本發明涉及功率(lv)放(fang)大器及高頻(pin)電力電子變換領域，特別(bie)是一種(zhong)模塊化開關(guan)功率(lv)放(fang)大器及其控制方法。

背景技術：

傳統的(de)功(gong)(gong)率(lv)放(fang)大(da)器的(de)線性特性好(hao)以(yi)(yi)及波(bo)形畸(ji)變率(lv)小，但面臨的(de)主要問題是效(xiao)(xiao)率(lv)低、功(gong)(gong)率(lv)容量小、散熱(re)效(xiao)(xiao)果(guo)差(cha)，因而(er)在(zai)某些大(da)功(gong)(gong)率(lv)場合應用受到局限。近(jin)些年國內(nei)也研制出一系列的(de)功(gong)(gong)放(fang)產品，但就其(qi)在(zai)輸出的(de)頻(pin)段以(yi)(yi)及波(bo)形的(de)失真(zhen)度方(fang)面還遠遠落后于美國等(deng)(deng)西方(fang)發達國家。因此，為滿足(zu)大(da)功(gong)(gong)率(lv)容量的(de)需求(qiu)，在(zai)音頻(pin)功(gong)(gong)放(fang)、聲納探測等(deng)(deng)特殊工業場合研究開關(guan)功(gong)(gong)率(lv)放(fang)大(da)器具有重要意(yi)義。

功(gong)(gong)(gong)(gong)率(lv)放(fang)大(da)(da)(da)(da)(da)器根(gen)據功(gong)(gong)(gong)(gong)率(lv)管(guan)工作(zuo)方式不(bu)同(tong)可分(fen)為模擬(ni)功(gong)(gong)(gong)(gong)率(lv)放(fang)大(da)(da)(da)(da)(da)器和數(shu)字(zi)(zi)功(gong)(gong)(gong)(gong)率(lv)放(fang)大(da)(da)(da)(da)(da)器。依據目(mu)前研究現狀(zhuang)，絕大(da)(da)(da)(da)(da)多數(shu)功(gong)(gong)(gong)(gong)率(lv)放(fang)大(da)(da)(da)(da)(da)電(dian)路(lu)仍主要基于(yu)(yu)模擬(ni)電(dian)路(lu)拓撲。模擬(ni)功(gong)(gong)(gong)(gong)率(lv)放(fang)大(da)(da)(da)(da)(da)器具有優異的(de)(de)(de)波形放(fang)大(da)(da)(da)(da)(da)特(te)性(xing),輸出(chu)波形畸變率(lv)很小。模擬(ni)功(gong)(gong)(gong)(gong)率(lv)放(fang)大(da)(da)(da)(da)(da)器的(de)(de)(de)特(te)點是(shi)(shi)失(shi)真小、響應快(kuai),輸入輸出(chu)信號基本上是(shi)(shi)線性(xing)關(guan)(guan)系即(ji)功(gong)(gong)(gong)(gong)率(lv)放(fang)大(da)(da)(da)(da)(da)器的(de)(de)(de)線性(xing)好(hao),但(dan)是(shi)(shi)由于(yu)(yu)其(qi)存在直流導通損(sun)耗(hao),導致效率(lv)低。而(er)與線性(xing)功(gong)(gong)(gong)(gong)率(lv)放(fang)大(da)(da)(da)(da)(da)器不(bu)同(tong)，工作(zuo)于(yu)(yu)開關(guan)(guan)狀(zhuang)態的(de)(de)(de)d類放(fang)大(da)(da)(da)(da)(da)器即(ji)開關(guan)(guan)功(gong)(gong)(gong)(gong)率(lv)放(fang)大(da)(da)(da)(da)(da)器，它(ta)的(de)(de)(de)工作(zuo)狀(zhuang)態處(chu)于(yu)(yu)開關(guan)(guan)方式。在這種功(gong)(gong)(gong)(gong)率(lv)放(fang)大(da)(da)(da)(da)(da)器中，大(da)(da)(da)(da)(da)幅度(du)減(jian)少(shao)了功(gong)(gong)(gong)(gong)率(lv)輸出(chu)器件(jian)的(de)(de)(de)功(gong)(gong)(gong)(gong)耗(hao)。由于(yu)(yu)數(shu)字(zi)(zi)功(gong)(gong)(gong)(gong)率(lv)放(fang)大(da)(da)(da)(da)(da)器的(de)(de)(de)效率(lv)很高(gao)，因此(ci)它(ta)的(de)(de)(de)體(ti)積僅為相同(tong)功(gong)(gong)(gong)(gong)率(lv)的(de)(de)(de)線性(xing)功(gong)(gong)(gong)(gong)率(lv)放(fang)大(da)(da)(da)(da)(da)器的(de)(de)(de)30％左右，同(tong)時重量(liang)也大(da)(da)(da)(da)(da)為減(jian)輕。

