ABB ACS800-67, System Description And Start-Up Manual

Page: 31 / 120

System description 31
Example limit curves
According to this example, electrical power network failure (eg, voltage dip/sag) may not
cause instability above the limit line 1 or disconnection of the converter from the grid. The
limit curves for voltage at the grid connection in case of a fault in the grid are shown below.
U denotes the remaining grid voltage and U
N
the converter nominal voltage.
Description of parameter settings
The parameter settings of the grid fault ride-through function are described in section Grid
support on page 34 .
0 t
1
Time
0
100
U / U
N
(%)
Fault occurs
Limit line 1
Long-term remaining voltage level after fault
clearance
t
2
t
3
Limit line 2
Ride-through and grid support may
be required
Tripping required/allowed
Ride-through required and grid
support may be required
Normal operation