一、功率表和功率因數表區別

功率因數指(zhi)有功功率和視在(zai)功率的(de)比值(zhi)，一般用符號λ表(biao)示，即：λ=P/S。在(zai)正弦(xian)交流電路中，功率因數等于電壓與電流之間的(de)相位差（ψ）的(de)余弦(xian)值(zhi)，用符號COSψ表(biao)示。此時，COSψ=λ。

功(gong)率(lv)因(yin)數(shu)表是指單相交(jiao)流電(dian)路或電(dian)壓對稱(cheng)負載平衡的三相交(jiao)流電(dian)路中(zhong)測(ce)量功(gong)率(lv)因(yin)數(shu)的儀表。常(chang)見的功(gong)率(lv)因(yin)數(shu)表有電(dian)動系(xi)、鐵磁電(dian)動系(xi)、電(dian)磁系(xi)和變(bian)換器式等(deng)幾種(zhong)。

功率表也(ye)叫瓦特(te)表，是一(yi)(yi)種測(ce)量電(dian)功(gong)(gong)(gong)(gong)率(lv)的儀(yi)器。電(dian)功(gong)(gong)(gong)(gong)率(lv)包括(kuo)有(you)功(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)率(lv)、無功(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)率(lv)和視在(zai)功(gong)(gong)(gong)(gong)率(lv)。未作(zuo)特(te)殊說明時，功(gong)(gong)(gong)(gong)率(lv)表一(yi)(yi)般(ban)是指(zhi)測(ce)量有(you)功(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)率(lv)的儀(yi)表。

二、功率因數表能替代功率表嗎

功(gong)率(lv)因(yin)數(shu)表不(bu)能(neng)(neng)替代功(gong)率(lv)表，它們有(you)著不(bu)同的功(gong)能(neng)(neng)和應用(yong)場景(jing)。

功(gong)(gong)(gong)(gong)(gong)率因數表(biao)(biao)只測(ce)量(liang)(liang)功(gong)(gong)(gong)(gong)(gong)率因數和(he)(he)其他電氣參(can)數，不(bu)能(neng)直接測(ce)量(liang)(liang)實際(ji)功(gong)(gong)(gong)(gong)(gong)率和(he)(he)其他功(gong)(gong)(gong)(gong)(gong)率值(zhi)。而功(gong)(gong)(gong)(gong)(gong)率表(biao)(biao)則可以同時測(ce)量(liang)(liang)實際(ji)功(gong)(gong)(gong)(gong)(gong)率、有功(gong)(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)(gong)率、無功(gong)(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)(gong)率和(he)(he)視在(zai)功(gong)(gong)(gong)(gong)(gong)率等(deng)多個參(can)數。

功率因數表和功率表的應用(yong)范圍也有所不同(tong)。功率(lv)因(yin)(yin)(yin)數表主(zhu)要用(yong)于測(ce)量(liang)電(dian)(dian)路(lu)中的功率(lv)因(yin)(yin)(yin)數，通常應用(yong)于檢測(ce)電(dian)(dian)路(lu)中的無功功率(lv)和(he)功率(lv)因(yin)(yin)(yin)數等(deng)(deng)參數，以(yi)優化電(dian)(dian)路(lu)負載和(he)提高電(dian)(dian)能利用(yong)效率(lv)。功率(lv)表則可用(yong)于測(ce)量(liang)電(dian)(dian)路(lu)中各種功率(lv)值，廣泛應用(yong)于家庭(ting)、工業(ye)(ye)、商業(ye)(ye)等(deng)(deng)領(ling)域中的電(dian)(dian)力監測(ce)和(he)控(kong)制。

三、功率因數和功率的關系

功(gong)(gong)(gong)率(lv)(lv)因(yin)數(shu)(shu)(shu)和功(gong)(gong)(gong)率(lv)(lv)的(de)關系是(shi)：功(gong)(gong)(gong)率(lv)(lv)因(yin)數(shu)(shu)(shu)=有(you)功(gong)(gong)(gong)功(gong)(gong)(gong)率(lv)(lv)/視在功(gong)(gong)(gong)率(lv)(lv)。功(gong)(gong)(gong)率(lv)(lv)因(yin)數(shu)(shu)(shu)是(shi)有(you)功(gong)(gong)(gong)功(gong)(gong)(gong)率(lv)(lv)與視在功(gong)(gong)(gong)率(lv)(lv)的(de)比值，它的(de)大小(xiao)與電(dian)路的(de)負(fu)載性質(zhi)有(you)關。對于電(dian)感設備比如電(dian)動機(ji)等，功(gong)(gong)(gong)率(lv)(lv)因(yin)數(shu)(shu)(shu)小(xiao)于1。有(you)功(gong)(gong)(gong)功(gong)(gong)(gong)率(lv)(lv)和功(gong)(gong)(gong)率(lv)(lv)因(yin)數(shu)(shu)(shu)的(de)關系可以用公(gong)式P=UIcosφ表示，其中(zhong)cosφ就是(shi)功(gong)(gong)(gong)率(lv)(lv)因(yin)數(shu)(shu)(shu)。