----- Analyzer of power supply quality CAVA-251 / CAVA-252 / CAVA-253 ------- Page No. 7
4.2.- Parameters referred Power Supply Quality
4.2.1.- Harmonics
The CAVA provides the measurement of the harmonic distortion of the voltage
wave. This distortion can be referred either to the fundamental amplitude (%D) or to
the RMS value of the signal (%THD).
4.2.2.- Flicker
The CAVA measures and records both the flicker (WA) and the severity (Pst).
RMS
Flicker
(WA)
: Value of the Flicker RMS that is defined as the average
result of the weighted Flicker value due to each frequency.
( )
∑
∑
=
=
N
n
n
N
weighted
Flic
FT
V
dV
n
Flic
RMS
1
2
2
1
ker
%
ker
Severity
(Pst)
: From perceptivity values obtained and at the end of each
period the analyzer calculates the severity (Pst), which gives a short-term flicker
measurement.
Where (P
0.1
, P
1
, P
3
, P
10
y P
50
) are coefficients that indicate the maximum
perceptivity reached during the l 0,1%, 1%, 3%, 10% & 50% of the defined Pst
period.
50
10
3
1
1
.
0
08
,
0
28
,
0
0657
,
0
0525
,
0
0314
,
0
P
P
P
P
P
Pst
Severity
+
+
+
+
=
=
(
)
2
_
FLICKER
RMS
ty
Perceptivi
=
