無(wu)工(gong)頻(pin)變(bian)壓(ya)器(qi)的(di)高(gao)頻(pin)開(kai)關(guan)電(dian)源(yuan)結(jie)構(gou)。將(qiang)這(zhe)種(zhong)開(kai)關(guan)型(xing)穩(wen)壓(ya)電(dian)源(yuan)應(ying)用(yong)於(yu)UPS中(zhong)作(zuo)為(wei)輔(fu)助(zhu)電(dian)源(yuan)的(di)形(xing)式(shi)較(jiao)多(duo),但(dan)常(chang)見(xian)的(di)有(you)3種(zhong)類(lei)型(xing):他(ta)勵(li)式(shi)反(fan)激(ji)電(dian)源(yuan)、他(ta)勵(li)式(shi)正(zheng)激(ji)電(dian)源(yuan)以(yi)及(ji)具(ju)有(you)自(zi)身(shen)反(fan)饋(kui)的(di)直(zhi)流(liu)變(bian)換(huan)器(qi)。
( 1 )他(ta)勵(li)式(shi)反(fan)激(ji)電(dian)源(yuan)圖(tu)4 -38所(suo)示(shi)即(ji)為(wei)他(ta)勵(li)式(shi)反(fan)激(ji)電(dian)源(yuan)的(di)原(yuan)理(li)電(dian)路(lu)圖(tu),圖(tu)中(zhong)高(gao)壓(ya)開(kai)關(guan)管(guan)VT在(zai)占(zhan)空(kong)比(bi)為(wei)δ= Ton/ Ton的(di)脈(mo)衝(chong)驅(qu)動(dong)下(xia)或(huo)導(dao)通(tong)或(huo)關(guan)斷(duan),直(zhi)流(liu)電(dian)壓(ya)V;被(bei)變(bian)換(huan)為(wei)高(gao)頻(pin)方(fang)波(bo)交(jiao)流(liu)電(dian)壓(ya),經(jing)變(bian)壓(ya)器(qi)給(ji)輸(shu)出(chu)電(dian)容(rong)C和(hu)負(fu)載(zai)提(ti)供(gong)能(neng)量(liang)。
由(you)圖(tu)4 -38可(ke)知(zhi),由(you)於(yu)開(kai)關(guan)管(guan)的(di)驅(qu)動(dong)脈(mo)衝(chong)是(shi)由(you)其(qi)他(ta)電(dian)路(lu)供(gong)給(ji),故(gu)稱(chen)之(zhi)為(wei)他(ta)勵(li)式(shi)。輸(shu)出(chu)電(dian)容(rong)器(qi)C和(hu)負(fu)載(zai)R是(shi)在(zai)開(kai)關(guan)管(guan)截(jie)止(zhi)時(shi)從(zong)變(bian)壓(ya)器(qi)次(ci)級(ji)獲(huo)得(dei)能(neng)量(liang),因(yin)而(er)稱(chen)之(zhi)為(wei)反(fan)激(ji)電(dian)源(yuan)。其(qi)工(gong)作(zuo)原(yuan)理(li)可(ke)簡(jian)述(shu)如(ru)下(xia)。
①當(dang)驅(qu)動(dong)脈(mo)衝(chong)為(wei)高(gao)電(dian)平(ping)時(shi),開(kai)關(guan)管(guan)VT從(zong)截(jie)止(zhi)變(bian)成(cheng)導(dao)通(tong),變(bian)壓(ya)器(qi)的(di)初(chu)級(ji)線(xian)圈(juan)N。流(liu)過(guo)的(di)電(dian)流(liu)p線(xian)性(xing)增(zeng)加(jia)，在(zai)Np上(shang)產(chan)生(sheng)-極(ji)性(xing)為(wei)上(shang)正(zheng)下(xia)負(fu)的(di)感(gan)應(ying)電(dian)勢(shi),使(shi)次(ci)級(ji)線(xian)圈(juan)N。產(chan)生(sheng)一(yi)極(ji)性(xing). 