一、功率表和功率因數表區別

功(gong)(gong)率因數(shu)(shu)指有功(gong)(gong)功(gong)(gong)率和(he)視在(zai)功(gong)(gong)率的比(bi)值，一(yi)般用符(fu)號λ表(biao)(biao)示，即：λ=P/S。在(zai)正弦交流電(dian)路中，功(gong)(gong)率因數(shu)(shu)等(deng)于電(dian)壓(ya)與電(dian)流之間的相位差（ψ）的余弦值，用符(fu)號COSψ表(biao)(biao)示。此時，COSψ=λ。

功率因(yin)(yin)數表是指單相交流電(dian)路或(huo)電(dian)壓對稱負載平衡(heng)的三相交流電(dian)路中(zhong)測(ce)量功率因(yin)(yin)數的儀表。常見的功率因(yin)(yin)數表有電(dian)動(dong)系(xi)、鐵磁電(dian)動(dong)系(xi)、電(dian)磁系(xi)和變(bian)換器式等幾(ji)種。

功率表也叫瓦特表(biao)，是(shi)一種測(ce)量(liang)電(dian)功率(lv)(lv)的儀器。電(dian)功率(lv)(lv)包括有功功率(lv)(lv)、無功功率(lv)(lv)和視(shi)在功率(lv)(lv)。未作特殊說明時，功率(lv)(lv)表(biao)一般是(shi)指測(ce)量(liang)有功功率(lv)(lv)的儀表(biao)。

二、功率因數表能替代功率表嗎

功率因數表(biao)不能替代功率表(biao)，它們有(you)著(zhu)不同的功能和(he)應用場(chang)景。

功(gong)(gong)率(lv)因數(shu)表只(zhi)測量功(gong)(gong)率(lv)因數(shu)和其(qi)他(ta)電氣參數(shu)，不能(neng)直接(jie)測量實際功(gong)(gong)率(lv)和其(qi)他(ta)功(gong)(gong)率(lv)值。而功(gong)(gong)率(lv)表則可以同時測量實際功(gong)(gong)率(lv)、有功(gong)(gong)功(gong)(gong)率(lv)、無功(gong)(gong)功(gong)(gong)率(lv)和視在功(gong)(gong)率(lv)等(deng)多個參數(shu)。

功率因數表和功率表的(de)應用(yong)(yong)范(fan)圍也有所不同。功(gong)率(lv)(lv)因(yin)(yin)數(shu)表(biao)主要用(yong)(yong)于(yu)測量(liang)(liang)電(dian)路中(zhong)(zhong)的(de)功(gong)率(lv)(lv)因(yin)(yin)數(shu)，通常應用(yong)(yong)于(yu)檢(jian)測電(dian)路中(zhong)(zhong)的(de)無功(gong)功(gong)率(lv)(lv)和(he)功(gong)率(lv)(lv)因(yin)(yin)數(shu)等(deng)參數(shu)，以優化電(dian)路負載和(he)提高電(dian)能利用(yong)(yong)效率(lv)(lv)。功(gong)率(lv)(lv)表(biao)則(ze)可用(yong)(yong)于(yu)測量(liang)(liang)電(dian)路中(zhong)(zhong)各種(zhong)功(gong)率(lv)(lv)值，廣泛(fan)應用(yong)(yong)于(yu)家(jia)庭、工業、商業等(deng)領(ling)域中(zhong)(zhong)的(de)電(dian)力監測和(he)控(kong)制。

三、功率因數和功率的關系

功(gong)(gong)率(lv)(lv)(lv)(lv)因(yin)(yin)數(shu)(shu)(shu)(shu)和(he)功(gong)(gong)率(lv)(lv)(lv)(lv)的(de)關(guan)系是(shi)：功(gong)(gong)率(lv)(lv)(lv)(lv)因(yin)(yin)數(shu)(shu)(shu)(shu)=有功(gong)(gong)功(gong)(gong)率(lv)(lv)(lv)(lv)/視在功(gong)(gong)率(lv)(lv)(lv)(lv)。功(gong)(gong)率(lv)(lv)(lv)(lv)因(yin)(yin)數(shu)(shu)(shu)(shu)是(shi)有功(gong)(gong)功(gong)(gong)率(lv)(lv)(lv)(lv)與視在功(gong)(gong)率(lv)(lv)(lv)(lv)的(de)比值(zhi)，它的(de)大小與電(dian)(dian)路的(de)負載(zai)性質有關(guan)。對于電(dian)(dian)感設備比如電(dian)(dian)動機等(deng)，功(gong)(gong)率(lv)(lv)(lv)(lv)因(yin)(yin)數(shu)(shu)(shu)(shu)小于1。有功(gong)(gong)功(gong)(gong)率(lv)(lv)(lv)(lv)和(he)功(gong)(gong)率(lv)(lv)(lv)(lv)因(yin)(yin)數(shu)(shu)(shu)(shu)的(de)關(guan)系可以用公式P=UIcosφ表示，其中cosφ就是(shi)功(gong)(gong)率(lv)(lv)(lv)(lv)因(yin)(yin)數(shu)(shu)(shu)(shu)。