電力(li)設(she)備(bei)的(de)接(jie)(jie)(jie)地(di)引(yin)下(xia)(xia)(xia)線與(yu)(yu)(yu)地(di)網(wang)的(de)可(ke)靠、有效連(lian)接(jie)(jie)(jie)是設(she)備(bei)安全運行(xing)的(de)根本保(bao)障(zhang)。接(jie)(jie)(jie)地(di)引(yin)下(xia)(xia)(xia)線是電力(li)設(she)備(bei)與(yu)(yu)(yu)地(di)網(wang)的(de)連(lian)接(jie)(jie)(jie)部(bu)分(fen)，在電力(li)設(she)備(bei)的(de)長時間運行(xing)過程(cheng)中，連(lian)接(jie)(jie)(jie)處有可(ke)能(neng)因受潮等因素影(ying)響，出現節點(dian)銹(xiu)蝕、甚至斷裂等現象，導致接(jie)(jie)(jie)地(di)引(yin)下(xia)(xia)(xia)線與(yu)(yu)(yu)主接(jie)(jie)(jie)地(di)網(wang)連(lian)接(jie)(jie)(jie)點(dian)電阻(zu)增大，從而不能(neng)滿足電力(li)規程(cheng)的(de)要求。該(gai)用于變電站(zhan)內各個電力(li)設(she)備(bei)接(jie)(jie)(jie)地(di)引(yin)下(xia)(xia)(xia)線之間的(de)導通電阻(zu)值的(de)測量。
地網(wang)接(jie)地引下線導通(tong)測試儀(yi)產品(pin)特性：
1、輸出(chu)電(dian)流10A，抗(kang)干擾性(xing)強，具有輸出(chu)電(dian)流延(yan)時功(gong)能；
2、恒流輸出，無需人工(gong)調節，更不需短路調零(ling)；
3、測(ce)試效率高，無充放電過程，只(zhi)需2秒鐘就可完成(cheng)一個點的(de)測(ce)量；
4、操作簡單，只需按下測量(liang)鍵，即可得(de)到測量(liang)結(jie)果(guo)；
5、直流電(dian)(dian)阻(zu)測(ce)量，消除了測(ce)試電(dian)(dian)阻(zu)值與(yu)被測(ce)電(dian)(dian)阻(zu)的影響；
6、面(mian)板與機箱成(cheng)一體結構，具有很好的(de)抗震性。
地網接地導通測試(shi)儀結(jie)構(gou)和原理：
接地導通測試儀主要由提供測試電流的異頻電源、電流和電壓測量電路以及微電腦測控系統組成。儀器通過測量接地裝置的電位升高與流入接地裝置的電流之比來測量接地阻抗。
異(yi)頻恒流(liu)(liu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)可輸(shu)(shu)(shu)出(chu)頻率(lv)為(wei)(wei)45Hz或55Hz的(de)正弦波(bo)測(ce)(ce)試電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)，輸(shu)(shu)(shu)出(chu)頻率(lv)受微電(dian)(dian)(dian)(dian)(dian)(dian)(dian)腦(nao)系統(tong)控制。其輸(shu)(shu)(shu)出(chu)經(jing)過(guo)隔離后(hou)(hou)通(tong)過(guo)儀器(qi)(qi)面板上的(de)C1、C2兩個端子輸(shu)(shu)(shu)出(chu)。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓放(fang)大器(qi)(qi)為(wei)(wei)一個高(gao)輸(shu)(shu)(shu)入(ru)阻(zu)(zu)抗(kang)(kang)(kang)放(fang)大器(qi)(qi)，它將(jiang)P1、P2兩端的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓放(fang)大后(hou)(hou)送給濾(lv)波(bo)器(qi)(qi)。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)放(fang)大器(qi)(qi)將(jiang)從電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)互(hu)感器(qi)(qi)取得(de)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)信(xin)號(hao)進(jin)行(xing)放(fang)大后(hou)(hou)送給濾(lv)波(bo)器(qi)(qi)。濾(lv)波(bo)器(qi)(qi)用(yong)于(yu)濾(lv)除(chu)干擾信(xin)號(hao)，只允許45Hz和(he)55Hz信(xin)號(hao)通(tong)過(guo)。A/D轉換器(qi)(qi)用(yong)于(yu)將(jiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓和(he)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)信(xin)號(hao)轉換為(wei)(wei)數(shu)字信(xin)號(hao)以便微電(dian)(dian)(dian)(dian)(dian)(dian)(dian)腦(nao)系統(tong)進(jin)行(xing)分(fen)析處理。用(yong)戶(hu)啟(qi)動接地(di)(di)阻(zu)(zu)抗(kang)(kang)(kang)測(ce)(ce)量(liang)(liang)后(hou)(hou)，地(di)(di)網接地(di)(di)導通(tong)測(ce)(ce)試儀先開啟(qi)異(yi)頻電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)使之(zhi)(zhi)輸(shu)(shu)(shu)出(chu)頻率(lv)為(wei)(wei)45Hz的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)，待電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)穩定之(zhi)(zhi)后(hou)(hou)，微電(dian)(dian)(dian)(dian)(dian)(dian)(dian)腦(nao)系統(tong)通(tong)過(guo)A/D轉換器(qi)(qi)取得(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓和(he)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)波(bo)形數(shu)據，進(jin)行(xing)數(shu)字濾(lv)波(bo)后(hou)(hou)計算(suan)出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓V45和(he)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)I45及其相位(wei)差,再進(jin)一步計算(suan)出(chu)阻(zu)(zu)抗(kang)(kang)(kang)Z45、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)分(fen)量(liang)(liang)R45和(he)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)抗(kang)(kang)(kang)分(fen)量(liang)(liang)X45。然后(hou)(hou)，切換異(yi)頻電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)的(de)輸(shu)(shu)(shu)出(chu)頻率(lv)為(wei)(wei)55Hz，經(jing)過(guo)同樣的(de)步驟后(hou)(hou)可計算(suan)出(chu)阻(zu)(zu)抗(kang)(kang)(kang)Z55、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)分(fen)量(liang)(liang)R55和(he)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)抗(kang)(kang)(kang)分(fen)量(liang)(liang)X55。取Z45 和(he)Z55的(de)平均值作為(wei)(wei)工頻接地(di)(di)阻(zu)(zu)抗(kang)(kang)(kang)Z50后(hou)(hou)，關閉異(yi)頻電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)，通(tong)過(guo)液晶屏顯示測(ce)(ce)量(liang)(liang)結果。因此阻(zu)(zu)抗(kang)(kang)(kang)測(ce)(ce)量(liang)(liang)時，儀器(qi)(qi)測(ce)(ce)量(liang)(liang)的(de)是兩電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓輸(shu)(shu)(shu)入(ru)端P1、P2之(zhi)(zhi)間的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓與電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)(yuan)輸(shu)(shu)(shu)出(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)之(zhi)(zhi)比。
