Planning The Electrical Installation; Chapter Overview; Options; Line Reactors (L1) - ABB DCS880 series Hardware Manual

Planning the electrical installation

Chapter overview

This chapter contains the instructions that must be followed when selecting the
motor, cables, protections, cable routing and way of operation for the drive system.
Always follow local regulations. This chapter applies to all DCS880 converter
modules.
Attention:
If the recommendations given by ABB are not followed, the drive may experience
problems not covered by warranty. See also

Options

Line reactors (L1)

For armature and field supply.
When thyristor converters operate, the line voltage is short-circuited during
commutation from one thyristor to the next. This operation causes voltage dips in the
mains PCC (point of common coupling). For the connection of a power converter
system to the mains, one of the following configurations applies:
Line
Line
Configuration A
When using a converter, a minimum of impedance is required to
ensure proper performance of the snubber circuit. Use a line reactor
PCC
to meet this minimum impedance requirement. The value must
(P )
cc
therefore not drop below 1 % u
should not exceed 10 % u
u > 1%
k L1
converters outputs.
Configuration B
If special requirements have to be met at the PCC (standards like EN
L
Line
61 800-3, DC and AC drives at the same line, etc), different criteria
must be applied for selecting a line reactor. These requirements are
often defined as a voltage dip in percent of the nominal supply
PCC
voltage. The combined impedance of Z
(P )
cc
L
series impedance of the installation. The ratio between the line
L1
impedance and the line reactor impedance determines the voltage dip
at the PCC. In such cases, line chokes with an impedance around 4 %
are often used.
Example calculation with u
Voltage dip = Z
Technical Guide.
3ADW000462R0101 DCS880 Hardware Manual e a
Technical
(relative impedance voltage). It
k
, due to considerable voltage drops at the
k
= 1 % and u
kLine
/ (Z + Z ) = 20 %. Detailed calculations see
Line Line L1
Guide.
and Z constitute the total
Line L1
= 4 %:
kL1
Planning the electrical installation
21