對于(yu)(yu)追(zhui)求大(da)(da)(da)功(gong)(gong)(gong)率(lv)的(de)(de)(de)(de)(de)(de)場合，開(kai)(kai)(kai)關(guan)功(gong)(gong)(gong)率(lv)放(fang)大(da)(da)(da)器(qi)(qi)(qi)無疑是最佳選擇。早(zao)期有(you)人(ren)提(ti)出了開(kai)(kai)(kai)關(guan)功(gong)(gong)(gong)率(lv)放(fang)大(da)(da)(da)器(qi)(qi)(qi)的(de)(de)(de)(de)(de)(de)概念(nian)，只(zhi)是受當(dang)時技(ji)術水(shui)平(ping)的(de)(de)(de)(de)(de)(de)限制，開(kai)(kai)(kai)關(guan)功(gong)(gong)(gong)率(lv)放(fang)大(da)(da)(da)器(qi)(qi)(qi)輸出波形嚴重畸變，因此沒有(you)取得很大(da)(da)(da)的(de)(de)(de)(de)(de)(de)發展(zhan)。由于(yu)(yu)電(dian)力電(dian)子器(qi)(qi)(qi)件的(de)(de)(de)(de)(de)(de)研(yan)究(jiu)，出現了許多(duo)新型(xing)全(quan)控型(xing)器(qi)(qi)(qi)件,如igbt和mosfet等,電(dian)力電(dian)子器(qi)(qi)(qi)件的(de)(de)(de)(de)(de)(de)開(kai)(kai)(kai)關(guan)頻(pin)(pin)率(lv)也大(da)(da)(da)大(da)(da)(da)提(ti)高(gao),開(kai)(kai)(kai)關(guan)功(gong)(gong)(gong)率(lv)放(fang)大(da)(da)(da)器(qi)(qi)(qi)重新引起了人(ren)們的(de)(de)(de)(de)(de)(de)密切關(guan)注。迄(qi)今(jin)，國外數字功(gong)(gong)(gong)率(lv)放(fang)大(da)(da)(da)器(qi)(qi)(qi)的(de)(de)(de)(de)(de)(de)研(yan)究(jiu)己經達到了一個很高(gao)的(de)(de)(de)(de)(de)(de)水(shui)平(ping)。例如美國德州(zhou)義器(qi)(qi)(qi)公司(si)和apex公司(si)相繼推出了pwm型(xing)音(yin)頻(pin)(pin)功(gong)(gong)(gong)放(fang)用集(ji)成電(dian)路元(yuan)件。早(zao)在2000年左右，日本就已經有(you)人(ren)研(yan)制成功(gong)(gong)(gong)了10kw出頻(pin)(pin)率(lv)為(wei)100khz的(de)(de)(de)(de)(de)(de)開(kai)(kai)(kai)關(guan)功(gong)(gong)(gong)率(lv)放(fang)大(da)(da)(da)器(qi)(qi)(qi)，其整個頻(pin)(pin)寬范圍內的(de)(de)(de)(de)(de)(de)thd都小于(yu)(yu)10％,5khz內的(de)(de)(de)(de)(de)(de)thd小于(yu)(yu)2％；目前國外功(gong)(gong)(gong)率(lv)放(fang)大(da)(da)(da)器(qi)(qi)(qi)的(de)(de)(de)(de)(de)(de)研(yan)究(jiu)主要是結合開(kai)(kai)(kai)關(guan)功(gong)(gong)(gong)率(lv)放(fang)大(da)(da)(da)器(qi)(qi)(qi)與線性(xing)功(gong)(gong)(gong)放(fang)進行研(yan)究(jiu)，希(xi)望(wang)既能提(ti)高(gao)放(fang)大(da)(da)(da)器(qi)(qi)(qi)的(de)(de)(de)(de)(de)(de)效率(lv)有(you)充分(fen)結合了線性(xing)功(gong)(gong)(gong)放(fang)的(de)(de)(de)(de)(de)(de)線性(xing)度好的(de)(de)(de)(de)(de)(de)優(you)勢；

