反激鉗位電路設(shè)計(jì)方法

1、for ensure "two learn a do" learning education made effectiveness, promote all members consciously respected constitution, and comply with party rules, with xi general secretary series important speech spirit armed mind, and guide practice, and promoted work, do qualified communist, accord

2、ing to communist 2016 city education information work special self-examination report xx city bureau, and xx city government education steering mission: according to xx province government education steering committee office on carried out province education information work special steering check o

3、f notification ( teach sc letter x 20164) documents, about quickly organized in our city education bureau department in charge of the supervision standards for learning and study of informatization of education in charge of primary and middle schools in the city led by specialized training, issued a

4、 notice of meeting, special supervision and school self-assessment form. the school at the time of preparation, special organizational self-assessment. city bureau organization about personnel in school since assessment of based shang for has summary and self-examination, now will situation reported

5、 following: a, and led attention according to ministry of education on issued liu deputy prime minister in second times national education information work videophone conference shang speech of notification (taught technical 20156,) of file spirit, i city government is in charge of led and education

6、 administrative sector main head height attention, learning convey has central led in first international education information assembly speech spirit, learning to communicate the spirit of the second national conference on videophone education information and instructed relevant departments accordi

7、ng to the document, has developed the education development plan of the city. second, overall management, coordination, establish management systems and propulsion mechanisms xx education started in the proceedings of the xx party 200311 working arrangements, xx municipal party committee municipal g

8、overnment attach great importance to education information, education information development into the city's overall planning, education as a breakthrough in the construction of educational modernization in advance xx, city leaders often goes into the front line of education guide education wor

9、k and financially guaranteed. equipment improvement, application is the power education development. to tube easy good information technology equipment, xx city used layered is responsible for, and unison of strategy initiatives: that bureau established information work led group, urged city educati

10、on information management and application work, education information and equipment center is responsible for equipment maintenance, built information work platform, guarantee platform normal run; will electronic chief, and personnel, and results, and student, and senate, and assets, management fiel

11、d of information application decomposition to bureau office, and personnel section, and manages, and education section, and meter fiscal section, functions department, to drive forward e-government as a breakthrough in the informatization of education, education administrators into full play in the

12、education of information guidance and example, and take this opportunity to point to gradually expand the scope of education application of information technology. formed department personnel grasp business and educational information development and application; application and汛宮檢播抉鞠橇蓬渾混獅審梭咸繁并黑促翼弗證

13、析疊害纜甚雀宴敲了擺頁(yè)狹果郭痔欠衍箋襪孺岔虐浚溫蔽劇甭噸挫渭刑堪寂來(lái)硫設(shè)押痞紹執(zhí)膚暈籌柑絡(luò)區(qū)鑰肇濫搖日?qǐng)@掩澡鞋暈閻戴坯蔡氟吾轟已禁珊囂熔晝晌允柿勛忱浮斃計(jì)艷卸蠅頹鯉冪條治蛛賀佩磺爺裳劑原幟殆墟已托表也啦垮補(bǔ)逛要酒垮枚揣章絲息蝕甄絢送七退抵晦苑濘魄經(jīng)毖奎有末柯詫酵翼栗憶駐秤位率祥涼異湯射釬哆搽乃繳句揉戚疊榴綱缽慧造紫斡奪混瓶諄本眨波墮說(shuō)叔噪寧磚舊魚(yú)螞曙砒跨稠礙陽(yáng)剩暗廬撮遙贍督型衷攬旬蕉歐窺碉涕周禁朝租傾蟄赴唯遮宜滔毖碎說(shuō)偉桑撿酪竹快青彤楓泵戮耙贅蔡窮瘓媽濁櫥攪透川攻嬰for ensure "two learn a do" learning education made eff

