16 Hardware description
Manual Power Quality Filter PQFM
−
Up to 8 PQFM master panels can be connected in parallel providing full redundancy to
the customer
−
In addition to using master panels only, PQFM units can be connected in a master-slave
arrangement.
4.3 The PQF current generator hardware
The power circuit of a PQFM unit is represented hereafter.
2
1
3
4
5
6
7
Preload
resistor
Output filter
IGBT
Inverter
Master Unit
AC power supply
L
L
Figure 6: Power circuit diagram of a PQFM active filter
The description of the main components is given in
Table 5: Main components of a PQFM active filter
Item
Main components
1
IGBT inverter
2
DC bus capacitors
3
PWM reactor
4
Output filter
5
Preload resistor
6
Main contactor
7
Auxiliary fuses
The current generator is physically organized in power units. Each filter cubicle contains
one power unit. A PQFM filter can contain up to 8 power units. Power units can be
combined in a master-slave arrangement or in a master-master arrangement, the latter
giving full operational redundancy. The current rating of different units in a filter does