為(wei)了最(zui)大(da)(da)限度的(de)提(ti)高(gao)(gao)輸(shu)(shu)出(chu)(chu)頻(pin)率(lv)及輸(shu)(shu)出(chu)(chu)波形(xing)的(de)質(zhi)量，提(ti)高(gao)(gao)輸(shu)(shu)出(chu)(chu)電(dian)(dian)(dian)(dian)壓(ya)波形(xing)的(de)電(dian)(dian)(dian)(dian)平(ping)(ping)(ping)數(shu)改善(shan)波形(xing)質(zhi)量，提(ti)高(gao)(gao)輸(shu)(shu)出(chu)(chu)電(dian)(dian)(dian)(dian)壓(ya)波形(xing)的(de)等(deng)效(xiao)開(kai)(kai)關(guan)(guan)頻(pin)率(lv)來提(ti)高(gao)(gao)輸(shu)(shu)出(chu)(chu)頻(pin)率(lv)。鉗(qian)位多(duo)(duo)電(dian)(dian)(dian)(dian)平(ping)(ping)(ping)開(kai)(kai)關(guan)(guan)功率(lv)放(fang)(fang)大(da)(da)器因輸(shu)(shu)出(chu)(chu)電(dian)(dian)(dian)(dian)平(ping)(ping)(ping)數(shu)較多(duo)(duo)，其(qi)中單相(xiang)輸(shu)(shu)出(chu)(chu)為(wei)三電(dian)(dian)(dian)(dian)平(ping)(ping)(ping)，相(xiang)間(jian)輸(shu)(shu)出(chu)(chu)可高(gao)(gao)達五(wu)電(dian)(dian)(dian)(dian)平(ping)(ping)(ping)；鉗(qian)位電(dian)(dian)(dian)(dian)路具(ju)有(you)輸(shu)(shu)出(chu)(chu)的(de)電(dian)(dian)(dian)(dian)平(ping)(ping)(ping)數(shu)多(duo)(duo)，應用(yong)在(zai)在(zai)數(shu)字(zi)功率(lv)放(fang)(fang)大(da)(da)器上具(ju)有(you)很(hen)大(da)(da)優(you)勢；在(zai)實現(xian)模塊化的(de)鉗(qian)位功率(lv)模塊后，通(tong)過(guo)級聯或并聯極大(da)(da)的(de)提(ti)高(gao)(gao)了等(deng)效(xiao)的(de)開(kai)(kai)關(guan)(guan)頻(pin)率(lv)，能(neng)(neng)滿(man)足中壓(ya)大(da)(da)功率(lv)負(fu)荷(he)的(de)需(xu)求。在(zai)過(guo)去的(de)20年中，針對多(duo)(duo)電(dian)(dian)(dian)(dian)平(ping)(ping)(ping)變換器人們提(ti)出(chu)(chu)了很(hen)多(duo)(duo)調制(zhi)(zhi)(zhi)策略：階梯(ti)波脈寬調制(zhi)(zhi)(zhi)、正弦波脈寬調制(zhi)(zhi)(zhi)、消諧波pwm法(fa)、空間(jian)矢量脈寬調制(zhi)(zhi)(zhi)、三角載波移(yi)相(xiang)pwm法(fa)等(deng)，還有(you)用(yong)于電(dian)(dian)(dian)(dian)機(ji)控(kong)制(zhi)(zhi)(zhi)的(de)模型預測控(kong)算法(fa)，因其(qi)具(ju)有(you)較強的(de)魯棒(bang)性廣泛應用(yong)于電(dian)(dian)(dian)(dian)機(ji)控(kong)制(zhi)(zhi)(zhi)場(chang)合。隨(sui)著電(dian)(dian)(dian)(dian)力電(dian)(dian)(dian)(dian)子技(ji)術(shu)和自動控(kong)制(zhi)(zhi)(zhi)技(ji)術(shu)的(de)發(fa)展(zhan),尤其(qi)是大(da)(da)功率(lv)新(xin)型高(gao)(gao)頻(pin)開(kai)(kai)關(guan)(guan)器件的(de)出(chu)(chu)現(xian)，開(kai)(kai)關(guan)(guan)的(de)速率(lv)和耐(nai)壓(ya)耐(nai)流能(neng)(neng)力大(da)(da)大(da)(da)提(ti)高(gao)(gao)，同時(shi)，隨(sui)著單片機(ji)，dsp等(deng)微處理器的(de)迅(xun)速發(fa)展(zhan)，數(shu)字(zi)功率(lv)放(fang)(fang)大(da)(da)器的(de)工業實現(xian)以(yi)及整(zheng)體性能(neng)(neng)都得(de)到(dao)了很(hen)大(da)(da)的(de)提(ti)升。

