status and inventions in electrical power and thruster...
TRANSCRIPT
Status and Inventions in Electrical Power and Thruster Systems
for Drillships and Semi Submersible Rigs
Alf Kåre Ådnanes Brenda WolakABB Marine ABB Marine
Oslo, Norway Houston, Texas USA
Dynamic Positioning Conference
DPC, Houston – Sep 28-30, 2004
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Introduction
Electric Power System Description
ExperiencesResponse time dynamics of load reduction/blackout prevention
Diesel engine governor and AVR fault tolerance
Special characteristics of electric installations for ships and rigs
Harmonic distortion
Technology EvolutionElectric Power Generation and Distributions
Variable Speed Drives
Electrical Podded Thrusters
Outline
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Deepwater Drilling VesselsMore than 25 deepwater drilling vessels build after 1997
Drillships and Semi Subs
Dynamic PositioningDP2 or DP3, (or “DP2.5”)
Electrical SystemMedium Voltage, 6 or 11kV
2, 4, 6, 8 -split
Variable Speed ThrustersElectrically driven with Current Source or Voltage Source Converters
Mechanical or podded azimuthing thrusters
Drilling DrivesDC (SCR) drives
PWM Single or Multidrive
Regenerative or not
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Electric Power System for Drillship
GG
M
ACAC
M
ACAC
M
ACAC
M
ACAC
GG
ACDC
ACDC DC
M
DC
AC
M
DC
AC
M
DC
AC
M
DC
AC
M
DC
AC
M
DC
AC
M
DC
AC
M
DC
AC
M
DC
AC
M
DC
AC
M
DC
AC
M
DC
AC
GG GG
M
ACAC
M
ACAC
GG
M
ACAC
M
ACAC
GG GG GG
M
ACAC
M
ACAC
M
ACAC
M
ACAC
Drilling packageAC Multidrive
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El. Power System for Semi Submersible
GG
M
ACAC
M
ACAC
M
ACAC
M
ACAC
GG
ACDC
ACDC DC
M
DC
AC
M
DC
AC
M
DC
AC
M
DC
AC
M
DC
AC
M
DC
AC
M
DC
AC
M
DC
AC
M
DC
AC
M
DC
AC
M
DC
AC
M
DC
AC
GG GG
M
ACAC
M
ACAC
GG
M
ACAC
M
ACAC
GG
Drilling packageAC Multidrive
M
ACAC
M
ACAC
M
ACAC
M
ACAC
GG
M
ACAC
M
ACAC
GG
M
ACAC
M
ACAC
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Black-outBlack-out
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Prime Mover - Diesel Engine
0
50
100
150
200
250
300
350
0 % 20 % 40 % 60 % 80 % 100 % 120 %
[%MCR]
[g/k
Wh
]
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Power Management Power Reduction
PavailablePA,1 - PA,N
LoadReduction/Shedding
t
Auto stop
Tstop
PA,start
Tstart
PA,stop
PA,normalAuto start
Power reduction, critical situation
Power reduction, non-critical
PavailablePA,1 - PA,N
LoadReduction/Shedding
t
Auto stop
Tstop
PA,start
Tstart
PA,stop
PA,normalAuto start
Power reduction, critical situation
Power reduction, non-critical
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Black-out Prevention
PMS functions:• Automatic start/
stop of diesel generators
• Calculation of available power on each bus
• Load control• Black-out
prevention and recovery
• Heavy consumer handling
OPERATORWORKSTATION
MAIN CONTROLLER
REMOTE I/OCABINET
REMOTE I/O CABINET
SWITCHBOARD/GENERATOR PANEL
ENGINE SAFETY & CONTROL SYSTEM INTERFACE
- HARDWIREDENGINE CONTROL& SAFETY SYSTEM
DIESEL GENERATOR
COMMUNICATION NETWORK
COMMUNICATIONNETWORKAZIPOD
THRUSTER
FREQUENCY CONVERTER
COMMUNICATION NETWORK
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Black-out Prevention Functions
Thruster and thruster drives: Variable speed FPP thrusters must have a load reduction scheme, either monitoring the network frequency and/or receiving a fast load reduction signal from the power management system, either as a power phase-back signal, maximum power limitation signal.Drilling drives:Similar to the requirements of the thruster drives, with built-in priorities for the individual drilling drives.Power management system:The power management system includes blackout prevention with load reduction/load shedding functionality. Dynamic positioning system:The dynamic positioning system is also equipped with a power limitation function, normally based on a permitted maximum powerconsumption signal from the power management system. Generally, this has shown to be effective in avoiding overloading of the running plant, but not fast enough to handle faults and loss of diesel-generator sets
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VSI Drives FPP load red
PMS blackout prevention
DP power limitation
Fixed speed CPP load red
Time before under-frequency (Illustrative)
100%
10 sec
200% 300%
5 sec
1 sec
0,5 sec
0,1 sec
Loadx MCR
Worst case overload
Risk forBlackout
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Governor or AVR Faults
