一、前言

　　開關電源系統(tong)是(shi)(shi)(shi)弱電(dian)控(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)強電(dian)的(de)(de)(de)系統(tong)。開(kai)(kai)關(guan)(guan)電(dian)源(yuan)系統(tong)主(zhu)要(yao)可(ke)以(yi)分為主(zhu)功(gong)率(lv)電(dian)路和控(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)電(dian)路兩部(bu)分。主(zhu)功(gong)率(lv)電(dian)路是(shi)(shi)(shi)由變(bian)換(huan)(huan)器(qi)構成。變(bian)換(huan)(huan)器(qi)是(shi)(shi)(shi)應(ying)用功(gong)率(lv)半導體器(qi)件，對電(dian)能進行變(bian)換(huan)(huan)的(de)(de)(de)裝置(zhi)，變(bian)換(huan)(huan)量包括電(dian)壓、電(dian)流、頻率(lv)和波形等方面，以(yi)達到電(dian)能更好符(fu)合各種不同用電(dian)設備要(yao)求(qiu)的(de)(de)(de)目的(de)(de)(de)。這(zhe)是(shi)(shi)(shi)通(tong)過(guo)對功(gong)率(lv)半導體器(qi)件的(de)(de)(de)開(kai)(kai)關(guan)(guan)的(de)(de)(de)控(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)來(lai)實(shi)現的(de)(de)(de)。因此(ci)主(zhu)功(gong)率(lv)電(dian)路是(shi)(shi)(shi)開(kai)(kai)關(guan)(guan)電(dian)源(yuan)控(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)系統(tong)中(zhong)的(de)(de)(de)被(bei)控(kong)(kong)(kong)(kong)對象，而控(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)功(gong)率(lv)半導體器(qi)件的(de)(de)(de)開(kai)(kai)關(guan)(guan)以(yi)實(shi)現既(ji)定的(de)(de)(de)性能是(shi)(shi)(shi)控(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)裝置(zhi)的(de)(de)(de)主(zhu)要(yao)工(gong)(gong)作(zuo)(zuo)。將被(bei)控(kong)(kong)(kong)(kong)對象和控(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)裝置(zhi)按照一定的(de)(de)(de)方式連接(jie)起來(lai)，組成一個有機(ji)的(de)(de)(de)總體，就(jiu)構成開(kai)(kai)關(guan)(guan)電(dian)源(yuan)的(de)(de)(de)控(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)系統(tong)，這(zhe)樣的(de)(de)(de)電(dian)路即為控(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)電(dian)路。控(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)系統(tong)的(de)(de)(de)工(gong)(gong)作(zuo)(zuo)方式有多種，其(qi)中(zhong)最基本的(de)(de)(de)一種是(shi)(shi)(shi)基于(yu)反饋控(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)原(yuan)理的(de)(de)(de)閉(bi)環控(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)系統(tong)。而大部(bu)分的(de)(de)(de)開(kai)(kai)關(guan)(guan)電(dian)源(yuan)控(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)系統(tong)是(shi)(shi)(shi)閉(bi)環控(kong)(kong)(kong)(kong)制(zhi)(zhi)(zhi)系統(tong)。

　　二、閉環控制原理

　　通常，我們把被控(kong)量(liang)送回到(dao)控(kong)制(zhi)系統(tong)的(de)輸(shu)入(ru)(ru)端，與參據量(liang)相比較產生誤差信號的(de)過(guo)(guo)程，稱(cheng)為(wei)(wei)反(fan)饋(kui)(kui)。若(ruo)反(fan)饋(kui)(kui)的(de)信號是與參據量(liang)相減，使(shi)得(de)產生的(de)偏差越來越小，稱(cheng)為(wei)(wei)負反(fan)饋(kui)(kui)。由于引入(ru)(ru)了(le)被控(kong)量(liang)的(de)反(fan)饋(kui)(kui)信息，整個控(kong)制(zhi)過(guo)(guo)程成(cheng)為(wei)(wei)閉合(he)的(de)，因(yin)此也稱(cheng)閉環控(kong)制(zhi)，如圖1所(suo)示。