技術實現要素：

本發明所要解(jie)決的技(ji)術問題是，針對現有技(ji)術不足，提(ti)供一種模塊化開關(guan)功率放大(da)器及其控制方法。

為解決上(shang)述(shu)技術問題，本發明所(suo)采用(yong)的技術方案是：一種模塊化開關功率放大器(qi)，包(bao)括依次連(lian)(lian)接(jie)的前級的三相不可控(kong)整流電(dian)路(lu)、中間(jian)級高(gao)頻(pin)dc-dc電(dian)路(lu)和后級二極管鉗位的兩相三電(dian)平逆變(bian)(bian)電(dian)路(lu)；所(suo)述(shu)中間(jian)級高(gao)頻(pin)dc-dc電(dian)路(lu)包(bao)括全(quan)橋(qiao)逆變(bian)(bian)電(dian)路(lu)，所(suo)述(shu)全(quan)橋(qiao)逆變(bian)(bian)電(dian)路(lu)與(yu)高(gao)頻(pin)變(bian)(bian)壓器(qi)的原(yuan)邊相連(lian)(lian)，所(suo)述(shu)高(gao)頻(pin)變(bian)(bian)壓器(qi)的副邊與(yu)lc濾(lv)波電(dian)路(lu)連(lian)(lian)接(jie)。

所述中(zhong)間級高(gao)頻dc-dc電路(lu)控(kong)制方(fang)法包括以下(xia)步驟(zou)：

1)檢測高頻變壓器輸出側的總直流電壓udc，將直流側電壓的參考值udc^ref減去采樣得(de)到的直(zhi)流側電(dian)容電(dian)壓，然后(hou)送入(ru)電(dian)壓pi控制器調解處(chu)理(li)后(hou)得(de)到電(dian)壓環調制信號i*；

2)將(jiang)(jiang)電壓環調制(zhi)信號i*通過(guo)限幅(fu)電路限幅(fu)后得到(dao)全橋(qiao)逆變(bian)電路的占(zhan)(zhan)空比信號d，并(bing)將(jiang)(jiang)占(zhan)(zhan)空比信號送入(ru)載波調制(zhi)環節，移相調制(zhi)輸出(chu)得到(dao)功率模塊(kuai)的pwm驅動信號，分別驅動全橋(qiao)逆變(bian)電路，達到(dao)期望的輸出(chu)電壓。

相應的，本發明還提供了一(yi)種鉗位多電平電壓平衡(heng)及死(si)區補(bu)償控制(zhi)方(fang)法，包(bao)括以下步驟：

1)分別對(dui)高頻變(bian)壓(ya)器的輸(shu)(shu)出(chu)電(dian)(dian)壓(ya)的分電(dian)(dian)壓(ya)進行(xing)采(cai)樣，得到udc1和udc2，并實(shi)時檢測高頻變(bian)壓(ya)器的輸(shu)(shu)出(chu)電(dian)(dian)流(liu)il，通(tong)過輸(shu)(shu)出(chu)電(dian)(dian)流(liu)及采(cai)樣電(dian)(dian)壓(ya)確定調(diao)制模式；

