Gossen MetraWatt A2000 - Page 9

GMC-I Messtechnik GmbH 9
Display of Reactive Power
DIN =
calculation of reactive power per Sign = calculation of reactive power with + or–
DIN 40110 without + or – sign
1. Q
4. Q3. Q
P = –
Q = +
P = +
Q = +
P = –
Q = +
P = +
Q = +
E
P–
E
Q–
E
P–
E
Q–
E
P+
E
Q+
E
P+
E
Q+
PF = cap PF = ind
PF = capPF = ind
11
0
0
2. Q
Q
S
2
P
2
–=
1. Q
4. Q3. Q
P = –
Q = +
P = +
Q = +
P = –
Q = –
P = +
Q = –
E
P–
E
Q+
E
P–
E
Q–
E
P+
E
Q+
E
P+
E
Q–
PF = ind PF = ind
PF = capPF = cap
11
0
0
2. Q
Q
1
TN
-------
u
0
TN

t it
TN
4
-------
–


dt
=
Comp = com pensating reactive power 
(reactive power is only produced if current 
and voltage have different + or - signs)
1. Q
4. Q3. Q
P = –
Q = 0
P = +
Q = +
P = –
Q = 0
P = +
Q = –
E
P–
E
Q+
E
P–
E
Q–
E
P+
E
Q+
E
P+
E
Q–
PF = 1.0 PF = ind
PF = capPF = 1.0
11
0
0
2. Q
Q
2
TN
-------
– u
0
TN

t itdt=
for u(t) · i(t) < 0
Calculation of Collective Values
U
avg
U
12
U
23
U
31
++3=
U

U
1
2
U
2
2
U
3
2
++=
I

I
1
2
I
2
2
I
3
2
++=
(without I
N
)
S

U

I

=
P

P
1
P
2
P
3
++=
Q

S

2
P

2
–=
(per DIN)
Q

Q
1
Q
2
Q
3
++=
(others)
PF

P

S

=