China Power Grid in 2003. In 2005, two other interconnection agreements were made between the South China Power Grid with North, Northeast and Central China Power Grid, and the Northwest China Power Grid and the Central China Power Grid. Finally, in 2009, the interconnection of Central China Power Grid and the East China Power Grid was made. In today’s China, the Chinese power transmission systems are composed of 330 kV and 500 kV transmission lines as the backbone and six interconnected regional power grids and one Tibet power grid [26].It seems that the interconnectivity of regional power grids would help the delivery of wind powered outputs from wind-rich regions todemand centres. However, administrative and technical barriers still exist. First, the interconnectivity among regions is always considered as a backup to contingencies, and could not support the large-scale, long-distance electricity transmission [27]. In addition, the construction of transmission systems is far behind the expansion of wind power. The delivery of large amounts of wind power would be difficult due to limited transmission capacity. Furthermore, the quantity of inter-regional electricity transmission is fixed [27]. Additional wind power in the inter-regional transmission might have to go through complex administrative procedures and may result in profit reductions of conventional power plants.3. Are the backup systems geographically available and technically feasible?Power system operators maintain the security of power supply by holding power reserve capacities in operation. Although terminologies used in the classification of power reserves vary among countries [28], power reserves are always used to keep the production and generation in balance under a range of circumstances, including power plant outages, uncertain variations in load and fluctuations in power generations (such as wind) [29]. As wind speed varies on all time scales (e.g. from seconds to minutes and from months to years), the integration of fluctuating wind power generation induces additional system balancing requirements onthe operational timescale [29].A number of studies have examined the approaches to stabilize the electricity output from wind power plants. For example, Belanger and Gagnon [30] conducted a study on the compensation of wind power fluctuations by using hydropower in Canada. Nema et al. [31] discussed the application of wind combined solar PV power generation systems and concluded that the hybrid energy system was a viable alternative to current power supply systems in remote areas. In China, He et al. [2]investigated the choices of combined power generation systems. The combinations of wind-hydro, wind-diesel, wind-solar and wind-gas power were evaluated respectively. They found that, for instance, the wind-diesel hybrid systems were used at remote areas and isolated islands. This is because the wind-diesel hybrid systems have lower generation efficiency and higher generation costs compared to other generation systems. Currently, the wind-solar hybrid systems are not economically viable for large-scale application; thus, these systems have either been used at remote areas with limited electricity demand (e.g. Gansu Subei and Qinghai Tiansuo) or for lighting in some coastal cities [2]. Liu et al. [32] adopted the EnergyPLAN model to investigate the maximum wind power penetration level in the Chinese power system. The authors derived a conclusion that approximately 26% of national power demand could be supplied by wind power by the end of 2007. However, theauthors fail to explain the provision of power reserves at different time scales due to wind power integration.Because of the smoothing effects of dispersing wind turbines at different locations (as exemplified by Drake and Hubacek [33] for the U.K., Roques [34] for the E.U. and Kempton et al. [35] for the U.S.), the integration of wind power has a very small impact on the primary reserves which are available from seconds to minutes [36]. However, the increased reserve requirements are considerable on secondary reserves (available within 10–15 min) which mainly consist of hydropower plants and gas turbine power plants [29]. Besides, the long-term reserves, which are used to restore secondary reserves after a major power deficit, will be in operation to keep power production and consumption in balance for a longer timescale (from several minutes to several hours). In the following subsection, we examine the availability of power plants providing secondary and long-term reserves and investigate the viability of energy storage system in China.中文中国的风力发电–梦想还是现实？胡巴切克摘要经过近几年风力发电能力的巨大增长，中国现在拥有44.7吉瓦的风力发电。

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风力发电技术风能是非常重要并储量巨大的能源，它安全、清洁、充裕，能提供源源不绝，稳定的能源。

目前，利用风力发电已成为风能利用的主要形式，受到世界各国的高度重视，而且发展速度最快。

风能技术是一项高新技术，它涉及到气象学、空气动力学、结构力学、计算机技术、电子控制技术、材料学、化学、机电工程、电气工程、环境科学等十几个学科和专业，因此是一项系统技术，其难度毫不逊色于航天技术。

一、风能技术的划分：风能技术分为大型风电技术和中小型风电技术，虽然都属于风能技术，工作原理也相同，但是却属于完全不同的两个行业：具体表现在“政策导向不同、市场不同、应用领域不同、应用技术更是不同，完全属于同种产业中的两个行业。

