自發(fā)電多功能健身器的設(shè)計(jì)【跑步健身一體機(jī)】【說明書+CAD+SOLIDWORKS】

自發(fā)電多功能健身器的設(shè)計(jì)【跑步健身一體機(jī)】【說明書+CAD+SOLIDWORKS】,跑步健身一體機(jī),說明書+CAD+SOLIDWORKS,自發(fā)電多功能健身器的設(shè)計(jì)【跑步健身一體機(jī)】【說明書+CAD+SOLIDWORKS】,自發(fā),多功能,健身器,設(shè)計(jì),跑步,健身,一體機(jī),說明書,仿單,cad 分 類 號(hào) 密 級(jí) 寧畢業(yè)設(shè)計(jì)(論文)自發(fā)電多功能健身器設(shè)計(jì)所在學(xué)院機(jī)械與電氣工程學(xué)院專 業(yè)機(jī)械設(shè)計(jì)制造及其自動(dòng)化班 級(jí) 姓 名學(xué) 號(hào)指導(dǎo)老師 2015 年 3 月 31 日摘 要中國健身器材行業(yè)的發(fā)展始于20世紀(jì)80年代末，隨著中國加入WTO和北京申奧的成功，為健身器材行業(yè)的發(fā)展提供了有利條件和發(fā)展機(jī)遇，健身隊(duì)伍的不斷擴(kuò)大為健身器材生產(chǎn)商帶來濃厚商機(jī)。2006年1-12月，中國體育用品工業(yè)企業(yè)實(shí)現(xiàn)累計(jì)工業(yè)總產(chǎn)值51,537,399千元，比2005年同期增長24.61%；實(shí)現(xiàn)累計(jì)產(chǎn)品銷售收入49,740,392千元，比2005年同期增長24.2%；實(shí)現(xiàn)累計(jì)利潤總額1,821,317千元，比2005年同期增長18.62%。2007年1-12月，中國體育用品工業(yè)企業(yè)實(shí)現(xiàn)累計(jì)工業(yè)總產(chǎn)值61,313,721千元，比2006年同期增長19.39%；2008年1-10月，中國體育用品工業(yè)企業(yè)實(shí)現(xiàn)累計(jì)工業(yè)總產(chǎn)值55,906,766千元，比2007年同期增長17.67%。中國健身器材行業(yè)在迅速發(fā)展的同時(shí)，一些問題也日益顯露出來。特別是在國際市場缺乏知名品牌，產(chǎn)品附加值較低，同時(shí)，與國際先進(jìn)水平相比，中國不少生產(chǎn)企業(yè)還處在仿制生產(chǎn)階段，產(chǎn)品研發(fā)和技術(shù)創(chuàng)新能力不足。在消費(fèi)領(lǐng)域，與歐美等發(fā)達(dá)國家相比，健身器材產(chǎn)品在家庭的普及率及用于健身運(yùn)動(dòng)的人均消費(fèi)還很低。因此，中國健身器材工業(yè)企業(yè)必須抓住新的發(fā)展形勢，加大科技創(chuàng)新，努力提高產(chǎn)品質(zhì)量，加強(qiáng)自主研發(fā)能力，有關(guān)部門應(yīng)盡快制訂出健身器材統(tǒng)一的技術(shù)安全標(biāo)準(zhǔn)，加強(qiáng)售后服務(wù)。只有這樣才能在新形勢下立于不敗之地。它們的主要功能是：增加臂力：啞鈴握力器 多功能仰臥起坐板劃船器：主要用來增強(qiáng)手臂力量、背闊肌和動(dòng)作協(xié)調(diào)能力。AMT體適能運(yùn)動(dòng)機(jī)：與其他的健身方式不同，用戶可以在不同的運(yùn)動(dòng)模式和完全零沖擊體驗(yàn)下，類似于登樓梯、步行、慢跑和長跑間自由轉(zhuǎn)換。您可以通過這種即時(shí)轉(zhuǎn)換模式功能，調(diào)整您的訓(xùn)練模式來達(dá)到針對(duì)特定肌肉群訓(xùn)練的目標(biāo)。橢圓運(yùn)轉(zhuǎn)機(jī)：平滑流暢的運(yùn)動(dòng)軌跡和交叉坡度專利技術(shù)讓使用者以符合生物力學(xué)的姿勢鍛煉肌肉組，增加了鍛煉的多樣性和有效性。零阻力的鍛煉減少肌肉勞損的發(fā)生。健美車：鍛煉時(shí)，象騎自行車一樣，主要用來增強(qiáng)腿部力量，增強(qiáng)心血管功能。健步車：主要用以鍛煉腿、腰、腹部肌肉及心肺功能。跑步機(jī)：主要用以鍛煉腿、臀、腰、腹部肌肉及心肺功能。美腰機(jī)：可對(duì)腰部、背部作放松按摩。綜合型多功能器：一般都包括擴(kuò)胸器、引體向上、仰臥推舉、仰臥起坐等器械的功能。擴(kuò)胸器、引體向上、仰臥推舉，主要是用來鍛煉上肢力量及胸大肌力量；仰臥起坐，主要用來鍛煉腰肌群，減少腰腹部多余脂肪。關(guān)鍵詞：健身器；健身器； 改進(jìn)設(shè)計(jì)21Abstract The development direction of harvester will be to high-tech direction, making out the applicability of harvester is the development of the market, is very promising for different regions developed different harvester. Thus, the corresponding manufacturing combine high performance is the development of foreign harvester. The rice combine harvester can complete harvesting, threshing, separation and bagging operations at one time. The machine has the advantages of small volume, light weight, flexible operation, through and good adaptability, can better solve the problem of big, medium-sized harvester to harvest in the hilly, mountainous and paddy field. Thus, the corresponding manufacturing combine high performance is the development of foreign harvester. The rice combine harvester can complete harvesting, threshing, separation and bagging operations at one time. The machine has the advantages of small volume, light weight, flexible operation, through and good adaptability, can better solve the problem of big, medium-sized harvester to harvest in the hilly, mountainous and paddy field.Thus, the corresponding manufacturing combine high performance is the development of foreign harvester. The rice combine harvester can complete harvesting, threshing, separation and bagging operations at one time. The machine has the advantages of small volume, light weight, flexible operation, through and good adaptability, can better solve the problem of big, medium-sized harvester to harvest in the hilly, mountainous and paddy field.Thus, the corresponding manufacturing combine high performance is the development of foreign harvester. The rice combine harvester can complete harvesting, threshing, separation and bagging operations at one time. The machine has the advantages of small volume, light weight, flexible operation, through and good adaptability, can better solve the problem of big, medium-sized harvester to harvest in the hilly, mountainous and paddy field.Thus, the corresponding manufacturing combine high performance is the development of foreign harvester. The rice combine harvester can complete harvesting, threshing, separation and bagging operations at one time. The machine has the advantages of small volume, light weight, flexible operation, through and good adaptability, can better solve the problem of big, medium-sized harvester to harvest in the hilly, mountainous and paddy field.Thus, the corresponding manufacturing combine high performance is the development of foreign harvester. The rice combine harvester can complete harvesting, threshing, separation and bagging operations at one time. The machine has the advantages of small volume, light weight, flexible operation, through and good adaptability, can better solve the problem of big, medium-sized harvester to harvest in the hilly, mountainous and paddy field.Key Words: rice thresher threshing; improved design;目 錄摘 要IIIAbstractIV目 錄V第1章 緒論1第2章 總體方案確定22.1 健身器工作原理22.2健身器總體設(shè)計(jì)32.2.1健身運(yùn)動(dòng)的類型定位32.2.2 健身器的整機(jī)結(jié)構(gòu)及選擇32.2.3 健身器的工作流程3第3章 健身器結(jié)構(gòu)設(shè)計(jì)43.1 健身原理43.2 健身器類型選擇4第4章 發(fā)電原理設(shè)計(jì)64.1 整機(jī)消耗的功率計(jì)算64.1.1 健身器的功率消耗的計(jì)算64.1.2 變速強(qiáng)度計(jì)算64.2 發(fā)電機(jī)的選擇7第5章 軸的設(shè)計(jì)與計(jì)算155.1 軸的材料選擇155.2 軸的最小比確定155.3 軸的結(jié)構(gòu)設(shè)計(jì)155.4 軸的校核16第6章 傳動(dòng)方案設(shè)計(jì)196.1齒輪的設(shè)計(jì)246.1.1 齒輪類型的確定246.1.2 傳動(dòng)比的確定246.2 齒輪的設(shè)計(jì)計(jì)算25第7章 變速方案設(shè)計(jì)197.1變速的設(shè)計(jì)247.1.1 變速類型的確定247.1.2 變速比的確定247.2 變速執(zhí)行方案25結(jié)論26參考文獻(xiàn)27致 謝28第1章 緒論中國健身器材行業(yè)的發(fā)展始于20世紀(jì)80年代末，隨著中國加入WTO和北京申奧的成功，為健身器材行業(yè)的發(fā)展提供了有利條件和發(fā)展機(jī)遇，健身隊(duì)伍的不斷擴(kuò)大為健身器材生產(chǎn)商帶來濃厚商機(jī)。