圖1  反饋(kui)控制框圖

　　三、基本組成

　　控制裝置(zhi)是(shi)由(you)具(ju)有一定(ding)職能的各種(zhong)基本元器(qi)件組成。系統的元器(qi)件按照(zhao)職能分類主(zhu)要有以下(xia)幾(ji)種(zhong)：

　　測量(liang)(liang)單(dan)元：其職能是檢測被(bei)控(kong)制的物理量(liang)(liang)。這個被(bei)控(kong)量(liang)(liang)一般為主(zhu)功率(lv)電(dian)(dian)路(lu)的輸出電(dian)(dian)壓、主(zhu)功率(lv)電(dian)(dian)路(lu)的輸入電(dian)(dian)流等。

　　給(gei)定(ding)單元：其(qi)職(zhi)能是給(gei)出與期望的被控量(liang)相對應的參據(ju)量(liang)，即(ji)給(gei)定(ding)量(liang)。在開關電源(yuan)系統(tong)中，給(gei)定(ding)量(liang)一(yi)般(ban)為直流常量(liang)或(huo)者是交(jiao)流正弦量(liang)。

　　比較單(dan)元：其職(zhi)能(neng)是將檢測到的(de)被控制量的(de)實際值與參據量進行比較，求出他們之間的(de)偏(pian)差。

　　校(xiao)正單(dan)元：即補(bu)償(chang)單(dan)元，用串聯方式或(huo)者反饋方式（并聯方式）等方式連接在系(xi)(xi)統(tong)中，以改(gai)善系(xi)(xi)統(tong)的(de)性能。這(zhe)個補(bu)償(chang)網(wang)絡是(shi)控制系(xi)(xi)統(tong)的(de)核心部(bu)分，是(shi)決定控制系(xi)(xi)統(tong)性能的(de)關鍵部(bu)分。可(ke)以通過(guo)(guo)由電(dian)阻(zu)、電(dian)容組成的(de)無源或(huo)有(you)源網(wang)絡實現，也可(ke)以通過(guo)(guo)MCU、DSP這(zhe)些數字器件輔(fu)助(zhu)實現。

　　四、外作用類型

　　一般加(jia)在(zai)開關電源系統上的(de)(de)(de)外(wai)作(zuo)用有兩種類型(xing)：一種是有用輸入，它決定系統被控(kong)(kong)量的(de)(de)(de)變化規律，比如給(gei)定量；一種是系統不希望有的(de)(de)(de)外(wai)作(zuo)用，即擾動，它破壞有用輸入對系統的(de)(de)(de)控(kong)(kong)制。在(zai)實際系統中，擾動是不可避免的(de)(de)(de)。這樣的(de)(de)(de)擾動包括：主(zhu)(zhu)功率電路輸入電壓的(de)(de)(de)波(bo)動，主(zhu)(zhu)功率電路輸出電流的(de)(de)(de)波(bo)動或者負載的(de)(de)(de)波(bo)動，元器件參數的(de)(de)(de)溫度漂移等。

      五、基本控(kong)制方式

　　反饋控(kong)制(zhi)是系(xi)統(tong)最基本的控(kong)制(zhi)方式(shi)，也是應用最廣(guang)泛的一種控(kong)制(zhi)方式(shi)。此(ci)外，還有開環控(kong)制(zhi)方式(shi)和復合控(kong)制(zhi)方式(shi)，它們(men)都有著各自的特點和不同的應用場合。

　　（1）反饋(kui)控制方(fang)式

　　如前面(mian)所提及，反饋控(kong)制(zhi)(zhi)方式(shi)是按照偏差(cha)進行控(kong)制(zhi)(zhi)的(de)，其(qi)特(te)點(dian)是不(bu)論什么原因(yin)使被(bei)控(kong)量偏離期望值而出現偏差(cha)時(shi)，必定會產生(sheng)一個相應的(de)控(kong)制(zhi)(zhi)作用去減小或消除這個偏差(cha)，使被(bei)控(kong)量與(yu)期望值趨于一致。可見，按照反饋控(kong)制(zhi)(zhi)方式(shi)設計的(de)控(kong)制(zhi)(zhi)系統(tong)，具有(you)(you)抑制(zhi)(zhi)任何內、外擾動對被(bei)控(kong)量產生(sheng)影響的(de)能力，有(you)(you)較高的(de)穩態精度。