因此，在中国风力机械行业会议上已经把大型风电和中小型风电区分出来分别对待。

此外，为满足市场不同需求，延伸出来的风光互补技术不仅推动了中小型风电技术的发展，还为中小型风电开辟了新的市场。

1、大型风电技术：我国大型风电技术与国际还有一定差距。

大型风电技术起源于丹麦、荷兰等一些欧洲国家，由于当地风能资源丰富，风电产业受到政府的助推，大型风电技术和设备的发展在国际上遥遥领先。

目前我国政府也开始助推大型风电技术的发展，并出台一系列政策引导产业发展。

大型风电技术都是为大型风力发电机组设计的，而大型风力发电机组应用区域对环境的要求十分严格，都是应用在风能资源丰富的资源有限的风场上，常年接受各种各样恶劣的环境考研，环境的复杂多变性，对技术的高度要求就直线上升。

目前国内大型风电技术普遍还不成熟，大型风电的核心技术仍然依靠国外，国家政策的引导使国内的风电项目发疯一样在各地上马，各地都期望能借此分得一杯羹。

名副其实的“疯电”借着政策的东风开始燎原之势。

虽然风电项目纷纷上马，但多为配套类型，完全拥有自主知识产权的大型风电系统技术和核心技术少之又少。

还需经历几年环境考验的大型风电技术才能逐渐成熟。

此外，大型风电技术中发电并网的技术还在完善，一系列的问题还在制约大型风电技术的发展。

2、中小型风电技术：我国中小型风电技术可以与国际相媲美。

在本世纪70年代中小型风电技术在我国风况资源较好的内蒙、新疆一带就已经得到了发展，最初中小型风电技术被广泛应用在送电到乡的项目中为一家一户的农牧民家用供电，随着技术的更新不断的完善与发展，不仅能单独应用还能与光电组合互补已被广泛应用于分布式独立供电。

这些年来随着我国中小型风电出口的稳步提升。

在国际上，我国的中小型风电技术和风光互补技术已跃居国际领先地位。

中小型风电技术成熟受自然资源限制相对较小，作为分布式独立发电效果显著不仅可以并网，而且还能结合光电形成更稳定可靠的风光互补技术，况且技术完全自主国产化。

无论从技术还是价格在国际上都十分具有竞争优势；加上现在在国际已打响了中小型风电的中国品牌；“墙内开花墙外香”已愈演愈烈。

在国内最具技术优势和竞争力中小型风力发电一直是被政府和政策遗忘的一个角落，究其原因，在早期国家一直把中小型风力发电定位到内蒙、新疆等偏远地区农牧民使用且归入农机类，价格低廉、粗制滥造、性能可靠度低、安全无保障使用地多为人烟稀少区、国内市场大多都在丧失可靠性的前提下大打价格战；在人们潜意识里形成较差的认识，因此得不到国家的重视和发展。

目前国内中小型风电的技术中“低风速启动、低风速发电、变桨矩、多重保护等等一系列技术得到国际市场的瞩目和国际客户的一致认可，已处于国际领先地位。

况且中小型风电技术最终是为满足分布式独立供电的终端市场，而非如大型风电技术是满足发电并网的国内垄断性市场，技术的更新速度必须适应广阔而快速发展的市场需求。

3、风光互补技术：风光互补技术是整合了中小型风电技术和太阳能技术，综合了各种应用领域的新技术，其涉及的领域之多、应用范围之广、技术差异化之大，是各种单独技术所无法比拟的。

风能和太阳能是目前全球在新能源利用方面技术最成熟、最具规模化和产业化发展的行业，单独的风能和单独的太阳能都有其开发的弊端，而风力发电和太阳能发电两者互补性的结合实现了两种新能源在自然资源的配置方面、技术方案的整合方面、性能与价格的对比方面都达到了对新能源综合利用的最合理，不但降低了满足同等需求下的单位成本，而且扩大了市场的应用范围，还提高了产品的可靠性。

此外：太阳能和风能同属新能源，太阳能比风能起步要晚的多，太阳能光伏发电30元/瓦左右的价格受大众所认可，可转化率仅有15%左右；而中小型风力发电的价格仅为同等的1/5-1/6转化率却有60%-80%，仅此低的价格更有甚者还在打压，光电生产过程中对环境造成的污染远大于风电，却比风电能得到长足的发展，这样的对比反差耐人沉思......，如果从人们用能的角度，最终是为了满足用电，从发电量来衡量风能的成本要比太阳能经济许多。

