“Ship Electric Grids” & “Power Management Systems”

5th and 6th MARINELIVE Workshops

“Ship Electric Grids” & “Power Management Systems”

Exploita*on of sha/ generators for green efficient ship opera*on – Electric Machine selec*on and opera*on on ship's electrical power system

E. Chatzinikolaou, C. Patsios, A. Sarigiannidis and A. Kladas National Technical University of Athens, Faculty of Electrical and Computer Engineering, Laboratory of Electrical Machines and Power Electronics

IntroducFon ShaG generators (SGs): • mounted on the propeller sha/ between main propulsion engine and propeller variable speed • used with Diesel Generators and other non-­‐conven9onal sources for genera9ng power on ships

Benefits:

• Economical power produc9on by u9lizing the ship’s main engines • Small space requirement • Low installa9on cost • Low noise levels • High reliability

Drawbacks: • Unable to run in parallel with diesel generators (PTO/GCR) • No electric power genera9on in the harbor • Increases the load on the main engine of the ship

5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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ShaG Generator Topologies (1) • Power Take Off/Gear Constant RaFo (PTO/GCR) – frequency of the generator propor9onal to the speed of the propulsion engine – constant frequency

controllable pitch induc9on propeller generator

(IG)

• Power Take Off/Renk Constant Frequency (PTO/RCF) – sha/ speed constant, owing to a mul9-­‐level gearbox – wound rotor synchronous generators: the most common machine topology

5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

3

ShaG Generator Topologies (2) • Power Take Off/Constant Frequency Electrical (PTO/CFE) – generator, step-­‐up gear and electrical control equipment

– slow-­‐running generator with electrical control equipment

– Low-­‐speed direct-­‐driven permanent magnet synchronous generators (PMSGs): elimina9on of the gearbox, higher efficiency, no field winding required 5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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Main objecFves of this study

– Replace the exis9ng SG (PTO/GCR topology) of an electric power system of a Ro-­‐Ro ship with a PMSG mounted directly to the sha/ (PTO/CFE) according to findings on previous published paper on 3rd & 4th Marinelive workshops – Propose an innova9ve control system in order to : Ø Ensure constant frequency and voltage under variable engine speed Ø Enable opera9on of the sha/ generator as motor in case of failure of the main engine or running in parallel with it

– Validate opera9on of the proposed system build the complete model of the ship power system and simulated for four different opera9ng modes : Ø Isolated opera9on of diesel generators Ø Parallel opera9on of sha/ generators and diesel generators Ø Isolated opera9on of sha/ generators Ø Emergency opera9on with the sha/ generator running in motor mode

– Examine the benefits of implemen9ng the proposed control scheme compared to the exis9ng configura9on, in terms of fuel savings

5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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Ship power system • • •

4 diesel engines 12.000 kW • 3 diesel generators 2.100 kVA • 2 sha/ generators 2.400 kVA

1 emergency diesel generator 1.125 kVA Frequency 60 Hz, 2 voltage levels (440 V, 230V) Consumers

Active Power (ΚW) 1621

Motor Control Centers (MCCs) Consumers directly 880.3 connected to 440 V Consumers connected via 638.8 transformers (440 or 230 V) Thrusters 2192

5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

Reactive Power (KVAr) 1005

545.79

369.08

1359.04

6

Design & comparison of two Synchronous Generators for SG applicaFons PMSG of PTO/CFE topology and Salient Pole Synchronous Generator (SPSG) of (PTO/ GCR topology) have been designed via Finite Element Method with the same nominal Power (P=2.4MW) According to previously published analysis in 3rd & 4th Marinelive workshops, PMSG has superior electromagneFc characterisFcs (around 20%) in terms of torque ripple, harmonic content of the induced back electromagne9c force, improving the produced power quality Therefore PMSG has been adopted for the SG applica9on

•

•

•

Magnetic flux density distribution under full load operation

5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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ShaG generator control system The proposed control system for the sha/ generators consist of : • The machine side converter control v Ac9ve power control during generator mode v Speed control during motor mode • The grid side converter control v Grid voltage control v Dc link voltage control

5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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Machine  side  converter  control  •  Ac9ve  power  control  (speed  control  in  motor  mode)  performed  by  a  PI  controller  •   Field  oriented  control  :  vď śâ€Ż  Using  a  d-­â€?q  reference  frame,  rota9ng  synchronously  to  the  machine’s    đ?‘š đ?‘› speed  T =− (+L − L 0i i − Â Ďˆ i )  2 e

Set  Â

isd = 0 Â

đ?‘

đ?‘?

sq

đ?‘šđ?‘ đ?‘›đ?‘?