2)兩相三電平逆變(bian)電路的直流側上下電容電壓允(yun)許偏差為(wei)|δumax|，并計算δu＝udc1-udc2；

3)若(ruo)|δu|<|δumax|，則保持(chi)原有的(de)(de)(de)載(zai)波(bo)(bo)不變(bian)，若(ruo)|δu|>|δumax|，輸出波(bo)(bo)形(xing)為正半周；當il>0，δu<0時，工(gong)作狀(zhuang)(zhuang)態(tai)由(you)模(mo)(mo)(mo)式(shi)1切(qie)(qie)換到(dao)模(mo)(mo)(mo)式(shi)2，當il>0，δu>0時，工(gong)作狀(zhuang)(zhuang)態(tai)由(you)模(mo)(mo)(mo)式(shi)2切(qie)(qie)換到(dao)模(mo)(mo)(mo)式(shi)1，其中(zhong)模(mo)(mo)(mo)式(shi)1的(de)(de)(de)電(dian)(dian)流經(jing)左(zuo)(zuo)橋(qiao)(qiao)臂(bei)(bei)(bei)(bei)(bei)第(di)(di)(di)一開(kai)(kai)關(guan)管s11、第(di)(di)(di)二(er)開(kai)(kai)關(guan)管s12、負(fu)載(zai)及右橋(qiao)(qiao)臂(bei)(bei)(bei)(bei)(bei)第(di)(di)(di)三開(kai)(kai)關(guan)管s23、第(di)(di)(di)四二(er)極(ji)管d4構成回路，模(mo)(mo)(mo)式(shi)2電(dian)(dian)流經(jing)左(zuo)(zuo)橋(qiao)(qiao)臂(bei)(bei)(bei)(bei)(bei)第(di)(di)(di)一二(er)極(ji)管d1、第(di)(di)(di)二(er)開(kai)(kai)關(guan)管s12流經(jing)負(fu)載(zai)及右橋(qiao)(qiao)臂(bei)(bei)(bei)(bei)(bei)第(di)(di)(di)二(er)開(kai)(kai)關(guan)管s23、第(di)(di)(di)四開(kai)(kai)關(guan)管s24構成回路；輸出波(bo)(bo)形(xing)為負(fu)半周：當il>0，δu<0時，工(gong)作狀(zhuang)(zhuang)態(tai)由(you)模(mo)(mo)(mo)式(shi)4切(qie)(qie)換到(dao)模(mo)(mo)(mo)式(shi)3，當il>0，δu>0時，工(gong)作狀(zhuang)(zhuang)態(tai)由(you)模(mo)(mo)(mo)式(shi)3切(qie)(qie)換到(dao)模(mo)(mo)(mo)式(shi)4，其中(zhong)模(mo)(mo)(mo)式(shi)3的(de)(de)(de)電(dian)(dian)流經(jing)左(zuo)(zuo)橋(qiao)(qiao)臂(bei)(bei)(bei)(bei)(bei)第(di)(di)(di)一二(er)極(ji)管d1、第(di)(di)(di)二(er)開(kai)(kai)關(guan)管s12、負(fu)載(zai)及右橋(qiao)(qiao)臂(bei)(bei)(bei)(bei)(bei)第(di)(di)(di)三開(kai)(kai)關(guan)管s23、第(di)(di)(di)一開(kai)(kai)關(guan)管s21構成回路，模(mo)(mo)(mo)式(shi)4電(dian)(dian)流經(jing)左(zuo)(zuo)橋(qiao)(qiao)臂(bei)(bei)(bei)(bei)(bei)第(di)(di)(di)四開(kai)(kai)關(guan)管s14、第(di)(di)(di)三開(kai)(kai)關(guan)管s13流經(jing)負(fu)載(zai)及右橋(qiao)(qiao)臂(bei)(bei)(bei)(bei)(bei)第(di)(di)(di)三開(kai)(kai)關(guan)管s23、第(di)(di)(di)四二(er)極(ji)管d4構成回路；通過四種工(gong)作模(mo)(mo)(mo)式(shi)相互(hu)切(qie)(qie)換以維持(chi)中(zhong)性點(dian)電(dian)(dian)壓平衡；

4)當(dang)il>0時(shi)，在功放的(de)(de)信號(hao)源信號(hao)中(zhong)(zhong)疊加δur，其中(zhong)(zhong)δur為死(si)區時(shi)間與載波(bo)(bo)周期的(de)(de)比值，當(dang)il<0時(shi)，在功放的(de)(de)信號(hao)源信號(hao)中(zhong)(zhong)疊加-δur進行死(si)區補(bu)償(chang)，減小(xiao)三(san)次諧波(bo)(bo)含量，降低電流的(de)(de)畸變率(lv)；

