【正文】 (12) 式中， 1/ ?offtT ，故稱該電路為升壓斬波電路。因電感 C 值很大，基本保持輸出電壓 0u 為恒值，即為 0U 。該電路中使用一個(gè)全控型器件 PMOSFET，即為電力場效應(yīng)晶體管。 直流斬波電路實(shí)際上采用的就是 PWM 技術(shù)，這種電路把直流電壓斬成一系列脈沖，改變脈沖的占空比來獲得所需要的輸出電壓。與傳統(tǒng)的電路相比，本設(shè)計(jì)加入了MATLAB 仿真，這樣更直觀的顯示出了電路的工作狀態(tài)。 遼寧工程技術(shù)大學(xué) 電力電子技術(shù)課程設(shè)計(jì) 設(shè) 計(jì) 題 目 基于 51 單片機(jī)觸發(fā)的直流升壓斬波電路研究 指 導(dǎo) 教 師 劉春喜 院（系、部） 電氣控制工程 專 業(yè) 班 級(jí) 電力 101 班 學(xué) 號(hào) 1005030104 姓 名 馮旭 日 期 2021 年 1 月 13 日 摘 要 本設(shè)計(jì)基于 AT89S51 單片機(jī)為核心的 PWM 升壓斬波電路 (Boost Chopper)。同時(shí)相對(duì)于單純依靠電路元件而形成的觸發(fā)脈沖進(jìn)行的 PWM 調(diào)制，基于 AT89S51 單片機(jī)的 PWM 發(fā)生裝置具有電路 簡單，可調(diào)性高等特點(diǎn)。 PWM 控制方式是目前 采 用最廣泛的一種控制方式，它具有良好的調(diào)整特性。它是用柵極電壓來控制漏極電流的，因此它的一個(gè)顯著特點(diǎn)是驅(qū)動(dòng)電路簡單，需要的驅(qū)動(dòng)功率小；第二個(gè)顯著特點(diǎn)是開關(guān)速度快、工作頻率高。設(shè) V 處于通態(tài)的時(shí)間為 ont ，此階段電感 L 上積蓄的能量為 ontEI1 。電路中導(dǎo) 通角與關(guān)斷角的關(guān)系如下所示 1???? （ 13） 因此，式（ 12）可表示為 EαEβUo 111 ?? （ 14） 升壓斬波電 路之所以能使輸出電壓高于電源電壓，關(guān)鍵有兩個(gè)原因：一是電感 L 儲(chǔ)能之后具有使電壓泵升的作用，二是電容 C 的作用使得輸出電壓 OU 不變，但實(shí)際上 C 值不可能為無窮大，在此階段其向負(fù)載放電， OU 必然會(huì)有所下降，故實(shí)際輸出電壓會(huì)略低于式（ 14）所得結(jié)果。為獲得精準(zhǔn)的觸發(fā)脈沖，通 常選用 AT89S51單片機(jī)做為脈沖發(fā)生器。其電路圖如圖 32 所示，采用高速光隔（ 6N137）輸出，并將 PWM 的信號(hào)倒 相。注意，本最小應(yīng)用系統(tǒng)只能作 為小型的數(shù)字量測控單元。其主程序流程如圖 27 所示。但是計(jì)算機(jī)仿真卻可以解決這個(gè)問題。它支持連續(xù)、離散、及兩者混合的線性和非線性系統(tǒng)。即 馮旭：基于 51 單片機(jī)觸發(fā)的直流升壓斬波電路研究 10 VVV inout 10050501 11 1 ?????? ％? 滿足理論計(jì)算公式。 遇到的問題和困難： (1) 在計(jì)算元器件參數(shù)是缺少理論依據(jù)難以正確的計(jì)算相應(yīng)的參數(shù)。 雖然遇到了許多的困難但是我還是通過不斷的學(xué)習(xí)解決了這些難題。 (4) 在面對(duì)學(xué)習(xí)上的困難時(shí)一定要堅(jiān)持不懈的努力才能打敗困難，獲得更多以的知識(shí)。 （ 2）負(fù)載不變?yōu)?100? ，頻率 1KHz，占空比從 5%到 95%以等百分比遞增時(shí)，直流升壓斬波電路的負(fù)載輸出波形及輸出電壓大小。 設(shè)計(jì)必須按期完成。t charge you more than 35% of your pensation if you win the case. If you are thinking about signing up for a damagesbased agreement, you should make sure you39。s Premier League match at Chelsea on Sunday. I am going to be at the match tomorrow and I have asked to meet Yaya Toure, he told BBC Sport. For me it39。s actions. 遼寧工程技術(shù)大學(xué)電力電子技術(shù)課程設(shè)計(jì) 23 CSKA said they were surprised and disappointed by Toure39?？傆X得自己自己似乎應(yīng)該去做點(diǎn)什么，或者寫點(diǎn)什么。t really grow up, it seems is not so important。 Originally, this world, can produce a chemical reaction to an event, in addition to resolutely, have to do, and time. 原來，這個(gè)世界上，對(duì)某個(gè)事件能產(chǎn)生化學(xué)反應(yīng)的，除了非做不可的堅(jiān)決，還有，時(shí)間。也曾經(jīng)好像已經(jīng)下定了決心去做某件事，但更多的時(shí)候是最后又打起了退堂鼓。 Those were broken into various shapes of stationery。突然想到那件藍(lán)格子襯衫；那些被折成各種各樣形狀的信紙；那段從街角深巷伊始的友誼；還有那場還沒有開始就宣告了終結(jié)的邂逅計(jì)劃 …… 那些年那些天的非做不可，終于和青春一樣，都將在我們的人生中謝幕。t. Baumgartner still will free fall at a speed that would cause you and me to pass out, and no parachute is guaranteed to work higher than 25,000 feet (7,620 meters). cause there 。ll be traveling fast, so despite the distance, it will not be like diving into the deep end of a pool. It will be like he is diving into the shallow end. Skydiver preps for the big jump When he jumps, he is expected to reach the speed of sound 690 mph (1,110 kph) in less than 40 seconds. Like hitting the top of the water, he will begin to slow as he approaches the more dense air closer to Earth. But this will not be enough to stop him pletely. If he goes too fast or spins out of control, he has a stabilization parachute that can be deployed to slow him down. His team hopes it39。 Have declared the end of the encounter that haven39。那些曾經(jīng)所謂的非做不可，只是青蔥年華里自己給自己注射的一支強(qiáng)心劑，或者說，是自以為是的精神寄托罷了。s time, your ideas are always special to clear. Want, want, line is clear, as if nothing could shake his. Also once seemed to be determined to do something, but more often is he backed out at last. Dislike his cowardice, finally found that there are a lot of love, there are a lot of miss, like shadow really have been doomed. Those who do, just green years oneself give oneself an arm injection, or is a selfrighteous spiritual. 一個(gè)人的時(shí)候，自己 的想法總是特別地清晰。t want to give vent to out your inner voice can be in the high school children of the feelings in a period, but was eventually infarction when graduation party in the throat, later again stood on the pitch he has sweat profusely, looked at his thrown a basketball hoops, suddenly found himself has already can39。 The end of our life, and can meet many things really do? 而窮盡我們的一生，又能遇到多少事情是真正地非做不可？ During my childhood, think lucky money and new clothes are necessary for New Year, but as the advance of t