ZES ZIMMER LMG450, Руководство пользователя

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prCE-Harmonic measuring mode LMG450
106
DC component:
Udc
T
u t dt
t
T
=
=
∫
1
0
( ) Idc
T
i t dt
t
T
=
=
∫
1
0
( )
AC component:
Uac Utrms Udc
= − 2 2
Iac Itrms Idc
= − 2 2
crest factor:
Ucf
Upk
Utrms
=
Icf
Ipk
Itrms
=
total harmonic distortion:
Uthd
U
U
n
n
=






=
∑
1
2
2
40
Ithd
I
I
n
n
=






=
∑
1
2
2
40
The harmonic values ‘I(n)’ and ‘U(n)’ are calculated by using a DFT algorithm. The limit
values ‘Limit (n)’ are calculated according to IEC61000-3-2.
Power
active power:
cases other in dt t i t u
T
P
EN if I U dt t i t u
T
P
T
t
T
t
∫
∫
=
=
=
− − −






=
0
0
) ( ) (
1
2008 : 7 4 61000 ) 0 ( * ) 0 ( ) ( ) (
1
reactive power:
Q S P
= −
2 2
apparent power:
S Utrms Itrms
=
*
power factor:
λ =
P
S
Impedances
apparent impedance:
Z
Utrms
Itrms
=
active impedance:
Rser
P
Itrms
=
2
reactive impedance:
Xser
Q
Itrms
=
2
6.4 Display of values
For the display of the values we have the same rules like in the normal measuring mode (see
5.4, ‘Display of values’).