　　如圖2所示為電(dian)壓(ya)(ya)型控(kong)制Boost變換器控(kong)制框(kuang)圖，電(dian)壓(ya)(ya)反(fan)饋控(kong)制技術(shu)是開關電(dian)源系(xi)統中經典的反(fan)饋控(kong)制方法(fa)(fa)。這(zhe)是60年代后(hou)期開關穩(wen)壓(ya)(ya)電(dian)源剛(gang)剛(gang)開始發展(zhan)就采用的第一種控(kong)制方法(fa)(fa)，該方法(fa)(fa)與一些必要(yao)的過(guo)電(dian)流保護電(dian)路(lu)相結合，至今仍然被廣泛的應用。

圖2  電(dian)壓型控(kong)制 Boost 變換器控(kong)制框圖

　　（2）開(kai)環控制方式

　　開環(huan)控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)方(fang)式(shi)是指被(bei)控(kong)(kong)裝置(zhi)與(yu)被(bei)控(kong)(kong)對象(xiang)之(zhi)間只有順向作(zuo)用(yong)而沒有反向聯系的(de)(de)控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)過程。按這種控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)方(fang)式(shi)組(zu)(zu)成(cheng)(cheng)的(de)(de)控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)系統(tong)稱為開環(huan)控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)系統(tong)，其特(te)點(dian)是系統(tong)的(de)(de)輸出量不會對系統(tong)的(de)(de)控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)作(zuo)用(yong)發(fa)生影響。這種控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)方(fang)式(shi)也(ye)(ye)稱為前饋控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)、順饋控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)。開環(huan)控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)系統(tong)可以由按給定(ding)量控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)的(de)(de)控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)方(fang)式(shi)組(zu)(zu)成(cheng)(cheng)，也(ye)(ye)可以由按擾(rao)動(dong)控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)的(de)(de)控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)方(fang)式(shi)組(zu)(zu)成(cheng)(cheng)。

　　按(an)給定(ding)量控制的(de)(de)開環控制系統(tong)，其控制作用直(zhi)接由(you)控制系統(tong)的(de)(de)輸(shu)入量產生，給定(ding)一個(ge)輸(shu)入量，就(jiu)有一個(ge)輸(shu)出量與之相對應，控制精(jing)度完全取決于(yu)控制電路(lu)所用的(de)(de)元器件以及主功率電路(lu)的(de)(de)特性，如圖3所示(shi)。這種控制方式沒有自動(dong)修正(zheng)偏差的(de)(de)能力(li)，抗擾動(dong)能力(li)差。但由(you)于(yu)其結構簡單(dan)、調(diao)整方便、成本低，在精(jing)度要求(qiu)不高或擾動(dong)影響(xiang)較小的(de)(de)情況(kuang)下，這種控制方式還是(shi)有一定(ding)的(de)(de)實(shi)用價值。

圖3  按給定量控制(zhi)的開環(huan)控制(zhi)系(xi)統

如圖4所示的(de)采用(yong)(yong)電(dian)容(rong)的(de)開(kai)(kai)關功率變換器，一(yi)般為(wei)多級變換電(dian)路(lu)中的(de)其中一(yi)級，通常采用(yong)(yong)開(kai)(kai)環(huan)控制，效率和功率密度(du)較高，容(rong)易實(shi)現開(kai)(kai)關，具有廣泛的(de)應用(yong)(yong)前景。