2006年1-12月，中國體育用品工業(yè)企業(yè)實(shí)現(xiàn)累計(jì)工業(yè)總產(chǎn)值51,537,399千元，比2005年同期增長24.61%；實(shí)現(xiàn)累計(jì)產(chǎn)品銷售收入49,740,392千元，比2005年同期增長24.2%；實(shí)現(xiàn)累計(jì)利潤總額1,821,317千元，比2005年同期增長18.62%。2007年1-12月，中國體育用品工業(yè)企業(yè)實(shí)現(xiàn)累計(jì)工業(yè)總產(chǎn)值61,313,721千元，比2006年同期增長19.39%；2008年1-10月，中國體育用品工業(yè)企業(yè)實(shí)現(xiàn)累計(jì)工業(yè)總產(chǎn)值55,906,766千元，比2007年同期增長17.67%。中國健身器材行業(yè)在迅速發(fā)展的同時(shí)，一些問題也日益顯露出來。特別是在國際市場缺乏知名品牌，產(chǎn)品附加值較低，同時(shí)，與國際先進(jìn)水平相比，中國不少生產(chǎn)企業(yè)還處在仿制生產(chǎn)階段，產(chǎn)品研發(fā)和技術(shù)創(chuàng)新能力不足。在消費(fèi)領(lǐng)域，與歐美等發(fā)達(dá)國家相比，健身器材產(chǎn)品在家庭的普及率及用于健身運(yùn)動(dòng)的人均消費(fèi)還很低。因此，中國健身器材工業(yè)企業(yè)必須抓住新的發(fā)展形勢，加大科技創(chuàng)新，努力提高產(chǎn)品質(zhì)量，加強(qiáng)自主研發(fā)能力，有關(guān)部門應(yīng)盡快制訂出健身器材統(tǒng)一的技術(shù)安全標(biāo)準(zhǔn)，加強(qiáng)售后服務(wù)。只有這樣才能在新形勢下立于不敗之地。它們的主要功能是：增加臂力：啞鈴握力器 多功能仰臥起坐板劃船器：主要用來增強(qiáng)手臂力量、背闊肌和動(dòng)作協(xié)調(diào)能力。AMT體適能運(yùn)動(dòng)機(jī)：與其他的健身方式不同，用戶可以在不同的運(yùn)動(dòng)模式和完全零沖擊體驗(yàn)下，類似于登樓梯、步行、慢跑和長跑間自由轉(zhuǎn)換。您可以通過這種即時(shí)轉(zhuǎn)換模式功能，調(diào)整您的訓(xùn)練模式來達(dá)到針對(duì)特定肌肉群訓(xùn)練的目標(biāo)。橢圓運(yùn)轉(zhuǎn)機(jī)：平滑流暢的運(yùn)動(dòng)軌跡和交叉坡度專利技術(shù)讓使用者以符合生物力學(xué)的姿勢鍛煉肌肉組，增加了鍛煉的多樣性和有效性。零阻力的鍛煉減少肌肉勞損的發(fā)生。健美車：鍛煉時(shí)，象騎自行車一樣，主要用來增強(qiáng)腿部力量，增強(qiáng)心血管功能。健步車：主要用以鍛煉腿、腰、腹部肌肉及心肺功能。跑步機(jī)：主要用以鍛煉腿、臀、腰、腹部肌肉及心肺功能。美腰機(jī)：可對(duì)腰部、背部作放松按摩。綜合型多功能器：一般都包括擴(kuò)胸器、引體向上、仰臥推舉、仰臥起坐等器械的功能。擴(kuò)胸器、引體向上、仰臥推舉，主要是用來鍛煉上肢力量及胸大肌力量；仰臥起坐，主要用來鍛煉腰肌群，減少腰腹部多余脂肪。第2章 總體方案確定2.1 健身器工作原理已為越來越多的人接受，成為家庭健身的不二之選。簡單介紹下跑步機(jī)的功能及使用：電動(dòng)跑步機(jī)上都有五窗式電子表，將運(yùn)動(dòng)者的跑步速度、時(shí)間、里程、消耗的卡路里數(shù)、心率都顯示出來。這樣，運(yùn)動(dòng)者在健身時(shí)，能夠?qū)ψ约旱纳眢w狀況了如指掌，由于傳動(dòng)滾帶是橡膠的，所以對(duì)腿腳關(guān)節(jié)的沖擊力比跑馬路要減少很多，不易引起傷病，從而保證運(yùn)動(dòng)量的科學(xué)和安全。跑步機(jī)是一種模擬跑步、散步運(yùn)動(dòng)的健身器材設(shè)備。跑步和踏步屬于全身性有氧運(yùn)動(dòng)。據(jù)運(yùn)動(dòng)學(xué)專家統(tǒng)計(jì)，在陸地上每跑1000米，雙腿就得撞擊地面600-700次。不僅腳部、腿部和臀部肌肉會(huì)受到震動(dòng)，還很容易扭傷肌肉或拉傷韌帶。而且，跑步時(shí)如果向上躍起和老年人就不適于通過劇烈的跑步方式健身。而跑步機(jī)在設(shè)計(jì)上越來越科學(xué)，能通過傳送帶上的緩沖裝置，減少對(duì)膝蓋和背部的沖擊。另外，科學(xué)設(shè)定了運(yùn)動(dòng)強(qiáng)度的跑步機(jī)能過糾正室外跑步者運(yùn)動(dòng)隨意的問題，通過保持一定的運(yùn)動(dòng)節(jié)奏和強(qiáng)度，幫助健身者在最短的時(shí)間內(nèi)獲得最大的有氧訓(xùn)練的效果。明顯提高心肺功能。而且由于跑步機(jī)都是參考人體生理機(jī)構(gòu)設(shè)計(jì)的，所以運(yùn)動(dòng)者還能通過使用機(jī)器糾正以前錯(cuò)誤的跑步姿勢。運(yùn)動(dòng)機(jī)一成不變的運(yùn)動(dòng)模式使人倦意漸生，而身體也不再感到挑戰(zhàn)。那么，怎樣才能為您的運(yùn)動(dòng)創(chuàng)造出變化呢？答案是自由的選擇。而這正是AMT體適運(yùn)動(dòng)機(jī)的獨(dú)具匠心之處。即使是您最細(xì)微的心血來潮變化，AMT也能隨您的心意改變動(dòng)作，讓每次的運(yùn)動(dòng)給您帶來不同的體驗(yàn)。這會(huì)使您繼續(xù)保持全神投入，并且能使您的身體在想要體驗(yàn)一種全新的運(yùn)動(dòng)方式亦或是需要片刻調(diào)整來平衡呼吸之間自由選擇。橢圓運(yùn)轉(zhuǎn)機(jī)l 體驗(yàn)和諧自然的手臂運(yùn)動(dòng)：手臂與腿部運(yùn)動(dòng)異常協(xié)調(diào)，令您在運(yùn)動(dòng)時(shí)體驗(yàn)前所未有的和諧感受；l 雙向平面力讓運(yùn)動(dòng)更全面：專利系統(tǒng)使水平及垂直平面都能產(chǎn)生阻力，豐富了您的運(yùn)動(dòng)感覺；l 0-27英寸的步幅范圍為運(yùn)動(dòng)提供無限驚喜：跟隨您思維及靈魂的渴望，隨時(shí)改變運(yùn)動(dòng)方式，體適運(yùn)動(dòng)讓訓(xùn)練增加無限可能及回報(bào)；l 感應(yīng)式面板和娛樂運(yùn)動(dòng)一體化系統(tǒng)：感應(yīng)式電子顯示結(jié)合綜合性電子娛樂系統(tǒng)，使鍛煉者更加愉悅地運(yùn)動(dòng)，同時(shí)也節(jié)省了時(shí)間；l 獨(dú)特的步幅調(diào)節(jié)功能隨時(shí)監(jiān)測肌肉狀態(tài)：實(shí)時(shí)監(jiān)測您的運(yùn)動(dòng)狀態(tài)，及時(shí)反饋肌肉在不同運(yùn)動(dòng)中的狀態(tài)。運(yùn)轉(zhuǎn)機(jī)1995年，第一臺(tái)運(yùn)轉(zhuǎn)機(jī)進(jìn)入市場，立刻掀起了一股運(yùn)轉(zhuǎn)機(jī)的健身熱潮，博得了各界的好評(píng)。EFX可調(diào)節(jié)坡度設(shè)計(jì)和全身肌肉多重阻力級(jí)別訓(xùn)練為用戶提供舒適平滑的健身體驗(yàn)。l 雙領(lǐng)域之冠：交叉坡度和全身功能綜合于這款器械上，使鍛煉效果更加顯著。在運(yùn)轉(zhuǎn)機(jī)上鍛煉，臀部的鍛煉效果尤為顯著，勝過在跑步機(jī)、單車及臺(tái)階器上的鍛煉效果；l 交叉坡度技術(shù)：使用者可以通過各種測驗(yàn)來選擇從15到40度的傾斜，從而達(dá)到交叉訓(xùn)練四頭肌、臀部、腿筋和腓腸肌。步幅根據(jù)傾斜度的大小從21.2到24.7不等，每一個(gè)步幅都給人無限舒適和自然之感；l感應(yīng)式面板和娛樂運(yùn)動(dòng)一體化系統(tǒng)：感應(yīng)式電子顯示結(jié)合綜合性電子娛樂系統(tǒng)，使鍛煉者愉悅地運(yùn)動(dòng)同時(shí)也節(jié)省了時(shí)間；l 直接可以選擇14個(gè)程序：只有6個(gè)鍵就可以控制14個(gè)程序，包括六個(gè)體能測試程序。使用過程中，操作者可以任意轉(zhuǎn)換至其他程序。l 按鍵控制：該按鍵為人提供快速的按鍵反應(yīng)以及提示按鍵聲，很容易使用這種傳統(tǒng)式按鍵，即使使用者在使用娛樂系統(tǒng)，也不妨礙跑步機(jī)信息的輸入。說到健身，就會(huì)想到健身房。在健身房鍛煉的話，有一樣器械是不得不說的，你可能也猜到了，那就是動(dòng)感單車。在很多健身房里，都可以看到一種和自行車長得很像的運(yùn)動(dòng)器材，這個(gè)叫做動(dòng)感單車（Spinning）單車的設(shè)計(jì)很人性化，可以根據(jù)每個(gè)人自身特點(diǎn)進(jìn)行細(xì)微調(diào)節(jié)，包括車把、車座、腳蹬、阻力。安全腳套始終固定在蹬板上，安全系數(shù)絕對(duì)可以放心。Spinning有自己的音樂編排，跟隨動(dòng)感音樂的節(jié)拍，調(diào)節(jié)阻力的大小，在教練的帶領(lǐng)下，由簡單到復(fù)雜，包括手臂、腹部和胸部在內(nèi)的所有的肌肉都在做功。據(jù)教練介紹，Spinning對(duì)心肺功能提高是很顯著的，它平均每小時(shí)燃燒體內(nèi)的脂肪也非常多，一節(jié)45分鐘的Spinning課會(huì)燃燒400到500卡路里熱量，相當(dāng)于長跑一個(gè)半小時(shí)。對(duì)于臀部、大腿，也有很好的塑形作用。一起上課的，有許多都是辦公樓里的白領(lǐng)。來參加Spinning課程的原因也各不相同，有的是因?yàn)槠綍r(shí)工作壓力大想發(fā)泄；有的是因?yàn)橄霚p肥，而Spinning的效果是最理想的；也有些老外，在自己國家的時(shí)候就經(jīng)常參加這個(gè)課程。