一、前言

　　開關電源系(xi)(xi)(xi)統(tong)是(shi)(shi)弱電(dian)(dian)(dian)控(kong)(kong)(kong)制(zhi)(zhi)強電(dian)(dian)(dian)的(de)系(xi)(xi)(xi)統(tong)。開(kai)關(guan)電(dian)(dian)(dian)源系(xi)(xi)(xi)統(tong)主(zhu)要(yao)可以(yi)分(fen)(fen)為(wei)主(zhu)功(gong)(gong)率(lv)(lv)(lv)(lv)電(dian)(dian)(dian)路(lu)和控(kong)(kong)(kong)制(zhi)(zhi)電(dian)(dian)(dian)路(lu)兩部分(fen)(fen)。主(zhu)功(gong)(gong)率(lv)(lv)(lv)(lv)電(dian)(dian)(dian)路(lu)是(shi)(shi)由變換器(qi)構成(cheng)。變換器(qi)是(shi)(shi)應用功(gong)(gong)率(lv)(lv)(lv)(lv)半導體(ti)器(qi)件(jian)，對(dui)電(dian)(dian)(dian)能進行變換的(de)裝置(zhi)(zhi)，變換量包(bao)括電(dian)(dian)(dian)壓、電(dian)(dian)(dian)流、頻率(lv)(lv)(lv)(lv)和波形等方(fang)面，以(yi)達到電(dian)(dian)(dian)能更(geng)好符合各(ge)種不同用電(dian)(dian)(dian)設(she)備要(yao)求的(de)目的(de)。這(zhe)是(shi)(shi)通過對(dui)功(gong)(gong)率(lv)(lv)(lv)(lv)半導體(ti)器(qi)件(jian)的(de)開(kai)關(guan)的(de)控(kong)(kong)(kong)制(zhi)(zhi)來實現的(de)。因(yin)此主(zhu)功(gong)(gong)率(lv)(lv)(lv)(lv)電(dian)(dian)(dian)路(lu)是(shi)(shi)開(kai)關(guan)電(dian)(dian)(dian)源控(kong)(kong)(kong)制(zhi)(zhi)系(xi)(xi)(xi)統(tong)中的(de)被(bei)控(kong)(kong)(kong)對(dui)象，而(er)控(kong)(kong)(kong)制(zhi)(zhi)功(gong)(gong)率(lv)(lv)(lv)(lv)半導體(ti)器(qi)件(jian)的(de)開(kai)關(guan)以(yi)實現既定的(de)性能是(shi)(shi)控(kong)(kong)(kong)制(zhi)(zhi)裝置(zhi)(zhi)的(de)主(zhu)要(yao)工作。將(jiang)被(bei)控(kong)(kong)(kong)對(dui)象和控(kong)(kong)(kong)制(zhi)(zhi)裝置(zhi)(zhi)按照一(yi)定的(de)方(fang)式(shi)連接起來，組成(cheng)一(yi)個(ge)有機(ji)的(de)總(zong)體(ti)，就構成(cheng)開(kai)關(guan)電(dian)(dian)(dian)源的(de)控(kong)(kong)(kong)制(zhi)(zhi)系(xi)(xi)(xi)統(tong)，這(zhe)樣的(de)電(dian)(dian)(dian)路(lu)即為(wei)控(kong)(kong)(kong)制(zhi)(zhi)電(dian)(dian)(dian)路(lu)。控(kong)(kong)(kong)制(zhi)(zhi)系(xi)(xi)(xi)統(tong)的(de)工作方(fang)式(shi)有多種，其中最(zui)基(ji)本的(de)一(yi)種是(shi)(shi)基(ji)于反饋控(kong)(kong)(kong)制(zhi)(zhi)原理的(de)閉環控(kong)(kong)(kong)制(zhi)(zhi)系(xi)(xi)(xi)統(tong)。而(er)大部分(fen)(fen)的(de)開(kai)關(guan)電(dian)(dian)(dian)源控(kong)(kong)(kong)制(zhi)(zhi)系(xi)(xi)(xi)統(tong)是(shi)(shi)閉環控(kong)(kong)(kong)制(zhi)(zhi)系(xi)(xi)(xi)統(tong)。

