Status and Inventions in Electrical Power and Thruster ...dynamic-positioning.com/proceedings/dp2004/design_adnanes_pp.pdf · Status and Inventions in Electrical Power and Thruster

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

Owner

Text Box

Return to session directory

©BA

PIM

T -

2 -

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

©BA

PIM

T -

3 -

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

©BA

PIM

T -

4 -

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

©BA

PIM

T -

5 -

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

©BA

PIM

T -

6 -

Black-outBlack-out

©BA

PIM

T -

7 -

Prime Mover - Diesel Engine

0

50

100

150

200

250

300

350

0 % 20 % 40 % 60 % 80 % 100 % 120 %

[%MCR]

[g/k

Wh

]

©BA

PIM

T -

8 -

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

©BA

PIM

T -

9 -

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


©BA

PIM

T -

10 -

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

©BA

PIM

T -

11 -

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

©BA

PIM

T -

12 -

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




DIESEL GENERATOR



THRUSTER

FREQUENCY CONVERTER


Under

Over

kVAr

©BA

PIM

T -

13 -

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




DIESEL GENERATOR



THRUSTER

FREQUENCY CONVERTER


High

Low

kW

©BA

PIM

T -

14 -

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

©BA

PIM

T -

15 -

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

©BA

PIM

T -

16 -

Harmonic Distortion

©BA

PIM

T -

17 -

Harmonic Distortion

©BA

PIM

T -

18 -

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

©BA

PIM

T -

19 -

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.

©BA

PIM

T -

20 -

Semiconductors

IGBT Module(for low voltage drives)

IGCT Component(for medium voltage drives)

©BA

PIM

T -

21 -

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

©BA

PIM

T -

22 -

Electric Motor

Ventilation Unit

Bearing

Slipring Unit (Power/Data Transmission)

Air Cooling

Bearing, Shaft Seals

FP Propeller Shaft Line

Installation Block

Hydraulic Steering Unit

©BA

PIM

T -

23 -

Podded Thruster for Drilling Vessels

FP PropellerShaft seal protection cone

Propeller side bearing shield

Maintenance brake

Thrust bearing shield

Strut

Power & signal cables+ pipes



Maintenance brake


Strut




Maintenance brake


Strut


Stator

Thrust bearing

Rotor

Propeller side bearing

Shaft sealing



Maintenance brake


Strut




Maintenance brake


Strut




Maintenance brake


Strut


Stator

Thrust bearing

Rotor

Propeller side bearing

Shaft sealing

©BA

PIM

T -

24 -

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

Documents

Status and Inventions in Electrical Power and Thruster ...dynamic-positioning.com/proceedings/dp2004/design_adnanes_pp.pdf · Status and Inventions in Electrical Power and Thruster