負(fu)下(xia)正(zheng)的(di)感(gan)應(ying)電(dian)勢(shi),二(er)極(ji)管(guan)VD承(cheng)受(shou)反(fan)向(xiang)偏(pian)壓(ya)而(er)截(jie)止(zhi), ij為(wei)零(ling),變(bian)壓(ya)器(qi)不(bu)能(neng)將(qiang)輸(shu)入(ru)端(duan)能(neng)量(liang)傳(zhuan)送(song)到(dao)輸(shu)出(chu)端(duan),此(ci)時(shi)負(fu)載(zai)電(dian)流(liu)由(you)電(dian)容(rong)放(fang)電(dian)提(ti)供(gong),變(bian)壓(ya)器(qi)初(chu)級(ji)線(xian)圈(juan)電(dian)感(gan)儲(chu)存(cun)能(neng)量(liang)。
②當(dang)驅(qu)動(dong)脈(mo)衝(chong)為(wei)低(di)電(dian)平(ping)時(shi),開(kai)關(guan)管(guan)VT從(zong)導(dao)通(tong)變(bian)為(wei)截(jie)止(zhi), j趨(qu)向(xiang)於(yu)零(ling),變(bian)壓(ya)器(qi)初(chu)級(ji)線(xian)圈(juan)Ng的(di)磁(ci)通(tong)量(liang)變(bian)小(xiao),使(shi)次(ci)級(ji)線(xian)圈(juan)N變(bian)為(wei)上(shang)正(zheng)下(xia)負(fu)的(di)感(gan)應(ying)電(dian)勢(shi),二(er)極(ji)管(guan)VD導(dao)通(tong),給(ji)輸(shu)出(chu)電(dian)容(rong)C充(chong)電(dian),同(tong)時(shi)也(ye)向(xiang)負(fu)載(zai)供(gong)電(dian)。同(tong)普(pu)通(tong)開(kai)關(guan)電(dian)源(yuan)一(yi)樣(yang),其(qi)輸(shu)出(chu)電(dian)壓(ya)大(dai)小(xiao)的(di)調(diao)整(zheng)可(ke)通(tong)過(guo)調(diao)整(zheng)驅(qu)動(dong)脈(mo)衝(chong)的(di)占(zhan)空(kong)比(bi)δ= Ton/ Ts來(lai)實(shi)現(xian)。
( 2 )他(ta)勵(li)式(shi)正(zheng)激(ji)電(dian)源(yuan)如(ru)圖(tu)4-39所(suo)示(shi)為(wei)他(ta)勵(li)式(shi)正(zheng)激(ji)電(dian)源(yuan)原(yuan)理(li)圖(tu),它(ta)與(yu)反(fan)激(ji)式(shi)的(di)不(bu)同(tong)之(zhi)處(chu)在(zai)於(yu)開(kai)關(guan)管(guan)VT導(dao)通(tong)期(qi)間(jian),輸(shu)入(ru)端(duan)電(dian)源(yuan)經(jing)變(bian)壓(ya)器(qi)T向(xiang)輸(shu)出(chu)電(dian)容(rong)C和(hu)負(fu)載(zai)提(ti)供(gong)能(neng)量(liang)。在(zai)結(jie)構(gou)上(shang),變(bian)壓(ya)器(qi)T增(zeng)加(jia)了(liao)一(yi)個(ge)去(qu)磁(ci)線(xian)圈(juan)Nt。N的(di)匝(za)數(shuo)一(yi)般(pan)與(yu)N。相(xiang)同(tong),但(dan)也(ye)可(ke)不(bu)同(tong)。正(zheng)激(ji)式(shi)電(dian)源(yuan)的(di)工(gong)作(zuo)過(guo)程(cheng)與(yu)反(fan)激(ji)式(shi)電(dian)源(yuan)基(ji)本(ben)相(xiang)似(shi)。