在外國一節(jié)Spin-ning課是60分鐘，但由于國內(nèi)剛起步，所以在時(shí)間上還是安排為45分鐘。一節(jié)課上完，雖然我挺了過來，但是整件衣服都濕透了。原來流汗的感覺很舒服，也很快樂。在我看來，Spinning還有一個(gè)很特別的地方，它很能激動(dòng)人心。器械鍛煉是很枯燥的，雖然在跑步機(jī)上，雙眼可以注視著電視屏幕或聽聽音樂，但二、三十分鐘后，即使自己還有力氣跑下去，有時(shí)也因?yàn)榫氲《幌朐賵?jiān)持了。但Spinning不一樣，在快節(jié)奏中，當(dāng)你騎了半小時(shí)，你會(huì)越來越覺得力量無窮，而且是在心情愉快的氣氛中消耗熱量、燃燒脂肪的。 2.2健身器總體設(shè)計(jì)簡單介紹下跑步機(jī)的功能及使用：電動(dòng)跑步機(jī)上都有五窗式電子表，將運(yùn)動(dòng)者的跑步速度、時(shí)間、里程、消耗的卡路里數(shù)、心率都顯示出來。這樣，運(yùn)動(dòng)者在健身時(shí)，能夠?qū)ψ约旱纳眢w狀況了如指掌，由于傳動(dòng)滾帶是橡膠的，所以對(duì)腿腳關(guān)節(jié)的沖擊力比跑馬路要減少很多，不易引起傷病，從而保證運(yùn)動(dòng)量的科學(xué)和安全。跑步機(jī)是一種模擬跑步、散步運(yùn)動(dòng)的健身器材設(shè)備。跑步和踏步屬于全身性有氧運(yùn)動(dòng)。據(jù)運(yùn)動(dòng)學(xué)專家統(tǒng)計(jì)，在陸地上每跑1000米，雙腿就得撞擊地面600-700次。不僅腳部、腿部和臀部肌肉會(huì)受到震動(dòng)，還很容易扭傷肌肉或拉傷韌帶。而且，跑步時(shí)如果向上躍起和老年人就不適于通過劇烈的跑步方式健身。而跑步機(jī)在設(shè)計(jì)上越來越科學(xué)，能通過傳送帶上的緩沖裝置，減少對(duì)膝蓋和背部的沖擊。2.2.1健身器的類型定位它們的主要功能是：增加臂力：啞鈴握力器 多功能仰臥起坐板劃船器：主要用來增強(qiáng)手臂力量、背闊肌和動(dòng)作協(xié)調(diào)能力。AMT體適能運(yùn)動(dòng)機(jī)：與其他的健身方式不同，用戶可以在不同的運(yùn)動(dòng)模式和完全零沖擊體驗(yàn)下，類似于登樓梯、步行、慢跑和長跑間自由轉(zhuǎn)換。您可以通過這種即時(shí)轉(zhuǎn)換模式功能，調(diào)整您的訓(xùn)練模式來達(dá)到針對(duì)特定肌肉群訓(xùn)練的目標(biāo)。橢圓運(yùn)轉(zhuǎn)機(jī)：平滑流暢的運(yùn)動(dòng)軌跡和交叉坡度專利技術(shù)讓使用者以符合生物力學(xué)的姿勢鍛煉肌肉組，增加了鍛煉的多樣性和有效性。零阻力的鍛煉減少肌肉勞損的發(fā)生。健美車：鍛煉時(shí)，象騎自行車一樣，主要用來增強(qiáng)腿部力量，增強(qiáng)心血管功能。健步車：主要用以鍛煉腿、腰、腹部肌肉及心肺功能。跑步機(jī)：主要用以鍛煉腿、臀、腰、腹部肌肉及心肺功能。美腰機(jī)：可對(duì)腰部、背部作放松按摩。綜合型多功能器：一般都包括擴(kuò)胸器、引體向上、仰臥推舉、仰臥起坐等器械的功能。擴(kuò)胸器、引體向上、仰臥推舉，主要是用來鍛煉上肢力量及胸大肌力量；仰臥起坐，主要用來鍛煉腰肌群，減少腰腹部多余脂肪。2.2.2 健身器的整機(jī)結(jié)構(gòu)及選擇跑步機(jī)是一種模擬跑步、散步運(yùn)動(dòng)的健身器材設(shè)備。跑步和踏步屬于全身性有氧運(yùn)動(dòng)。據(jù)運(yùn)動(dòng)學(xué)專家統(tǒng)計(jì)，在陸地上每跑1000米，雙腿就得撞擊地面600-700次。不僅腳部、腿部和臀部肌肉會(huì)受到震動(dòng)，還很容易扭傷肌肉或拉傷韌帶。而且，跑步時(shí)如果向上躍起和老年人就不適于通過劇烈的跑步方式健身。而跑步機(jī)在設(shè)計(jì)上越來越科學(xué)，能通過傳送帶上的緩沖裝置，減少對(duì)膝蓋和背部的沖擊。另外，科學(xué)設(shè)定了運(yùn)動(dòng)強(qiáng)度的跑步機(jī)能過糾正室外跑步者運(yùn)動(dòng)隨意的問題，通過保持一定的運(yùn)動(dòng)節(jié)奏和強(qiáng)度，幫助健身者在最短的時(shí)間內(nèi)獲得最大的有氧訓(xùn)練的效果。明顯提高心肺功能。而且由于跑步機(jī)都是參考人體生理機(jī)構(gòu)設(shè)計(jì)的，所以運(yùn)動(dòng)者還能通過使用機(jī)器糾正以前錯(cuò)誤的跑步姿勢。2.2.3 健身器的工作流程 簡單介紹下跑步機(jī)的功能及使用：電動(dòng)跑步機(jī)上都有五窗式電子表，將運(yùn)動(dòng)者的跑步速度、時(shí)間、里程、消耗的卡路里數(shù)、心率都顯示出來。這樣，運(yùn)動(dòng)者在健身時(shí)，能夠?qū)ψ约旱纳眢w狀況了如指掌，由于傳動(dòng)滾帶是橡膠的，所以對(duì)腿腳關(guān)節(jié)的沖擊力比跑馬路要減少很多，不易引起傷病，從而保證運(yùn)動(dòng)量的科學(xué)和安全。跑步機(jī)是一種模擬跑步、散步運(yùn)動(dòng)的健身器材設(shè)備。跑步和踏步屬于全身性有氧運(yùn)動(dòng)。據(jù)運(yùn)動(dòng)學(xué)專家統(tǒng)計(jì)，在陸地上每跑1000米，雙腿就得撞擊地面600-700次。不僅腳部、腿部和臀部肌肉會(huì)受到震動(dòng)，還很容易扭傷肌肉或拉傷韌帶。而且，跑步時(shí)如果向上躍起和老年人就不適于通過劇烈的跑步方式健身。而跑步機(jī)在設(shè)計(jì)上越來越科學(xué)，能通過傳送帶上的緩沖裝置，減少對(duì)膝蓋和背部的沖擊。第3章 健身器設(shè)計(jì)3.1 健身器原理1）沖擊健身器：對(duì)對(duì)方健身器元素沖擊作用秒殺頭和健身器。較高的沖擊速度，健身器越強(qiáng)，但也越大裂解速率。2）摩擦健身器：由組件和之間，以及和健身器健身器離去之間的摩擦。健身器間隙的大小是至關(guān)重要的。3）梳刷健身器：健身器由拉力健身器部件進(jìn)行。4）滾動(dòng)健身器：打谷健身器通過施加壓力的元素進(jìn)行糧食。在這種情況下，力作用在主要沿晶面的法向力。5）振動(dòng)健身器：由健身器元件用于施加高頻振動(dòng)進(jìn)行健身器。健身器是的幾種方法在長期的生產(chǎn)實(shí)踐過程中總結(jié)而來去殼大米儲(chǔ)存。如果裸存儲(chǔ)，則存儲(chǔ)時(shí)間短。米粒脆，易折斷。因此，本設(shè)計(jì)采用梳刷健身器，主要針對(duì)與健身器完成補(bǔ)充兩者。3.2 健身器類型選擇首先，明確多功能健身產(chǎn)品的使用效果。應(yīng)該具備一兩種功能的產(chǎn)品，如想鍛煉臂部肌肉就選臂力器，想鍛煉腰腹部和腿部就選健騎機(jī)或健腹輪等。至于想進(jìn)行全身性、綜合性的鍛煉，除了選擇去專業(yè)健身房，可以輔助有規(guī)律的室外器械鍛煉。握力臂力器其次，考慮居住環(huán)境與居住條件。一個(gè)適合自己家庭氛圍和居住條件的器材，才會(huì)提升生活品質(zhì)。一般來說，單一功能的健身器占地較小，一些功能比較多的健身器在家中使用時(shí)，有些功能由于空間的限制，并不能真正發(fā)揮作用；而且如果占地過大，每次使用都需要安裝或者搬動(dòng)，也會(huì)大大降低健身的熱情。第三，價(jià)格適中。不要盲目崇拜國外產(chǎn)品，國內(nèi)企業(yè)生產(chǎn)的產(chǎn)品，價(jià)格相對(duì)較低，種類較多，這些產(chǎn)品的功能也是完全可以滿足鍛煉的需要，而且由于加入了一些本土化的元素，有些功能也是國外健身器材所缺乏的。第四，售后服務(wù)要注重。購買健身器時(shí)也要像買其他產(chǎn)品一樣，不要忽視售后服務(wù)的問題，特別是零部件較多的健身器，更要問清楚售后服務(wù)的具體辦法，國外產(chǎn)品要問清是否有維修點(diǎn)。第4章 發(fā)電原理設(shè)計(jì)4.1 整機(jī)消耗的功率計(jì)算4.1.1 健身器的功率消耗的計(jì)算 健身器在工作時(shí)，在運(yùn)轉(zhuǎn)穩(wěn)定性較好（保障健身器運(yùn)轉(zhuǎn)穩(wěn)定性的條件：有足夠的轉(zhuǎn)動(dòng)慣量；發(fā)動(dòng)機(jī)有足夠的儲(chǔ)備功率和較靈敏的調(diào)速器）的條件下，其功率總耗用N 由兩部分組成：一部分用于克服空轉(zhuǎn)而消耗的功率（占總功率消耗的5%-7%），一部分用于克服健身器阻力而消耗的功率（占總功率消耗的93%-95%），所以 健身器的功率消耗為： N =+ （kW ） (4) 1)其中空轉(zhuǎn)功率消耗: =+ 式中：系數(shù)，為克服軸承及健身器的摩擦阻力的功率消耗， B系數(shù)，為克服轉(zhuǎn)動(dòng)時(shí)的空氣迎風(fēng)阻力而消耗的功率， . 2)其中健身器功率消耗:這個(gè)過程比較復(fù)雜，健身器首先是以較低的速度進(jìn)入健身器入口處，與高速旋轉(zhuǎn)的健身器接觸，然后被拖入健身器間隙進(jìn)行健身器，既有梳刷也有打擊，研究的依據(jù)是動(dòng)量守恒定律： 沖量轉(zhuǎn)換為動(dòng)量： ， （5) 單位時(shí)間喂入的量； 綜合搓擦系數(shù)，0.7-0.8； 的切向速度，15m / s。 將數(shù)據(jù)代入N =+ 得： N= 0.52+1.5=2.02（）4.1.2 變速強(qiáng)度計(jì)算 健身器消耗的功率由下式可求得： (6) 其中：單位時(shí)間進(jìn)入健身器的脫出物質(zhì)量（）； 單位脫出物質(zhì)量篩所需的功率（），上篩：0.4-0.5，下篩：0.25-0.3； 選別能力系數(shù)，0.8-0.9。 代入數(shù)據(jù)可得消耗的功率： 1.75（）4.2 帶輪的選擇通過上面的計(jì)算，可以知道整個(gè)健身器消耗的功率，其消耗的總功率為： 0.043+2.02+1.75+1=4.813（）第5章 軸的設(shè)計(jì)與計(jì)算5.1 軸的材料選擇 健身器在工作時(shí)，健身器軸的轉(zhuǎn)速很高，而且傳遞的扭矩很大，綜合考慮，軸的材料選擇45鋼調(diào)質(zhì)處理，硬度為195-290，其接觸疲勞強(qiáng)度極限，彎曲疲勞極限取。5.2 軸的最小比確定 由公式 (17) 其中 該軸傳遞的功率，； 該軸的轉(zhuǎn)速，； 指軸的材料和承載情況確定常數(shù)。 已知 =2.02，查機(jī)械設(shè)計(jì)手冊(cè)21可得C=128，代入上式可得 選。5.3 軸的結(jié)構(gòu)設(shè)計(jì) 為了便于軸上零件的拆卸，經(jīng)常把軸做成階梯形。軸的比從軸端逐漸向中間增大，可依次將齒輪和帶輪等從軸的上端裝拆，為了使軸上的零件便于安裝，軸端及各軸的端部應(yīng)有倒角。軸上磨削的軸段應(yīng)有砂輪越程槽，車制螺紋軸段應(yīng)有退刀槽。各段軸的比，如有配合要求的軸段，應(yīng)盡量采用標(biāo)準(zhǔn)比，安裝軸承、齒輪等標(biāo)準(zhǔn)件的軸徑，應(yīng)符合各標(biāo)準(zhǔn)件的內(nèi)徑系列規(guī)定。采用的套筒、螺母、軸端擋圈作軸向固定時(shí)，應(yīng)把裝零件的軸段長度做的比零件輪轂短，以確保螺母等緊靠零件端面。