　　二、閉環控制原理

　　通常，我們(men)把被(bei)控(kong)量(liang)送回到(dao)控(kong)制系統的輸入端，與(yu)參據量(liang)相(xiang)比較產(chan)生誤差信(xin)號的過程，稱(cheng)為反饋(kui)。若反饋(kui)的信(xin)號是與(yu)參據量(liang)相(xiang)減，使(shi)得產(chan)生的偏差越來越小，稱(cheng)為負反饋(kui)。由于(yu)引入了被(bei)控(kong)量(liang)的反饋(kui)信(xin)息，整個控(kong)制過程成為閉合的，因此也稱(cheng)閉環控(kong)制，如圖1所示(shi)。

圖1  反饋(kui)控制框圖

　　三、基本組成

　　控制裝置是由具有一定職(zhi)能的各種基本元器件組(zu)成。系統的元器件按照職(zhi)能分類主(zhu)要有以(yi)下幾(ji)種：

　　測量單元：其職(zhi)能是檢測被控制的物理(li)量。這個被控量一般(ban)為(wei)主功率(lv)(lv)電路的輸(shu)出電壓、主功率(lv)(lv)電路的輸(shu)入電流等。

　　給定(ding)單元：其職能(neng)是(shi)給出(chu)與期望的被(bei)控量相對(dui)應的參據量，即給定(ding)量。在開關電源系(xi)統中，給定(ding)量一般為直流常量或者是(shi)交流正弦(xian)量。

　　比較(jiao)單元(yuan)：其職能是將檢測到的被控制量的實(shi)際值與參據量進(jin)行(xing)比較(jiao)，求出他們之(zhi)間的偏差。

　　校正單元：即補償(chang)單元，用串(chuan)聯方式(shi)(shi)或(huo)者反饋方式(shi)(shi)（并聯方式(shi)(shi)）等(deng)方式(shi)(shi)連接在系統中，以改善系統的(de)性能(neng)。這個補償(chang)網絡(luo)是(shi)控(kong)制(zhi)系統的(de)核(he)心(xin)部(bu)分，是(shi)決(jue)定控(kong)制(zhi)系統性能(neng)的(de)關鍵部(bu)分。可(ke)以通過由電阻、電容組成的(de)無源或(huo)有源網絡(luo)實現，也可(ke)以通過MCU、DSP這些數字器件輔助實現。

　　四、外作用類型

　　一般(ban)加(jia)在(zai)開(kai)關電(dian)源(yuan)系(xi)統(tong)(tong)上的(de)(de)(de)(de)外作用有兩種類型：一種是(shi)有用輸(shu)入，它(ta)決定(ding)系(xi)統(tong)(tong)被控(kong)量(liang)的(de)(de)(de)(de)變化規律，比如給定(ding)量(liang)；一種是(shi)系(xi)統(tong)(tong)不(bu)希望有的(de)(de)(de)(de)外作用，即擾動(dong)，它(ta)破壞(huai)有用輸(shu)入對系(xi)統(tong)(tong)的(de)(de)(de)(de)控(kong)制。在(zai)實際(ji)系(xi)統(tong)(tong)中，擾動(dong)是(shi)不(bu)可(ke)避免的(de)(de)(de)(de)。這樣的(de)(de)(de)(de)擾動(dong)包括：主(zhu)功率(lv)電(dian)路輸(shu)入電(dian)壓的(de)(de)(de)(de)波(bo)動(dong)，主(zhu)功率(lv)電(dian)路輸(shu)出電(dian)流(liu)的(de)(de)(de)(de)波(bo)動(dong)或者(zhe)負載(zai)的(de)(de)(de)(de)波(bo)動(dong)，元器(qi)件參數的(de)(de)(de)(de)溫度漂移(yi)等。

