功(gong)率(shuai)因(yin)數(shuo)校(jiao)正(zheng)的(di)方(fang)法(fa)主(zhu)要(yao)有(you)無(wu)源(yuan)功(gong)率(shuai)因(yin)數(shuo)校(jiao)正(zheng)和(hu)有(you)源(yuan)功(gong)率(shuai)因(yin)數(shuo)校(jiao)正(zheng)兩(liang)大(dai)類(lei)。
無(wu)源(yuan)功(gong)率(shuai)因(yin)數(shuo)校(jiao)正(zheng)電(dian)路(lu)是(shi)利(li)用(yong)電(dian)感(gan)和(hu)電(dian)容(rong)等(deng)元(yuan)器(qi)件(jian)組(zu)成(cheng)濾(lv)波(bo)器(qi)，將(qiang)輸(shu)入(ru)電(dian)流(liu)波(bo)形(xing)進(jin)行(hang)相(xiang)移(yi)和(hu)整(zheng)形(xing),采(cai)用(yong)這(zhe)種(zhong)方(fang)法(fa)可(ke)以(yi)使(shi)功(gong)率(shuai)因(yin)數(shuo)提(ti)高(gao)至(zhi)0.9以(yi)上(shang)，其(qi)優(you)點(dian)是(shi)電(dian)路(lu)簡(jian)單(shan),成(cheng)本(ben)低(di);缺(que)點(dian)是(shi)電(dian)路(lu)體(ti)積(ji)較(jiao)大(dai),並(bing)且(qie)可(ke)能(neng)在(zai)某(mou)些(xie)頻(pin)率(shuai)點(dian)產(chan)生(sheng)諧(xie)振(zhen)而(er)損(sun)壞(huai)用(yong)電(dian)設(she)備(bei)。無(wu)源(yuan)功(gong)率(shuai)因(yin)數(shuo)校(jiao)正(zheng)電(dian)路(lu)主(zhu)要(yao)適(kuo)用(yong)於(yu)小(xiao)功(gong)率(shuai)應(ying)用(yong)場(chang)合(ge)。
有(you)源(yuan)功(gong)率(shuai)因(yin)數(shuo)校(jiao)正(zheng)電(dian)路(lu)是(shi)在(zai)整(zheng)流(liu)器(qi)和(hu)濾(lv)波(bo)電(dian)容(rong)之(zhi)間(jian)增(zeng)加(jia)一(yi)個(ge)DC/DC開(kai)關(guan)變(bian)換(huan)器(qi)。其(qi)主(zhu)要(yao)思(si)想(xiang)如(ru)下(xia):選(xuan)擇(ze)輸(shu)入(ru)電(dian)壓(ya)為(wei)一(yi)個(ge)參(shen)考(kao)信(xin)號(hao),使(shi)得(dei)輸(shu)入(ru)電(dian)流(liu)跟(gen)蹤(zong)參(shen)考(kao)信(xin)號(hao),實(shi)現(xian)了(liao)輸(shu)入(ru)電(dian)流(liu)的(di)低(di)頻(pin)分(fen)量(liang)與(yu)輸(shu)入(ru)電(dian)壓(ya)為(wei)一(yi)個(ge)近(jin)似(shi)同(tong)頻(pin)同(tong)相(xiang)的(di)波(bo)形(xing),以(yi)提(ti)高(gao)功(gong)率(shuai)因(yin)數(shuo)和(hu)抑(yi)製(zhi)諧(xie)波(bo),同(tong)時(shi)采(cai)用(yong)電(dian)壓(ya)反(fan)饋(kui),使(shi)輸(shu)出(chu)電(dian)壓(ya)為(wei)近(jin)似(shi)平(ping)滑(hua)的(di)直(zhi)流(liu)輸(shu)出(chu)電(dian)壓(ya)。有(you)源(yuan)功(gong)率(shuai)因(yin)數(shuo)校(jiao)正(zheng)的(di)主(zhu)要(yao)優(you)點(dian)是(shi):可(ke)得(dei)到(dao)較(jiao)高(gao)的(di)功(gong)率(shuai)因(yin)數(shuo),如(ru)0.97 ~0.99 ,甚(shen)至(zhi)接(jie)近(jin)1 ;總(zong)諧(xie)波(bo)畸(ji)變(bian)(THD )低(di),可(ke)在(zai)較(jiao)寬(kuan)的(di)輸(shu)入(ru)電(dian)壓(ya)範(fan)圍(wei)內(nei)(如(ru)90 ~ 264VAC )工(gong)作(zuo);體(ti)積(ji)小(xiao),重(chong)量(liang)輕(qing),輸(shu)出(chu)電(dian)壓(ya)也(ye)保(bao)持(chi)恒(heng)定(ding)。
