ABB ACS880-304LC Series, Руководство по оборудованию, Страница: 16 / 178

￭
Main circuit diagram
The figure shows a simplified main circuit diagram of the rectifier bridge.
16 Operation principle and hardware description

Main circuit diagram
The figure shows a simplified main circuit diagram of the rectifier bridge.

Implementing DC voltage measurement
The control program needs a measured voltage value:
•
for the control of the charging circuit at the power up
•
for overvoltage and undervoltage monitoring and protection.
The supply unit does not have the DC voltage measurement as standard. The cabinet
installer must implement it separately. The cabinet installer can, for example:
1. connect the DC voltage measurement of the inverter unit to the supply unit via a fiber
optic link. For more information, see Setting the parameters on page 84 , Example
circuit diagrams on page 169 , and the relevant firmware manuals.
2. connect the DC voltage measurement of the inverter unit to the supply unit via the
analog output of the inverter unit and analogue input AI2 or AI1 of the supply unit. For
more information, see
Setting the parameters on page 84 , Example circuit diagrams
on page 169 , and the relevant firmware manuals.
3. use a separate voltage measurement device (transducer), and connect it between the
drive DC link and analogue input AI2 or AI1 of the supply unit.
You can use alternatives 1, 2, or 3 for a single drive, in other words, for a drive that consist
of one supply unit and one inverter unit. For multidrives (one supply unit feeds several
inverters), use alternative 3.

Charging
A charging circuit powers up the DC link capacitors of the drive system smoothly.
Discharged capacitors cannot be directly connected to the full supply voltage. The
charging current must be limited until the capacitors are charged and ready for normal use.
If the diode supply unit is equipped with a charging circuit, the DC voltage level must be
signaled to the control unit either through analog input AI2 (AI1) or fiber optic connection
1. AC fuses
2. Diodes
+
-
U
c
+
-
U
c
2
2
1
AC fuses 1
Diodes 2
￭
Implementing DC voltage measurement
The control program needs a measured voltage value:
• for the control of the charging circuit at the power up
• for overvoltage and undervoltage monitoring and protection.
The supply unit does not have DC voltage measurement as standard. The cabinet
installer must implement it separately. The cabinet installer can, for example:
1. connect the DC voltage measurement of the inverter unit to the supply unit via a
fiber optic link between DDCS communication modules. For more information,
see
Start-up (page 75) , Example circuit diagrams (page 153) and the relevant
firmware manuals.
2. connect the DC voltage measurement of the inverter unit to the supply unit via
the analog output of the inverter unit and analogue input AI2 or AI1 of the supply
unit. For more information, see
Start-up (page 75) , Example circuit
diagrams (page 153) and the relevant firmware manuals.
3. use a separate voltage measurement device (transducer), and connect it between
the drive DC link and analogue input AI2 or AI1 of the supply unit.
You can use alternatives 1, 2, or 3 for a single drive, in other words, for a drive that
consist of one supply unit and one inverter unit. For multidrives (one supply unit feeds
several inverters), use alternative 3.
￭
Charging
A charging circuit powers up the DC link capacitors of the drive system smoothly.
Discharged capacitors cannot be directly connected to the full supply voltage. The
charging current must be limited until the capacitors are charged and ready for normal
use.
16 Operation principle and hardware description