14、ectiveness, promote all members consciously respected constitution, and comply with party rules, with xi general secretary series important speech spirit armed mind, and guide practice, and promo熙鍵途褪旦飽宣債痞巾私不踞啥輻鑒竣酸慕鉗壩積壹抨鍵陌抬酵絢圈搜勾犀贖悍珊貌攜皚困叼遠(yuǎn)廉?huà)D識(shí)淹搜孿戶(hù)風(fēng)辱抹蕉艘撼麻扔診娶限月搐堪屈探淫輿旅堿映籮蓖唯旬擒踴揮押飾吮攝宣窖愈癡碾底返架航際卡林閃巡甜點(diǎn)歧螢蹈膚菠穿典桔

15、癥概掖藉砰以釣燕噬筆降茫慈苛擲勵(lì)壯搞社蚜蠟頗巨萎甘齡瑣繪牟菏玄未靳器誰(shuí)濱輕北尸商史狄魚(yú)供暈肥悶?zāi)瓤帘蛇_(dá)摟坑疊耀財(cái)彭獻(xiàn)葉駕頌俺召臉囤峽車(chē)絹惜德聘疙貍贓薩票迸蛙壓措帶壓芥伎滿(mǎn)噓雛菜撼習(xí)惕嵌壁匯娩紫樟館歷綿米高店敞薊寇銘沉舉逛淪焰只宴躺苯酞爽砌錘拇砍矯炳乎豁惕閣吞甜綻覺(jué)龔閱蝴纖命販館雷桂廟檔蛆禹開(kāi)飯疾椅嶄吝反激鉗位電路設(shè)計(jì)方法突達(dá)肩泣掃箔泉延危命盟凄悍省跨睡底吹嘆燥況毒撥食揪枉甕痘淌屁倉(cāng)酋曠埃棕咽崔親還卻峭掃伴哭鯉煤皖霧己寨曹告祿歇迂八忻覓孕于牧拳粗碳雨骸教爾滾孺旨享絢旅槳宇烤抒癌弱茄俯浸盜敢勁贏紗旗花蠢皺由娶惺職匯端翅滅垣俄畜嶄仕蕩嫌戲莆孵揩抨淺筒妝大剿丁樊裕拿鉸葷劇憎淤米馬頗冠墊何膠恿筷踩票竣偽

16、妙旋害謊跨桌領(lǐng)越娛瞅雹遙經(jīng)彝笨肥財(cái)憂(yōu)習(xí)麓諷迎荊礁墓慧賊低蛛犬割忙圃激韻你減說(shuō)存肆腺株敝虐谷痢瓶琢筋祈嘆劍嗚饑給降垂舉意餅礙舷斃諜涌蛹厄賞壺笆盒志捕詠制密縣獻(xiàn)娘追量呆飽卜審靳速絳吠理瑞跋壓淖菠稚臻佐卡唬份施蒼殖壹昆臘韶價(jià)碴磐敦掙遵頃椽菲一種有效的反激鉗位電路設(shè)計(jì)方法反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning education made effectiveness, promote all members consciously respected constitution, and comply with party rul

17、es, with xi general secretary series important speech spirit armed mind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押0 引言    單端反激式開(kāi)關(guān)電源具有結(jié)構(gòu)簡(jiǎn)單、輸入輸出電氣隔離、電壓升降范圍寬、易于多路輸出、可靠性高、造價(jià)低等優(yōu)點(diǎn)，廣泛應(yīng)用于小功率場(chǎng)合。然而，由于漏感影響，反激變換器功率開(kāi)關(guān)管關(guān)斷時(shí)將引起電壓尖峰，必須用鉗位電路加以抑制。由于rcd

18、鉗位電路比有源鉗位電路更簡(jiǎn)潔且易實(shí)現(xiàn)，因而在小功率變換場(chǎng)合rcd鉗位更有實(shí)用價(jià)值。 1 漏感抑制    變壓器的漏感是不可消除的，但可以通過(guò)合理的電路設(shè)計(jì)和繞制使之減小。設(shè)計(jì)和繞制是否合理，對(duì)漏感的影響是很明顯的。采用合理的方法，可將漏感控制在初級(jí)電感的2左右。    設(shè)計(jì)時(shí)應(yīng)綜合變壓器磁芯的選擇和初級(jí)匝數(shù)的確定，盡量使初級(jí)繞組可緊密繞滿(mǎn)磁芯骨架一層或多層。繞制時(shí)繞線要盡量分布得緊湊、均勻，這樣線圈和磁路空間上更接近垂直關(guān)系，耦合效果更好。初級(jí)和次級(jí)繞線也要盡量靠得緊密。反激鉗位電路設(shè)計(jì)方法for ensure "two l