风光互补整合了太阳能和风能优势，不仅为“节能、减排”开辟了新的天地，以应用科学来满足人类需求，为世界进入第四次革命打开了一页。

二、风力发电有三种运行方式：一是独立运行方式，通常是一台小型风力发电机向一户或几户提供电力，它用蓄电池蓄能，以保证无风时的用电；二是风力发电与其他发电方式（如柴油机发电）相结合，向一个单位或一个村庄或一个海岛供电；三是风力发电并入常规电网运行，向大电网提供电力，常常是一处风电场安装几十台甚至几百台风力发电机，这是风力发电的主要发展方向。

在风力发电系统中两个主要部件是风力机和发电机。

风力机向着变浆距调节技术、发电机向着变速恒频发电技术，这是风力发电技术发展的趋势，也是当今风力发电的核心技术。

下面简单介绍这两方面的情况。

1风力机的变浆距调节风力机通过叶轮捕获风能，将风能转换为作用在轮毂上的机械转矩。

变距调节方式是通过改变叶片迎风面与纵向旋转轴的夹角，从而影响叶片的受力和阻力，限制大风时风机输出功率的增加，保持输出功率恒定。

采用变距调节方式，风机功率输出曲线平滑。

在额定风速以下时，控制器将叶片攻角置于零度附近，不做变化，近似等同于定浆距调节。

在额定风速以上时，变浆距控制结构发生作用，调节叶片攻角，将输出功率控制在额定值附近。

变浆距风力机的起动速度较定浆距风力机低，停机时传递冲击应力相对缓和。

正常工作时，主要是采用功率控制，在实际应用中，功率与风速的立方成正比。

较小的风速变化会造成较大的风能变化。

由于变浆距调节风力机受到的冲击较之其它风力机要小得多，可减少材料使用率，降低整体重量。

且变距调节型风力机在低风速时，可使桨叶保持良好的攻角，比失速调节型风力机有更好的能量输出，因此比较适合于平均风速较低的地区安装。

变距调节的另外一个优点是，当风速达到一定值时，失速型风力机必须停机，而变距型风力机可以逐步变化到一个桨叶无负载的全翼展开模式位置，避免停机，增加风力机发电量。

变距调节的缺点是对阵风反应要求灵敏。

失速调节型风机由于风的振动引起的功率脉动比较小，而变距调节型风力机则比较大，尤其对于采用变距方式的恒速风力发电机，这种情况更明显，这样不要求风机的变距系统对阵风的响应速度要足够快，才可以减轻此现象。

2变速恒频风力发电机变速恒频风力发电机常采用交流励磁双馈型发电机，其结构如图1所示。

它的结构类似绕线型感应电机，只是转子绕组上加有滑环和电刷，这样一来，转子的转速与励磁的频率有关，从而，使得双馈型发电机的内部电磁关系既不同于异步发电机又不同于同步发电机，但它却具有异步机和同步机的某些特性。

交流励磁双馈变速恒频风力发电机不仅可以通过控制交流励磁的幅值、相位、频率来实现变速恒频，还可以实现有功、无功功率控制，对电网而言还能起无功补偿的作用。

交流励磁变速恒频双馈发电机系统有如下优点:允许原动机在一定范围内变速运行，简化了调整装置，减少了调速时的机械应力。

同时使机组控制更加灵活、方便，提高了机组运行效率。

需要变频控制的功率仅是电机额定容量的一部分，使变频装置体积减小，成本降低，投资减少。

调节励磁电流幅值，可调节发出的无功功率；调节励磁电流相位，可调节发出的有功功率。

应用矢量控制可实现有、无功功率的独立调节。

三、风能技术的发展需要不断的创新：目前，我国风能发展中技术创新还很薄弱，缺乏有自主知识产权的核心技术。

因此，在很大程度上还要从国外引进技术。

虽然，在知识经济到来的时代，所有国家都充分利用全球资源，通过技术引进和国际合作来缩小差距，提高竞争能力。

但是，如果没有自主创新能力，就不知道引进什么先进技术，引进以后也没有能力消化吸收，更不能进行再创新，这是一方面；另一方面，国外的核心技术是引进不来的，必须靠自主创新来掌握核心技术；再者，国内的自主创新技术需要政策给予配套、引导、扶持，拥有核心技术的风能产品要加大扶持力度，这样“墙内开花墙外香”的局面才能得以改变，创新的动力才能来自不断的创新。

总之：风电产业中的风能技术已从单一发电向各个需要用电的领域不断的创新，其附加产品也应运而生如:路灯、景观、交通监控、通讯、灌溉、种植、养殖、海水淡化、防火、警报、海岛高山等。

