Mega MEg40+ - Page 39

Měřící Energetické Aparáty
39
(7a)
e average eective value is sometimes used instead of the RMS value.
(7b)
Under normal circumstances, the values U
zc
and U
zp
are almost the same. In addition to
the total (or average) RMS value, for each value in the range of the recording interval
between the values U(l), the minimum and maximum values are searched
(8)
ese data are obtained for each voltage.
Similarly, for the recording intervals T
z
, characteristic phase current values are obtained.
From the RMS current values I(l) obtained in the measuring time intervals T
m
with the
serial numbers l = 1, 2, … L, for the recording interval T
z
, the total RMS current value is
calculated according to the formula
(9)
or the average RMS current value according to the formula
(10)
e values I
zc
and I
zp
can dier considerably. Besides, the minimum and maximum
current values are determined
(11)
in the recording intervals T
z
( )
lU
L
U
L
l
zc
∑
=
=
1
2
1
( )
∑
=
=
L
l
zc
lI
L
I
1
2
1
( )
∑
=
=
L
l
zp
lU
L
U
1
1
( )
lUU
l
z
min
min
=
( )
lUU
l
z
max
max
=
( )
∑
=
=
L
l
zp
lI
L
I
1
1
( )
lII
l
z
min
min
=
( )
lII
l
z
max
max
=