5)將疊加死區(qu)補償后的(de)信號與載波實(shi)時比較，并利(li)用載波層(ceng)疊調制策略，左右橋臂各(ge)輸出(chu)四路pwm信號驅動后級兩相三電(dian)(dian)平(ping)逆變(bian)電(dian)(dian)路橋臂的(de)功率(lv)器件(jian)。

輸出電(dian)(dian)流thd小于1％，電(dian)(dian)容電(dian)(dian)壓允許偏差(cha)|δumax|＝0。

電(dian)(dian)容電(dian)(dian)壓(ya)允許偏差取為(wei)|δumax|/udc＝1％～2％，udc為(wei)直流側(ce)電(dian)(dian)容電(dian)(dian)壓(ya)。

與現有(you)(you)技術(shu)相比(bi)，本發(fa)明所具有(you)(you)的有(you)(you)益效果(guo)為：本發(fa)明采(cai)用模塊化開(kai)關功(gong)率放(fang)大(da)器(qi)技術(shu)，采(cai)用高(gao)頻(pin)(pin)變(bian)壓(ya)(ya)器(qi)和移相全橋(qiao)減(jian)小了裝置的體積，并(bing)且實現輸出(chu)電(dian)(dian)壓(ya)(ya)可調(diao)；同(tong)時通過采(cai)用高(gao)頻(pin)(pin)開(kai)關電(dian)(dian)源移相調(diao)制策略、引(yin)入死(si)區補(bu)償(chang)方(fang)法，利用調(diao)制措施實現中性(xing)點電(dian)(dian)壓(ya)(ya)平衡(heng)，具有(you)(you)很強(qiang)的實用性(xing)，可實現電(dian)(dian)能的高(gao)效變(bian)換。

附圖說明

圖1為本發(fa)明(ming)一實(shi)施(shi)例的拓撲結構圖；

圖2為本發明一實施例的(de)移相(xiang)全橋的(de)控制框圖；

圖3(a)～圖3(d)為本發明(ming)一實施(shi)例(li)的(de)電流正向時(shi)電路的(de)四種工作模式。

具體實施方式

圖(tu)1為(wei)模塊化開(kai)關功率放(fang)(fang)大(da)器的(de)拓(tuo)(tuo)撲結(jie)構(gou)(gou)。目前研(yan)究的(de)開(kai)關功率放(fang)(fang)大(da)器輸出(chu)(chu)電(dian)(dian)壓調節依賴變(bian)(bian)壓器分(fen)檔調節，成(cheng)本(ben)(ben)高(gao)、體積大(da)；功率合成(cheng)采用(yong)(yong)多繞組方式，制造難，模塊一致性(xing)要求(qiu)高(gao)，結(jie)構(gou)(gou)固定，擴展性(xing)差，維(wei)護難度高(gao)，很(hen)難滿足負載實(shi)時變(bian)(bian)化的(de)需(xu)求(qiu)。為(wei)此本(ben)(ben)專利發(fa)明(ming)了一種模塊化開(kai)關功率放(fang)(fang)大(da)器及其控(kong)(kong)制方法，拓(tuo)(tuo)撲結(jie)構(gou)(gou)如圖(tu)1所示(shi)：該拓(tuo)(tuo)撲結(jie)構(gou)(gou)前級由電(dian)(dian)容(rong)濾(lv)波(bo)的(de)三相(xiang)不(bu)可(ke)控(kong)(kong)整流電(dian)(dian)路構(gou)(gou)成(cheng)；中間(jian)級是(shi)由高(gao)頻dc-dc電(dian)(dian)路構(gou)(gou)成(cheng)，采用(yong)(yong)全(quan)橋逆變(bian)(bian)電(dian)(dian)路與高(gao)頻變(bian)(bian)壓器的(de)原(yuan)邊相(xiang)連，高(gao)頻變(bian)(bian)壓器的(de)副邊為(wei)單相(xiang)不(bu)可(ke)控(kong)(kong)整流接(jie)lc濾(lv)波(bo)電(dian)(dian)路；后級由二(er)極管鉗位的(de)兩相(xiang)三電(dian)(dian)平逆變(bian)(bian)電(dian)(dian)路組成(cheng)，輸出(chu)(chu)部分(fen)與功放(fang)(fang)的(de)負載相(xiang)連。