( 1 )無(wu)源(yuan)功(gong)率(shuai)因(yin)數(shuo)校(jiao)正(zheng)無(wu)源(yuan)功(gong)率(shuai)因(yin)數(shuo)校(jiao)正(zheng)有(you)兩(liang)種(zhong)比(bi)較(jiao)基(ji)本(ben)的(di)方(fang)法(fa),即(ji)在(zai)整(zheng)流(liu)器(qi)與(yu)濾(lv)波(bo)電(dian)容(rong)之(zhi)間(jian)串(chuan)入(ru)無(wu)源(yuan)電(dian)感(gan)L和(hu)采(cai)用(yong)電(dian)容(rong)和(hu)二(er)極(ji)管(guan)網(wang)絡(lao)構(gou)成(cheng)填(tian)穀(gu)式(shi)無(wu)源(yuan)校(jiao)正(zheng)。如(ru)圖(tu)4-1 ( a )所(suo)示(shi),無(wu)源(yuan)電(dian)感(gan)L把(ba)整(zheng)流(liu)器(qi)與(yu)直(zhi)流(liu)電(dian)容(rong)C隔(ge)開(kai),因(yin)此(ci)整(zheng)流(liu)器(qi)和(hu)電(dian)感(gan)L間(jian)的(di)電(dian)壓(ya)可(ke)隨(sui)輸(shu)入(ru)電(dian)壓(ya)而(er)變(bian)動(dong),整(zheng)流(liu)二(er)極(ji)管(guan)的(di)導(dao)通(tong)角(jue)變(bian)大(dai),使(shi)輸(shu)入(ru)電(dian)流(liu)波(bo)形(xing)得(dei)到(dao)改(gai)善(shan)。
填(tian)穀(gu)式(shi)無(wu)源(yuan)校(jiao)正(zheng)的(di)基(ji)本(ben)思(si)想(xiang)是(shi)采(cai)用(yong)兩(liang)個(ge)串(chuan)聯(lian)電(dian)容(rong)作(zuo)為(wei)濾(lv)波(bo)電(dian)容(rong),選(xuan)配(pei)幾(ji)隻(zhi)二(er)極(ji)管(guan),使(shi)兩(liang)個(ge)直(zhi)流(liu)電(dian)容(rong)能(neng)夠(gou)串(chuan)聯(lian)充(chong)電(dian)、並(bing)聯(lian)放(fang)電(dian),以(yi)增(zeng)加(jia)二(er)極(ji)管(guan)的(di)導(dao)通(tong)角(jue),改(gai)善(shan)輸(shu)入(ru)側(zhai)功(gong)率(shuai)因(yin)數(shuo)。其(qi)電(dian)路(lu)如(ru)圖(tu)4-1 ( b )所(suo)示(shi),其(qi)基(ji)本(ben)原(yuan)理(li)為(wei):當(dang)輸(shu)入(ru)電(dian)壓(ya)瞬(shun)時(shi)值(zhi)上(shang)升(sheng)到(dao)1/2峰(feng)值(zhi)以(yi)上(shang)，即(ji)高(gao)於(yu)直(zhi)流(liu)濾(lv)波(bo)電(dian)容(rong)Ca和(hu)CJ2上(shang)的(di)直(zhi)流(liu)電(dian)壓(ya)時(shi),二(er)極(ji)管(guan)VD3導(dao)通(tong), VD1和(hu)VD因(yin)反(fan)偏(pian)而(er)截(jie)止(zhi),兩(liang)個(ge)直(zhi)流(liu)濾(lv)波(bo)電(dian)容(rong)Ca1和(hu)CJ2處(chu)於(yu)串(chuan)聯(lian)充(chong)電(dian)狀(zhuang)態(tai);當(dang)輸(shu)入(ru)電(dian)壓(ya)瞬(shun)時(shi)值(zhi)降(xiang)低(di)到(dao)1/ 2峰(feng)值(zhi)以(yi)下(xia),即(ji)低(di)於(yu)直(zhi)流(liu)濾(lv)波(bo)電(dian)容(rong)Co1和(hu)Cd2-上(shang)的(di)直(zhi)流(liu)電(dian)壓(ya)時(shi),二(er)極(ji)管(guan)VDj截(jie)止(zhi), VD_和(hu)VD2導(dao)通(tong),兩(liang)個(ge)直(zhi)流(liu)濾(lv)波(bo)電(dian)容(rong)Ca和(hu)Ca2處(chu)於(yu)並(bing)聯(lian)放(fang)電(dian)狀(zhuang)態(tai)。直(zhi)流(liu)濾(lv)波(bo)電(dian)容(rong)Cd1和(hu)CJ2充(chong)電(dian)和(hu)放(fang)電(dian)的(di)臨(lin)界(jie)點(dian)在(zai)輸(shu)入(ru)電(dian)壓(ya)的(di)1/2峰(feng)值(zhi)處(chu), arcsin( 1/2 ) =30° ,所(suo)以(yi)理(li)論(lun)上(shang)整(zheng)流(liu)二(er)極(ji)管(guan)的(di)導(dao)通(tong)角(jue)不(bu)小(xiao)於(yu)180°-30°x2=120° ,比(bi)采(cai)用(yong)一(yi)個(ge)直(zhi)流(liu)濾(lv)波(bo)電(dian)容(rong)時(shi)的(di)導(dao)通(tong)角(jue)明(ming)顯(xian)增(zeng)大(dai)。
