電磁灶常見調試功率方法

一、間隙加熱法

間(jian)隙施加(jia)激勵(li)(li)脈沖，使(shi)電(dian)(dian)磁(ci)灶斷續加(jia)熱(re)，控制斷續加(jia)熱(re)時(shi)間(jian)間(jian)隔來調節電(dian)(dian)磁(ci)灶的功(gong)率。該方式電(dian)(dian)路簡單，但是有通斷時(shi)的電(dian)(dian)磁(ci)噪聲(sheng)出(chu)現并且對供電(dian)(dian)電(dian)(dian)源有電(dian)(dian)流(liu)沖擊。采用該調功(gong)方式要(yao)注(zhu)意(yi)激勵(li)(li)脈沖的關(guan)(guan)斷必須(xu)在電(dian)(dian)流(liu)過零時(shi)刻，否則(ze)關(guan)(guan)斷時(shi)鍋底的電(dian)(dian)磁(ci)噪音較大。

二、脈沖功率輸出變壓器初級抽頭切換法

可通過控制電路分別接通三只交流接觸器的常開觸點J1-1、J2-1、J3-1，來接通脈沖功率輸出變壓器初(chu)級抽頭，以(yi)分別獲得(de)大、中(zhong)(zhong)、小(xiao)、三(san)擋功(gong)率(lv)。這種調功(gong)方(fang)(fang)式因為有(you)接觸器的(de)存在(zai)，機(ji)芯體積較大，但是在(zai)大、中(zhong)(zhong)、小(xiao)三(san)擋功(gong)率(lv)時都可以(yi)用頻率(lv)跟蹤的(de)方(fang)(fang)法使功(gong)率(lv)管(guan)工(gong)作在(zai)零電壓開關和零電流開關狀態。在(zai)所有(you)調功(gong)方(fang)(fang)式中(zhong)(zhong)該方(fang)(fang)式的(de)功(gong)率(lv)管(guan)的(de)溫升最低，電磁灶的(de)熱效率(lv)高(gao)達95%以(yi)上。

接觸器的接通與釋(shi)放必須先關斷激勵脈沖，使之(zhi)在功率輸出級無電流(liu)的狀態下進行切換。

該圖片由注冊用戶"安居樂"提供，版權聲明反饋

三、移相調脈寬法

電(dian)(dian)(dian)(dian)路中(zhong)，若(ruo)變壓器沒(mei)有抽頭，僅起到感應(ying)線圈與主電(dian)(dian)(dian)(dian)源的(de)(de)隔離(li)、與負載(zai)的(de)(de)匹配作用(yong)。T1、T2為左(zuo)(zuo)邊橋臂(bei)(bei)，T3、T4為右(you)邊橋臂(bei)(bei)。T1、T2的(de)(de)激(ji)勵脈沖反(fan)相并留有足夠(gou)的(de)(de)死區時間(jian)(jian)，保證T1、T2不致產生共態導通。同理，T3、T4的(de)(de)激(ji)勵脈沖反(fan)相并且(qie)也留有足夠(gou)的(de)(de)死區時間(jian)(jian)。當左(zuo)(zuo)右(you)橋臂(bei)(bei)的(de)(de)激(ji)勵脈沖相位差從(cong)180°~0°變化(hua)(hua)時，電(dian)(dian)(dian)(dian)磁灶的(de)(de)功(gong)率(lv)(lv)從(cong)最大至最小連續(xu)平(ping)滑(hua)地變化(hua)(hua)，半邊橋臂(bei)(bei)的(de)(de)功(gong)率(lv)(lv)管(guan)實現零(ling)電(dian)(dian)(dian)(dian)壓開(kai)關(guan)(guan)；另(ling)外半邊橋臂(bei)(bei)的(de)(de)功(gong)率(lv)(lv)管(guan)實現零(ling)電(dian)(dian)(dian)(dian)流開(kai)關(guan)(guan)。實際使用(yong)移相調(diao)脈寬法時，因(yin)省去了補償電(dian)(dian)(dian)(dian)感，當電(dian)(dian)(dian)(dian)磁灶功(gong)率(lv)(lv)較小時超前橋臂(bei)(bei)的(de)(de)零(ling)電(dian)(dian)(dian)(dian)壓開(kai)關(guan)(guan)將會失準，因(yin)此在小功(gong)率(lv)(lv)時宜改用(yong)間(jian)(jian)隙加熱的(de)(de)方法來調(diao)節功(gong)率(lv)(lv)。

