一、三相多功能電力儀表校驗方法
多功(gong)能(neng)電力儀表(biao)應定期(qi)進行校驗,保證(zheng)測量(liang)的準確性,具體的校驗方法步(bu)驟(zou)如下(xia):
1、校驗前
(1)查看多功能電力儀表是否接(jie)入儀表電源,有無(wu)示數。若無(wu)示數顯示,則檢查電源線,控(kong)制電源回(hui)路。
(2)外觀(guan)檢查,檢查是(shi)否(fou)(fou)有缺角,看是(shi)否(fou)(fou)有零件(jian)脫落(luo)或損壞之處,緊(jin)固件(jian)是(shi)否(fou)(fou)松動,電路連接線是(shi)否(fou)(fou)開焊(han)等顯示不正常情況。
(3)記(ji)錄下該多功能電(dian)(dian)力儀(yi)表的銘牌,包括(kuo)生產日(ri)期、廠家、精度(du)、出廠日(ri)期、編號、變比、型號、天氣情況(kuang)、環境溫度(du)、環境濕度(du)等。二(er)次(ci)回(hui)路清掃檢查(cha),電(dian)(dian)流(liu)表CT,電(dian)(dian)壓表PT,功率表PT/CT二(er)次(ci)側(ce)回(hui)路清掃,檢查(cha)。
2、主要參數校驗過程
(1)原理
次級線(xian)圈(quan)的額定(ding)電(dian)(dian)(dian)壓(ya)一(yi)般設(she)計(ji)為100V,與其配(pei)套使(shi)用的交流電(dian)(dian)(dian)壓(ya)表(biao)量程也應為100V,通過變(bian)比(bi)換(huan)算出(chu)一(yi)次側(ce)線(xian)電(dian)(dian)(dian)壓(ya)的標準(zhun)值。次級線(xian)圈(quan)的額定(ding)電(dian)(dian)(dian)流一(yi)般設(she)計(ji)為5A,與其配(pei)套使(shi)用的交流電(dian)(dian)(dian)流表(biao)量程也應為5A,通過變(bian)比(bi)換(huan)算出(chu)一(yi)次側(ce)相電(dian)(dian)(dian)流的標準(zhun)值,然(ran)后根(gen)據電(dian)(dian)(dian)流電(dian)(dian)(dian)壓(ya),換(huan)算出(chu)有功(gong)(gong)功(gong)(gong)率,無功(gong)(gong)功(gong)(gong)率等。
(2)電壓校驗
按(an)照多(duo)功能(neng)電力(li)(li)儀(yi)表(biao)說明(ming)書正確設置(zhi)儀(yi)表(biao)參(can)數(shu),在校(xiao)驗裝置(zhi)上(shang)輸入”11.547U”然后(hou)(hou)按(an)“Enter”鍵,則(ze)此時裝置(zhi)對多(duo)功能(neng)電力(li)(li)儀(yi)表(biao)ABC三相輸入11.547V相電壓(ya),二(er)次線電壓(ya)為20V。操作多(duo)功能(neng)電力(li)(li)儀(yi)表(biao)到電壓(ya)顯示(shi)界(jie)面,記錄(lu)下多(duo)功能(neng)電力(li)(li)儀(yi)表(biao)線電壓(ya)顯示(shi)數(shu)據(ju)。然后(hou)(hou)按(an)照上(shang)述方法分別(bie),在檢(jian)測裝置(zhi)輸入23.094U,34.642U,46.189U,57.737U,記錄(lu)多(duo)功能(neng)電力(li)(li)儀(yi)表(biao)線電壓(ya)顯示(shi)數(shu)據(ju)。
(3)電流校驗
檢測裝置上(shang)先按(an)Menu鍵進入主菜(cai)單,然(ran)后(hou)按(an)“1交流(liu)輸(shu)(shu)出(chu)“進入交流(liu)輸(shu)(shu)出(chu)界面,按(an)V/Y鍵,用于Y型(xing)(xing)或V型(xing)(xing)接(jie)線方式選擇,一般(ban)多(duo)(duo)數(shu)(shu)為Y型(xing)(xing)接(jie)法,按(an)IRange量程(cheng)鍵選擇合適量程(cheng),一般(ban)電(dian)(dian)(dian)(dian)流(liu)互感器二次(ci)側電(dian)(dian)(dian)(dian)流(liu)為5A。輸(shu)(shu)入”1I”然(ran)后(hou)按(an)Enter鍵,則此時裝置對(dui)儀表(biao)ABC三相輸(shu)(shu)入1安培(pei)電(dian)(dian)(dian)(dian)流(liu),調節多(duo)(duo)功(gong)能電(dian)(dian)(dian)(dian)力儀表(biao)到電(dian)(dian)(dian)(dian)流(liu)顯(xian)示界面,記(ji)錄(lu)(lu)下(xia)(xia)多(duo)(duo)功(gong)能電(dian)(dian)(dian)(dian)力儀表(biao)顯(xian)示數(shu)(shu)據(ju)。然(ran)后(hou)按(an)照上(shang)述方法,分(fen)別輸(shu)(shu)入2I,3I,4I,5I,記(ji)錄(lu)(lu)下(xia)(xia)多(duo)(duo)功(gong)能電(dian)(dian)(dian)(dian)力儀表(biao)顯(xian)示數(shu)(shu)據(ju)。
(4)有功功率,無功功率,功率因素校驗