Te =  đ?œ“pm isq  2

sd

sd sq

pm sq

Iđ?‘‘ ∗ = 0  Iđ?‘ž ∗ =

5th  and  6th  MARINELIVE  Workshops  on  “Ship  Electric  Gridsâ€?  and  “Power  Management  Systemsâ€? Â

2 Ă— Te  ms np đ?œ“pm

9 Â

Grid side converter control Control is performed on a d-­‐q reference frame, synchronously rota9ng at grid’s frequency ,by 2 parallel controllers : Ø Control of d components Ø Control of q components v Grid voltage control v DC link voltage control v ReacFve power control v Ιd current control v Iq current control

5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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Parallel operaFon of shaG generators and diesel generators (1) – Simula9on’s dura9on 4 sec – Insert thrusters at 1.5 sec

Power (KW)

Loads

Active power (ΚW)

Motor control centers (MCCs) Consumers directly connected to 440 V Consumers connected via transformers (440 or 230 V Thrusters

1621

Reactive power (KVAr) 1005

880.3

545.79

638.8

369.08

2192

1359.04

Sea service

Maneuvering service

(0-1.5 sec)

(1.5-4 sec)

Diesel generators

1680

18.5%

89%,89%,

Shaft generators

1920

80%, 80%

54.7%,70.6%

5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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Parallel operaFon of shaG generators and diesel generators (2) 800

Voltage drop 10% while inser9ng the thrusters which correspond to 69% of the exis9ng ship’s load.

The voltage returns to 98% of its nominal value at 0.8 sec. The specifica9ons define the limit of voltage drop at 16% of its nominal value for 20 sec.

600

Grid Voltage Vabc (V)

400 200 0 -200 -400 -600 -800

0

1

2 time (sec)

Grid voltage Vabc

FFT analysis -­‐ current

3

4

Total harmonic distor9on of 2.42 % for the voltage and 3.18 % for the current. The specifica9ons define a maximum of 5% for the total harmonic distor9on for both the voltage and current.

FFT analysis -­‐ voltage

5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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Parallel operaFon of shaG generators and diesel generators (3) 5 4 4

3 Active power Diesel generator (̣ W)

Active Power Shaft generator (MW)

2 1 0 -1 -2

3 2 1 0

-3 -1 -4

0

1

2

3

0

1

2

4

3

4

time (sec)

time (sec)

Sha/ generators ac9ve power

Diesel generators ac9ve power

4

5 4

2

Reactive Power Diesel generator (MVAr)

Reactive Power Shaft generator (MVAr)

3

1 0 -1

2 1 0

-2 -3

3

0

1

2

3

time (sec)

Sha/ generators reac9ve power

4

-1

0

1

2

3

4

time (sec)

Diesel generators reac9ve power

5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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Parallel operaFon of shaG generators and diesel generators (4) 1200

DC link voltage (V)

1150 1100

Response 9me 0.2 sec Maximum voltage rise at the start 16%

1050 1000 950 900

0

1

2

3

4

time (sec)

DC link voltage

500

Active Power Shaft generator Power control (KW)

Response 9me 0.2 sec Ac9ve power fluctua9on 160 kW.

Power Power Reference

0 -500 -1000 -1500 -2000 -2500 -3000 -3500

0

1

2

3

4

time (sec)

Ac9ve power control 5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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Improved power factor

• Sea service • Isolated opera9on of diesel generators : PF= 0.85 • Using sha/ generators as synchronous condensers : PF = 0.97 Improved by 14%

5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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Isolated operaFon of shaG generators(1) • • •

Simula9on’s dura9on 4 sec Insert thrusters at 2 sec Increase sha/ speed by 10% at 3 sec Loads

Motor control centers (MCCs) Consumers directly connected to 440 V Consumers connected via transformers (440 or 230 V) Thrusters

Active power Reactive (ΚW) power (KVAr) 587.4 364.188

195.7

121.33

68.9

36.84

275.9

171.058

5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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Isolated operaFon of shaG generators(2) 400

Voltage drop of 2% for 1 sec, during the inser9on of load corresponding to 32% of the systems load.