      五(wu)、基本(ben)控制方式

　　反(fan)饋(kui)控(kong)制是(shi)系(xi)統(tong)最基本的控(kong)制方(fang)式(shi)，也是(shi)應用最廣泛的一種控(kong)制方(fang)式(shi)。此外，還有(you)開(kai)環控(kong)制方(fang)式(shi)和復(fu)合控(kong)制方(fang)式(shi)，它們都有(you)著各自的特點(dian)和不同(tong)的應用場合。

　　（1）反饋控制(zhi)方(fang)式

　　如前面所提及，反饋控(kong)(kong)制(zhi)(zhi)(zhi)方式(shi)是按(an)照(zhao)偏(pian)差(cha)進(jin)行控(kong)(kong)制(zhi)(zhi)(zhi)的(de)，其特點(dian)是不論(lun)什么(me)原因使被控(kong)(kong)量(liang)偏(pian)離期望值(zhi)而出現(xian)偏(pian)差(cha)時，必定(ding)會產生(sheng)一個(ge)相應(ying)的(de)控(kong)(kong)制(zhi)(zhi)(zhi)作(zuo)用去減小或消除這(zhe)個(ge)偏(pian)差(cha)，使被控(kong)(kong)量(liang)與期望值(zhi)趨于一致。可見，按(an)照(zhao)反饋控(kong)(kong)制(zhi)(zhi)(zhi)方式(shi)設(she)計的(de)控(kong)(kong)制(zhi)(zhi)(zhi)系統(tong)，具有(you)抑制(zhi)(zhi)(zhi)任何內、外擾動對被控(kong)(kong)量(liang)產生(sheng)影響的(de)能力，有(you)較高的(de)穩態精(jing)度(du)。

　　如圖2所示為(wei)電(dian)壓(ya)型(xing)控制(zhi)(zhi)Boost變換(huan)器控制(zhi)(zhi)框圖，電(dian)壓(ya)反(fan)饋控制(zhi)(zhi)技術是開關電(dian)源系(xi)統中經典的(de)(de)(de)反(fan)饋控制(zhi)(zhi)方法(fa)。這是60年代(dai)后期(qi)開關穩壓(ya)電(dian)源剛剛開始發(fa)展就(jiu)采(cai)用(yong)的(de)(de)(de)第一(yi)種控制(zhi)(zhi)方法(fa)，該方法(fa)與一(yi)些必要的(de)(de)(de)過電(dian)流保(bao)護(hu)電(dian)路相結合，至今仍然(ran)被廣泛的(de)(de)(de)應用(yong)。

圖2  電壓型控(kong)制(zhi) Boost 變換器控(kong)制(zhi)框(kuang)圖

　　（2）開環控制(zhi)方式

　　開環(huan)控(kong)(kong)(kong)(kong)制(zhi)方式(shi)是(shi)(shi)指(zhi)被控(kong)(kong)(kong)(kong)裝置與被控(kong)(kong)(kong)(kong)對象之間只有(you)順(shun)向(xiang)作(zuo)用(yong)而沒有(you)反向(xiang)聯(lian)系(xi)(xi)的(de)控(kong)(kong)(kong)(kong)制(zhi)過程(cheng)。按這種控(kong)(kong)(kong)(kong)制(zhi)方式(shi)組成的(de)控(kong)(kong)(kong)(kong)制(zhi)系(xi)(xi)統稱為開環(huan)控(kong)(kong)(kong)(kong)制(zhi)系(xi)(xi)統，其特點(dian)是(shi)(shi)系(xi)(xi)統的(de)輸出(chu)量(liang)不會(hui)對系(xi)(xi)統的(de)控(kong)(kong)(kong)(kong)制(zhi)作(zuo)用(yong)發生影響。這種控(kong)(kong)(kong)(kong)制(zhi)方式(shi)也(ye)稱為前饋控(kong)(kong)(kong)(kong)制(zhi)、順(shun)饋控(kong)(kong)(kong)(kong)制(zhi)。開環(huan)控(kong)(kong)(kong)(kong)制(zhi)系(xi)(xi)統可以由按給定量(liang)控(kong)(kong)(kong)(kong)制(zhi)的(de)控(kong)(kong)(kong)(kong)制(zhi)方式(shi)組成，也(ye)可以由按擾動(dong)控(kong)(kong)(kong)(kong)制(zhi)的(de)控(kong)(kong)(kong)(kong)制(zhi)方式(shi)組成。

