YOKOGAWA WT333E - Page 119

App-13
IM WT310E-01EN
Appendix
1
2
3
4
5
6
7
8
App
Index
Series RLC Circuits
TheequationsbelowexpressthevoltagerelationshipswhenresistanceR
S
[Ω],inductanceL[H],and
capacitanceC[F]areconnectedinseries.
U = (URS)
2
+ (UL – UC)
2
= (IRS)
2
+ (IXL – IXC)
2
= I (RS)
2
+ (XL – XC)
2
= I RS
2
+ XS
2
I=
U
RS
2
+ XS
2
, Φ = tan
– 1
XS
RS
RS
I
URS
I
L
UL
C
UC
U
UC
UL
U
U
RS
Φ
TherelationshipbetweenresistanceR
S
, reactance X
S
, and impedance Z is expressed by the
equations below.
Z = RS
2
+ XS
2
X
S
= X
L
– X
C
Parallel RLC Circuits
TheequationsbelowexpressthecurrentrelationshipswhenresistanceR
P
[Ω],inductanceL[H],and
capacitanceC[F]areconnectedinparallel.
I = (IRP)
2
+ (IL – IC)
2
=
U=
IRPXP
RP
2
+ XP
2
, Φ = tan
– 1
RP
XP
RP
U
2
+
XL
U
–
XC
U
2
=
RP
1
2
+
XL
1
–
XC
1
2
U =
RP
1
2
+
XP
1
2
U
RP
L
C
I
I
RP
IL
IC
U
U
IC
IL
I
I
RP
Φ
TherelationshipbetweenresistanceR
P
, reactance X
P
, and impedance Z is expressed by the equations
below.
Z=
RPXP
RP
2
+ XP
2
XP=
XLXC
XC – XL
Appendix 2 Power Basics (Power, harmonics, and AC RLC circuits)