1、中國地質大學長城學院本科畢業論文外文資料翻譯系 別： 信息工程系 專 業： 電氣工程及其自動化 10外文資料翻譯譯文1 風機變槳系統概述 1.1風力發電機組控制系統硬件分別安裝在三個不同部分： 機艙控制，安裝在機艙內 。地面控制，安裝在塔架底部 。變槳控制，安裝在輪轂內部。1.2 人機界面觸摸屏顯示風機的運行狀況和參數，或者啟動或停止風機。1.3 風力發電機組四種控制方式： 1.3.1 定速定漿距控制發電機直接連到恒定頻率的電網,在發電時不進行空氣動力學控制。1.3.2 定速變漿距控制 發電機直接連到恒定頻率的電網,在大風時漿距控制用于調節功率。 1.3.3 變速定漿距控制 變頻器將發電機和電

2、網去耦(decouples),允許轉子速度通過控制發電機的反力矩改變。在大風時,減慢轉子直到空氣動力學失速限制功率到期望的水平。 1.4 變速變漿距控制 變頻器將發電機和電網去耦, 允許通過控制發電機的反力矩改變轉子速度。在大風時,漿距控制用于調節功率。2 變槳系統的工作原理 定漿距風機通過葉片的失速,即改變葉片橫斷面周圍流動的氣流,導致效率的損失,從而控制風機的最大輸出功率。 變漿距風機是通過葉片沿其縱向軸轉動,改變氣流對葉片的攻角,從而改變風力發電機組獲得的空氣動力轉矩,使發電機功率輸出保持穩定。 變槳伺服控制系統作為風力發電控制系統的外環,在風力發電機組的控制中起著十分重要的作用。它控制

3、風力發電機組的葉片節距角可以隨風速的大小進行自動調節。在低風速起動時,槳葉節距可以轉到合適的角度,使風輪具有最大的起動力矩；當風速過高時,通過調整槳葉節距,改變氣流對葉片的攻角,從而改變風力發電機組獲得的空氣動力轉矩,使發電機功率輸出保持穩定。3 變槳系統和定槳系統的比較 定槳距失速調節型風力發電機組 定獎距是指槳葉與輪載的連接是固定的，槳距角固定不變，即當風速變化時，槳葉的迎風角度不能隨之變化,槳葉翼型本身所具有的失速特性。當風速高于額定風速時，氣流的攻角增大到失速條件，使槳葉的表面產生渦流，效率降低，來限制發電機的功率輸出。為了提高風電機組在低風速時的效率，通常采用雙速發電機（即大/小發電

4、機）。在低風速段運行的，采用小電機使槳葉縣有較高的氣動效率，提高發電機的運行效率。 失速調節型的優點是失速調節簡單可靠，當風速變化引起的輸出功率的變化只通過槳葉的被動失速調節而控制系統不作任何控制，使控制系統大為減化。其缺點是葉片重量大（與變槳距風機葉片比較），槳葉、輪載、塔架等部件受力較大，機組的整體效率較低。 變槳距調節型風力發電機組是指通過變槳驅動裝置,帶動安裝在輪轂上的葉片轉動, 從而改變葉片槳距角的大小。其調節方法為：當風電機組達到運行條件時，控制系統命令變槳系統將槳距角調到45°，當轉速達到一定時，再調節到0°，直到風力機達到額定轉速并網發電；在運行過程中，當輸

5、出功率小于額定功率時，槳距角保持在0°位置不變，不作任何調節；當發電機輸出功率達到額定功率以后，調節系統根據輸出功率的變化調整槳距角的大小，使發電機的輸出功率保持在額定功率。 缺點是結構比較復雜，故障率相對較高。4 變槳系統的分類 4.1 變槳距系統根據其工作方式可分為統一變槳和獨立變槳二種方式 統一變槳距控制即機組所有槳葉都由一個執行機構驅動，或者三個執行機構同時驅動,槳葉節距角變化相同。由于液壓系統力矩大，在大型風力機統一變槳距方式一般都采用液壓方式。 獨立變槳距方式，每個槳葉都由獨立的變槳距執行機構驅動，如果其中一個變槳距執行結構出現故障，其它兩個槳葉仍能調節槳葉節距角,實現功

6、率控制，而統一變槳距執行結構出現故障，只能停機維修；另外自然界的風在整個風輪掃及面上分布是不均勻的，獨立槳葉控制可以根據各個槳葉上的風速不同進行調節，不僅能維持發電機輸出功率，而且能減小槳葉拍打振動，因此獨立槳葉控制比統一控制更具有一定的優勢。獨立變槳距控制將槳葉負載分別由單一的執機構承擔，所以一般都采用電機執行方式，電動機通過主動 齒輪帶動槳葉輪轂內齒圈，使槳葉節距角發生改變。但變槳距過程槳葉節距 角變化只是0 到90°。 但風力機組風速傳感器安裝在風輪后的機艙上，不能正確反映掃及面上的風速，因此控制時一般都以發電機額定功率或轉子轉速為界，即當發電機輸出功率（轉速）低于額定值時，進