　　按(an)給(gei)(gei)定(ding)量控(kong)(kong)制(zhi)的(de)開環控(kong)(kong)制(zhi)系統，其控(kong)(kong)制(zhi)作用(yong)直接由(you)(you)控(kong)(kong)制(zhi)系統的(de)輸入(ru)量產生(sheng)，給(gei)(gei)定(ding)一個輸入(ru)量，就有一個輸出量與之相對應，控(kong)(kong)制(zhi)精度完(wan)全(quan)取決于(yu)控(kong)(kong)制(zhi)電路所用(yong)的(de)元器件以及主(zhu)功率電路的(de)特(te)性，如圖3所示。這種(zhong)控(kong)(kong)制(zhi)方(fang)(fang)式沒(mei)有自(zi)動修正偏差的(de)能(neng)力，抗擾動能(neng)力差。但由(you)(you)于(yu)其結構(gou)簡單、調整方(fang)(fang)便、成本低，在(zai)精度要求不高或擾動影響較小的(de)情況下，這種(zhong)控(kong)(kong)制(zhi)方(fang)(fang)式還是(shi)有一定(ding)的(de)實用(yong)價值。

圖3  按給定量控制(zhi)的(de)開環(huan)控制(zhi)系統(tong)

如(ru)圖(tu)4所(suo)示的采(cai)用(yong)(yong)電容的開(kai)(kai)關(guan)(guan)功率變(bian)換器，一(yi)(yi)般為多級(ji)變(bian)換電路(lu)中的其(qi)中一(yi)(yi)級(ji)，通常采(cai)用(yong)(yong)開(kai)(kai)環控(kong)制，效率和功率密度較高(gao)，容易實現(xian)開(kai)(kai)關(guan)(guan)，具有廣泛的應用(yong)(yong)前景。

圖4  開(kai)環控(kong)制的開(kai)關(guan)電容(rong)功率變換器

　　按擾動(dong)(dong)(dong)控(kong)制(zhi)的(de)開環控(kong)制(zhi)系統，是(shi)利用可測量的(de)擾動(dong)(dong)(dong)量，產生一種補償(chang)作(zuo)用，以(yi)(yi)減(jian)少或抵(di)消擾動(dong)(dong)(dong)對(dui)輸出(chu)量的(de)影(ying)響，如圖5所示。這種控(kong)制(zhi)方式直接從擾動(dong)(dong)(dong)取得(de)信息，并據此(ci)改變被控(kong)量，因此(ci)其(qi)抗擾動(dong)(dong)(dong)性好，控(kong)制(zhi)精度(du)也較高，但它只(zhi)適用于(yu)擾動(dong)(dong)(dong)是(shi)可以(yi)(yi)測量的(de)場合，而且一個補償(chang)裝置只(zhi)能(neng)補償(chang)一個擾動(dong)(dong)(dong)因素(su)，對(dui)其(qi)余擾動(dong)(dong)(dong)均(jun)不起補償(chang)作(zuo)用。

