Appendix E: Calculations & Equations; Calculations; Definitions Of Symbols; Equations - Iskra MC320 User Manual

APPENDIX E: CALCULATIONS &
EQUATIONS
Calculations
Definitions of symbols
No Symbol Definition
1 M Sample factor
v
2 M Average interval
P
3 U Phase voltage (U1, U2 or U3)
f
4 U Phase‐to‐phase voltage (U12, U23 or U31)
ff
5 N Total number of samples in a period
6 n Sample number (0 ≤ n ≤ N)
7 x, y Phase number (1, 2 or 3)
8 i Current sample n
n
9 u Phase voltage sample n
fn
10 u Phase‐to‐phase voltage sample n
fFn
11 φ Power angle between current and phase voltage f (φ1, φ2 or φ3)
f
Equations
Voltage
N

2
u
n
= n 1 =
U
f
N
 
N


u u
xn yn
=
n 1 =
U
xy
N
72
Phase voltage
N ‐ 128 samples in one period (up to 65 Hz)
N ‐ 128 samples in M
Example: 400 Hz → M
2
Phase‐to‐phase voltage
u , u
x
N ‐ a number of samples in a period
Measuring centres – MC320, MC330, MC350 & MC350H ‐ User's Manual
APPENDIX E: CALCULATIONS & EQUATIONS
periods (above 65Hz)
v
= 7
v
‐ phase voltages (U )
y f