一、功率表測量的是什么功率

功(gong)(gong)(gong)(gong)(gong)率(lv)表測量的(de)(de)是電(dian)(dian)(dian)(dian)(dian)路中的(de)(de)有(you)功(gong)(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)(gong)率(lv)。有(you)功(gong)(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)(gong)率(lv)是指電(dian)(dian)(dian)(dian)(dian)路中真正(zheng)的(de)(de)功(gong)(gong)(gong)(gong)(gong)率(lv)消耗(hao)，也稱為實際有(you)用功(gong)(gong)(gong)(gong)(gong)率(lv)，如(ru)電(dian)(dian)(dian)(dian)(dian)動機輸出(chu)(chu)的(de)(de)機械功(gong)(gong)(gong)(gong)(gong)，或者燈泡發出(chu)(chu)的(de)(de)光能。有(you)功(gong)(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)(gong)率(lv)與(yu)電(dian)(dian)(dian)(dian)(dian)壓和電(dian)(dian)(dian)(dian)(dian)流的(de)(de)相位差(cha)有(you)關。當電(dian)(dian)(dian)(dian)(dian)壓和電(dian)(dian)(dian)(dian)(dian)流波形完全相同時，有(you)功(gong)(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)(gong)率(lv)最大，當相位差(cha)為90度時，有(you)功(gong)(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)(gong)率(lv)為0。

二、功率表的正確接線方法

在進行功率表(biao)接線時，必(bi)須遵守“發電(dian)機(ji)端”的接線規(gui)(gui)則。這(zhe)一規(gui)(gui)則主(zhu)要強調以下幾點(dian)：

1、電流線(xian)圈與電壓(ya)線(xian)圈的極性必須正確連接(jie)。標有“*”或“±”號的電流端鈕(niu)應接(jie)至(zhi)電源(yuan)的一(yi)端，另一(yi)端應接(jie)至(zhi)負載(zai)端。電流線(xian)圈需(xu)要串聯接(jie)入電路(lu)中。

2、電(dian)(dian)壓(ya)線圈的接(jie)線也(ye)需遵循一(yi)定(ding)的規則(ze)(ze)。標有“*”或“±”號的電(dian)(dian)壓(ya)端(duan)(duan)鈕應接(jie)到電(dian)(dian)源(yuan)同極性的端(duan)(duan)子(zi)上，另一(yi)個電(dian)(dian)壓(ya)端(duan)(duan)鈕則(ze)(ze)跨(kua)接(jie)到負載(zai)的另一(yi)端(duan)(duan)。電(dian)(dian)壓(ya)線圈并聯接(jie)入電(dian)(dian)路(lu)中(zhong)。

3、如果品牌功率表的(de)(de)接線正確，但發現功率表的(de)(de)指針反轉，這(zhe)可能是因為(wei)電(dian)(dian)流端鈕(niu)的(de)(de)連(lian)接錯誤。在這(zhe)種情(qing)況下，應將電(dian)(dian)流端鈕(niu)換(huan)接，而不(bu)是電(dian)(dian)壓端鈕(niu)。

4、功率表有兩種不同的接線方式，以滿足不同的測量需求(qiu)。

5、電(dian)(dian)(dian)壓(ya)(ya)線(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)前接方式：在這(zhe)種(zhong)(zhong)方式中(zhong)，功(gong)(gong)(gong)(gong)率(lv)(lv)(lv)表(biao)電(dian)(dian)(dian)壓(ya)(ya)線(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)兩(liang)端(duan)的(de)(de)電(dian)(dian)(dian)壓(ya)(ya)等(deng)于(yu)負(fu)載電(dian)(dian)(dian)壓(ya)(ya)加(jia)上功(gong)(gong)(gong)(gong)率(lv)(lv)(lv)表(biao)電(dian)(dian)(dian)流線(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)的(de)(de)電(dian)(dian)(dian)壓(ya)(ya)降。這(zhe)意味著在功(gong)(gong)(gong)(gong)率(lv)(lv)(lv)表(biao)的(de)(de)讀數中(zhong)會多出電(dian)(dian)(dian)流線(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)的(de)(de)功(gong)(gong)(gong)(gong)率(lv)(lv)(lv)消耗。這(zhe)種(zhong)(zhong)接線(xian)(xian)(xian)方式適用(yong)于(yu)負(fu)載電(dian)(dian)(dian)阻遠(yuan)比功(gong)(gong)(gong)(gong)率(lv)(lv)(lv)表(biao)電(dian)(dian)(dian)流線(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)電(dian)(dian)(dian)阻大得多的(de)(de)情況。在這(zhe)種(zhong)(zhong)電(dian)(dian)(dian)路中(zhong)，功(gong)(gong)(gong)(gong)率(lv)(lv)(lv)表(biao)電(dian)(dian)(dian)流線(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)中(zhong)的(de)(de)電(dian)(dian)(dian)流等(deng)于(yu)負(fu)載電(dian)(dian)(dian)流加(jia)上功(gong)(gong)(gong)(gong)率(lv)(lv)(lv)表(biao)的(de)(de)電(dian)(dian)(dian)壓(ya)(ya)線(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)中(zhong)的(de)(de)電(dian)(dian)(dian)流，即功(gong)(gong)(gong)(gong)率(lv)(lv)(lv)表(biao)的(de)(de)讀數中(zhong)多了(le)電(dian)(dian)(dian)壓(ya)(ya)線(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)的(de)(de)功(gong)(gong)(gong)(gong)率(lv)(lv)(lv)消耗。因此，這(zhe)種(zhong)(zhong)電(dian)(dian)(dian)路接法適用(yong)于(yu)負(fu)載電(dian)(dian)(dian)阻遠(yuan)比功(gong)(gong)(gong)(gong)率(lv)(lv)(lv)表(biao)電(dian)(dian)(dian)壓(ya)(ya)線(xian)(xian)(xian)圈(quan)(quan)(quan)(quan)(quan)(quan)電(dian)(dian)(dian)阻小得多的(de)(de)情況。

6、電(dian)壓(ya)線圈后(hou)接方式：這(zhe)種(zhong)(zhong)方式與前接方式相反(fan)，電(dian)壓(ya)線圈的(de)(de)連接在電(dian)流線圈之后(hou)。這(zhe)種(zhong)(zhong)接線方式適用于負載(zai)電(dian)阻較小的(de)(de)場合，因(yin)為這(zhe)樣(yang)可以減少(shao)電(dian)壓(ya)線圈的(de)(de)功率消(xiao)耗對(dui)測量結果的(de)(de)影響。

7、在(zai)實(shi)際(ji)測(ce)量中，被測(ce)功(gong)率(lv)一般比(bi)(bi)儀表本身(shen)損(sun)耗大得多，而功(gong)率(lv)表電流(liu)線(xian)(xian)圈的(de)損(sun)耗通常比(bi)(bi)電壓(ya)線(xian)(xian)圈損(sun)耗小，因此為了(le)滿足測(ce)量需求，通常會采用(yong)電壓(ya)線(xian)(xian)圈前接(jie)(jie)方(fang)式。然而，具體采用(yong)哪(na)種接(jie)(jie)線(xian)(xian)方(fang)式應根據被測(ce)功(gong)率(lv)與儀表本身(shen)損(sun)耗的(de)比(bi)(bi)例來確定。在(zai)實(shi)際(ji)操作中，應根據實(shi)際(ji)情況選擇合適(shi)的(de)接(jie)(jie)線(xian)(xian)方(fang)式，并遵守相應的(de)規則進行(xing)正確接(jie)(jie)線(xian)(xian)。