圖5  按擾動控(kong)制的開環(huan)控(kong)制系統

　　如圖6所(suo)示為(wei)單(dan)周期(qi)控(kong)制(zhi)(zhi)(zhi)Buck變(bian)換器控(kong)制(zhi)(zhi)(zhi)框圖，單(dan)周期(qi)控(kong)制(zhi)(zhi)(zhi)技術實際(ji)上(shang)就(jiu)是一種按擾(rao)動控(kong)制(zhi)(zhi)(zhi)的(de)開(kai)環(huan)控(kong)制(zhi)(zhi)(zhi)系統。它將主功率(lv)電路的(de)輸入電壓引(yin)入控(kong)制(zhi)(zhi)(zhi)，隨著輸入電壓的(de)變(bian)化，得到不同(tong)的(de)占空度，使得主功率(lv)電路的(de)輸出電壓跟(gen)隨給定量。理論上(shang)這(zhe)種控(kong)制(zhi)(zhi)(zhi)技術完(wan)全抵制(zhi)(zhi)(zhi)了主功率(lv)電路的(de)輸出電壓擾(rao)動，但是對負載的(de)擾(rao)動卻無(wu)能為(wei)力。

圖6  單周期控制(zhi) Buck 變換器控制(zhi)框(kuang)圖

 （3）復合控制方式

　　開環控制方式在技術上較反饋控制方式簡單，且對激勵響應快，但是僅僅只采用按給定量控制的前饋控制方式來控制，系統控制精度不高。而按擾動控制的開環控制系統只適用于擾動可以測量的場合。因此，比較合理的一種控制方式是把開環控制方式與反饋控制方式結合起來。這種控制方式稱為復合控制。利用控制系統的給定量，產生一種補償作用，使得被控量更好的跟隨給定量。另外，對主要擾動采用適當的補償裝置來實現擾動控制。同時，再組成反饋控制系統實現按偏差控制，以消除其余擾動產生的偏差。這樣，系統的主要外作用已被補償，反饋控制系統比較容易設計，控制效果也會更好。這種將前饋控制和反饋控制相結合的控制方式稱為復合控制。
如(ru)圖7所示(shi)為(wei)具有輸(shu)(shu)(shu)入(ru)(ru)電(dian)(dian)壓(ya)前(qian)饋(kui)的(de)(de)(de)(de)平(ping)均(jun)(jun)電(dian)(dian)流(liu)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)(zhi)Boost變換器(qi)的(de)(de)(de)(de)PFC控(kong)(kong)(kong)制(zhi)(zhi)(zhi)(zhi)框圖，這種控(kong)(kong)(kong)制(zhi)(zhi)(zhi)(zhi)方法(fa)為(wei)雙環(huan)(huan)(huan)反(fan)饋(kui)的(de)(de)(de)(de)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)(zhi)方法(fa)，外環(huan)(huan)(huan)為(wei)母線電(dian)(dian)壓(ya)平(ping)均(jun)(jun)值(zhi)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)(zhi)環(huan)(huan)(huan)，內環(huan)(huan)(huan)為(wei)輸(shu)(shu)(shu)入(ru)(ru)電(dian)(dian)流(liu)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)(zhi)環(huan)(huan)(huan)。