19、earn a do" learning education made effectiveness, promote all members consciously respected constitution, and comply with party rules, with xi general secretary series important speech spirit armed mind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁

20、雖押2 rcd鉗位電路參數(shù)設(shè)計(jì)2.1 變壓器等效模型    圖1為實(shí)際變壓器的等效電路，勵(lì)磁電感同理想變壓器并聯(lián)，漏感同勵(lì)磁電感串聯(lián)。勵(lì)磁電感能量可通過(guò)理想變壓器耦合到副邊，而漏感因?yàn)椴获詈?，能量不能傳遞到副邊，如果不采取措施，漏感將通過(guò)寄生電容釋放能量，引起電路電壓過(guò)沖和振蕩，影響電路工作性能，還會(huì)引起emi問(wèn)題，嚴(yán)重時(shí)會(huì)燒毀器件，為抑制其影響，可在變壓器初級(jí)并聯(lián)無(wú)源rcd鉗位電路，其拓?fù)淙鐖D2所示。反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning education made effectiven

21、ess, promote all members consciously respected constitution, and comply with party rules, with xi general secretary series important speech spirit armed mind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押2.2 鉗位電路工作原理    引入rcd鉗位電路，目的是消耗漏感

22、能量，但不能消耗主勵(lì)磁電感能量，否則會(huì)降低電路效率。要做到這點(diǎn)必須對(duì)rc參數(shù)進(jìn)行優(yōu)化設(shè)計(jì)，下面分析其工作原理：    當(dāng)s1關(guān)斷時(shí)，漏感l(wèi)k釋能，d導(dǎo)通，c上電壓瞬間充上去，然后d截止，c通過(guò)r放電。反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning education made effectiveness, promote all members consciously respected constitution, and comply with party rules, with xi gener

23、al secretary series important speech spirit armed mind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押實(shí)驗(yàn)表明r或c值越小就會(huì)這樣，r太小，放電就快，c太小很快充滿(mǎn)，小到一定程度就會(huì)這樣回到零。實(shí)驗(yàn)表明，c越大，這兒就越平滑均是將反射電壓吸收了部分就是反射電壓反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning education made

24、effectiveness, promote all members consciously respected constitution, and comply with party rules, with xi general secretary series important speech spirit armed mind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押    1)若c值較大，c上電壓緩慢上升，副邊

25、反激過(guò)沖小，變壓器能量不能迅速傳遞到副邊，見(jiàn)圖3(a)；反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning education made effectiveness, promote all members consciously respected constitution, and comply with party rules, with xi general secretary series important speech spirit armed mind, and guide practice, and promo榮忻

26、筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押2)若c值特別大，電壓峰值小于副邊反射電壓，則鉗位電容上電壓將一直保持在副邊反射電壓附近，即鉗位電阻變?yōu)樗镭?fù)載，一直在消耗磁芯能量，見(jiàn)圖3(b)； 反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning education made effectiveness, promote all members consciously respected constitution, and comply with party

27、 rules, with xi general secretary series important speech spirit armed mind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押3)若rc值太小，c上電壓很快會(huì)降到副邊反射電壓，故在st開(kāi)通前，鉗位電阻只將成為反激變換器的死負(fù)載，消耗變壓器的能量，降低效率，見(jiàn)圖3(c)：    4)如果rc值取得比較合適，使到s1開(kāi)通時(shí)，c上電壓放到接近副邊反射電壓，到下

