Monitoring & Control
254 PRS-7367
are displayed in HMI with 0.5s updating rate.
Parameter setting of AC measure quantity contains the following items:
Here is the calculation theory of measurement voltage U and current I,
is the sampling rate of
measurement:
The active power and reactive power can be calculated by voltage U and current I, the current
phase number can be set to two or three according to the project requirements, the calculated
formula is different as following:
(1)
Active/Reactive power calculated by three-meter method
1
[ ( ) ( ) ( ) ( ) ( ) ( )]
a a b b c c
P U n I n U n I n U n I n
N
1 3 3 3
[ ( ) ( ) ( ) ( ) ( ) ( )]
4 4 4
a a b b c c
Q U n I n N U n I n N U n I n N
N
Active/Reactive power calculated by two-meter method
nInUnInU
N
P
ccbaab
1
)
4
3
()
4
3
(
1
NnInUNnInU
N
Q
ccbaab
can be calculated by P and Q as following formula:
5.3.3 Settings
Table 5.3-1 Parameter Setting of AC Measure Quantity