電(dian)(dian)(dian)力(li)設(she)(she)(she)備(bei)的(de)接(jie)地(di)引下(xia)線(xian)(xian)與(yu)地(di)網(wang)的(de)可靠、有效連接(jie)是(shi)設(she)(she)(she)備(bei)安全運行的(de)根(gen)本保障。接(jie)地(di)引下(xia)線(xian)(xian)是(shi)電(dian)(dian)(dian)力(li)設(she)(she)(she)備(bei)與(yu)地(di)網(wang)的(de)連接(jie)部分，在電(dian)(dian)(dian)力(li)設(she)(she)(she)備(bei)的(de)長時間運行過程中，連接(jie)處(chu)有可能(neng)因(yin)受潮等(deng)因(yin)素影(ying)響(xiang)，出現(xian)(xian)節點銹蝕、甚至(zhi)斷裂等(deng)現(xian)(xian)象，導致接(jie)地(di)引下(xia)線(xian)(xian)與(yu)主接(jie)地(di)網(wang)連接(jie)點電(dian)(dian)(dian)阻(zu)增大，從而(er)不能(neng)滿足電(dian)(dian)(dian)力(li)規程的(de)要求。該用于(yu)變電(dian)(dian)(dian)站內(nei)各個電(dian)(dian)(dian)力(li)設(she)(she)(she)備(bei)接(jie)地(di)引下(xia)線(xian)(xian)之間的(de)導通電(dian)(dian)(dian)阻(zu)值的(de)測量。

地(di)網接地(di)引下線(xian)導通測試儀產品特性：  

1、輸(shu)出電(dian)流10A，抗干擾性強，具有輸(shu)出電(dian)流延時(shi)功能(neng)；

2、恒(heng)流輸出(chu)，無需人工調節，更不需短路調零；

3、測試效(xiao)率高，無充放(fang)電過程，只(zhi)需2秒鐘就可完成一個點(dian)的測量(liang)；

4、操作簡單(dan)，只需(xu)按下測量鍵，即可(ke)得(de)到測量結(jie)果(guo)；

5、直流電阻(zu)測量，消(xiao)除(chu)了(le)測試(shi)電阻(zu)值與被(bei)測電阻(zu)的(de)影響(xiang)；

6、面板與機箱成(cheng)一體結構，具有很好的抗震性(xing)。

地網(wang)接地導通測試儀結構和原(yuan)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)(liu)(liu)電(dian)(dian)(dian)(dian)源可輸(shu)出(chu)頻率(lv)為(wei)45Hz或55Hz的正弦(xian)波(bo)(bo)測(ce)(ce)(ce)試電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)，輸(shu)出(chu)頻率(lv)受微(wei)電(dian)(dian)(dian)(dian)腦(nao)系(xi)統控制。其輸(shu)出(chu)經(jing)過(guo)隔離后(hou)(hou)(hou)通(tong)(tong)過(guo)儀器面板(ban)上的C1、C2兩個端(duan)子輸(shu)出(chu)。電(dian)(dian)(dian)(dian)壓(ya)放大(da)(da)器為(wei)一(yi)個高輸(shu)入阻(zu)(zu)抗(kang)放大(da)(da)器，它將P1、P2兩端(duan)的電(dian)(dian)(dian)(dian)壓(ya)放大(da)(da)后(hou)(hou)(hou)送(song)(song)給濾波(bo)(bo)器。電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)放大(da)(da)器將從(cong)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)互(hu)感(gan)器取得的電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)信(xin)號(hao)進行放大(da)(da)后(hou)(hou)(hou)送(song)(song)給濾波(bo)(bo)器。濾波(bo)(bo)器用(yong)(yong)(yong)于(yu)濾除干擾信(xin)號(hao)，只允許45Hz和(he)55Hz信(xin)號(hao)通(tong)(tong)過(guo)。A/D轉換器用(yong)(yong)(yong)于(yu)將電(dian)(dian)(dian)(dian)壓(ya)和(he)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)信(xin)號(hao)轉換為(wei)數字信(xin)號(hao)以便微(wei)電(dian)(dian)(dian)(dian)腦(nao)系(xi)統進行分(fen)析處理。用(yong)(yong)(yong)戶啟動接地(di)(di)阻(zu)(zu)抗(kang)測(ce)(ce)(ce)量(liang)后(hou)(hou)(hou)，地(di)(di)網接地(di)(di)導通(tong)(tong)測(ce)(ce)(ce)試儀先開(kai)啟異(yi)頻電(dian)(dian)(dian)(dian)源使之輸(shu)出(chu)頻率(lv)為(wei)45Hz的電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)，待(dai)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)穩定之后(hou)(hou)(hou)，微(wei)電(dian)(dian)(dian)(dian)腦(nao)系(xi)統通(tong)(tong)過(guo)A/D轉換器取得電(dian)(dian)(dian)(dian)壓(ya)和(he)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)波(bo)(bo)形數據，進行數字濾波(bo)(bo)后(hou)(hou)(hou)計算(suan)(suan)出(chu)電(dian)(dian)(dian)(dian)壓(ya)V45和(he)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)I45及其相位差,再進一(yi)步計算(suan)(suan)出(chu)阻(zu)(zu)抗(kang)Z45、電(dian)(dian)(dian)(dian)阻(zu)(zu)分(fen)量(liang)R45和(he)電(dian)(dian)(dian)(dian)抗(kang)分(fen)量(liang)X45。然后(hou)(hou)(hou)，切(qie)換異(yi)頻電(dian)(dian)(dian)(dian)源的輸(shu)出(chu)頻率(lv)為(wei)55Hz，經(jing)過(guo)同樣的步驟(zou)后(hou)(hou)(hou)可計算(suan)(suan)出(chu)阻(zu)(zu)抗(kang)Z55、電(dian)(dian)(dian)(dian)阻(zu)(zu)分(fen)量(liang)R55和(he)電(dian)(dian)(dian)(dian)抗(kang)分(fen)量(liang)X55。取Z45 和(he)Z55的平均值作為(wei)工頻接地(di)(di)阻(zu)(zu)抗(kang)Z50后(hou)(hou)(hou)，關(guan)閉(bi)異(yi)頻電(dian)(dian)(dian)(dian)源，通(tong)(tong)過(guo)液晶屏顯示測(ce)(ce)(ce)量(liang)結果。因(yin)此阻(zu)(zu)抗(kang)測(ce)(ce)(ce)量(liang)時，儀器測(ce)(ce)(ce)量(liang)的是兩電(dian)(dian)(dian)(dian)壓(ya)輸(shu)入端(duan)P1、P2之間的電(dian)(dian)(dian)(dian)壓(ya)與電(dian)(dian)(dian)(dian)源輸(shu)出(chu)電(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)之比。