31
NA11 - Manual - 02 - 2009
FUNCTION CHARACTERISTICS
Samples are processed by means DFT (Discrete Fourier Transform) algorithm and the phase and
amplitude of fundamental are computed:
Phase currents I
L1
,
I
L2
,
I
L3
Residual current I
E
Calculated
For the following measures, the RMS value of fundamental component is returned:
Maximum current between I
L1
-I
L2
-I
L3
(I
LMAX
)
Minimum current between I
L1
-I
L2
-I
L3
(I
LMIN
)
Average current between I
L1
-I
L2
-I
L3
(I
L
)
On demand
Fixed demand (I
L1FIX
, I
L2FIX
, I
L3FI
)
Inside an adjustable time interval t
FIX
, an average magnitude is calculated for phase currents I
L1
,
I
L2
, I
L3
of measures taken every second. The average values are stored at the end of the same time
interval.
Rolling demand (I
L1ROL
, I
L2ROL
, I
L3ROL
, ±P
ROL
, ±Q
ROL
)
Inside an adjustable time interval N
ROL
∙t
ROL
, an average magnitude is calculated for phase currents
I
L1
, I
L2
, I
L3
of measures taken every second, where t
ROL
is the length of any time subinterval and
N
ROL
is the number of the time intervals. The average values are stored at the end of the same time
subinterva.
•
•
•
•
•
•
•
IL1.ai
(I
n
)
ACQUISITION
i
L1
, i
L2
, i
L3
DFT
TA
≈
I
L1
, I
L2
, I
L3
IL1.ai
(I
n
)
ACQUISITION
i
L1
, i
L2
, i
L3
DFT
TA
≈
I
L1
, I
L2
, I
L3
IE.ai
(I
En
)
ACQUISITION
i
E
DFT
TA
≈
I
E
IE.ai
(I
En
)
ACQUISITION
i
E
DFT
TA
≈
I
E
Fix-Demand.ai
1s
I
L1FIX
, I
L2FIX
,I
L3FIX
t
FIX
(I
n
)
I
L2
I
L1
I
L3
I
LxFIX
I
Lxn
t
FIX
∙ 60
t
FIX
∙ 60
n=1
¥
1
t
FIX
t
FIX
t
FIX
Fix-Demand.ai
1s
I
L1FIX
, I
L2FIX
,I
L3FIX
t
FIX
(I
n
)
I
L2
I
L1
I
L3
I
LxFIX
I
Lxn
t
FIX
∙ 60
t
FIX
∙ 60
n=1
¥
1
t
FIX
t
FIX
t
FIX
Rol-Demand.ai
I
L1ROL
I
L2ROL
I
L3ROL
(I
n
)
I
L2
I
L1
I
L3
012345
1s
t
ROL
t
ROL
N
ROL
t
ROL
t
ROL
t
ROL
6
t
ROL
I
LxROL
= I
Lxk
t
ROL
∙60
t
ROL
∙60
k=1
¥
N
ROL
n=1 n
¥
1
N
ROL
1
Maximum value of averages inside time interval t
ROL
Average inside time interval
t
ROL
Rol-Demand.ai
I
L1ROL
I
L2ROL
I
L3ROL
(I
n
)
I
L2
I
L1
I
L3
012345
1s
t
ROL
t
ROL
N
ROL
t
ROL
t
ROL
t
ROL
6
t
ROL
I
LxROL
= I
Lxk
t
ROL
∙60
t
ROL
∙60
k=1
¥
N
ROL
n=1 n
¥
1
N
ROL
1
Maximum value of averages inside time interval t
ROL
Average inside time interval
t
ROL