當(dang)驅(qu)動(dong)信(xin)號(hao)為(wei)高(gao)電(dian)平(ping)時(shi), VT從(zong)截(jie)止(zhi)變(bian)為(wei)導(dao)通(tong)Np線(xian)圈(juan)流(liu)過(guo)電(dian)流(liu)逐(zhu)漸(jian)增(zeng)大(dai)在(zai)N。線(xian)圈(juan)上(shang)產(chan)生(sheng)一(yi)上(shang)正(zheng)下(xia)負(fu)的(di)電(dian)動(dong)勢(shi),同(tong)時(shi)次(ci)級(ji)線(xian)圈(juan)Ng也(ye)產(chan)生(sheng)一(yi)個(ge)上(shang)正(zheng)下(xia)負(fu)的(di)感(gan)應(ying)電(dian)勢(shi),二(er)極(ji)管(guan)VD2導(dao)通(tong),輸(shu)入(ru)端(duan)能(neng)量(liang)經(jing)變(bian)壓(ya)器(qi)T、二(er)極(ji)管(guan)VD2提(ti)供(gong)給(ji)電(dian)感(gan)L、電(dian)容(rong)C和(hu)負(fu)載(zai)。
當(dang)驅(qu)動(dong)脈(mo)衝(chong)為(wei)低(di)電(dian)平(ping)時(shi),開(kai)關(guan)管(guan)VT從(zong)導(dao)通(tong)變(bian)成(cheng)截(jie)止(zhi),趨(qu)向(xiang)於(yu)零(ling),感(gan)應(ying)電(dian)動(dong)勢(shi)的(di)方(fang)向(xiang)相(xiang)反(fan)(上(shang)負(fu)下(xia)正(zheng))，使(shi)二(er)極(ji)管(guan)VD2截(jie)止(zhi),二(er)極(ji)管(guan)VD;正(zheng)向(xiang)導(dao)通(tong),電(dian)感(gan)L向(xiang)負(fu)載(zai)提(ti)供(gong)能(neng)量(liang)。這(zhe)時(shi)去(qu)磁(ci)線(xian)圈(juan)N的(di)感(gan)應(ying)電(dian)勢(shi)為(wei).上(shang)正(zheng)下(xia)負(fu), VD1二(er)極(ji)管(guan)導(dao)通(tong),以(yi)使(shi)Nt上(shang)存(cun)儲(chu)的(di)能(neng)量(liang)通(tong)過(guo)VD1回(hui)送(song)到(dao)直(zhi)流(liu)輸(shu)入(ru)回(hui)路(lu),起(qi)到(dao)去(qu)磁(ci)作(zuo)用(yong)。
對(dui)於(yu)正(zheng)激(ji)式(shi)變(bian)換(huan)器(qi),驅(qu)動(dong)脈(mo)衝(chong)的(di)占(zhan)空(kong)比(bi)一(yi)般(pan)不(bu)能(neng)大(dai)於(yu)0.5。若(ruo)大(dai)於(yu)0.5 ,易(yi)使(shi)變(bian)壓(ya)器(qi)初(chu)級(ji)繞(rao)組(zu)中(zhong)存(cun)儲(chu)的(di)能(neng)量(liang)在(zai)一(yi)個(ge)周(zhou)期(qi)內(nei)無(wu)法(fa)釋(shi)放(fang)完(wan),在(zai)開(kai)關(guan)管(guan)再(zai)次(ci)導(dao)通(tong)時(shi),去(qu)磁(ci)電(dian)流(liu)不(bu)為(wei)零(ling),在(zai)開(kai)關(guan)管(guan)集(ji)電(dian)極(ji)會(kuai)引(yin)起(qi)很(hen)大(dai)的(di)尖(jian)峰(feng)電(dian)流(liu),使(shi)變(bian)壓(ya)器(qi)趨(qu)於(yu)飽(bao)和(hu),而(er)導(dao)致(zhi)開(kai)關(guan)管(guan)VT損(sun)壞(huai)。
( 3 )反(fan)饋(kui)式(shi)輔(fu)助(zhu)電(dian)源(yuan)輔(fu)助(zhu)電(dian)源(yuan)也(ye)可(ke)以(yi)通(tong)過(guo)高(gao)頻(pin)變(bian)壓(ya)器(qi)獲(huo)得(dei)輸(shu)出(chu)後(hou)反(fan)饋(kui)過(guo)來(lai)提(ti)供(gong),此(ci)時(shi)需(xu)要(yao)一(yi)個(ge)啟(qi)動(dong)電(dian)路(lu)提(ti)供(gong)瞬(shun)時(shi)能(neng)量(liang),使(shi)PW M型(xing)電(dian)源(yuan)啟(qi)動(dong)。