圖4  開(kai)環控制的開(kai)關(guan)電容功率變(bian)換器

　　按擾(rao)動(dong)(dong)(dong)(dong)控(kong)制(zhi)的(de)開(kai)環控(kong)制(zhi)系統，是利用可測(ce)量(liang)的(de)擾(rao)動(dong)(dong)(dong)(dong)量(liang)，產生一(yi)(yi)種補(bu)償(chang)作用，以(yi)減少或抵消擾(rao)動(dong)(dong)(dong)(dong)對輸出量(liang)的(de)影(ying)響，如圖5所示。這種控(kong)制(zhi)方式直接從擾(rao)動(dong)(dong)(dong)(dong)取(qu)得信息，并據此改變被控(kong)量(liang)，因此其抗擾(rao)動(dong)(dong)(dong)(dong)性好，控(kong)制(zhi)精度也(ye)較(jiao)高，但它(ta)只適用于擾(rao)動(dong)(dong)(dong)(dong)是可以(yi)測(ce)量(liang)的(de)場合，而且一(yi)(yi)個(ge)補(bu)償(chang)裝置(zhi)只能補(bu)償(chang)一(yi)(yi)個(ge)擾(rao)動(dong)(dong)(dong)(dong)因素，對其余擾(rao)動(dong)(dong)(dong)(dong)均不起補(bu)償(chang)作用。

圖5  按(an)擾動控制(zhi)的(de)開環控制(zhi)系統

　　如圖6所(suo)示為單周期控制(zhi)(zhi)Buck變換器控制(zhi)(zhi)框圖，單周期控制(zhi)(zhi)技術實際上就(jiu)是一種按(an)擾動控制(zhi)(zhi)的(de)(de)開環控制(zhi)(zhi)系(xi)統。它將主功(gong)率(lv)(lv)電(dian)(dian)路(lu)的(de)(de)輸(shu)入(ru)電(dian)(dian)壓引入(ru)控制(zhi)(zhi)，隨著輸(shu)入(ru)電(dian)(dian)壓的(de)(de)變化，得(de)到不同的(de)(de)占空度，使得(de)主功(gong)率(lv)(lv)電(dian)(dian)路(lu)的(de)(de)輸(shu)出電(dian)(dian)壓跟隨給定量(liang)。理論上這種控制(zhi)(zhi)技術完(wan)全抵制(zhi)(zhi)了主功(gong)率(lv)(lv)電(dian)(dian)路(lu)的(de)(de)輸(shu)出電(dian)(dian)壓擾動，但是對負載(zai)的(de)(de)擾動卻無能(neng)為力。

