真(zhen)空度(du)真(zhen)空開(kai)關(guan)測試儀測算原理 工(gong)作(zuo)原理

本儀(yi)器采用(yong)磁控放電法進行測量。將(jiang)(jiang)真空(kong)開關滅弧室(shi)的兩(liang)觸(chu)頭拉開一(yi)定的距離(li)(li)，施加電場脈(mo)沖(chong)高(gao)壓(ya)，將(jiang)(jiang)滅弧室(shi)置于螺(luo)(luo)線(xian)管圈(quan)(quan)內(nei)或將(jiang)(jiang)新型電磁線(xian)圈(quan)(quan)置于滅弧室(shi)外側，向線(xian)圈(quan)(quan)通以大電流(liu)，從而在(zai)滅弧室(shi)內(nei)產(chan)生與高(gao)壓(ya)同步的脈(mo)沖(chong)磁場。這樣，在(zai)脈(mo)沖(chong)強磁場和強電場的作用(yong)下，滅弧室(shi)中的帶電離(li)(li)子(zi)作螺(luo)(luo)旋運動，并與殘余氣體(ti)分子(zi)發生碰撞(zhuang)電離(li)(li)，所產(chan)生的離(li)(li)子(zi)電流(liu)與殘余氣體(ti)密度即真空(kong)度近似成比例關系。對于不同(tong)的真空管型(xing)號(hao)（管型(xing)），由于其結(jie)構不同(tong)，在同(tong)等(deng)觸頭開(kai)距、同(tong)等(deng)真空度(du)、同(tong)等(deng)電場與磁場的條件(jian)下，離子電流(liu)的大小也不相(xiang)同(tong)。通過實驗可(ke)以標定出各(ge)種管型(xing)的(de)(de)真空度與離子(zi)電流間的(de)(de)對應(ying)關(guan)系(xi)曲線。當測知離子(zi)電流后，就可(ke)以通過查詢(xun)該管型(xing)的(de)(de)離子(zi)電流一真空度曲線獲得該管型(xing)的(de)(de)真空度。

在常規磁控放電測(ce)試滅弧室的真(zhen)空度時，為了提高其測(ce)試靈敏(min)度，需(xu)從斷路器上卸下滅弧室，并置于螺(luo)線(xian)(xian)管(guan)線(xian)(xian)管(guan)內。這樣(yang)一來，滅弧室在重新裝回斷路器時需(xu)要調整(zheng)機械參數，工作(zuo)量很大并需(xu)專業人員。而使用(yong)新型磁(ci)控線圈(quan)可以(yi)從側面(mian)包(bao)圍滅(mie)弧室，這樣就不必拆卸滅(mie)弧室。而采用(yong)單(dan)片(pian)微

機(ji)進行同步控制(zhi)與數據采集(ji)處(chu)理，提高(gao)了(le)滅弧室真空(kong)度的現場測試靈敏度。

真空度真空開關測(ce)試(shi)儀  工作原(yuan)理

真空(kong)度測試儀框圖如圖1所示(shi)。

圖(tu)2   放電波形圖(tu)

整機由測量控(kong)制(zhi)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)、電(dian)(dian)(dian)(dian)場(chang)(chang)(chang)高壓(ya)產生電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)、磁場(chang)(chang)(chang)線圈(quan)電(dian)(dian)(dian)(dian)流(liu)控(kong)制(zhi)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)、通(tong)(tong)訊、打印機、液(ye)晶(jing)顯(xian)示(shi)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)等組成。其工作過(guo)程為：由測量控(kong)制(zhi)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)發出指令(ling)，由開關電(dian)(dian)(dian)(dian)源給磁場(chang)(chang)(chang)電(dian)(dian)(dian)(dian)容充電(dian)(dian)(dian)(dian)，通(tong)(tong)過(guo)控(kong)制(zhi)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)監(jian)控(kong)，當磁場(chang)(chang)(chang)電(dian)(dian)(dian)(dian)容上的電(dian)(dian)(dian)(dian)壓(ya)達(da)到預定值后(hou)，控(kong)制(zhi)電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)發出兩(liang)路(lu)(lu)(lu)控(kong)制(zhi)信號分別控(kong)制(zhi)電(dian)(dian)(dian)(dian)場(chang)(chang)(chang)高壓(ya)的輸出和磁場(chang)(chang)(chang)線圈(quan)電(dian)(dian)(dian)(dian)流(liu)的導(dao)通(tong)(tong)，使滅弧室處于強電(dian)(dian)(dian)(dian)場(chang)(chang)(chang)、強磁場(chang)(chang)(chang)的狀態中(zhong)，滅弧室開始放(fang)電(dian)(dian)(dian)(dian)，產生離子電(dian)(dian)(dian)(dian)流(liu)I，如圖2中(zhong)的曲線I所示(shi)。該電(dian)(dian)(dian)(dian)流(liu)經取(qu)樣電(dian)(dian)(dian)(dian)阻R和預處理電(dian)(dian)(dian)(dian)路(lu)(lu)(lu)后(hou)輸入單(dan)片機，最后(hou)經運算(suan)由液(ye)晶(jing)顯(xian)示(shi)屏(ping)顯(xian)示(shi)測得的真空度(du)值。