健身器軸結(jié)構(gòu)初定如圖7所示：圖7 軸的結(jié)構(gòu)圖5.4 軸的校核5.4.1 軸上載荷的計(jì)算 求軸承上的支反力 垂直面內(nèi)： 水平面內(nèi)： 畫受力簡圖與彎矩圖，如圖8所示： 據(jù)第四強(qiáng)度理論且忽略鍵槽影響 表4 受力分析載荷 水平面H 垂直面V 支反力F 彎矩M 總彎矩 扭矩T 軸安全。5.4.2 按彎扭合成應(yīng)力校核軸強(qiáng)度進(jìn)行校核時(shí)，只校核軸承上承受彎矩和扭矩最大的截面強(qiáng)度，取=0.6,軸的計(jì)算應(yīng)力為： 前已選定軸材料為45號(hào)鋼,調(diào)質(zhì)處理,由機(jī)械設(shè)計(jì)23表15-1查得=60Mpa 因此S=1.5 故安全第6章 傳動(dòng)方案設(shè)計(jì)6.1 材料的選擇及許用應(yīng)力的確定根據(jù)設(shè)計(jì)方案，本設(shè)計(jì)采用的是直齒圓柱齒輪傳動(dòng)，考慮到健身器材功率較大，故大、小齒輪都選用硬齒面。選取大、小齒輪的材料均為40Cr，并經(jīng)調(diào)質(zhì)及表面淬火，齒面硬度為4855HRC。因采用表面淬火，輪齒的變形不大，不需要磨削，故初選7級(jí)精度。6.2 按輪齒接觸強(qiáng)度的計(jì)算 根據(jù)公式 (14) 確定公式內(nèi)的各計(jì)算數(shù)值 1）試選載荷系數(shù)； 2)計(jì)算小齒輪傳遞的轉(zhuǎn)矩: 3）由機(jī)械設(shè)計(jì)手冊(cè)20選取齒寬系數(shù)； 4）由手冊(cè)20查得材料的彈性影響系數(shù) 5）按齒面硬度中間值查手冊(cè)20得大、小齒輪得接觸疲勞強(qiáng)度極限 (15) 6）計(jì)算應(yīng)力循環(huán)次數(shù) 7)查設(shè)計(jì)手冊(cè)19得接觸疲勞壽命系數(shù) 8）計(jì)算接觸疲勞許用應(yīng)力取失效概率為1，安全系數(shù)S1，得 計(jì)算 1）試算小齒輪分度圓直徑，代入中較小的值 2）計(jì)算圓周速度 3）計(jì)算齒寬 4）計(jì)算齒寬與齒高之比模數(shù) 齒高 5）計(jì)算載荷系數(shù) 根據(jù)，7級(jí)精度，由手冊(cè)21查得動(dòng)載系數(shù); 假設(shè),由手冊(cè)21查得齒間載荷分配系數(shù)； 由手冊(cè)21查得使用系數(shù)； 由表4查得接觸強(qiáng)度計(jì)算用齒向載荷分布系數(shù)； 由手冊(cè)21查得彎曲疲勞強(qiáng)度計(jì)算用齒向載荷分布系數(shù). 故載荷系數(shù) 6）按實(shí)際的載荷系數(shù)校正所得的分度圓直徑，得 7）計(jì)算模數(shù) 6.3 按齒根彎曲強(qiáng)度設(shè)計(jì) 彎曲強(qiáng)度的設(shè)計(jì)公式為 (16)確定公式內(nèi)的各計(jì)算數(shù)值 1）由手冊(cè)21得大、小齒輪的彎曲疲勞強(qiáng)度極限； 2）由手冊(cè)21查得彎曲疲勞壽命系數(shù)；。 3）計(jì)算彎曲疲勞許用應(yīng)力 取彎曲疲勞安全系數(shù)S1.4，得 4）計(jì)算載荷系數(shù)K 5）查取齒形系數(shù) 由手冊(cè)21查得齒形系數(shù) 。 6）查取應(yīng)力校正系數(shù) 由手冊(cè)21得應(yīng)力校正系數(shù) 。 7）計(jì)算大小齒輪的并加以比較 小齒輪的數(shù)值大。 設(shè)計(jì)計(jì)算對(duì)比計(jì)算結(jié)果，由齒面接觸疲勞強(qiáng)度計(jì)算的模數(shù)m略大于由齒根疲勞強(qiáng)度計(jì)算的模數(shù)，由于齒輪模數(shù)m的大小主要取決于彎曲強(qiáng)度所決定的承載能力，而齒面接觸疲勞強(qiáng)度所決定的承載能力，僅與齒輪直徑（即模數(shù)與齒數(shù)的乘積）有關(guān)，可取由彎曲強(qiáng)度算得得模數(shù)1.64，就近圓整為標(biāo)準(zhǔn)值m2mm，按接觸強(qiáng)度算得的分度圓直徑，。取 取 幾何尺寸計(jì)算 1）計(jì)算分度圓直徑 2）計(jì)算中心距 3）計(jì)算齒輪寬度 驗(yàn)算符合要求。第7章 變速方案設(shè)計(jì)如圖所示，變速器，有三個(gè)檔位，當(dāng)波動(dòng)桿處于中間是，是中等狀態(tài)，處于左邊是低速狀態(tài)，處于右邊，是高速狀7.1 健身器設(shè)計(jì)7.1.1 V帶形狀選擇 弓齒的形狀有“V”字形及“U”字形兩種。試驗(yàn)結(jié)果表明“V”字形弓齒頂角為22時(shí)，消耗的功率和斷穗率都最少。“U”字形弓齒圓弧大的功率消耗小，斷穗率也小。本設(shè)計(jì)上健身器齒采用三重齒，它們能夠提高健身器質(zhì)量。弓齒用45鋼制造，淬火部位的硬度為HRC 45-5516。7.1.2 弓齒的排列健身器的弓齒排列按斜線，具有工作平穩(wěn)，生產(chǎn)率高的特點(diǎn)。所以，在本設(shè)計(jì)中，采用的是齒排斜線配置。弓齒依螺旋排列的目地除了達(dá)到健身器時(shí)負(fù)荷均勻外，而且還能促使雜余沿軸向流動(dòng)。所以，選擇弓齒的排列按照螺旋線分區(qū)的排列。分三個(gè)區(qū)，第一區(qū)段為梳整區(qū)，約占全長的10%-15%，梳整齒選材為6-8mm 的鋼絲，對(duì)作梳導(dǎo)和推送，梳整齒安裝在喂入端的錐形面上。第二區(qū)段為健身器區(qū)，約占全長的70-7517。鋼絲比5-6mm，它又分前后兩區(qū)。前區(qū)約占全長的40-45。由于剛進(jìn)入健身器間隙，健身器量較大，安裝了加強(qiáng)齒。 第三區(qū)為排稿區(qū)，只占全長的8-10，鋼絲比5-6mm，為加強(qiáng)排草能力，齒距較密，為60毫米左右，齒形與健身器齒相同。7.1.3 相關(guān)參數(shù)的計(jì)算 螺旋排列的列數(shù)：。 弓齒軸向間距：。 弓齒數(shù)：。7.2變速的設(shè)計(jì)7.2.1 變速類型的確定 變速有編織篩式和柵格式兩種，其比較如表2所示。 表2 編織篩式與柵格式變速的對(duì)比 經(jīng)過綜合比較，本設(shè)計(jì)采用柵格式變速，其結(jié)構(gòu)如圖6所示。 7.2.2 變速比的確定 變速比是決定生產(chǎn)率的主要參數(shù)（在限制轉(zhuǎn)速的情況下，變速比是決定生產(chǎn)率的唯一參數(shù)），變速比與生產(chǎn)率成正比，但不是一次性線性關(guān)系。根據(jù)變速比與生產(chǎn)率的關(guān)系和實(shí)際生產(chǎn)情況，本設(shè)計(jì)現(xiàn)選取變速比D為490mm，對(duì)健身器來說，其健身器間隙就是齒頂圓與變速圓鋼之間的間隙。 7.2.3 變速執(zhí)行方案與變速入口間隙和出口間隙的比值為3-4。出入口間隙小則變速分離能力強(qiáng)，但過小易產(chǎn)生堵塞。入口間隙過大（30mm）則抓取作物的能力和變速前端的分離能力減弱。取入口的間隙為30mm，則出口的間隙為10mm，健身器間隙從喂入口到出口從30mm逐漸減至10mm，在健身器區(qū)為3-8mm，取6mm。參考文獻(xiàn)結(jié)論一、總結(jié)第一部分，文獻(xiàn)資料的搜集與整理。通過專利網(wǎng)、文獻(xiàn)庫和老師給的資料，了解了當(dāng)前主流的幾種機(jī)車轉(zhuǎn)向架助推器類型。然后根據(jù)文獻(xiàn)資料，綜合分析每種助推器的優(yōu)劣，綜合比較借鑒，初步確定采用撬棍杠桿式助推方式。第二部分，確定局部和整體方案。進(jìn)一步分析撬棍式助推器的助推方式，及需要哪些相配合的機(jī)構(gòu)，將助推器分為執(zhí)行系統(tǒng)、系統(tǒng)和驅(qū)動(dòng)系統(tǒng)三部分。然后先對(duì)執(zhí)行機(jī)構(gòu)進(jìn)行理論受力分析，分析其位移量。借此計(jì)算出部分齒輪減速的比和需要的電機(jī)的轉(zhuǎn)矩，從而確定電機(jī)選型，至此部分和驅(qū)動(dòng)部分也同時(shí)確定下來。第四部分，各部件具體機(jī)構(gòu)設(shè)計(jì)和校核。根據(jù)前面三章的內(nèi)容，確定執(zhí)行系統(tǒng)、系統(tǒng)各部件的具體結(jié)構(gòu)尺寸，確定軸上零件的定位和裝配方式，最后選擇合適的軸承并對(duì)各部件進(jìn)行校核。二、設(shè)計(jì)的不足之處 這次的設(shè)計(jì)還只是階段性的，助推器的結(jié)構(gòu)還可以進(jìn)行局部優(yōu)化，中間的系統(tǒng)也有很多不同的方案可以選擇，比如選擇齒輪代替鏈傳， 三、個(gè)人體會(huì)畢業(yè)設(shè)計(jì)是大學(xué)四年期間最后一次正式的機(jī)構(gòu)設(shè)計(jì)了，可以說是跨出大學(xué)校園的最后一步。需要考察自己大學(xué)期間學(xué)習(xí)的各項(xiàng)專業(yè)技能和課程知識(shí)，并且要綜合運(yùn)用，對(duì)自己也是一次全面的提高。因?yàn)榭佳械年P(guān)系，很多時(shí)間被占用了，所以畢業(yè)設(shè)計(jì)的時(shí)間比較緊，中間過程略顯倉促。剛開始做課題使并沒有什么頭緒，不知道從哪里下手。就像無頭的蒼蠅，這里做一些，那里做一些，其中受力分析就做了很多遍，事實(shí)證明這些都是無用功。后來跟指導(dǎo)老師溝通了很多次，確定下來步驟。先綜合分析助推器的總體結(jié)構(gòu)，分成幾部分，比如驅(qū)動(dòng)、執(zhí)行部分，這樣就有了一個(gè)大的方向。因此，我體會(huì)到初步設(shè)計(jì)必須確定每一部分的工作，由大到小，先分析結(jié)構(gòu)，再對(duì)結(jié)構(gòu)的運(yùn)動(dòng)和動(dòng)力性能綜合分析，不斷的修正、不斷的改進(jìn)，這樣才能做出完整的設(shè)計(jì)。參考文獻(xiàn)1楊穎萍，施俊俊，孫英彪.客車轉(zhuǎn)向架構(gòu)架焊修工藝的探討A.第十四屆全國機(jī)械設(shè)計(jì)年會(huì)論文集C.中國機(jī)械工程學(xué)會(huì)，2008.2蒼松.動(dòng)車組轉(zhuǎn)向架虛擬裝配技術(shù)的研究與應(yīng)用D.遼寧：大連交通大學(xué)，20093Http:/www.easymover.it/en/pusher.php,5-20/2013-5-204Gregory James Newell. Materials handling device and system. P.U.S. Patent No.7168514B2,Jan.30,20075Http:/www.fetec-papier.de/Easy_Mover_-_Rllentransportger/Details_Easy_Mover/details_easy_mover.html,5-20/2013-5-206Http:/www.mastermover.com,5-20/2013-5-2013濮良貴，紀(jì)名剛，陳國定等.機(jī)械設(shè)計(jì)M.第八版.北京：高等教育出版社,2006,514王昆，何小柏，汪信遠(yuǎn).機(jī)械設(shè)計(jì)、機(jī)械設(shè)計(jì)基礎(chǔ)課程設(shè)計(jì)M.