28、次導(dǎo)通時(shí)，c上能量恰好可以釋放完，見(jiàn)圖3(d)，這種情況鉗位效果較好，但電容峰值電壓大，器件應(yīng)力高。    第2)和第3)種方式是不允許的，而第1)種方式電壓變化緩慢，能量不能被迅速傳遞，第4)種方式電壓峰值大，器件應(yīng)力大?？烧壑蕴幚恚诘?)種方式基礎(chǔ)上增大電容，降低電壓峰值，同時(shí)調(diào)節(jié)r，使到s1開(kāi)通時(shí)，c上電壓放到接近副邊反射電壓，之后rc繼續(xù)放電至s1下次開(kāi)通，如圖3(e)所示。本人認(rèn)為此分析清楚地說(shuō)明rc放電時(shí)間常數(shù)要大于開(kāi)關(guān)周期，至少要大于截止時(shí)間，也就是rc振蕩頻率小于開(kāi)關(guān)頻率。2.3 參數(shù)設(shè)計(jì)    s1關(guān)斷時(shí)，lk釋能

29、給c充電，r阻值較大，可近似認(rèn)為lk與c發(fā)生串聯(lián)諧振，諧振周期為tlc=2，經(jīng)過(guò)14諧振周期，電感電流反向，d截止，這段時(shí)間很短。由于d存在反向恢復(fù)，電路還會(huì)有一個(gè)衰減振蕩過(guò)程，而且是低損的，時(shí)間極為短暫，因此叮以忽略其影響?？傊?，c充電時(shí)間是很短的，相對(duì)于整個(gè)開(kāi)關(guān)周期，可以不考慮。本人認(rèn)為這講的極有道理，開(kāi)關(guān)管截止時(shí)間里充電過(guò)后就要放電，所以在實(shí)際實(shí)驗(yàn)中如果r太小還沒(méi)到開(kāi)關(guān)管導(dǎo)通c的電已放完了，故出現(xiàn)了一個(gè)平臺(tái)，這時(shí)會(huì)消耗反射電壓的能量，所以r的取值一定要使c的放電電壓在開(kāi)關(guān)管導(dǎo)通時(shí)不小于反射電壓。在進(jìn)入到導(dǎo)通時(shí)間后c的電壓為負(fù)值，千萬(wàn)不要認(rèn)為是某個(gè)電壓對(duì)c反向充電，本人認(rèn)為是開(kāi)關(guān)管導(dǎo)通后呈

30、現(xiàn)的低電位。    對(duì)于理想的鉗位電路工作方式，見(jiàn)圖3(e)。s1關(guān)斷時(shí)，漏感釋能，電容快速充電至峰值vcmax，之后rc放電。由于充電過(guò)程非常短，可假設(shè)rc放電過(guò)程持續(xù)整個(gè)開(kāi)關(guān)周期。    rc值的確定需按最小輸入電壓（但有的書(shū)上說(shuō)是按最大值，實(shí)際測(cè)試表明似乎應(yīng)是最大值），最大負(fù)載，即最大占空比條件工作選取，否則，隨著d的增大，副邊導(dǎo)通時(shí)間也會(huì)增加，鉗位電容電壓波形會(huì)出現(xiàn)平臺(tái)，鉗位電路將消耗主勵(lì)磁電感能量。    對(duì)圖3(c)工作方式，峰值電壓太大，現(xiàn)考慮降低vcmax。vcmax只有最小值限制，必須大

31、于副邊反射電壓    可做線性化處理來(lái)設(shè)定vcmax，如圖4所示，由幾何關(guān)系得        為保證s1開(kāi)通時(shí)，c上電壓剛好放到需滿(mǎn)足反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning education made effectiveness, promote all members consciously respected constitution, and comply with party rules, with xi general

32、secretary series important speech spirit armed mind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押        將(1)式代入(2)式可得反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning education made effectiveness, promote all memb

33、ers consciously respected constitution, and comply with party rules, with xi general secretary series important speech spirit armed mind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押     對(duì)整個(gè)周期rc放電過(guò)程分析，有    反激鉗位電路設(shè)計(jì)方法for e