該(gai)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)(zhi)方法(fa)將(jiang)輸(shu)(shu)(shu)出(chu)電(dian)(dian)壓(ya)的(de)(de)(de)(de)平(ping)均(jun)(jun)值(zhi)作(zuo)為(wei)反(fan)饋(kui)與(yu)基(ji)準(zhun)比較(jiao)，產(chan)生(sheng)的(de)(de)(de)(de)誤(wu)差(cha)信(xin)(xin)(xin)(xin)號(hao)(hao)經由(you)電(dian)(dian)壓(ya)補(bu)償器(qi)進行(xing)(xing)調(diao)節(jie)。產(chan)生(sheng)的(de)(de)(de)(de)信(xin)(xin)(xin)(xin)號(hao)(hao)與(yu)輸(shu)(shu)(shu)入(ru)(ru)電(dian)(dian)壓(ya)有效值(zhi)一起，控(kong)(kong)(kong)制(zhi)(zhi)(zhi)(zhi)正弦波基(ji)準(zhun)的(de)(de)(de)(de)幅(fu)值(zhi)。再將(jiang)輸(shu)(shu)(shu)入(ru)(ru)電(dian)(dian)流(liu)作(zuo)為(wei)反(fan)饋(kui)與(yu)正弦波基(ji)準(zhun)進行(xing)(xing)比較(jiao)，產(chan)生(sheng)的(de)(de)(de)(de)誤(wu)差(cha)信(xin)(xin)(xin)(xin)號(hao)(hao)經由(you)電(dian)(dian)流(liu)補(bu)償器(qi)進行(xing)(xing)調(diao)節(jie)產(chan)生(sheng)調(diao)制(zhi)(zhi)(zhi)(zhi)信(xin)(xin)(xin)(xin)號(hao)(hao)，再將(jiang)該(gai)調(diao)制(zhi)(zhi)(zhi)(zhi)信(xin)(xin)(xin)(xin)號(hao)(hao)與(yu)載(zai)波比較(jiao)得(de)到(dao)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)(zhi)信(xin)(xin)(xin)(xin)號(hao)(hao)，得(de)到(dao)所需的(de)(de)(de)(de)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)(zhi)信(xin)(xin)(xin)(xin)號(hao)(hao)，外環(huan)(huan)(huan)的(de)(de)(de)(de)作(zuo)用，主(zhu)要(yao)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)(zhi)輸(shu)(shu)(shu)出(chu)電(dian)(dian)壓(ya)，內環(huan)(huan)(huan)主(zhu)要(yao)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)(zhi)輸(shu)(shu)(shu)入(ru)(ru)電(dian)(dian)流(liu)的(de)(de)(de)(de)波形，保(bao)證輸(shu)(shu)(shu)入(ru)(ru)電(dian)(dian)流(liu)的(de)(de)(de)(de)正弦度。引(yin)入(ru)(ru)了輸(shu)(shu)(shu)入(ru)(ru)電(dian)(dian)壓(ya)前(qian)饋(kui)，克服輸(shu)(shu)(shu)入(ru)(ru)電(dian)(dian)壓(ya)擾動對輸(shu)(shu)(shu)出(chu)電(dian)(dian)壓(ya)的(de)(de)(de)(de)影響(xiang)。