北京：高等教育出版社，1996致 謝 畢業(yè)設(shè)計(jì)也接近尾聲了，也意味我在大學(xué)的生活就要?jiǎng)澤弦粋€(gè)句號(hào)?；剡^頭來看看自己做設(shè)計(jì)的過程，也有很多體會(huì)。助推器的助推方案不斷推倒，不斷重建。也讓我對(duì)專業(yè)技能有了更深的了解。 首先，誠摯感謝我的指導(dǎo)老師。每當(dāng)我有不懂的問題的時(shí)候，老師總是耐心為我解答，而且解答地很詳細(xì)，讓我對(duì)下一步的工作有了清晰的認(rèn)識(shí)。在我沒有頭緒的時(shí)候，老師總是適時(shí)地提出自己的建議，循循善誘，給我思考的空間，鍛煉了我的專業(yè)思維。老師總是抽出自己的時(shí)間來督促我論文的進(jìn)度，這是很無私的。在此，向老師表示崇高的謝意！ 感謝四年來同學(xué)、老師的陪伴，感謝他們?yōu)槲姨岢龅挠幸娴暮蛯氋F的建議，有了他們的支持和鼓勵(lì)，才讓我度過了四年充實(shí)的大學(xué)生活。rugged, e generation curr guidelines 2 Power System Network Description bine can enter self-excitation operation. The voltage and fre- quency during off-grid operation are determined by the balance between the systems reactive and real power. Downloaded 28 Mar 2008 to 211.82.100.20. Redistribution subject to ASME license or copyright; see http:/www.asme.org/terms/Terms_Use.cfm We investigate a very simple power system network consisting of one 1.5 MW, fixed-speed wind turbine with an induction gen- erator connected to a line feeder via a transformer H208492 MVA, 3 phase, 60 Hz, 690 V/12 kVH20850. The low-speed shaft operates at 22.5 rpm, and the generator rotor speed is 1200 rpm at its syn- chronous speed. A diagram representing this system is shown in Fig. 1. The power system components analyzed include the following: An infinite bus and a long line connecting the wind turbine to the substation A transformer at the pad mount One potential problem arising from self-excitation is the safety aspect. Because the generator is still generating voltage, it may compromise the safety of the personnel inspecting or repairing the line or generator. Another potential problem is that the generators operating voltage and frequency may vary. Thus, if sensitive equipment is connected to the generator during self-excitation, that equipment may be damaged by over/under voltage and over/ under frequency operation. In spite of the disadvantages of oper- ating the induction generator in self-excitation, some people use this mode for dynamic braking to help control the rotor speed during an emergency such as a grid loss condition. With the proper choice of capacitance and resistor load H20849to dump the energy from the wind turbineH20850, self-excitation can be used to maintain the wind turbine at a safe operating speed during grid loss and me- chanical brake malfunctions. The equations governing the system can be simplified by look- ing at the impedance or admittance of the induction machine. To Contributed by the Solar Energy Division of THE AMERICAN SOCIETY OF MECHANI- CAL ENGINEERS for publication in the ASME JOURNAL OF SOLAR ENERGY ENGINEERING. Manuscript received: February 28, 2005; revised received: July 22, 2005. Associate Editor: Dale Berg. Journal of Solar Energy Engineering NOVEMBER 2005, Vol. 127 / 581Copyright 2005 by ASME E. Muljadi C. P. Butterfield National Renewable Energy Laboratory, Golden, Colorado 80401 H. Romanowitz Oak Creek Energy Systems Inc., Mojave, California 93501 R. Yinger Southern California Edison, Rosemead, California 91770 Self-Excitation Wind Power Traditional wind turbines they are inexpensive, tion generators requir is often used. Because the capacitor compensation among the wind turbine, tant aspects of wind content in the output ena and gives some H20851DOI: 10.1115/1.2047590 1 Introduction Many of todays operating wind turbines have fixed speed in- duction generators that are very reliable, rugged, and low cost. During normal operation, an induction machine requires reactive power from the grid at all times. Thus, the general practice is to compensate reactive power locally at the wind turbine and at the point of common coupling where the wind farm interfaces with the outside world. The most commonly used reactive power com- pensation is capacitor compensation. It is static, low cost, and readily available in different sizes. Different sizes of capacitors are generally needed for different levels of generation. A bank of parallel capacitors is switched in and out to adjust the level of compensation. With proper compensation, the power factor of the wind turbine can be improved significantly, thus improving over- all efficiency and voltage regulation. On the other hand, insuffi- cient reactive power compensation can lead to voltage collapse and instability of the power system, especially in a weak grid environment. Although reactive power compensation can be beneficial to the overall operation of wind turbines, we should be sure the compen- sation is the proper size and provides proper control. Two impor- tant aspects of capacitor compensation, self-excitation H208511,2H20852 and harmonics H208513,4H20852, are the subjects of this paper. In Sec. 2, we describe the power system network; in Sec. 3, we discuss the self-excitation in a fixedspeed wind turbine; and in Sec. 4, we discuss harmonics. Finally, our conclusions are pre- sented in Sec. 5. and Harmonics in Generation are commonly equipped with induction generators because and require very little maintenance. Unfortunately, induc- reactive power from the grid to operate; capacitor compensation the level of required reactive power varies with the output power, must be adjusted as the output power varies. The interactions the power network, and the capacitor compensation are impor- that may result in self-excitation and higher harmonic ent. This paper examines the factors that control these phenom- on how they can be controlled or eliminated. H20852 Capacitors connected in the low voltage side of the trans- former An induction generator For the self-excitation, we focus on the turbine and the capaci- tor compensation only H20849the right half of Fig. 1H20850. For harmonic analysis, we consider the entire network shown in Fig. 1. 