【正文】 電路組成。單片機(jī)完成信息的讀取、運(yùn)算、傳送和控制功能。把INT0()做為外部中斷源的請求信號, 用于計數(shù)器的復(fù)位。, 輸出信號經(jīng)驅(qū)動器電路放大,用于控制逆變電路中可控硅晶閘管的通斷。從而控制電源頻率的大小。 最小脈沖問題分析由于硬件原因，任何微控制器都不能輸出寬度無限小的脈沖，這就使得理想SPWM脈沖序列中小于一定寬度的窄脈沖不能正常輸出，即最小脈沖問題。對于C8051單片機(jī)，它的PCA所能輸出的最小脈沖取決于其中斷服務(wù)程序執(zhí)行的時間，所以其最小脈沖問題不容忽視。解決該問題的具體方法有：（1）采用匯編語言編寫中斷服務(wù)子程序并且應(yīng)用最精簡省時的指令，減小最小脈沖的寬度；（2）在計算SPWM波脈沖寬度時，對寬度小于PCA所能輸出最小寬度的脈沖進(jìn)行修正，使它們的寬度為最小脈沖的寬度；（3）限制調(diào)制比M，使SPWM脈沖序列中不會含有過多的小脈沖?？偨Y(jié)本設(shè)計是基于C8051系列單片機(jī)控制的交流變頻調(diào)速系統(tǒng)的設(shè)計,主要介紹了變頻調(diào)速技術(shù)，脈寬調(diào)制技術(shù)、單片機(jī)程序設(shè)計等問題，這是一個非常實用的控制系統(tǒng)。系統(tǒng)的設(shè)計主要包括硬件和軟件設(shè)計兩個部分。 頻調(diào)速技術(shù)作為高新技術(shù)、基礎(chǔ)技術(shù)、和節(jié)能技術(shù)，已經(jīng)滲透到經(jīng)濟(jì)領(lǐng)域的所有技術(shù)部門中。我國以后在變頻調(diào)速技術(shù)方面應(yīng)積極做的工作如下: (1) 應(yīng)用變頻調(diào)速技術(shù)來改造傳統(tǒng)的產(chǎn)業(yè)，節(jié)約能源及提高產(chǎn)品質(zhì)量，獲得較好的經(jīng)濟(jì)效益和社會效益。 (2) 大力發(fā)展變頻調(diào)速技術(shù)，必需把我國變頻調(diào)速技術(shù)提高到一個新水平，縮小與世界先進(jìn)水平的差距，提高自主開發(fā)能力，滿足國民經(jīng)濟(jì)重點工程建設(shè)和市場的需求。 (3) 規(guī)范我國變頻調(diào)速技術(shù)方面的標(biāo)準(zhǔn)，提高產(chǎn)品可靠性工藝水平，實現(xiàn)規(guī)模化、標(biāo)準(zhǔn)化生產(chǎn)。畢業(yè)設(shè)計是對大學(xué)四年學(xué)習(xí)的一個測試，它是教學(xué)計劃中學(xué)生必修的最后一個教學(xué)環(huán)節(jié)，是實現(xiàn)教學(xué)、科研、工程實踐結(jié)合的重要結(jié)合點。它的主要目的是培養(yǎng)學(xué)生綜合運(yùn)用所學(xué)知識和技能去分析和解決本專業(yè)范圍內(nèi)的一般工程技術(shù)問題，建立正確的設(shè)計思想，掌握工程設(shè)計的一般程序和方法。通過畢業(yè)設(shè)計，進(jìn)行工程知識和工程技能的綜合訓(xùn)練，使學(xué)生一走上工作崗位就具有較強(qiáng)的應(yīng)用生產(chǎn)現(xiàn)場正在使用和近期可能推廣使用的技術(shù)去解決工程實際問題的能力。畢業(yè)設(shè)計對我們來說是一件相對龐大而瑣碎的工作,要綜合運(yùn)用各種學(xué)過和沒學(xué)過的東西。通過此次畢業(yè)設(shè)計，我學(xué)習(xí)了很多新知識、新方法、新觀點，更是對我大學(xué)學(xué)習(xí)的一個很好的總結(jié)。在設(shè)計過程中，我進(jìn)一步加深了對電力電子的學(xué)習(xí)；煉了我的學(xué)習(xí)能力、分析問題與解決問題的能力，也鍛煉了我克服困難的勇氣和決心。這些都為我以后的工作奠定了良好的基石，因此我感到收獲很大。參考文獻(xiàn)[1] 李良仁. 變頻調(diào)速技術(shù)與應(yīng)用[M].北京：電子工業(yè)出版社，2004[2] 王兆安，張明勛. 同步電動機(jī)調(diào)速系統(tǒng)[M].北京：機(jī)械工業(yè)出版社，2002[3] 顏世鋼. 電力電子技術(shù)問答[M].北京：機(jī)械工業(yè)出版社，2007[4] 和 [M].北京：北京航天航空大學(xué)出版社，2005[5] [M].山東：山東科學(xué)技術(shù)出版社，2005[6] 陳國呈. PWM的變頻調(diào)速及軟開關(guān)電力變換技術(shù)[M]. 北京：機(jī)械工業(yè)出版社，2002，[7] 丁斗章. 變頻調(diào)速技術(shù)與系統(tǒng)應(yīng)用[M]. 北京：機(jī)械工業(yè)出版社，2002[8] 李錫雄,陳婉兒. 脈寬調(diào)制技術(shù)[M]. 武漢：華中理工大學(xué)出版社，1996[9] 王兆安. 電力電子技術(shù)[M]. 4版. 北京：機(jī)械工業(yè)出版社，2002，145166[10] 吳守箴等著. 電氣傳動的脈寬調(diào)制控制技術(shù)[M]. 北京： 機(jī)械工業(yè)出版社，2004[11] 吳守箴臧英杰等著. 電氣傳動的脈寬調(diào)制控制技術(shù)[J]. 機(jī)械工業(yè)出版社，2004[12] 張毅剛. 單片機(jī)原理及應(yīng)用[M]. 高等教育出版社，2004[13] 電力電子單片機(jī)控制技術(shù)[M]. 北京：機(jī)械工業(yè)出版社，2007[14] Idris ，Yatim .. Direct torque control of induction machines with constant switching frequency and reduced torque ripple[J]. IEEE Transactions on Industrial Elec tronics, 2004[15] Faiz J., MohseniZonoozi, Hossein novel technique for estimation and control of stator flux of a salientpole PMSM in DTC method based on Transactions[J] on IE, 2003g an employment tribunal claimEmployment tribunals sort out disagreements between employers and employees.You may need to make a claim to an employment tribunal if: you don39。t agree with the disciplinary action your employer has taken against you your employer dismisses you and you think that you have been dismissed unfairly.For more information about dismissal and unfair dismissal, seeDismissal.You can make a claim to an employment tribunal, even if you haven39。