五.R、L、C元件的有功功率和无功功率 PR=UIcOs=UIcos00=UR=U/R RQ=inp=Usi0°=0 UIcosp=Ulcos90=0 L QL=Ulsin =Ulsin900=UFF2XL PCUIcoS=Ulcos(909=0 Cc=Ulsin o=Ulsi(90)=-U1E-FXc五. R、L、C元件的有功功率和无功功率 u i R + - PR =UIcos =UIcos0 =UI=I 2R=U2 /R QR =UIsin =UIsin0 =0 i u L + - PL=UIcos =UIcos90 =0 QL =UIsin =UIsin90 =UI=I2XL i u C + - PC=UIcos =UIcos(-90)=0 QC =UIsin =UIsin (-90)= -UI= － I 2XC