圖6  單周期控制 Buck 變換器控制框圖

 （3）復合控制方(fang)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。
如圖7所示(shi)為(wei)(wei)具有輸(shu)(shu)入(ru)(ru)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)前饋的(de)(de)(de)(de)(de)平(ping)均電(dian)(dian)(dian)(dian)(dian)流(liu)控(kong)(kong)(kong)制(zhi)(zhi)Boost變換器(qi)(qi)的(de)(de)(de)(de)(de)PFC控(kong)(kong)(kong)制(zhi)(zhi)框圖，這種控(kong)(kong)(kong)制(zhi)(zhi)方(fang)法(fa)為(wei)(wei)雙環(huan)反饋的(de)(de)(de)(de)(de)控(kong)(kong)(kong)制(zhi)(zhi)方(fang)法(fa)，外環(huan)為(wei)(wei)母(mu)線電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)平(ping)均值(zhi)控(kong)(kong)(kong)制(zhi)(zhi)環(huan)，內(nei)環(huan)為(wei)(wei)輸(shu)(shu)入(ru)(ru)電(dian)(dian)(dian)(dian)(dian)流(liu)控(kong)(kong)(kong)制(zhi)(zhi)環(huan)。該控(kong)(kong)(kong)制(zhi)(zhi)方(fang)法(fa)將(jiang)輸(shu)(shu)出(chu)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)的(de)(de)(de)(de)(de)平(ping)均值(zhi)作為(wei)(wei)反饋與基準比(bi)(bi)較(jiao)(jiao)，產(chan)生(sheng)(sheng)的(de)(de)(de)(de)(de)誤差信(xin)號(hao)(hao)經由電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)補償(chang)器(qi)(qi)進(jin)行(xing)調(diao)節。產(chan)生(sheng)(sheng)的(de)(de)(de)(de)(de)信(xin)號(hao)(hao)與輸(shu)(shu)入(ru)(ru)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)有效值(zhi)一起，控(kong)(kong)(kong)制(zhi)(zhi)正(zheng)(zheng)弦(xian)波(bo)基準的(de)(de)(de)(de)(de)幅值(zhi)。再將(jiang)輸(shu)(shu)入(ru)(ru)電(dian)(dian)(dian)(dian)(dian)流(liu)作為(wei)(wei)反饋與正(zheng)(zheng)弦(xian)波(bo)基準進(jin)行(xing)比(bi)(bi)較(jiao)(jiao)，產(chan)生(sheng)(sheng)的(de)(de)(de)(de)(de)誤差信(xin)號(hao)(hao)經由電(dian)(dian)(dian)(dian)(dian)流(liu)補償(chang)器(qi)(qi)進(jin)行(xing)調(diao)節產(chan)生(sheng)(sheng)調(diao)制(zhi)(zhi)信(xin)號(hao)(hao)，再將(jiang)該調(diao)制(zhi)(zhi)信(xin)號(hao)(hao)與載波(bo)比(bi)(bi)較(jiao)(jiao)得到(dao)控(kong)(kong)(kong)制(zhi)(zhi)信(xin)號(hao)(hao)，得到(dao)所需的(de)(de)(de)(de)(de)控(kong)(kong)(kong)制(zhi)(zhi)信(xin)號(hao)(hao)，外環(huan)的(de)(de)(de)(de)(de)作用，主要控(kong)(kong)(kong)制(zhi)(zhi)輸(shu)(shu)出(chu)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，內(nei)環(huan)主要控(kong)(kong)(kong)制(zhi)(zhi)輸(shu)(shu)入(ru)(ru)電(dian)(dian)(dian)(dian)(dian)流(liu)的(de)(de)(de)(de)(de)波(bo)形，保證輸(shu)(shu)入(ru)(ru)電(dian)(dian)(dian)(dian)(dian)流(liu)的(de)(de)(de)(de)(de)正(zheng)(zheng)弦(xian)度(du)。引入(ru)(ru)了輸(shu)(shu)入(ru)(ru)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)前饋，克服輸(shu)(shu)入(ru)(ru)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)擾動對輸(shu)(shu)出(chu)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)的(de)(de)(de)(de)(de)影響(xiang)。