移相調脈寬法的(de)缺點是IGBT管子中的(de)續流二極管中有較大(da)的(de)電(dian)流通過，功率管的(de)工作(zuo)狀態(tai)不如上述變壓器抽(chou)頭法來得好，其(qi)優(you)點是可連續調節功率，省去了三只(zhi)交流接觸器。

四、改變整流電壓法

三相整(zheng)(zheng)(zheng)(zheng)(zheng)流(liu)(liu)模塊(kuai)(kuai)改用可控整(zheng)(zheng)(zheng)(zheng)(zheng)流(liu)(liu)模塊(kuai)(kuai)，用0-10V的(de)控制電(dian)(dian)(dian)(dian)壓(ya)改變可控整(zheng)(zheng)(zheng)(zheng)(zheng)流(liu)(liu)模塊(kuai)(kuai)整(zheng)(zheng)(zheng)(zheng)(zheng)流(liu)(liu)后的(de)直流(liu)(liu)輸(shu)(shu)出(chu)(chu)電(dian)(dian)(dian)(dian)壓(ya)來改變電(dian)(dian)(dian)(dian)磁灶(zao)的(de)輸(shu)(shu)出(chu)(chu)功(gong)率(lv)(lv)(lv)。在(zai)額定(ding)輸(shu)(shu)入電(dian)(dian)(dian)(dian)壓(ya)下，整(zheng)(zheng)(zheng)(zheng)(zheng)流(liu)(liu)模塊(kuai)(kuai)全導通(tong)，獲得(de)額定(ding)最大功(gong)率(lv)(lv)(lv)，在(zai)非額定(ding)最大功(gong)率(lv)(lv)(lv)下由于整(zheng)(zheng)(zheng)(zheng)(zheng)流(liu)(liu)輸(shu)(shu)出(chu)(chu)的(de)直流(liu)(liu)電(dian)(dian)(dian)(dian)壓(ya)下降，功(gong)率(lv)(lv)(lv)呈(cheng)現出(chu)(chu)與(yu)電(dian)(dian)(dian)(dian)壓(ya)的(de)平方關系下降。該調(diao)功(gong)方式的(de)優(you)點是(shi)電(dian)(dian)(dian)(dian)路(lu)簡(jian)單，可連續調(diao)功(gong)，在(zai)整(zheng)(zheng)(zheng)(zheng)(zheng)個調(diao)功(gong)范(fan)圍內均可實現頻率(lv)(lv)(lv)跟蹤。該電(dian)(dian)(dian)(dian)路(lu)缺點是(shi)調(diao)功(gong)時可控整(zheng)(zheng)(zheng)(zheng)(zheng)流(liu)(liu)模塊(kuai)(kuai)沒(mei)有(you)全導通(tong)，有(you)斬波缺口，對電(dian)(dian)(dian)(dian)磁兼容性指標影響較(jiao)大。要使電(dian)(dian)(dian)(dian)磁兼容性指標過關，對電(dian)(dian)(dian)(dian)源濾(lv)波器和整(zheng)(zheng)(zheng)(zheng)(zheng)流(liu)(liu)濾(lv)波電(dian)(dian)(dian)(dian)路(lu)要求較(jiao)高，該部分的(de)元件數(shu)相對較(jiao)多，整(zheng)(zheng)(zheng)(zheng)(zheng)機體積和成本增加。