tappealedagainst the disciplinary action your employer has taken against you. However, if you win your case, the tribunal may reduce any pensation awarded to you as a result of your failure to appeal.Remember that in most cases you must make an application to an employment tribunal within three months of the date when the event you are plaining about happened. If your application is received after this time limit, the tribunal will not usually accept it.If you are worried about how the time limits apply to you, take advice from one of the organisations listed underFurther help.Employment tribunals are less formal than some other courts, but it is still a legal process and you will need to give evidence under an oath or affirmation.Most people find making a claim to an employment tribunal challenging. If you are thinking about making a claim to an employment tribunal, you should get help straight away from one of the organisations listed underFurther help.If you are being represented by a solicitor at the tribunal, they may ask you to sign an agreement where you pay their fee out of your pensation if you win the case. This is known as adamagesbased agreement. In England and Wales, your solicitor can39。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。re clear about the terms of the agreement. It might be best to get advice from an experienced adviser, for example, at a Citizens Advice Bureau. To find your nearest CAB, including those that give advice by , click onnearest CAB.For more information about making a claim to an employment tribunal, seeEmployment tribunals.The (lack of) air up there Watch mCayman Islandsbased Webb, the head of Fifa39。s antiracism taskforce, is in London for the Football Association39。s 150th anniversary celebrations and will attend City39。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 about how he felt and I would like to speak to him first to find out what his experience was.Uefa hasopened disciplinary proceedings against CSKAfor the racist behaviour of their fans duringCity39。s 21 win.Michel Platini, president of European football39。s governing body, has also ordered an immediate investigation into the referee39。s actions.CSKA said they were surprised and disappointed by Toure39。s plaint. In a statement the Russian side added: We found no racist insults from fans of CSKA.Age has reached the end of the beginning of a word. May be guilty in his seems to passing a lot of different life became the appearance of the same day。 May be back in the past, to oneself the paranoid weird belief disillusionment, these days, my mind has been very messy, in my mind constantly. Always feel oneself should go to do something, or write something. Twenty years of life trajectory deeply shallow, suddenly feel something, do it.　　一字開頭的年齡已經(jīng)到了尾聲?；蛟S是愧疚于自己似乎把轉(zhuǎn)瞬即逝的很多個不同的日子過成了同一天的樣子；或許是追溯過去，對自己那些近乎偏執(zhí)的怪異信念的醒悟，這些天以來，思緒一直很凌亂，在腦海中不斷糾纏?？傆X得自己自己似乎應(yīng)該去做點什么，或者寫點什么。二十年的人生軌跡深深淺淺，突然就感覺到有些事情，非做不可了。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 the age, will be more and more found that those