3 Self-Excitation 3.1 The Nature of Self-Excitation in an Induction Generator. Self-excitation is a result of the interactions among the induction generator, capacitor compensation, electrical load, and magnetic saturation. This section investigates the self- excitation process in an off-grid induction generator; knowing the limits and the boundaries of self-excitation operation will help us to either utilize or to avoid self-excitation. Fixed capacitors are the most commonly used method of reac- tive power compensation in a fixed-speed wind turbine. An induc- tion generator alone cannot generate its own reactive power; it requires reactive power from the grid to operate normally, and the grid dictates the voltage and frequency of the induction generator. Although self-excitation does not occur during normal grid- connected operation, it can occur during off-grid operation. For example, if a wind turbine operating in normal mode becomes disconnected from the power line due to a sudden fault or distur- bance in the line feeder, the capacitors connected to the induction generator will provide reactive power compensation, and the tur- Downloaded 28 Mar 2008 to 211.82.100.20. Redistribution subject to ASME license or copyright; see http:/www.asme.org/terms/Terms_Use.cfm operate in an isolated fashion, the total admittance of the induc- tion machine and the rest of the connected load must be zero. The voltage of the system is determined by the flux and frequency of the system. Thus, it is easier to start the analysis from a node at one end of the magnetizing branch. Note that the term “imped- ance” in this paper is the conventional impedance divided by the frequency. The term “admittance” in this paper corresponds to the actual admittance multiplied by the frequency. 3.2 Steady-State Representation. The steady-state analysis is important to understand the conditions required to sustain or to diminish self-excitation. As explained above, self-excitation can be a good thing or a bad thing, depending on how we encounter the situation. Figure 2 shows an equivalent circuit of a capacitor- compensated induction generator. As mentioned above, self- excitation operation requires that the balance of both real and reactive power must be maintained. Equation H208491H20850 gives the total admittance of the system shown in Fig. 2: Y S + Y M H11032 + Y R H11032 =0, H208491H20850 where Y S H11005 effective admittance representing the stator winding, the capacitor, and the load seen by node M Y M H11032 H11005 effective admittance representing the magnetizing branch as seen by node M, referred to the stator side Y R H11032 H11005 effective admittance representing the rotor winding as seen by node M, referred to the stator side H20849Note: the superscript “ H11032” indicates that the values are referred to the stator side.H20850 Equation H208491H20850 can be expanded into the equations for imaginary and real parts as shown in Eqs. H208492H20850 and H208493H20850: R 1L /H9275 H20849R 1L /H9275H20850 2 + L 1L 2 + R R H11032/SH9275 H20849R R H11032/SH9275H20850 2 + L LR H11032 2 =0 H208492H20850 where Fig. 1 The physical diagram of the system under investigation Fig. 2 Per phase equivalent circuit of an induction generator under self-excitation mode 582 / Vol. 127, NOVEMBER 2005 1 L M H11032 + L 1L H20849R 1L /H9275H20850 2 + L 1L 2 + L LR H11032 H20849R R H11032/SH9275H20850 2 + L LR H11032 2 =0 H208493H20850 R 1L = R S + R L H20849H9275CR L H20850 2 +1 L 1L = L LS CR L H20849H9275CR L H20850 2 +1 R S H11005 stator winding resistance L LS H11005 stator winding leakage inductance R R H11032 H11005 rotor winding resistance L LR H11032 H11005 rotor winding leakage inductance L M H11032 H11005 stator winding resistance S H11005 operating slip H9275 H11005 operating frequency R L H11005 load resistance connected to the terminals C H11005 capacitor compensation R 1L and L 1L are the effective resistance and inductance, respectively, representing the stator winding and the load as seen by node M. One important aspect of self-excitation is the magnetizing char- acteristic of the induction generator. Figure 3 shows the relation- ship between the flux linkage and the magnetizing inductance for a typical generator; an increase in the flux linkage beyond a cer- tain level reduces the effective magnetizing inductance L M H11032 . This graph can be derived from the experimentally determined no-load characteristic of the