可见风能这个新兴产业的发展能带动了无数个传统产业的发展与转型，而风能在各个领域的应用技术成了这些产业发展的风向标。

即将引发的世界革命必将来自于以风能技术等新能源产业的革命。

Wind Power Generation TechnologyWind is very important and reserves of energy,it is safe,clean,and can provide abundant energy,stability of the stream.Now,use wind power has become the main form of wind,the world's attention,and the fastest.Wind energy technology is a high-tech;it relates more than a dozen of subjects,including meteorology, aerodynamics,structural mechanics,computer technology,electronic control technology,material science, chemistry,electrical engineering,electrical engineering,so the difficulty of a system technology may beyond the difficulty of space technology.First,The division of wind energy technologies:Wind energy technology is divided into large-scale wind power technology and small and medium sized wind power technology,although both are wind energy technology,working principles are the same,the two industries are completely different:specific performance of the"policy orientation is different in different markets,different applications,applied technology is different,totally belong to the same kinds of industries in the two sectors.Therefore,in China machinery industry meeting on the wind to large wind power and wind power to distinguish between small and medium treated separately.In addition,to meet different market needs, extending from the wind and solar technology has not only promoted the development of small wind power technology,but also for the small wind power opens up new markets.rge-scale wind power technology:The technology of large-scale wind power in China still has a certain gap between international.The technology of large-scale wind power technology originated in Denmark and some other European countries,the wind power industry propelled by the government,because of the local wind resource-rich, large-scale wind power technology and equipment ahead of the international development.Our government has also started to boost the development of large-scale wind power technology,and a range of policies to guide industry rge-scale wind power technology are for the large-scale wind turbine design, wind turbine applications for large area on the very strict environmental requirements are applied to limited resources,wind energy resource-rich wind field,to accept a variety of perennial bad environment that something was the complex nature of the environment,high demands on the technology up on the line. Currently large-scale wind power technology in general is not yet ripe,the core technology of large-scale wind power still rely on foreign,national policy guidance to the domestic wind power project launched in various places,like crazy,all over look forward to slice.Worthy of the name"mad electricity"through the wind began to Negative effect and Precaution policy.Although wind power projects have been started,but more as complementary type,complete with independent intellectual property rights of large-scale wind power systems technology and core technology few.The test environment needs to have been a large-scale wind power technology to mature.In addition,the large-scale wind power generation technology and network technology has also improved a number of issues still restrict the development of large-scale wind power technology.2.The technology of small wind power:The technology of small wind power in China could compare with the international technology.In1970s,the small wind power technology in China had been developed which has wind resources for abetter situation,including Inner Mongolia,Xinjiang areas,the first small wind power technology is widely used in power transmission project to the Township for a one of farmers and herdsmen household power supply,continuously updated as the technology improvement and development,not only alone but also with the combination of complementary optical has been widely used in distributed independent power supply. These years as Chinese exports of small and medium wind steadily.Internationally,China's small and medium sized wind power technology and wind and solar technology have leapt to international leadership.Small wind power technology is mature and relatively small by natural resource constraints,distributed independent power as a significant effect not only connected,but also the formation of more stable and reliable combination of optical complementary technologies scenery Moreover,technology is completely self-localization.Both from a technical or price in the international arena are very competitive;with international has now started a small wind power in China brand;"wall flower wall Hong"has intensified.In the country's most technical advantages and competitiveness of small and medium wind power has always been forgotten by the government and policy in a corner of reasons,in the early states has been to locate the small and medium sized wind power in Inner Mongolia,Xinjiang,farmers and herdsmen in remote areas to use and return into the agricultural class,low cost,shoddy,low-performance reliability,security,no security of land mostly sparsely populated areas,most of the domestic market are subject to loss of reliability of large price war;in people subconsciously form a poor understanding of So get national attention and development.Domestic small wind power technology in the"low wind start,low wind speed generation,pitch moment, multiple protection,and a series of technical attention by the international market and international clients unanimously approved,has a leading position.Moreover,the small and medium Wind power technology is ultimately distributed independent power supply to meet end-market,rather than large-scale wind power generation and network technologies to meet the domestic monopoly market,technology,update rate must be adapted to a broad and rapidly growing market.3.wind and solar technology:Wind is the integration of technical skills and the Small and Medium Wind Energy Solar Energy Technology,combines a variety of applications of new technology,and it covers many areas,the wide range of applications,technical differentiation is so great that a variety of techniques which can separate match.Wind and solar power is currently