ABB ACS6000 - LSU (12-Pulse) Circuit Diagram; LSU Block Diagram; Main Components in a 12-Pulse LSU Cabinet

03 POWER ELECTRONICS AND CABINET FEATURES
3BHS212794 E01 REV M ACS6000 USER MANUAL 56/278
Figure 3-6 LSU block diagram
Figure 3-7 LSU (12-pulse) circuit diagram
(1) LSU
(2) DC-link
(3) INU
(4) Motor
(1) Thyristor crowbar
(2) Diode rectifier
(3) Snubber circuit
(4) di/dt choke
Table 3-2 Main components in a 12-pulse LSU cabinet
Component Description
12-pulse diode
rectifier
Snubber circuit Limits the rate of the voltage rise (dv/dt) across the
diodes and the crowbar thyristors.
di/dt limiting
reactors
Define the current rise in the thyristor crowbar.
Thyristor crowbar Protection circuit that activates when a short-
circuit occurs. By applying protection firing, the thyristor
crowbar short-circuits the rectifier to prevent further
damage of the drive.
1 2 3
4
DC (-)
DC (+)
1L1
1L2
1L3
2L2
2L3
2L1
1
1
2 3 4
4