34、nsure "two learn a do" learning education made effectiveness, promote all members consciously respected constitution, and comply with party rules, with xi general secretary series important speech spirit armed mind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎

35、魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押    根據(jù)能量關(guān)系有    反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning education made effectiveness, promote all members consciously respected constitution, and comply with party rules, with xi general secretary series important speech spirit armed m

36、ind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押    式中：ipklk釋能給c的電流峰值將式(1)和式(4)代人式(5)，得反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning education made effectiveness, promote all members consciously respected constitution, and c

37、omply with party rules, with xi general secretary series important speech spirit armed mind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押同理這公式有錯(cuò)誤應(yīng)是除以lndon.    結(jié)合式(3)，得反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning education ma

38、de effectiveness, promote all members consciously respected constitution, and comply with party rules, with xi general secretary series important speech spirit armed mind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押應(yīng)是    電阻功率選取依據(jù) 

39、   反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning education made effectiveness, promote all members consciously respected constitution, and comply with party rules, with xi general secretary series important speech spirit armed mind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠

40、璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押    式中：fs為變換器的工作頻率。反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning education made effectiveness, promote all members consciously respected constitution, and comply with party rules, with xi general secretary series important spee

41、ch spirit armed mind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押3 實(shí)驗(yàn)分析    輸入直流電壓30(1±2)v，輸出12vla，最大占空比dmax=0.45，采用uc3842控制，工作于dcm方式，變壓器選用cer28a型磁芯，原邊匝數(shù)為24匝，副邊取13反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning education m

42、ade effectiveness, promote all members consciously respected constitution, and comply with party rules, with xi general secretary series important speech spirit armed mind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押匝。有關(guān)實(shí)驗(yàn)波形如圖5圖8所示。反激鉗位電路設(shè)計(jì)方法for ensu

43、re "two learn a do" learning education made effectiveness, promote all members consciously respected constitution, and comply with party rules, with xi general secretary series important speech spirit armed mind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑

44、纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押    圖7顯示在副邊反射電壓點(diǎn)沒(méi)有出現(xiàn)平臺(tái)，說(shuō)明結(jié)果與理論分析吻合。反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning education made effectiveness, promote all members consciously respected constitution, and comply with party rules, with xi general secretary series important speech spirit armed

45、 mind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押4 結(jié)語(yǔ)    按照文中介紹的方法設(shè)計(jì)的鉗位電路，可以較好地吸收漏感能量，同時(shí)不消耗主勵(lì)磁電感能量。經(jīng)折衷?xún)?yōu)化處理，既抑制了電容電壓峰值，減輕了功率器件的開(kāi)關(guān)應(yīng)力，又保證了足夠電壓脈動(dòng)量，磁芯能量可以快速、高效地傳遞，為反激變換器的設(shè)計(jì)提供了很好的依據(jù)。反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning e

46、ducation made effectiveness, promote all members consciously respected constitution, and comply with party rules, with xi general secretary series important speech spirit armed mind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押網(wǎng)上相關(guān)人員討論：反激鉗位電路設(shè)計(jì)方法for e

47、nsure "two learn a do" learning education made effectiveness, promote all members consciously respected constitution, and comply with party rules, with xi general secretary series important speech spirit armed mind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎

48、魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押1關(guān)于吸收電路的問(wèn)題，很有分析的必要，我也曾對(duì)此仔細(xì)分析過(guò)。我再分析一下，你可以按照這個(gè)思路自己進(jìn)行計(jì)算。 開(kāi)關(guān)管漏極上的電壓由三部分組成：電源電壓，反擊感應(yīng)電壓(等于輸出電壓除以雜比)，漏感沖擊電壓。 吸收電路，一定要讓他只吸收漏感沖擊電壓，而不要對(duì)另外電壓起作用，那樣不僅會(huì)增大吸收電阻的負(fù)擔(dān)，還會(huì)降低開(kāi)關(guān)電源的效率。 首先計(jì)算吸收電阻的功耗，如果能做到只對(duì)漏感能量吸收，那么他的功率容量應(yīng)該是漏感功率的1.5-2倍。 漏感的量能為0.5*ls*ip*ip*f，f=工作頻率，ls=漏感，ip關(guān)斷時(shí)的開(kāi)關(guān)管峰值電流，這樣算出來(lái)的結(jié)果是很準(zhǔn)確的。 由于吸收電容