( 2 )有(you)源(yuan)功(gong)率(shuai)因(yin)數(shuo)校(jiao)正(zheng)
①有(you)源(yuan)功(gong)率(shuai)因(yin)數(shuo)校(jiao)正(zheng)的(di)主(zhu)電(dian)路(lu)結(jie)構(gou)有(you)源(yuan)功(gong)率(shuai)因(yin)數(shuo)校(jiao)正(zheng)電(dian)路(lu)的(di)主(zhu)電(dian)路(lu)通(tong)常(chang)采(cai)用(yong)DC/DC開(kai)關(guan)變(bian)換(huan)器(qi),其(qi)中(zhong)輸(shu)出(chu)升(sheng)壓(ya)型(xing)( Boost )變(bian)換(huan)器(qi)具(ju)有(you)電(dian)感(gan)電(dian)流(liu)連(lian)續(xu)的(di)特(te)點(dian),儲(chu)能(neng)電(dian)感(gan)也(ye)可(ke)用(yong)作(zuo)濾(lv)波(bo)電(dian)感(gan)來(lai)抑(yi)製(zhi)EMI噪(zao)聲(sheng)。此(ci)外(wai)，Boost變(bian)換(huan)器(qi)還(huan)具(ju)有(you)電(dian)流(liu)畸(ji)變(bian)小(xiao)、輸(shu)出(chu)功(gong)率(shuai)大(dai)和(hu)驅(qu)動(dong)電(dian)路(lu)簡(jian)單(shan)等(deng)優(you)點(dian),所(suo)以(yi)使(shi)用(yong)極(ji)為(wei)廣(guang)泛(fan)。除(chu)采(cai)用(yong)升(sheng)壓(ya)輸(shu)出(chu)變(bian)換(huan)器(qi)外(wai), Buck-Boost、Flyback、 Cuk變(bian)換(huan)器(qi)都(du)可(ke)作(zuo)為(wei)有(you)源(yuan)功(gong)率(shuai)校(jiao)正(zheng)的(di)主(zhu)電(dian)路(lu)。
②有(you)源(yuan)功(gong)率(shuai)因(yin)數(shuo)校(jiao)正(zheng)的(di)控(kong)製(zhi)方(fang)法(fa)有(you)源(yuan)功(gong)率(shuai)因(yin)數(shuo)校(jiao)正(zheng)技(ji)術(zhu)的(di)思(si)路(lu)是(shi),控(kong)製(zhi)已(yi)整(zheng)流(liu)後(hou)的(di)電(dian)流(liu),使(shi)之(zhi)在(zai)對(dui)濾(lv)波(bo)大(dai)電(dian)容(rong)充(chong)電(dian)之(zhi)前(qian)能(neng)與(yu)整(zheng)流(liu)後(hou)的(di)電(dian)壓(ya)波(bo)形(xing)相(xiang)同(tong),從(zong)而(er)避(bi)免(wen)形(xing)成(cheng)電(dian)流(liu)脈(mo)衝(chong), 達(da)到(dao)改(gai)善(shan)功(gong)率(shuai)因(yin)數(shuo)的(di)目(mu)的(di)。有(you)源(yuan)功(gong)率(shuai)因(yin)數(shuo)校(jiao)正(zheng)電(dian)路(lu)原(yuan)理(li)如(ru)圖(tu)4-2所(suo)示(shi)，主(zhu)電(dian)路(lu)是(shi)一(yi)個(ge)全(quan)波(bo)整(zheng)流(liu)器(qi),實(shi)現(xian)AC/DC的(di)變(bian)換(huan),電(dian)壓(ya)波(bo)形(xing)不(bu)會(kuai)失(shi)真(zhen);在(zai)濾(lv)波(bo)電(dian)容(rong)C之(zhi)前(qian)是(shi)一(yi)個(ge)Boost變(bian)換(huan)器(qi),實(shi)現(xian)升(sheng)壓(ya)式(shi)DC/DC變(bian)換(huan)。從(zong)控(kong)製(zhi)回(hui)路(lu)來(lai)看(kan),它(ta)由(you)一(yi)個(ge)電(dian)壓(ya)外(wai)環(huan)和(hu)一(yi)個(ge)電(dian)流(liu)內(nei)環(huan)構(gou)成(cheng)。在(zai)工(gong)作(zuo)過(guo)程(cheng)中(zhong),升(sheng)壓(ya)電(dian)感(gan)L1中(zhong)的(di)電(dian)流(liu)受(shou)到(dao)連(lian)續(xu)監(jian)控(kong)與(yu)調(diao)節(jie),使(shi)之(zhi)能(neng)跟(gen)隨(sui)整(zheng)流(liu)後(hou)正(zheng)弦(xian)半(ban)波(bo)電(dian)壓(ya)波(bo)形(xing)。