圖(tu)4-40是(shi)反(fan)饋(kui)式(shi)輔(fu)助(zhu)電(dian)源(yuan)的(di)一(yi)一(yi)個(ge)例(li)子(zi)。
這(zhe)是(shi)一(yi)個(ge)直(zhi)接(jie)從(zong)電(dian)網(wang)整(zheng)流(liu)的(di)正(zheng)激(ji)單(shan)端(duan)開(kai)關(guan)型(xing)穩(wen)壓(ya)電(dian)源(yuan),輔(fu)助(zhu)電(dian)源(yuan)V由(you)起(qi)振(zhen)後(hou)高(gao)頻(pin)變(bian)壓(ya)器(qi)T1的(di)一(yi)組(zu)副(fu)邊(bian)輸(shu)出(chu)電(dian)壓(ya)通(tong)過(guo)二(er)極(ji)管(guan)VD106提(ti)供(gong),中(zhong)間(jian)虛(xu)線(xian)框(kuang)內(nei)是(shi)輔(fu)助(zhu)電(dian)源(yuan)的(di)啟(qi)動(dong)電(dian)路(lu),在(zai)電(dian)網(wang)合(ge)閘(zha)時(shi),電(dian)容(rong)C2通(tong)過(guo)電(dian)阻(zu)Rr充(chong)電(dian),其(qi)電(dian)壓(ya)被(bei)穩(wen)壓(ya)管(guan)VZ鉗(qian)位(wei)。C2是(shi)-個(ge)容(rong)量(liang)較(jiao)大(dai)(如(ru)圖(tu)中(zhong)為(wei)600μF)的(di)低(di)壓(ya)電(dian)解(xie)電(dian)容(rong),用(yong)以(yi)儲(chu)能(neng)。R:阻(zu)值(zhi)較(jiao)大(dai) ,以(yi)限(xian)製(zhi)穩(wen)態(tai)時(shi)穩(wen)壓(ya)管(guan)VZ的(di)工(gong)作(zuo)電(dian)流(liu)。當(dang)C2充(chong)電(dian)完(wan)畢(bi)後(hou),按(an)下(xia)啟(qi)動(dong)按(an)鈕(niu)開(kai)關(guan)K ,晶(jing)體(ti)管(guan)VT]通(tong)過(guo)R2獲(huo)得(dei)偏(pian)流(liu)而(er)啟(qi)振(zhen),壓(ya)器(qi)Tg副(fu)邊(bian)繞(rao)組(zu)N503的(di)正(zheng)向(xiang)電(dian)壓(ya)通(tong)過(guo)二(er)極(ji)管(guan)VD502饋(kui)送(song)給(ji)正(zheng)激(ji)單(shan)端(duan)開(kai)關(guan)電(dian)源(yuan)的(di)控(kong)製(zhi)電(dian)路(lu)和(hu)驅(qu)動(dong)電(dian)路(lu)，高(gao)壓(ya)開(kai)關(guan)管(guan)獲(huo)得(dei)正(zheng)向(xiang)基(ji)極(ji)驅(qu)動(dong)而(er)導(dao)通(tong),高(gao)頻(pin)變(bian)壓(ya)器(qi)T1的(di)副(fu)邊(bian)繞(rao)組(zu)Nz獲(huo)得(dei)正(zheng)向(xiang)電(dian)壓(ya), 並(bing)通(tong)過(guo)VD106作(zuo)為(wei)輔(fu)助(zhu)電(dian)源(yuan)提(ti)供(gong),啟(qi)動(dong)電(dian)路(lu)的(di)作(zuo)用(yong)即(ji)告(gao)完(wan)成(cheng)。
反(fan)饋(kui)式(shi)輔(fu)助(zhu)電(dian)源(yuan)作(zuo)為(wei)PWM型(xing)開(kai)關(guan)電(dian)源(yuan)本(ben)身(shen)的(di)一(yi)組(zu)負(fu)載(zai)，可(ke)取(qu)代(dai)死(si)負(fu)載(zai),從(zong)而(er)可(ke)望(wang)提(ti)高(gao)效(xiao)率(shuai),體(ti)積(ji)也(ye)不(bu)大(dai),但(dan)電(dian)路(lu)比(bi)較(jiao)複(fu)雜(za)。
