Grid-Side And Rotor-Side Converters - ABB ACS800 Series Hardware Manual

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Gear box
Rotor
hub
Rotor bearing
Blade

Grid-side and rotor-side converters

The grid-side converter is an IGBT based module equipped with AC or DC fuse and
optional devices. It has an RDCU control unit with IGBT power supply control
program. The grid-side converter is controlled by the rotor-side converter control unit
via a fibre optic link. (The RDCU is fitted with an RDCO DDCS Communication
Option module containing fibre optic terminals.)
The grid-side converter rectifies three phase AC current to direct current for the
intermediate DC link of the converter. The intermediate DC link supplies the rotor-
side converter. The line filter suppresses the AC voltage and current harmonics.
As default, the grid-side converter controls the DC link voltage to the peak value of
the line-to-line voltage. The DC voltage reference can be set also higher by a
parameter (see ACS800 Grid-side Control Program Firmware Manual
[3AUA000075077 (English)]. The control of the IGBT power semiconductors is
based on the Direct Torque Control (DTC) method typically used in motor control of
the converter. Two line currents and DC link voltage are measured and used for the
control.
The rotor-side converter consists of two IGBT based converter modules and
employs the NDCU-33 control unit. The converter is equipped with Doubly-fed
Induction Generator Control Program, which also controls the grid-side converter
module via a fibre optic link.
Hardware description
Brake
Doubly-fed
generator
Pitch drive
Stator contactor
MCB3
MCB3 on/off
control
Wind turbine converter
ABRU
INU ISU LCL
ACBU
Converter control
Wind turbine controller
Line coupling
Main circuit
Medium voltage
breaker
transformer
MCB1
MCB emergency
switch off control
MCB1 on/off
control
MCB2
MCB control
switchgear
MCB