五、調頻法

在(zai)最(zui)大功(gong)率(lv)時使電(dian)路(lu)(lu)工(gong)(gong)作在(zai)近諧振狀(zhuang)(zhuang)態下，提高激勵脈沖頻率(lv)，電(dian)路(lu)(lu)工(gong)(gong)作在(zai)失諧狀(zhuang)(zhuang)態下，功(gong)率(lv)減小。該方法(fa)的(de)(de)優點(dian)是(shi)(shi)電(dian)路(lu)(lu)簡單，但是(shi)(shi)當電(dian)磁(ci)灶輸出(chu)功(gong)率(lv)較大時若發生調(diao)(diao)功(gong)，電(dian)流(liu)相(xiang)位滯后(hou)電(dian)壓(ya)相(xiang)位較大，在(zai)較大電(dian)流(liu)的(de)(de)狀(zhuang)(zhuang)態下關(guan)斷，功(gong)率(lv)管(guan)管(guan)耗較大，這樣，即使散熱器上(shang)的(de)(de)溫升并沒有明顯升高，也有可能管(guan)芯已(yi)過熱而損壞ICBT功(gong)率(lv)模塊，因(yin)此在(zai)8kW以上(shang)的(de)(de)功(gong)率(lv)時不宜(yi)采用該方法(fa)調(diao)(diao)功(gong)。

六、變壓器初級抽頭切換、調頻、調壓法

通過變壓器初級(ji)(ji)抽(chou)頭的(de)切換來獲得大、中、小三(san)擋功(gong)(gong)(gong)(gong)(gong)(gong)率(lv)，由于脈沖功(gong)(gong)(gong)(gong)(gong)(gong)率(lv)輸(shu)出(chu)變(bian)壓(ya)器的(de)使用(yong)，使得功(gong)(gong)(gong)(gong)(gong)(gong)率(lv)輸(shu)出(chu)級(ji)(ji)與負載匹配良好，功(gong)(gong)(gong)(gong)(gong)(gong)率(lv)級(ji)(ji)能(neng)工(gong)作(zuo)在(zai)(zai)(zai)最佳狀(zhuang)態(tai)。在(zai)(zai)(zai)大、中、小三(san)擋功(gong)(gong)(gong)(gong)(gong)(gong)率(lv)處用(yong)頻(pin) 率(lv)跟蹤的(de)方(fang)法使功(gong)(gong)(gong)(gong)(gong)(gong)率(lv)管(guan)工(gong)作(zuo)在(zai)(zai)(zai)零(ling)電(dian)(dian)壓(ya)開(kai)(kai)(kai)關(guan)(guan)和零(ling)電(dian)(dian)流開(kai)(kai)(kai)關(guan)(guan)狀(zhuang)態(tai)下(xia)。在(zai)(zai)(zai)小擋到(dao)中擋、中擋到(dao)大擋調(diao)功(gong)(gong)(gong)(gong)(gong)(gong)范(fan)圍(wei)內再用(yong)微調(diao)激勵脈沖頻(pin)率(lv)的(de)方(fang)法來連續調(diao)節(jie)功(gong)(gong)(gong)(gong)(gong)(gong)率(lv)，此時功(gong)(gong)(gong)(gong)(gong)(gong)率(lv)管(guan)工(gong)作(zuo)在(zai)(zai)(zai)零(ling)電(dian)(dian)壓(ya)開(kai)(kai)(kai)關(guan)(guan)和 零(ling)電(dian)(dian)流開(kai)(kai)(kai)通，近似零(ling)電(dian)(dian)流關(guan)(guan)斷狀(zhuang)態(tai)下(xia)。在(zai)(zai)(zai)小擋到(dao)零(ling)功(gong)(gong)(gong)(gong)(gong)(gong)率(lv)范(fan)圍(wei)內用(yong)調(diao)頻(pin)的(de)方(fang)法會破壞(huai)功(gong)(gong)(gong)(gong)(gong)(gong)率(lv)管(guan)零(ling)電(dian)(dian)壓(ya)開(kai)(kai)(kai)關(guan)(guan)的(de)狀(zhuang)態(tai)，則采用(yong)調(diao)節(jie)輸(shu)出(chu)整(zheng)流電(dian)(dian)壓(ya)的(de)方(fang)法來調(diao)節(jie)功(gong)(gong)(gong)(gong)(gong)(gong)率(lv)。

這(zhe)種(zhong)調(diao)功(gong)(gong)方(fang)式相對(dui)較為復雜，成(cheng)本也(ye)高，其突出優點(dian)是調(diao)功(gong)(gong)范圍(wei)大、功(gong)(gong)率輸出級與負載匹配良好、電磁灶(zao)在8kW功(gong)(gong)率時散熱器溫升不(bu)超過(guo)6℃（在25℃的環境(jing)溫度下(xia)測試）。