User’s Manual 7M
59
APPENDIX C: EQUATIONS
NUMBER
SYMBOL
DEFINITION
1
MP
Average interval
2
U
f
Phase voltage (U
1
, U
2
or U
3
)
3
U
ff
Phase-to-phase voltage (U
12
, U
23
or U
31
)
4
N
Total number of samples in a period
5
n
Sample number (0 ≤ n ≤ N)
6
x, y
Phase number (1, 2 or 3)
7
i
n
Current sample n
8
U
fn
Phase voltage sample n
9
U
ffn
Phase-to-phase voltage sample n
10
ф
f
Power angle between current and phase voltage f ( ф
1
, ф
2
or ф
3
)
VOLTAGE
Phase voltage
samples in averaging interval (up to 65 Hz)
Phase-to-phase voltage
u
x
, u
y
− phase voltages (U
f
)
N − a number of samples in averaging interval
CURRENT
Phase current
N − samples in averaging interval (up to 65 Hz)