圖7  具有輸入(ru)電壓(ya)前饋的(de)平均電流控制 Boost 變換器的(de)PFC

　　六、校正方式

　　對控(kong)(kong)制系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)的(de)(de)(de)(de)(de)要求，通常(chang)以性(xing)(xing)能指(zhi)標的(de)(de)(de)(de)(de)形(xing)(xing)式給(gei)出。而為(wei)了使系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)獲得滿意(yi)的(de)(de)(de)(de)(de)性(xing)(xing)能，必須(xu)對控(kong)(kong)制系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)進(jin)行設計(ji)和(he)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)(zheng)，也(ye)就是在(zai)(zai)系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)中適當(dang)(dang)的(de)(de)(de)(de)(de)位(wei)置(zhi)(zhi)(zhi)(zhi)(zhi)加進(jin)適當(dang)(dang)的(de)(de)(de)(de)(de)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)(zheng)裝置(zhi)(zhi)(zhi)(zhi)(zhi)。校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)(zheng)裝置(zhi)(zhi)(zhi)(zhi)(zhi)彌補了原系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)的(de)(de)(de)(de)(de)性(xing)(xing)能缺陷。按照校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)(zheng)裝置(zhi)(zhi)(zhi)(zhi)(zhi)在(zai)(zai)開(kai)關電源(yuan)系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)中的(de)(de)(de)(de)(de)連接(jie)(jie)方式，控(kong)(kong)制系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)的(de)(de)(de)(de)(de)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)(zheng)方式可(ke)以分為(wei)串聯(lian)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)(zheng)、反(fan)饋(kui)(kui)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)(zheng)、前饋(kui)(kui)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)(zheng)、復合校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)(zheng)等。如圖8所示(shi)為(wei)系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)(zheng)裝置(zhi)(zhi)(zhi)(zhi)(zhi)位(wei)置(zhi)(zhi)(zhi)(zhi)(zhi)示(shi)意(yi)圖，G（S）為(wei)被控(kong)(kong)對象（主功(gong)率電路）；串聯(lian)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)(zheng)裝置(zhi)(zhi)(zhi)(zhi)(zhi)一(yi)般連接(jie)(jie)在(zai)(zai)G（S）之(zhi)前，串接(jie)(jie)與(yu)系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)前向(xiang)通道之(zhi)中，如G1（S）益所示(shi)；反(fan)饋(kui)(kui)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)(zheng)裝置(zhi)(zhi)(zhi)(zhi)(zhi)連接(jie)(jie)在(zai)(zai)系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)局部反(fan)饋(kui)(kui)通路之(zhi)中，如G2（S）位(wei)置(zhi)(zhi)(zhi)(zhi)(zhi)所示(shi)；補償(chang)給(gei)定(ding)量的(de)(de)(de)(de)(de)前饋(kui)(kui)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)(zheng)裝置(zhi)(zhi)(zhi)(zhi)(zhi)接(jie)(jie)在(zai)(zai)系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)給(gei)定(ding)量之(zhi)后的(de)(de)(de)(de)(de)前向(xiang)通道之(zhi)上，形(xing)(xing)成(cheng)(cheng)前饋(kui)(kui)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)(zheng)通路，如G3（S）位(wei)置(zhi)(zhi)(zhi)(zhi)(zhi)所示(shi)，補償(chang)擾(rao)動(dong)量的(de)(de)(de)(de)(de)前饋(kui)(kui)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)(zheng)裝置(zhi)(zhi)(zhi)(zhi)(zhi)接(jie)(jie)在(zai)(zai)系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)可(ke)測試的(de)(de)(de)(de)(de)振(zhen)動(dong)量之(zhi)后，形(xing)(xing)成(cheng)(cheng)一(yi)條附(fu)加的(de)(de)(de)(de)(de)通道，如G4（S）位(wei)置(zhi)(zhi)(zhi)(zhi)(zhi)所示(shi)。前饋(kui)(kui)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)(zheng)裝置(zhi)(zhi)(zhi)(zhi)(zhi)可(ke)以單獨作(zuo)用與(yu)開(kai)環控(kong)(kong)制系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)，也(ye)可(ke)以作(zuo)為(wei)反(fan)饋(kui)(kui)控(kong)(kong)制系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)的(de)(de)(de)(de)(de)附(fu)加校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)(zheng)而組(zu)成(cheng)(cheng)復合校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)(zheng)控(kong)(kong)制系(xi)統(tong)(tong)(tong)(tong)(tong)(tong)。

圖(tu)(tu)8  系統校正裝置(zhi)位置(zhi)示意圖(tu)(tu)

　　七、小結

　　開關(guan)電(dian)源系統(tong)通過(guo)控(kong)制(zhi)(zhi)(zhi)電(dian)路對主功率電(dian)路的控(kong)制(zhi)(zhi)(zhi)實現電(dian)能的變換(huan)。開關(guan)電(dian)源系統(tong)有(you)多種(zhong)控(kong)制(zhi)(zhi)(zhi)方(fang)式，而控(kong)制(zhi)(zhi)(zhi)方(fang)式的核心是(shi)校(xiao)正方(fang)式。究竟選用(yong)哪種(zhong)控(kong)制(zhi)(zhi)(zhi)方(fang)式，系統(tong)如何校(xiao)正，取決于系統(tong)主功率電(dian)路的被控(kong)量(liang)的性(xing)質、抗擾動(dong)性(xing)要(yao)求、技術實現的方(fang)便性(xing)、經濟性(xing)要(yao)求、環境使用(yong)條件等因素。