一、功率表測量的是什么功率

功率(lv)(lv)(lv)表測量的(de)是(shi)(shi)電(dian)(dian)路(lu)(lu)中的(de)有功功率(lv)(lv)(lv)。有功功率(lv)(lv)(lv)是(shi)(shi)指(zhi)電(dian)(dian)路(lu)(lu)中真正(zheng)的(de)功率(lv)(lv)(lv)消耗，也(ye)稱為實際(ji)有用功率(lv)(lv)(lv)，如電(dian)(dian)動(dong)機(ji)輸(shu)出的(de)機(ji)械(xie)功，或(huo)者燈泡發出的(de)光(guang)能。有功功率(lv)(lv)(lv)與電(dian)(dian)壓(ya)和(he)電(dian)(dian)流(liu)的(de)相位(wei)差有關。當(dang)電(dian)(dian)壓(ya)和(he)電(dian)(dian)流(liu)波形完全相同時(shi)，有功功率(lv)(lv)(lv)最大(da)，當(dang)相位(wei)差為90度(du)時(shi)，有功功率(lv)(lv)(lv)為0。

二、功率表的正確接線方法

在進行功(gong)率表(biao)接(jie)線時，必須遵守“發電機端”的接(jie)線規則(ze)。這一規則(ze)主要強調以下幾點：

1、電流(liu)線(xian)圈與電壓線(xian)圈的極性必須正確連接。標有“*”或(huo)“±”號(hao)的電流(liu)端鈕應接至電源的一端，另一端應接至負載(zai)端。電流(liu)線(xian)圈需要串(chuan)聯接入電路中。

2、電(dian)壓(ya)(ya)線(xian)圈(quan)的(de)(de)接線(xian)也需遵循一(yi)定(ding)的(de)(de)規(gui)則。標有“*”或“±”號的(de)(de)電(dian)壓(ya)(ya)端鈕應接到電(dian)源(yuan)同極性的(de)(de)端子上(shang)，另(ling)一(yi)個電(dian)壓(ya)(ya)端鈕則跨接到負載的(de)(de)另(ling)一(yi)端。電(dian)壓(ya)(ya)線(xian)圈(quan)并(bing)聯接入電(dian)路中。

3、如果品牌功率表的(de)接線正確，但發現(xian)功率表的(de)指針反轉，這可能是因(yin)為電流端鈕(niu)(niu)的(de)連接錯(cuo)誤。在這種情(qing)況下，應將電流端鈕(niu)(niu)換(huan)接，而不(bu)是電壓端鈕(niu)(niu)。

4、功率(lv)表有兩種不同(tong)的接線方(fang)式，以滿足(zu)不同(tong)的測量(liang)需(xu)求(qiu)。

5、電(dian)(dian)(dian)壓(ya)(ya)(ya)線(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)前接(jie)方式：在(zai)這種(zhong)方式中(zhong)(zhong)(zhong)，功(gong)(gong)(gong)率(lv)(lv)表(biao)(biao)電(dian)(dian)(dian)壓(ya)(ya)(ya)線(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)兩(liang)端的(de)(de)電(dian)(dian)(dian)壓(ya)(ya)(ya)等(deng)于負(fu)(fu)(fu)載(zai)電(dian)(dian)(dian)壓(ya)(ya)(ya)加上功(gong)(gong)(gong)率(lv)(lv)表(biao)(biao)電(dian)(dian)(dian)流(liu)線(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)的(de)(de)電(dian)(dian)(dian)壓(ya)(ya)(ya)降。這意味著在(zai)功(gong)(gong)(gong)率(lv)(lv)表(biao)(biao)的(de)(de)讀數中(zhong)(zhong)(zhong)會多(duo)(duo)出電(dian)(dian)(dian)流(liu)線(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)的(de)(de)功(gong)(gong)(gong)率(lv)(lv)消耗。這種(zhong)接(jie)線(xian)(xian)(xian)(xian)方式適(shi)用于負(fu)(fu)(fu)載(zai)電(dian)(dian)(dian)阻遠比功(gong)(gong)(gong)率(lv)(lv)表(biao)(biao)電(dian)(dian)(dian)流(liu)線(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)電(dian)(dian)(dian)阻大(da)得多(duo)(duo)的(de)(de)情況(kuang)。在(zai)這種(zhong)電(dian)(dian)(dian)路(lu)中(zhong)(zhong)(zhong)，功(gong)(gong)(gong)率(lv)(lv)表(biao)(biao)電(dian)(dian)(dian)流(liu)線(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)中(zhong)(zhong)(zhong)的(de)(de)電(dian)(dian)(dian)流(liu)等(deng)于負(fu)(fu)(fu)載(zai)電(dian)(dian)(dian)流(liu)加上功(gong)(gong)(gong)率(lv)(lv)表(biao)(biao)的(de)(de)電(dian)(dian)(dian)壓(ya)(ya)(ya)線(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)中(zhong)(zhong)(zhong)的(de)(de)電(dian)(dian)(dian)流(liu)，即功(gong)(gong)(gong)率(lv)(lv)表(biao)(biao)的(de)(de)讀數中(zhong)(zhong)(zhong)多(duo)(duo)了電(dian)(dian)(dian)壓(ya)(ya)(ya)線(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)的(de)(de)功(gong)(gong)(gong)率(lv)(lv)消耗。因此(ci)，這種(zhong)電(dian)(dian)(dian)路(lu)接(jie)法適(shi)用于負(fu)(fu)(fu)載(zai)電(dian)(dian)(dian)阻遠比功(gong)(gong)(gong)率(lv)(lv)表(biao)(biao)電(dian)(dian)(dian)壓(ya)(ya)(ya)線(xian)(xian)(xian)(xian)圈(quan)(quan)(quan)電(dian)(dian)(dian)阻小得多(duo)(duo)的(de)(de)情況(kuang)。

6、電壓線(xian)圈后接方式(shi)(shi)：這(zhe)種方式(shi)(shi)與前接方式(shi)(shi)相反(fan)，電壓線(xian)圈的(de)連接在電流線(xian)圈之后。這(zhe)種接線(xian)方式(shi)(shi)適用于負載(zai)電阻(zu)較小的(de)場合，因為這(zhe)樣可(ke)以減(jian)少電壓線(xian)圈的(de)功率消(xiao)耗對(dui)測量結果的(de)影響。

7、在實際測(ce)量中，被測(ce)功(gong)率(lv)(lv)一般比(bi)儀表(biao)本(ben)身損耗大(da)得多(duo)，而功(gong)率(lv)(lv)表(biao)電(dian)(dian)流線圈的(de)損耗通常比(bi)電(dian)(dian)壓線圈損耗小，因此(ci)為了(le)滿足(zu)測(ce)量需求，通常會采用電(dian)(dian)壓線圈前(qian)接(jie)(jie)方式。然(ran)而，具(ju)體采用哪種(zhong)接(jie)(jie)線方式應(ying)根據(ju)被測(ce)功(gong)率(lv)(lv)與儀表(biao)本(ben)身損耗的(de)比(bi)例來(lai)確定。在實際操作中，應(ying)根據(ju)實際情況選擇合適的(de)接(jie)(jie)線方式，并遵(zun)守相應(ying)的(de)規則進(jin)行正(zheng)確接(jie)(jie)線。