ABB UNITROL-6000 Excitation systems
UNITROL® 6000 Medium
The customizable solution
UNITROL® 6000 Medium is designed for small to medium static
excitation systems. It is as well a benchmark in flexibility, reliability
and connectivity for brushless and critical steam generating units.
With single/double channel configuration (additional
backup channel on request) and a wide selection
of thyristor bridge modules, UNITROL® 6000
Medium can be configured to meet all field data
and availability requirements.
Selected applications
• Hydro power plant
• Pumped storage power plant
• Combined cycle power plant
• Critical Steam power plant with brushless
excitation, Ifn 200 A, 400 Hz supply
Engineered solutions:
• Online supply transfer
• Electric braking
Main Features UNITROL® 6000 Medium
Customizable Yes
DC current rage <1,800 A
Backup channel Yes / Optional
Converter redundancy Single, twin, twin + backup
Max. converters 3
H configuration No
Converter types D1, D2, D3, D4, D5
PSS 2B/2C
APSS No
PEC controller generation 2
IEC 61850 Optional
Field breaker AC or DC

UNITROL® 6000 X-power
The solution for large power
applications
UNITROL® 6000 X-power is designed for large power generation units
and brings a new benchmark in flexibility, reliability and connectivity.
With single/double channel control configuration
(additional backup controller on request) and
a wide selection of thyristor bridge modules,
UNITROL® 6000 X-power can be configured to meet
all field data and availability requirements.
Selected applications
• Nuclear power plant, field current Ifn >10,000 A
• Underground hydro power plant, Ifn 4,500 A, with
redundant air-to-water heat exchanger system
• Gas turbine power plant, MEGATROL package with
Ifn 6,000 A and static frequency converter 15 MW
for turbine starting
• Coal-fired power plant, Ifn 3,500 A, power part in
IP54 container, detached AVR cabinet with >150 m
distance apart
• Hydro power plant, Ifn 4,000 A, two DC field
circuit breakers, one for DC backup excitation
Main Features UNITROL® 6000 X-power
Customizable Yes
DC current rage 1,800 A < X < 12,000 A
Backup channel Yes / Optional
Converter redundancy Single, twin, n-x
Max. converters 8
H configuration Yes
Converter types D5, UNL13300, UNL14300
PSS 2B/2C/4B
APSS Yes
PEC controller generation 3
IEC 61850 Yes
Field breaker AC (4,000) or DC
Control functions
All regulation, protection, and monitoring functions required for the
secure operation of the generator are included as standard software
features. To meet specific demands of any application, the software can
easily be configured and adapted for the requirements.
Closed-loop control
• Voltage regulator with PID filter (AUTO mode)
• Field current regulator with PI filter (MAN mode)
• Reactive and/or active current droop compensation
• Limiter circuits to ensure that the generator
operates within safe limits:
- Maximum and minimum field current
- Maximum stator current, dependent on machine
cooling media temperature
- P/Q under-excitation
- Volt/Hertz
• Manual restrict to keep the generator within safe
limits, even though controlled in manual mode
• Power factor/reactive load control
• Power system stabilizer
Protection and monitoring functions
• Monitoring and protection functions can be freely
configured on three action levels:
- Alarm signal only
- Changeover to redundant circuits
- Instantaneous excitation trip to protect the
assets
Major available functions
• Overcurrent protection (instantaneous/inverse
time)
• Volt/Hertz protection
• Loss of field protection
• Rotor temperature
• Thyristor conduction monitoring
• Actual value monitoring
Data and event recording
The internal event recorder function can handle
and store up to 2,000 events, each provided
with a real-time stamp. The data recorder contains
a preconfigured part that records a huge set of
measurements and internal signals. It is automatically triggered in case of a fault, to enable efficient troubleshooting and continuous improvement
with the aim to maximize the availability. Additional
free configurable high-speed recorders are
available to be utilized during compliance testing
or analysis of network events.
System time synchronization
The system clock of all the controllers can be
synchronized with a time source by Simple Network
Time Protocol (SNTP) with an accuracy of up to 1 ms
to allow efficient troubleshooting and align
excitation event-logs with other loggers of the
plant and minimize the time to get the unit back
on the grid.
Power system stabilizer (PSS)
The PSS function improves the stability of the
generator and the transmission system by using
the excitation to damp power oscillations.
PSS types optionally available for UNITROL® 6000:
• PSS 2A/2B/2C in accordance with IEEE standard
421.5-2016
• PSS 4B/4C in accordance with IEEE standard
421.5-2016
• Adaptive PSS (APSS) developed by ABB
Switzerland, which optimizes the PSS settings
based on the current network conditions, to
maximize availability and avoid trips due
to insufficient damping in weak networks