圖2為移相全橋的控制框圖，將直流側電壓的參考值udc^ref減去采樣(yang)得(de)到(dao)(dao)的(de)直流側電(dian)(dian)容(rong)電(dian)(dian)壓，然后(hou)(hou)送入電(dian)(dian)壓pi控制器調解處理后(hou)(hou)得(de)到(dao)(dao)電(dian)(dian)壓環調制信(xin)號(hao)i*，將(jiang)i*通過限幅電(dian)(dian)路(lu)限幅后(hou)(hou)得(de)到(dao)(dao)全(quan)橋逆變電(dian)(dian)路(lu)的(de)占空比信(xin)號(hao)d，并將(jiang)占空比信(xin)號(hao)送入載(zai)波調制環節(jie)，輸出得(de)到(dao)(dao)功率模(mo)塊(kuai)的(de)pwm驅動信(xin)號(hao)，分別(bie)驅動中間級(ji)的(de)全(quan)橋逆變電(dian)(dian)路(lu)，達到(dao)(dao)期望的(de)輸出電(dian)(dian)壓；

圖(tu)3(a)～圖(tu)3(d)為本(ben)發明一實施例的(de)(de)電(dian)(dian)(dian)流(liu)正向時(shi)(shi)(shi)電(dian)(dian)(dian)路的(de)(de)四種工(gong)作模(mo)式(shi)，分別對高頻(pin)變壓(ya)器的(de)(de)輸(shu)(shu)(shu)出(chu)(chu)電(dian)(dian)(dian)壓(ya)的(de)(de)分電(dian)(dian)(dian)壓(ya)進(jin)行采樣得到(dao)udc1和udc2，并實時(shi)(shi)(shi)檢測(ce)輸(shu)(shu)(shu)出(chu)(chu)電(dian)(dian)(dian)流(liu)il，通過輸(shu)(shu)(shu)出(chu)(chu)電(dian)(dian)(dian)流(liu)及(ji)采樣電(dian)(dian)(dian)壓(ya)確定調(diao)制模(mo)式(shi)，依據(ju)工(gong)程經驗選取|δumax|，并計算δu＝udc1-udc2，若(ruo)|δu|<|δumax|，則保持原有的(de)(de)載波不變，若(ruo)|δu|>|δumax|輸(shu)(shu)(shu)出(chu)(chu)波形(xing)為正半周(zhou)(zhou)時(shi)(shi)(shi)：當(dang)(dang)il>0，δu<0時(shi)(shi)(shi)，工(gong)作狀態(tai)由(you)模(mo)式(shi)1到(dao)模(mo)式(shi)2；當(dang)(dang)il>0，δu>0時(shi)(shi)(shi),工(gong)作狀態(tai)由(you)模(mo)式(shi)2到(dao)模(mo)式(shi)1；輸(shu)(shu)(shu)出(chu)(chu)波形(xing)為負半周(zhou)(zhou)時(shi)(shi)(shi)：當(dang)(dang)il>0，δu<0時(shi)(shi)(shi)，工(gong)作狀態(tai)由(you)模(mo)式(shi)4到(dao)模(mo)式(shi)3；當(dang)(dang)il>0，δu>0時(shi)(shi)(shi),工(gong)作狀態(tai)由(you)模(mo)式(shi)3到(dao)模(mo)式(shi)4；當(dang)(dang)il>0時(shi)(shi)(shi)，在調(diao)制信(xin)(xin)號中疊(die)(die)(die)加(jia)δur，當(dang)(dang)il<0時(shi)(shi)(shi),在調(diao)制信(xin)(xin)號中疊(die)(die)(die)加(jia)-δur進(jin)行死(si)區補償(chang)(chang)，減小了三次(ci)諧(xie)波含量(liang)，降低(di)電(dian)(dian)(dian)流(liu)的(de)(de)畸變率(lv)，將疊(die)(die)(die)加(jia)死(si)區補償(chang)(chang)后的(de)(de)信(xin)(xin)號與載波實時(shi)(shi)(shi)比(bi)較并利用載波層疊(die)(die)(die)調(diao)制策略，左右(you)橋臂(bei)各輸(shu)(shu)(shu)出(chu)(chu)的(de)(de)四路pwm信(xin)(xin)號驅動后級鉗位電(dian)(dian)(dian)路橋臂(bei)的(de)(de)功率(lv)器件(jian)。