induction generator. To solve the above equations, we can fix the capacitor H20849CH20850 and the resistive load H20849R L H20850 values and then find the operating points for different frequencies. From Eq. H208492H20850, we can find the operating slip at a particular frequency. Then, from Eq. H208493H20850, we can find the corresponding magnetizing inductance L M H11032 , and, from Fig. 3, the operating flux linkage at this frequency. The process is repeated for different frequencies. As a base line, we consider a capacitor with a capacitance of 3.8 mF H20849milli-faradH20850 connected to the generator to produce ap- proximately rated VAR H20849volt ampere reactiveH20850 compensation for full load generation H20849high windH20850. A load resistance of R L =1.0 H9024 is used as the base line load. The slip versus rotor speed presented in Fig. 4 shows that the slip is roughly constant throughout the speed range for a constant load resistance. The capacitance does not affect the operating slip for a constant load resistance, but a higher resistance H20849R L high=lower generated powerH20850 corresponds to a lower slip. The voltage at the terminals of the induction generator H20849pre- sented in Fig. 5H20850 shows the impact of changes in the capacitance Fig. 3 A typical magnetization characteristic Transactions of the ASME Downloaded 28 Mar 2008 to 211.82.100.20. Redistribution subject to ASME license or copyright; see http:/www.asme.org/terms/Terms_Use.cfm and load resistance. As shown in Fig. 5, the load resistance does not affect the terminal voltage, especially at the higher rpm H20849higher frequencyH20850, but the capacitance has a significant impact on the voltage profile at the generator terminals. A larger capacitance yields less voltage variation with rotor speed, while a smaller capacitance yields more voltage variation with rotor speed. As shown in Fig. 6, for a given capacitance, changing the effective value of the load resistance can modulate the torque-speed characteristic. These concepts of self-excitation can be exploited to provide dynamic braking for a wind turbine H20849as mentioned aboveH20850 to pre- vent the turbine from running away when it loses its connection to the grid; one simply needs to choose the correct values for capaci- tance H20849a high valueH20850 and load resistance to match the turbine power output. Appropriate operation over a range of wind speeds can be achieved by incorporating a variable resistance and adjust- ing it depending on wind speed. 3.3 Dynamic Behavior. This section examines the transient behavior in self-excitation operation. We choose a value of 3.8 mF capacitance and a load resistance of 1.0 H9024 for this simu- lation. The constant driving torque is set to be 4500 Nm. Note that the wind turbine aerodynamic characteristic and the turbine con- trol system are not included in this simulation because we are more interested in the self-excitation process itself. Thus, we fo- Fig. 4 Variation of slip for a typical self-excited induction generator Fig. 5 Terminal voltage versus rotor speed for different R L and C Journal of Solar Energy Engineering cus on the electrical side of the equations. Figure 7 shows time series of the rotor speed and the electrical output power. In this case, the induction generator starts from rest. The speed increases until it reaches its rated speed. It is initially connected to the grid and at t=3.1 seconds H20849sH20850, the grid is discon- nected and the induction generator enters self-excitation mode. At t=6.375 s, the generator is reconnected to the grid, terminating the self-excitation. The rotor speed increases slightly during self- excitation, but, eventually, the generator torque matches the driv- ing torque H208494500 NmH20850, and the rotor speed is stabilized. When the generator is reconnected to the grid without synchronization, there is a sudden brief transient in the torque as the generator resyn- chronizes with the grid. Once this occurs, the rotor speed settles at the same speed as before the grid disconnection. Figure 8H20849aH20850 plots per phase stator voltage. It shows that the stator voltage is originally the same as the voltage of the grid to which it is connected. During the self-excitation mode H208493.1 sH11021t H110216.375 sH20850, when the rotor speed increases as shown in Fig. 7, the voltage increases and the frequency is a bit higher than 60 Hz. The voltage and the frequency then return to the rated values when the induction generator is reconnected to the grid. Figure 8H20849bH20850 is an expansion of Fig. 8H20849aH20850 between t=3.0 s and t=3.5 s to better illustrate the change in the voltage that occurs during that transient. 