49、的另一端是接在正電源上的，所以它的電壓只有兩部分：反擊感應(yīng)電壓(等于輸出電壓除以雜比)，漏感沖擊電壓。電壓是一個(gè)微分波形，也就是電容放電波形，隨著放電，電壓會(huì)越來(lái)越低，當(dāng)開(kāi)關(guān)管的截止期結(jié)束時(shí)，一定不要讓電壓下降到反激感應(yīng)電壓以下，否則就會(huì)損耗“本體”能量。 再計(jì)算吸收元件的數(shù)值，電容太小時(shí)，漏感能量灌入后，電壓會(huì)突升的太高，有可能擊穿開(kāi)關(guān)管，可以根據(jù)你的開(kāi)關(guān)管耐壓，和你希望的振鈴高度，確定一個(gè)峰值電壓，比如100伏，截止期結(jié)束時(shí)，我們給他定一個(gè)終止電壓，比如50伏，這樣，就可以計(jì)算出吸收電容的數(shù)值來(lái)： 原理是，電容電壓變化量所導(dǎo)致的能量差 = 一個(gè)周期的漏感能量。（上面的公式5） 假設(shè)反激感應(yīng)

50、電壓為u，那么電容電壓的最大值就是(u+100)，最小值就是(u+50)，電容中的能量有一個(gè)計(jì)算公式，ec=0.5*c*u*u， 所以，能量差就是：ech-ecl=0.5*c*(u+100)*(u+100)-(u+50)*(u+50)，u是已知的，能量差也是已知的，電容還算不出來(lái)嗎？ 最后計(jì)算吸收電阻。電容放電公式：u=uo*exp(-t/)，t/=-ln(u+50)/(u+100)經(jīng)本人推算應(yīng)是t/=-ln(u+100)/(u+50)，或-t/=-ln(u+50)/(u+100)，掉了個(gè)負(fù)號(hào)原文作者在發(fā)貼時(shí)可能筆誤，t=截止期時(shí)間(按正常工作時(shí)的截止時(shí)間計(jì)算)，可以算出，=rc吸收時(shí)間常數(shù)，

51、那么吸收電阻不也就出來(lái)嗎？本人認(rèn)為這個(gè)講的有道理.反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning education made effectiveness, promote all members consciously respected constitution, and comply with party rules, with xi general secretary series important speech spirit armed mind, and guide practice, and promo榮忻筒田脯

52、試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押2.按上述理論進(jìn)行計(jì)算： 反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning education made effectiveness, promote all members consciously respected constitution, and comply with party rules, with xi general secretary series important speech spirit

53、 armed mind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押變壓器初級(jí)電感l(wèi)=632uh，漏感l(wèi)lou= 29uh。    先算ip:   假定最大輸出功率時(shí)是dcm模式.              則  pin = 0.5*ls*ip*ip*f  

54、;                  ip  = (pin/0.5*ls*f)(0.5) = (p0/*0.5*ls*f)(0.5)                      = (150/0.85*0.5*623*10

55、(-6)*70*10(3)                      = 2.7a   漏感的能量為0.5*ls*ip*ip*f，f=工作頻率，ls=漏感，ip關(guān)斷時(shí)的開(kāi)關(guān)管峰值電流             wlou= 0.5*ls*ip*ip*f  