7、行變速恒頻控制，最大捕獲風能；而當輸出功率（轉速）高于額定值時，進行變槳距控制，維持發電機功率在額定值附近。 要實現真正的獨立變槳,輸入變量包括槳葉節距角變化和風速，以及每個槳葉受力等,實現多變量控制，但由于風速傳感器不能反映每個槳葉上的風速情況，而且復雜的控制程序也很難在工程中實現，所以目前工程上仍然采用統一變槳，即三個槳葉同時動作。 4.2根據執行機構的類型可分為液壓變槳和電動變槳。 4.3電動變槳根據所用電機可以分為直流伺服和交流伺服兩種類型。 4.3.1直流型電變槳伺服控制系統 直流型變槳系統主要由以下特點：采用串激直流電機,起動力矩大。對于轉動重達數噸直徑數十米的葉片有好處； 由于采

8、用直流無級調速,低速性能好； 不允許空載運行,否則會引起“飛車”； 電機有碳刷,維修困難； 加后備電池比較方便。 4.3.2交流型電變槳伺服控制系統 交流型變槳系統主要由以下特點： 采用交流永磁同步電機或交流異步電機,結構簡單維修工作量小； 代表了伺服控制系統的發展方向； 必須加ups；以便在電網突然斷電或其它緊急情況停機時, 變槳伺服系統可以通過自備的ups短暫供電,使變槳系統完成收槳及采取予定的其它安全措施。 5 變槳系統的組成 變槳系統主要由plc可逆直流調速裝置直流電機絕對式位置編碼器等組成,并由蓄電池作為后備電源。 plc組成變漿的控制系統,它通過現場總線(例如can總線)和主控制系

9、統通信,接受主控制系統的指令(主要是槳葉轉動的速度和角度指令),并控制可逆直流調速裝置驅動直流電機帶動槳葉朝要求的方向和角度轉動,同時plc還負責蓄電池的充電控制蓄電池電壓的監控等輔助控制。6 主要技術性能指標 6.1伺服電機 額定轉速 2500 rpm 額定輸出電流 17a 額定轉矩 20.0 nm 電源電壓 三相ac380v 絕緣等級 f級 冷卻方式 自然冷卻 防護等級 ip64 環境溫度 2540 制動裝置 選件 編碼器 絕對值位置編碼器 6.2伺服驅動系統 額定輸出功率 7.5kw 額定輸出電流 24a 額定輸出電壓 3×0-400v(ac) 輸入電壓 3×ac38

10、0v(2510) 過載能力 43a/30秒 冷卻方式 散熱器外置自然冷卻 防護等級 ip24或更高 環境溫度 2540 制動電阻 外加 配置現場總線 can總線 保護功能 電機三相短路保護過載保護電源過壓保護等外文原文1 fan pitch system overview1.1 wind turbine control system hardware were installed in three different parts the cabin control, installed inside the cabin. ground control, mounted on the

11、bottom of the tower. pitch control, internally mounted on the hub.1.2 man-machine interface the touch screen displays the operational status and parameters of the fan, or to start or stop the fan.1.3 wind turbine the four control way1.3.1 constant speed given pitch controlthe

12、0;generator is directly connected to the constant frequency of the grid, theaerodynamic control is not performed when the power generation.1.3.2 constant speed variable pitch controlthe generator is directly connected to the constant frequency of the power gri

13、d, power is used to adjust the pitch control in high winds.1.3.3 variable speed and pitch controlthe inverter of the generator and grid decoupling (decouples), to allow the rotor speed by the anti-torque control of the generator changes. in high winds, slow down the rotor until aerodynamic stall lim

14、it power to the desired level.1.4 variable speed pitch controlinverter generator and grid decoupling change permitted by the anti-torque control of the generator rotor speed. in high winds, the pitch control is used to adjust the power.2 pitch system worksfixed pitch by a stall of the blade, i.e. to

15、 change the airflow flowing around the blade cross section, resulting in a loss of efficiency, thereby controlling the maximum output power of the blower fan.the variable pitch fan is through the vanes to rotate along its longitudinal axis to change the angle of attack of the airflow to the blades,

16、thereby changing the the aerodynamic torque obtained by the wind turbine generator, so that the generator power output stable.pitch servo control system as the outer ring of wind power control system, plays a very important role in the control of the wind turbine. it controls the blade pitch angle o

17、f the wind turbine can automatically adjust the size of the wind velocity. the start of the low wind speed, the blade pitch can go to the right angle, so that the wind wheel has a maximum starting torque;, thereby changing wind when the wind velocity is too high, by adjusting the blade pitch, and to