AVR faults:• Under excitation
• Inductive (kVAr import)
• Under voltage• Min kVAR
• Over excitation• Capacitive
(kVAr) export• Over voltage• Max Amp
• Intermittent faults• Rear• Combinations
of over and under excitation
OPERATORWORKSTATION
MAIN CONTROLLER
REMOTE I/OCABINET
REMOTE I/O CABINET
SWITCHBOARD/GENERATOR PANEL
ENGINE SAFETY & CONTROL SYSTEM INTERFACE
- HARDWIREDENGINE CONTROL& SAFETY SYSTEM
DIESEL GENERATOR
COMMUNICATION NETWORK
COMMUNICATIONNETWORKAZIPOD
THRUSTER
FREQUENCY CONVERTER
COMMUNICATION NETWORK
Under
Over
kVAr
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Governor or AVR Faults
Governor faults:• To low fuel
• kW reduces• RPM may
reduce• To excessive fuel
• kW increases• RPM may
increase• Intermittent faults
• Rear• Combinations
OPERATORWORKSTATION
MAIN CONTROLLER
REMOTE I/OCABINET
REMOTE I/O CABINET
SWITCHBOARD/GENERATOR PANEL
ENGINE SAFETY & CONTROL SYSTEM INTERFACE
- HARDWIREDENGINE CONTROL& SAFETY SYSTEM
DIESEL GENERATOR
COMMUNICATION NETWORK
COMMUNICATIONNETWORKAZIPOD
THRUSTER
FREQUENCY CONVERTER
COMMUNICATION NETWORK
High
Low
kW
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Diesel Generator Monitoring System
Correlationalgorithm
Ui
Qi
Disconnect
Ii
Trig limit and
time delaysettings
DemagnetizeVoting
algorithmU1-U4
Q1-Q4
I1-I4
Excitation Fault
Excitation Alarm
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Electric System CharacteristicsVoltage
Time, µs1 2 3
Switching transient
Normalized impulse
Voltage
Winding turn number
Winding with linear voltage distribution:- Voltage distribution- Voltage gradient
1 2 3 4 . . . . . . . . . . . N
Winding with non-linear voltage distribution- Voltage distribution- Voltage gradient
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Harmonic Distortion
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Harmonic Distortion
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Harmonic Distortion (Examples)
<4%<5%**)<6..7%<5%*)THD Distribution bus
<4%<5%**)6..8%10..13%THD Main bus
24-pulseQ24-pulse12-pulse6-pulseNB: With High Gen Load
*) with harmonic filter**) closed bus tie
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12-pulse Drives
Vdc/2
Phase 1
+
0
_
Phase 2 Phase 3
Vdc/2
M M M M M MR R
MM
Medium Voltage Single Drive forThrusters and Propulsion
Low Voltage Multi Drive forDrilling, Winches, etc.
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Semiconductors
IGBT Module(for low voltage drives)
IGCT Component(for medium voltage drives)
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Drive Technology Map (Indicative)
315
2’000
P (kW)
U (kV)
27’000
5’000
6’000
40’000
30’000
Motor Voltage1.0 2.41.5 4.5 6.03.3
Mot
or P
ower
9’000
10’000
16’000
6.91.8
Cyclo-converters
CSI
690
VSIIGCT
VSIIGBT
VSI: Voltage Source Inverters with PWM or DTC
CSI: Current Source Inverterswith Thyristors
Cyclo: Direct Converterwith Thyristors
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Electric Motor
Ventilation Unit
Bearing
Slipring Unit (Power/Data Transmission)
Air Cooling
Bearing, Shaft Seals
FP Propeller Shaft Line
Installation Block
Hydraulic Steering Unit
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Podded Thruster for Drilling Vessels
FP PropellerShaft seal protection cone
Propeller side bearing shield
Maintenance brake
Thrust bearing shield
Strut
Power & signal cables+ pipes
FP PropellerShaft seal protection cone
Propeller side bearing shield
Maintenance brake
Thrust bearing shield
Strut
Power & signal cables+ pipes
FP PropellerShaft seal protection cone
Propeller side bearing shield
Maintenance brake
Thrust bearing shield
Strut
Power & signal cables+ pipes
Stator
Thrust bearing
Rotor
Propeller side bearing
Shaft sealing
FP PropellerShaft seal protection cone
Propeller side bearing shield
Maintenance brake
Thrust bearing shield
Strut
Power & signal cables+ pipes
FP PropellerShaft seal protection cone
Propeller side bearing shield
Maintenance brake
Thrust bearing shield
Strut
Power & signal cables+ pipes
FP PropellerShaft seal protection cone
Propeller side bearing shield
Maintenance brake
Thrust bearing shield
Strut
Power & signal cables+ pipes
Stator
Thrust bearing
Rotor
Propeller side bearing
Shaft sealing
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Summary
The fleet of deepwater drilling rigs has generally performed well
Design, engineering, constructionCrewEquipment selection
Electric power generation and distributionExperiences
Technology evolutionDesign improvementsComputerizationMV IGBT and IGCT convertersPodded thrusters