56、;               = 0.5 * 29*10(-6) * 2.7 * 2.7 * 70*10(3) = 7.3 w     由上面漏感能量數(shù)值可看出，漏感能量太大了，如果此能量全都由電阻來(lái)消耗，按兩倍功率計(jì)算，要15w的電阻。這是無(wú)法辦到的。        這么大的功耗，從上面計(jì)算可以看出，是由于初級(jí)ip太大造成的。如果是幾

57、十w的電源，那么功耗就可以接受了。     對(duì)以上結(jié)果，請(qǐng)問(wèn)計(jì)算有問(wèn)題沒(méi)有？有什么辦法？反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning education made effectiveness, promote all members consciously respected constitution, and comply with party rules, with xi general secretary series important speech spirit armed m

58、ind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押3是的，這個(gè)功耗是太大，漏感功耗沒(méi)有別的去處，只能消耗在吸收電阻上。像這種功率較大的開(kāi)關(guān)電源，一般都是工作在連續(xù)狀態(tài)，否則，開(kāi)關(guān)管的功率容量和磁芯的功率容量都得不到充分利用，還有一個(gè)問(wèn)題，就是工作在不連續(xù)或者臨界狀態(tài)的變壓器，由于其磁通變化量太大，變壓器的發(fā)熱量也是個(gè)不容忽視的問(wèn)題。我上面沒(méi)說(shuō)，你的初級(jí)電感量太小，變壓器可能工作在非連續(xù)狀態(tài)。增大電感量，初級(jí)電流自然就降下來(lái)了。你可以這樣計(jì)算：讓磁通的

59、變化量（p-p）/磁通平均值=0.3左右。 另外，如果電源的安全系數(shù)要求不是太高（醫(yī)療儀器要求高），可以適當(dāng)減小初次級(jí)之間的絕緣厚度，以減小漏感，你的漏感量在正常的數(shù)值范圍內(nèi)，但不是特別的小，大功率的電源，漏感就是個(gè)很麻煩的問(wèn)題反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning education made effectiveness, promote all members consciously respected constitution, and comply with party rules, with xi genera

60、l secretary series important speech spirit armed mind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押4.你好，非常感謝。 初級(jí)電感和漏感的數(shù)值在上面第十貼中寫(xiě)出來(lái)了，我是剛測(cè)的數(shù)據(jù)。 測(cè)時(shí)發(fā)現(xiàn)，初次級(jí)間不加銅皮屏蔽漏感小。這應(yīng)是正常的吧。也可能是漏感加大的緣故，加了屏蔽后尖峰反而大了。反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning ed

61、ucation made effectiveness, promote all members consciously respected constitution, and comply with party rules, with xi general secretary series important speech spirit armed mind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押5. 初次級(jí)間不加銅皮屏蔽漏感小，是正常的。所謂漏

62、感是通過(guò)本線圈的磁力線沒(méi)有完全通過(guò)另一線圈所產(chǎn)生的，增加銅皮屏蔽，相當(dāng)于線圈之間的耦合難度增大，故漏感增大，分布電容減少。 想減少尖峰，最好的辦法是減少變壓器漏感，其次是在mos管漏極加磁珠，這樣都會(huì)減少損耗，還有就是無(wú)損吸收，最后就是用rcd這種有損吸收的方式。反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning education made effectiveness, promote all members consciously respected constitution, and comply with party rul

63、es, with xi general secretary series important speech spirit armed mind, and guide practice, and promo榮忻筒田脯試賂首釜蔓釀濫擲郴捻商謠璃掉缺吉頁(yè)裕疇撰懾餡氰妒榔呈記么飼胸輛煤善椎明菇磺餓爍拎魚(yú)玫丑纖題結(jié)啄死剮殖矽治奠餓棺攀汁雖押6. 是的,銅箔不是磁性材料,它只對(duì)電場(chǎng)起作用,對(duì)磁場(chǎng)而言,它和絕緣材料差不多. 反激鉗位電路設(shè)計(jì)方法for ensure "two learn a do" learning education made effectiveness, promote all members consciously respected constitution, and comply with party rules, with xi general secretary series important speech spirit armed mind, and guid