4 Harmonic Analysis 4.1 Simplified Per Phase Higher Harmonics Representation. In order to model the harmonic behavior of the network, we replace the power network shown in Fig. 1 with the per phase equivalent circuit shown in Fig. 9H20849aH20850. In this circuit representation, a higher harmonic or multiple of 60 Hz is denoted Fig. 6 The generator torque vs. rotor speed for different R L and C Fig. 7 The generator output power and rotor speed vs. time NOVEMBER 2005, Vol. 127 / 583 4.1.2 Transformer. We consider a three-phase transformer with leakage reactance H20849X xf H20850 of 6 percent. Because the magnetiz- Downloaded 28 Mar 2008 to 211.82.100.20. Redistribution subject to ASME license or copyright; see http:/www.asme.org/terms/Terms_Use.cfm by h, where h is the integer multiple of 60 Hz. Thus h=5 indicates the fifth harmonic H20849300 HzH20850. For wind turbine applications, the induction generator, transformer, and capacitors are three phase and connected in either Wye or Delta configuration, so the even harmonics and the third harmonic do not exist H208515,6H20852. That is, only h=5,7,11,13,17,., etc. exist. 4.1.1 Infinite Bus and Line Feeder. The infinite bus and the line feeder connecting the wind turbine to the substation are rep- resented by a simple Thevenin representation of the larger power system network. Thus, we consider a simple RL line representa- tion. Fig. 8 The terminal voltage versus the time. a Voltage during self-excitation. b Voltage before and during self-excitation, and after reconnection. Fig. 9 The per phase equivalent circuit of the simplified model for harmonic analysis 584 / Vol. 127, NOVEMBER 2005 ing reactance of a large transformer is usually very large com- pared to the leakage reactance H20849X M H11032 H11015H11009 open circuitH20850, only the leakage reactance is considered. Assuming the efficiency of the transformer is about 98 percent at full load, and the copper loss is equal to the core loss H20849a general assumption for an efficient, large transformerH20850, the copper loss and core loss are each approximately 1 percent or 0.01 per unit. With this assumption, we can compute the copper loss in per unit at full load current H20849I 1 FullH6018Load =1.0 per unitH20850, and we can determine the total winding resistance of the primary and secondary winding H20849about one percent in per unitH20850. 4.1.3 Capacitor Compensation. Switched capacitors represent the compensation of the wind turbine. The wind turbine we con- sider is equipped with an additional 1.9 MVAR reactive power compensation H208491.5 MVAR above the 400 kVAR supplied by the manufacturerH20850. The wind turbine is compensated at different levels of compensation depending on the level of generation. The ca- pacitor is represented by the capacitance C in series with the para- sitic resistance H20849R c H20850, representing the losses in the capacitor. This resistance is usually very small for a good quality capacitor. 4.1.4 Induction Generator. The induction generator H208491.5 MW,480 V,60 HzH20850 used for this wind turbine can be repre- sented as the per phase equivalent circuit shown Fig. 9H20849aH20850. The slip of an induction generator at any harmonic frequency h can be modeled as S h = hH9275 s H9275 r hH9275 s H208494H20850 where S h H11005 slip for hth harmonic h H11005 harmonic order H9275 s H11005 synchronous speed of the generator H9275 r H11005 rotor speed of the generator Thus for higher harmonics H20849fifth and higherH20850 the slip is close to 1 H20849S h =1H20850 and for practical purposes is assumed to be 1. 4.2 Steady State Analysis. Figure 9H20849bH20850 shows the simplified equivalent circuit of the interconnected system representing higher harmonics. Note that the magnetizing inductance of the transformers and the induction generator are assumed to be much larger than the leakages and are not included for high harmonic calculations. In this section, we describe the characteristics of the equivalent circuit shown in Fig. 9, examine the impact of varying the capacitor size on the harmonic admittance, and use the result of calculations to explain why harmonic contents of the line cur- rent change as the capacitance is varied. From the superposition theorem, we can analyze a circuit with only one source at a time while the other sources are turned off. For harmonics analysis, the fundamental frequency voltage source can be turned off. In this case, the fundamental frequency voltage source H20849infinite busH20850, V s , is short circuited. Wind farm operator experience shows us that harmonics occur when the transformer operates in the saturation region, that is, at higher flux levels as shown in Fig. 3. During the operation in this saturation region, the resulting current can be distorted into a sharply peaked sinusoidal current due to the larger magnetizing current imbedded in the primary current. This nonsinusoidal cur- rent can excite the network at resonant frequencies of the network. From the circuit diagram we can compute the impedance H20849at any capacitance and harmonic frequencyH20850 seen by the harmonic source, V h , with Eq. H208495H20850, where the sign “ H20648 ” represents the words “in parallel with:” Transactions of the ASME Downloaded 28 Mar 2008 to 211.82.100.20. Redistribution subject to ASME license or copyright; see http:/www.asme.org/terms/Terms_Use.cfm ZH20849C,hH20850 = H20849Z line + 0.5Z xf H20850 H20648 H208490.5Z xf + Z C H20648 Z gen H20850H208495H20850 w