圖7  具有輸入電壓前饋(kui)的平均電流(liu)控制(zhi) Boost 變(bian)換器的PFC

　　六、校正方式

　　對控制(zhi)(zhi)系(xi)統(tong)(tong)(tong)的(de)(de)(de)要(yao)求，通常以(yi)(yi)性(xing)能(neng)指標(biao)的(de)(de)(de)形式(shi)給出。而(er)(er)為(wei)了使系(xi)統(tong)(tong)(tong)獲(huo)得滿意(yi)的(de)(de)(de)性(xing)能(neng)，必須(xu)對控制(zhi)(zhi)系(xi)統(tong)(tong)(tong)進行設計和校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)，也就(jiu)是在(zai)(zai)系(xi)統(tong)(tong)(tong)中(zhong)(zhong)適當(dang)的(de)(de)(de)位置(zhi)(zhi)加(jia)進適當(dang)的(de)(de)(de)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)裝置(zhi)(zhi)。校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)裝置(zhi)(zhi)彌補了原(yuan)系(xi)統(tong)(tong)(tong)的(de)(de)(de)性(xing)能(neng)缺陷。按照校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)裝置(zhi)(zhi)在(zai)(zai)開(kai)(kai)關電源系(xi)統(tong)(tong)(tong)中(zhong)(zhong)的(de)(de)(de)連接(jie)(jie)(jie)方式(shi)，控制(zhi)(zhi)系(xi)統(tong)(tong)(tong)的(de)(de)(de)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)方式(shi)可以(yi)(yi)分為(wei)串聯(lian)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)、反饋(kui)(kui)(kui)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)、前(qian)(qian)(qian)饋(kui)(kui)(kui)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)、復合校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)等。如(ru)圖(tu)8所(suo)示為(wei)系(xi)統(tong)(tong)(tong)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)裝置(zhi)(zhi)位置(zhi)(zhi)示意(yi)圖(tu)，G（S）為(wei)被控對象(xiang)（主功(gong)率電路(lu)）；串聯(lian)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)裝置(zhi)(zhi)一般連接(jie)(jie)(jie)在(zai)(zai)G（S）之(zhi)前(qian)(qian)(qian)，串接(jie)(jie)(jie)與系(xi)統(tong)(tong)(tong)前(qian)(qian)(qian)向通道之(zhi)中(zhong)(zhong)，如(ru)G1（S）益所(suo)示；反饋(kui)(kui)(kui)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)裝置(zhi)(zhi)連接(jie)(jie)(jie)在(zai)(zai)系(xi)統(tong)(tong)(tong)局(ju)部反饋(kui)(kui)(kui)通路(lu)之(zhi)中(zhong)(zhong)，如(ru)G2（S）位置(zhi)(zhi)所(suo)示；補償給定量(liang)的(de)(de)(de)前(qian)(qian)(qian)饋(kui)(kui)(kui)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)裝置(zhi)(zhi)接(jie)(jie)(jie)在(zai)(zai)系(xi)統(tong)(tong)(tong)給定量(liang)之(zhi)后(hou)的(de)(de)(de)前(qian)(qian)(qian)向通道之(zhi)上，形成前(qian)(qian)(qian)饋(kui)(kui)(kui)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)通路(lu)，如(ru)G3（S）位置(zhi)(zhi)所(suo)示，補償擾動量(liang)的(de)(de)(de)前(qian)(qian)(qian)饋(kui)(kui)(kui)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)裝置(zhi)(zhi)接(jie)(jie)(jie)在(zai)(zai)系(xi)統(tong)(tong)(tong)可測試的(de)(de)(de)振動量(liang)之(zhi)后(hou)，形成一條附加(jia)的(de)(de)(de)通道，如(ru)G4（S）位置(zhi)(zhi)所(suo)示。前(qian)(qian)(qian)饋(kui)(kui)(kui)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)裝置(zhi)(zhi)可以(yi)(yi)單獨(du)作用與開(kai)(kai)環(huan)控制(zhi)(zhi)系(xi)統(tong)(tong)(tong)，也可以(yi)(yi)作為(wei)反饋(kui)(kui)(kui)控制(zhi)(zhi)系(xi)統(tong)(tong)(tong)的(de)(de)(de)附加(jia)校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)而(er)(er)組成復合校(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)(xiao)正(zheng)(zheng)控制(zhi)(zhi)系(xi)統(tong)(tong)(tong)。

圖(tu)8  系(xi)統校正裝置位置示意圖(tu)

　　七、小結

　　開關電(dian)(dian)源(yuan)系統通過控(kong)(kong)制(zhi)(zhi)電(dian)(dian)路(lu)對(dui)主功(gong)率電(dian)(dian)路(lu)的(de)(de)控(kong)(kong)制(zhi)(zhi)實現電(dian)(dian)能的(de)(de)變換。開關電(dian)(dian)源(yuan)系統有多種(zhong)控(kong)(kong)制(zhi)(zhi)方(fang)(fang)式，而控(kong)(kong)制(zhi)(zhi)方(fang)(fang)式的(de)(de)核心是校正方(fang)(fang)式。究竟選用哪種(zhong)控(kong)(kong)制(zhi)(zhi)方(fang)(fang)式，系統如何校正，取決于系統主功(gong)率電(dian)(dian)路(lu)的(de)(de)被(bei)控(kong)(kong)量(liang)的(de)(de)性(xing)質(zhi)、抗擾動(dong)性(xing)要求、技術實現的(de)(de)方(fang)(fang)便性(xing)、經(jing)濟性(xing)要求、環(huan)境(jing)使用條件等因素(su)。