106
Appendix
1. Calculation methods of ME96SS (for 3 phase unbalanced system with neutral)
Item
Normal mode
IEC mode
Remark
R.m.s current for phase p
N
i
I
1
N
0
k
2
k
p
p
∑
−
=
=
R.m.s neutral current
(
)
N
i
i
i
I
1
N
0
k
2
k
3
k
2
k
1
N
∑
−
=
+
+
=
Lp-N r.m.s voltage
N
v
V
1
N
0
k
2
k
pN
pN
∑
−
=
=
Lp-Lg r.m.s voltage
(
)
N
v
v
V
1
N
0
k
2
k
pN
k
gN
pg
∑
−
=
−
=
Active power for phase p
(
)
∑
−
=
×
⋅
=
1
N
0
k
k
p
k
pN
p
i
v
N
1
P
Apparent power for phase p
p
pN
p
I
V
S
×
=
Reactive power for phase p
(
)
∑
−
=
×
⋅
=
1
N
0
k
k
p
90
k
pN
p
i
v
N
1
Q
_
where i
90_pk
is the current waveform
shifted by 90°.
2
p
2
p
p
P
S
Q
−
=
Refer to page
69 for the sign.
Power factor for phase p
2
p
2
p
p
p
Q
P
P
PF
+
=
p
p
p
S
P
PF
=
Refer to page
69 for the sign.
Total active power
3
2
1
P
P
P
P
+
+
=
Total reactive power
3
2
1
Q
Q
Q
Q
+
+
=
Refer to page
69 for the sign.
Total apparent power
3
2
1
S
S
S
S
+
+
=
2
2
Q
P
S
+
=
Total power factor
2
2
Q
P
P
PF
+
=
S
P
PF
=
Refer to page
69 for the sign.