18、 change the angle of attack of the airflow to the blades aerodynamic torque obtained by the generator set, the generator power output to maintain stability.3 pitch system and the comparison of fixed-blade systemfixed-blade away from the stall adjustment type wind turbine given award from the connect

19、ion of the paddle wheel load is fixed, the pitch angle is fixed, that is, when the wind changes, the windward angle of the blade can not be changes, bladethe airfoil itself has stall characteristics. when the wind speed is higher than the rated wind speed, the angle of attack of the air flow is incr

20、eased to a stall condition, the eddy current is generated on the surface of the blades, reducing efficiency, and to limit the power output of the generator. in order to improve the efficiency of wind turbines in low wind speeds, usually a two-speed generator (ie, large / small generator). segment ru

21、nning at low wind speeds, using a small motor to the blades county high aerodynamic efficiency and to improve the operating efficiency of the generator. stall adjusting the advantages of the type stall regulation is simple and reliable, passive stall regulated only by the blades when the wind speed

22、changes caused by variations in output power and the control system without any control, the control system greatly reduced. the disadvantage is that the weight of leaves (comparison with variable pitch fan blades), paddle wheel load, tower components by a larger force, and lower the overall efficie

23、ncy of the unit. the pitch adjustment wind turbines generating means through the pitch drive means, driving the rotation of the blades mounted on the hub, thereby changing the size of the blade pitch angle. adjustment method: when the wind turbine operating conditions, the control system comman

24、ds pitch pitch angle adjusted to 45 °, and then adjusted to 0 ° when the speed reaches a certain reach the rated speed until the wind turbine to the grid; during operation, when the output power is less than the rated power, the pitch angle to maintain the same, does not make any adjustmen

25、t in the 0 ° position; reach rated power when the generator output power, the regulation system adjusted according to the changes in the output power of the pitch angle size, so that the output power of the generator is maintained at the rated power. the disadvantage is that the more complex st

26、ructure, a relatively high failure rate.4 pitch classification4.1 variable pitch unified pitch and independent pitch system in accordance with its work can be divided into two kinds of waysunified variable pitch control that crew all blades by an executive agency drive, or drive three implementing a

27、gencies, the blade pitch angle changes. the torque of the hydraulic system, unified in a large wind turbine pitch distance is generally hydraulically. independent variable pitch mode, each blade by the independent pitch actuator driver, if one pitch implementation of structural failure, and the

28、 other two blades can still adjust the blade pitch angle, the power control, unified pitch implementation of structural failure, only a maintenance shutdown; further, the nature of the wind in the sweep of the entire wind wheel and the surface is not uniformly distributed, independent blade control

29、may be adjusted depending on the wind speed on the respective blades, not only to maintain the generator output power, but also can reduce the blade flapping vibration, independent blade control more than unified control has certain advantages. independent variable pitch control blade load borne by

30、a single executive agency, so generally used motor execution, motor internal ring gear paddle wheels driven by the drive gear, the blade pitch angle changes. but the pitch process changes in the pitch angle of the blade only from 0 to 90 °. but on wind turbines wind speed sensor is installed in

31、 the cabin after the wind wheel, can not correctly reflect the sweep and surface wind speed, control generator rated power or rotor speed is bounded generally low, that is, when the generator output power (speed) rated vscf control, maximum capture of wind energy; higher than the rated output power

32、(speed), pitch control and maintain the generator power rating near. to achieve a truly independent pitch input variables, including changes in blade pitch angle and wind speed, and each blade force multivariable control, but because of the wind speed sensor does not reflect the wind speed on each b

33、lade, and the complexity of the control program it is difficult to achieve in the project, so the project still unified pitch, that the three blades at the same time.4.2 can be divided according to the type of the implementing agency the hydraulic pitch, and the electric pitch.4.3 electric pitch dep

34、ending on the motor can be divided into two types of dc servo and ac servo.4.3.1 dc electric pitch servo control systemdc pitch system mainly consists of the following characteristics: a series wound dc motor starting torque. tens of meters in diameter blade rotation weighing several tons, is good;

35、dc stepless speed, low-speed performance; does not allow no-load operation, otherwise it would cause "speed" motor carbon brush, maintenance difficulties; canadian the backup battery is more convenient.4.3.2 ac electric pitch servo control systemac-type pitch system mainly consists of the

36、following characteristics: ac permanent magnet synchronous motors, or ac induction motor, simple structure, maintenance workload is small; represents the development direction of the servo control system; must be added to the ups; sudden power failure so that the grid or otheremergency shutdown, the

37、 pitch servo system can briefly owned the ups power supply system to complete the closing paddle and take other safety measures predetermined pitch.5 the composition of the pitch systemthe pitch system mainly by the plc, reversible, absolute position encoder dc speeder, dc motor by the battery as a backup power supply. plc composed of the pitch control system via