the world in the use of new energy technology the most mature,most large-scale and industrial development of the industry,separate and individual solar wind has its drawbacks of development,but both wind and solar power complementary combined to realize the two new configuration of energy in natural resources,the technical programs of integration,performance and price compared to aspects of the new energy source for the most reasonable,not only reduces the demand to meet under the same unit cost and expand the scope of application of the market,also increases the reliability of the product.In addition:solar and wind power are both new energy,solar energy than the wind started to be late more than30per solar PV/W by the general public about the price of recognition can be converted to a15%rate; while the price of small wind power conversion rate is only1/5-1/6of the same60%-80%,only the low price Worse still suppressed,photoelectric production of pollution on the environment greater than wind power, than substantial development in wind energy,this comparison contrast twist of meditation......,if people use the energy from the point of view,our goal is to meet the electricity from wind power generating capacity to measure the cost of solar energy economy than many.Wind,solar and wind power integration advantages,not only for the"energy saving,emission reduction," opened up new horizons for the application of science to meet human needs,for the world to open a fourth revolution.Second，Wind power has three kinds of operation mode:one is independent operation mode,usually a small wind generators to one or a few families to provide power,storage battery energy,to ensure the electricity without wind,Second is the wind turbines and other power mode(such as engine power),combining to a unit or an village or an island power supply,Three is wind power into conventional power operate and to provide electric power grid,is often a wind tens or hundreds of sets installed wind generators,this is the main development direction of wind power.Wind power system in the two main parts is wind machine and generators.Wind turbines to change from adjusting technique,plasma generator toward VSCF technology,this is the development trend of wind power technology is the core technology nowadays wind turbines.The following simple introduction of this two respects.1the change of wind plasma from regulationWind turbines impeller,will capture the wind by converting wind effects on the mechanical wheel torque.Change is the change from adjustment with vertical axis wind leaf surface of Angle,thus affecting the force and the blade,when the wind resistance increases,the output power of the fan is kept constant power output.By regulating mode,fan from the output power curve is smooth.In the rated wind leaf Angle of attack, controller will be placed near zero,do not change,approximate distance equal to adjust for pulp.In the rated wind above,variable structure control function from pulp,adjust the blade Angle of attack,the output power control in near ratings.Change from the wind plasma starting from wind speed is set slurry machine downtime at low impact stress relative ease.The normal work,is mainly adopts power control,in practical applications,power and speed is directly proportional to the set.Small changes will cause the wind changes of wind.Due to the change of wind from pulp by adjusting the impact than other wind from small,can reduce material utilization rate,reduce overall weight.And the change of wind from accommodation type at low speed,can make the blades,keep good Angle of attack than accommodation type stall wind turbines have better energy output,therefore is suitable for low average speed of the region.Change from another advantage of regulation,when the winds reach a certain value,stall type of wind and downtime,must from type machine can gradually changes to the wind load without a blades of open mode,avoid wing,increase of wind turbine.Change is to adjust the defect is sensitive response requires gusts.Because the wind accommodation type stall fan vibration power pulse are small,and accommodation type from wind turbines is bigger,especially for the change from the constant speed windmills way,this kind of circumstance,this does not require more obvious change in the fan is the response speed of wind system to fast enough,can reduce this phenomenon.Third,the development of wind energy technology requires constantinnovation:At present,China's wind energy development in technological innovation is still very weak,the lack of core technologies with independent intellectual property.Thus,much would import technology from abroad. Although the arrival of knowledge economy era,all countries take full advantage of global resources and international cooperation through the introduction of technology to bridge the gap and improve competitiveness.But if there is no capability of independent innovation,not know what the introduction of advanced technologies,are not able to absorb the future,can not carry out another record,which is on the one hand;on the other hand,the core technology is the introduction of foreign countries cannot,and must be rely on innovation to master the core technology;Moreover,the domestic policy of independent innovation of technology needs to supporting,guiding,supporting,with the core technology of wind energy products to be increasing support,such a"wall flower wall incense"situation can be change,innovation and power can come from constant innovation.In short:the wind power industry continuing to creating in a single generation from wind energy technology to power the various areas of need,its additional products have emerged such as:street,landscape, traffic control,communication,irrigation,planting,breeding,sea water desalination,fire,alarm,islands, mountains and so on.Shows the development of wind energy in this new industry can be brought about numerous development and transformation of traditional industries,but the application of wind energy technology in various fields has become the industry's benchmark.World revolution will be caused by wind energy technology from the New Energy and Industrial revolution.。