日(ri)期(qi)：
2021-03-25
瀏(liu)覽(lan)次(ci)數(shuo):
在(zai)電(dian)工(gong)原(yuan)理(li)中(zhong),線(xian)性(xing)電(dian)路(lu)的(di)功(gong)率(shuai)因(yin)數(shuo)PF ( Power Factor )習(xi)慣(guan)定(ding)義(yi)為(wei)cosφ，φ是(shi)正(zheng)弦(xian)電(dian)壓(ya)和(hu)正(zheng)弦(xian)電(dian)流(liu)間(jian)的(di)相(xiang)角(jue)差(chai)。但(dan)在(zai)各(ge)種(zhong)整(zheng)流(liu)濾(lv)波(bo)電(dian)路(lu)使(shi)輸(shu)入(ru)電(dian)壓(ya)為(wei)正(zheng)弦(xian)，電(dian)流(liu)也(ye)會(kuai)發(fa)生(sheng)嚴(yan)重(chong)畸(ji)變(bian)。
此(ci)時(shi),功(gong)率(shuai)因(yin)數(shuo)的(di)定(ding)義(yi)為(wei)PF=有(you)功(gong)功(gong)率(shuai)/視(shi)在(zai)功(gong)率(shuai)在(zai)上(shang)式(shi)中(zhong), 通(tong)常(chang)將(qiang)有(you)功(gong)功(gong)率(shuai)等(deng)於(yu)瞬(shun)時(shi)功(gong)率(shuai)的(di)平(ping)均(jun)值(zhi),視(shi)在(zai)功(gong)率(shuai)定(ding)義(yi)為(wei)電(dian)壓(ya)有(you)效(xiao)值(zhi)和(hu)電(dian)流(liu)有(you)效(xiao)值(zhi)的(di)乘(sheng)積(ji)。
在(zai)整(zheng)流(liu)電(dian)路(lu)中(zhong),略(lüe)去(qu)諧(xie)波(bo)電(dian)流(liu)的(di)二(er)次(ci)效(xiao)應(ying),可(ke)以(yi)認(ren)為(wei)輸(shu)，入(ru)電(dian)壓(ya)為(wei)正(zheng)弦(xian),輸(shu)入(ru)電(dian)流(liu)為(wei)非(fei)正(zheng)弦(xian),這(zhe)裏(li)電(dian)流(liu)的(di)有(you)效(xiao)值(zhi)為(wei)
式(shi)中(zhong), Irms( n)是(shi)第(di)n次(ci)諧(xie)波(bo)的(di)有(you)效(xiao)值(zhi)。
設(she)基(ji)波(bo)電(dian)流(liu)滯(zhi)後(hou)於(yu)輸(shu)入(ru)電(dian)壓(ya)的(di)角(jue)度(duo)為(wei)θ ,則(ze)電(dian)路(lu)的(di)PF為(wei):
式(shi)中(zhong), Kg=Irms( 1) /Irms , K.稱(chen)為(wei)電(dian)流(liu)波(bo)形(xing)畸(ji)變(bian)因(yin)子(zi); Kg=cosθ , Kg稱(chen)為(wei)相(xiang)移(yi)因(yin)子(zi),即(ji)功(gong)率(shuai)銦(yin)數(shuo)為(wei)電(dian)流(liu)波(bo)形(xing)畸(ji)變(bian)因(yin)子(zi)與(yu)相(xiang)移(yi)因(yin)子(zi)之(zhi)積(ji)。
