There are two PF set-points to be set in TPF-56/16. The UPPER limit and
the LOWER limit
.
TPF-56 ensures that PF-UPPER is never exceeded.
Additionally, “No change band” to minimum KVAR band size equal to
smallest bank KVAR x 1.5 ensures no hunting during the low KW loading.
TPF-56 is normally set for PF settings as per first two diagrams shown
where PFLOWER is inductive. This philosophy helps to optimize the
system maximum KVAR to be used as well as reduces the number of
switching operations during higher loading conditions. This ensures better
life expectancies of the switched capacitors as well as the switching
devices.
This methodology of KVAR compensation reduces the complex settings
that are used by conventional PF relays. The settings like C/K ratio and
KVAR offsets/shifts are eliminated which makes TPF-56 user friendly and
thus easy to commission.
For all the three conditions shown in the above diagrams, 4-quadrant
operation is achieved. Typical example of 4-quadrant operation is “Co-
Generation Plants” and “Wind-Power Generation”. But with most
conventional consumer applications, only +Ve KW is seen, where the
Auto Synchronization feature can be used.
KVAR
(Ind)
KVAR
(Cap)
PF
LOWER.
PF
UPPER.
-
KW
PF
LOWER.
PF
UPPER.
smallest
Capacitor bank
KVAR X 1.5 width.
KW.
Case-3: PF-UPPER & PF-LOWER both set as Capacitive:
No change band.
Capacitor addition band.
Capacitor removal band.
Intelligent Power Factor Controller TPF-56
17 of 56
Version 1.1.5 22
nd
March, 2016
