MI 2792 PowerQ4 Plus
Theory and internal operation
104
Total power factor (vector):
St
Pt
PFtot
.
(16)
Figure 5.2: Vector representation of total power calculus
5.1.7 Energy
Standard compliance:
IEC 61557-12 (Annex A)
Energy counters are linked to RECORDER functionality. Energy counters measure
energy only when RECORDER is active. After power off/on procedure and before start
of recording, all counters are cleared.
Instrument use 4-quadrant measurement technique which use two active energy
counters (eP
+
, eP
-
) and two reactive (eQ
+
, eQ
-
), as shown on bellow.
Le
ad
La
g
Le
ad
La
g
Figure 5.3: Energy counters and quadrant relationship
Instrument has 3 different counters sets:
1. Total counters
TOT EN
are intended for measuring energy over a complete
recording. When recorder starts it sums the energy to existent state of the
counters.