A、有功(gong)(gong)功(gong)(gong)率(lv)(lv):在(zai)檢測裝置上選擇(ze)好電壓電流(liu)相(xiang)對應的量程和接線方式,輸(shu)(shu)入(ru)57.737U然(ran)后按Enter鍵。按快捷鍵區“Φ試驗點1.0”,調整(zheng)儀表功(gong)(gong)率(lv)(lv)為(wei)有功(gong)(gong)功(gong)(gong)率(lv)(lv)模式,輸(shu)(shu)入(ru)”1I”然(ran)后按Enter鍵,則此時裝置對多功(gong)(gong)能電力儀表ABC三(san)相(xiang)輸(shu)(shu)入(ru)1安(an)培電流(liu),線電壓100V。調節多功(gong)(gong)能電力儀表到(dao)有功(gong)(gong)功(gong)(gong)率(lv)(lv)顯示界面,記錄下數(shu)據(ju)。然(ran)后按照上述(shu)方法,分別(bie)輸(shu)(shu)入(ru)2I,3I,4I,5I,記錄下數(shu)據(ju)。
B、無功(gong)功(gong)率(lv):在檢測裝置上按快捷鍵區“Φ試驗點0.0L”或“Φ試驗點0.0C”調整(zheng)多功(gong)能電力儀(yi)表(biao)功(gong)率(lv)為無功(gong)功(gong)率(lv)模式,然后在分別輸入1I、2I、3I、4I、5I,調節多功(gong)能電力儀(yi)表(biao)到(dao)無功(gong)功(gong)功(gong)率(lv)顯示界面,記錄下數據。
C、功率(lv)因素:在檢(jian)測(ce)裝置(zhi)上分別按快捷鍵(jian)區“Φ試驗點0.0L”、“Φ試驗點0.5L”、“試驗點1.0”、“Φ試驗點0.8C”、“Φ試驗點0.5C”、“Φ試驗點0.0C”,調節多功能電(dian)力(li)儀表到(dao)功率(lv)因素顯示界面,記(ji)錄(lu)下數據。
3、校驗后
(1)對(dui)電源控(kong)制(zhi)回路經行檢查,由于實(shi)驗所斷開(kai)的控(kong)制(zhi)開(kai)關(guan),拔掉的熔絲,都要經行復歸。
(2)對于直接加(jia)線到多功能電力儀(yi)表上的實(shi)驗,實(shi)驗后要注意復歸過(guo)功能電力儀(yi)表上的原來所(suo)脫(tuo)開的導線,保證接線正確(que)。
(3)對(dui)于端子排上(shang)電(dian)壓,電(dian)流回路進行(xing)檢查,由于實驗所(suo)拆的滑片,導線都要(yao)經(jing)行(xing)復歸。
二、多功能電力儀表校驗常見問題及處理方法
多功能電(dian)力(li)儀表校驗過程(cheng)中,可能會遇到(dao)一些問(wen)題(ti),下面為(wei)大家介紹一下這些問(wen)題(ti)的處(chu)理方(fang)法:
1、為了檢測儀表(biao)回(hui)路(lu),一般(ban)情況下先(xian)從端(duan)子(zi)排(pai)上進行實(shi)驗。因(yin)此要注(zhu)意通過變壓器二(er)(er)次(ci)側向(xiang)一次(ci)側反向(xiang)送(song)電,必須先(xian)把相對應的電壓二(er)(er)次(ci)側回(hui)路(lu)斷開。一般(ban)也要在端(duan)子(zi)排(pai)上把電流互感(gan)器二(er)(er)次(ci)測的回(hui)路(lu)滑片脫開。
2、進行(xing)電(dian)壓(ya)校驗時,注意電(dian)壓(ya)回路(lu)是否有電(dian)器元件導致所加的電(dian)壓(ya)分(fen)壓(ya),造成數(shu)據的誤差。
3、若端(duan)子排線路(lu)(lu)復雜,無法進(jin)行試驗(yan),則可以直接(jie)把(ba)電壓,電流(liu)加在儀表上,應(ying)注意要脫(tuo)開(kai)外電路(lu)(lu),所加電壓線的(de)觸頭(tou)應(ying)該保持(chi)一定(ding)間隙,防止(zhi)短路(lu)(lu)。
4、若發現(xian)所測電(dian)(dian)壓(ya),電(dian)(dian)流數據(ju)有微(wei)小波動(dong)時,因先檢(jian)查是否所加(jia)頻(pin)率是50Hz,然(ran)后(hou)先把電(dian)(dian)壓(ya),電(dian)(dian)流加(jia)到滿量程,一(yi)般情況下可(ke)以消除波動(dong)。
5、若發現所測的電(dian)(dian)(dian)壓,電(dian)(dian)(dian)流,有功(gong)(gong),無功(gong)(gong)的值(zhi)與標準值(zhi)有明顯差異時,因先(xian)檢(jian)(jian)查(cha)是(shi)否(fou)是(shi)回路(lu)問(wen)題,加錯(cuo)線或者相(xiang)序(xu)弄等,然后在檢(jian)(jian)查(cha)是(shi)否(fou)是(shi)該表變比(bi)問(wen)題,與之(zhi)前所記錄的電(dian)(dian)(dian)壓互(hu)感器、電(dian)(dian)(dian)流互(hu)感器變比(bi),進(jin)行比(bi)較。若設(she)置錯(cuo)誤(wu),則對(dui)多(duo)功(gong)(gong)能電(dian)(dian)(dian)力儀表進(jin)行設(she)置,設(she)置正確后,在進(jin)行校驗。
6、若(ruo)發現所(suo)測電流表,功率表是顯示負數,則要(yao)檢查是否是所(suo)加電流極性錯誤(wu)。