300

Grid voltage Vabc (V)

200 100 0 -100 -200 -300 -400

0

1

2 time (sec)

Grid voltage Vabc

FFT analysis – voltage

3

4

Total harmonic distor9on of 2.74% for the voltage and 2.46% for the current

FFT analysis – current

5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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Isolated operaFon of shaG generators(3) 2 1.5

Active Power Shaft generators (MW)

1 0.5 0 -0.5 -1 -1.5 -2

0

1

2

3

4

time (sec)

Sha/ generators ac9ve power

Response 9me of the controller 0.9 sec.

1

Reactive Power Shaft generator (MVAr)

0.5

0

-0.5

-1

-1.5

0

1

2 time (sec)

3

4

Sha/ generators reac9ve power 5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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Isolated operaFon of shaG generators(4) 1200

DC link voltage (V)

1150

Response 9me of dc voltage controller 0.2 sec maximum voltage rise at start 14%

1100 1050 1000 950 900

0

1

2

3

4

time (sec)

DC link voltage

Response 9me of ac9ve power controller 0.03 sec, for 10% increase in sha/ speed.

200

0.5

Active Power Active Power Reference

0

x 10

4

Torque Torque Reference

0 Electromagnetic Torque (Nm)

Active Power control shaft generators (KW)

-200 -400 -600 -800 -1000 -1200

-1 -1.5 -2 -2.5

-1400 -1600

-0.5

0

1

2

3

time (sec)

Ac9ve power control

4

-3

0

1

2

3

4

time (sec)

Electromagne9c torque control

5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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Emergency operaFon -­‐ shaG generator running in motor mode(1) Simula9on’s dura9on 10 sec

• •

Change in torque at the sha/ every 1.5 sec

Time (sec) Shaft torque (Nm)

0-1.5

1.5-3

3-4.5

4.5-6

6-7.5

7.5-9

0.1*8 5000

0.5*8 5000

0.75*8 5000

0.9*8 5000

0.25*8 5000

0.5*8 5000

Shaft speed (RPM)

215

8

x 10

215

215

215

215

9-1 0 0

215

Voltage drop less than 1.8% of the nominal value.

215

4

400

7 300 200

5

Grid voltage Vabc (V)

Shaft Torque (̤ m)

6

4 3

100 0 -100

2

-200

1

-300

0

0

1

2

3

4

5

6

7

time (sec)

Sha/ torque

8

9

10

-400

0

1

2

3

4

5

6

7

8

9

10

time (sec)

Grid voltage Vabc

5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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Emergency operaFon -­‐ shaG generator running in motor mode(2) 0.5

5 4.5 4 Active Power Diesel generators (MW)

Active Power Shaft motor (MW)

0 -0.5 -1 -1.5

3.5 3 2.5 2 1.5 1

-2

0.5 -2.5

0

1

2

3

4

5

6

7

8

9

0

10

0

1

2

3

4

time (sec)

Sha/ motor ac9ve power 0.2

7

8

9

10

4 3.5 Reactive Power Diesel generators (MVAr)

-0.2 Reactive Power Shaft motor (MVAr)

6

Diesel generators ac9ve power

4.5

0

-0.4 -0.6 -0.8 -1

3 2.5 2 1.5 1

-1.2 -1.4

5 time (sec)

0.5 0

1

2

3

4

5

6

7

8

time (sec)

Sha/ motor reac9ve power

9

10

0

0

1

2

3

4

5

6

7

8

9

10

time (sec)

Diesel generators reac9ve power

5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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Emergency operaFon -­‐ shaG generator running in motor mode(3) 350

Shaft motor speed (rad/sec)

300 250 200 150 100 Speed Speed Reference

50 0 -50

0

1

2

3

4

5

6

7

8

9

10

time (sec)

Motor speed control 10

x 10

4

Torque Torque Reference

Electromagnetic Torque Shaft motor (Nm)

8

• R e s p o n s e 9 m e o f s p e e d controller 0.04 sec and 23% maximum decelera9on of the motor (at 165 RPM) for 400% rise in sha/ torque.

• R e s p o n s e 9 m e o f s p e e d controller 0.06 sec and 38% maximum accelera9on (at 330 RPM) for 72% reduc9on of sha/ torque.

6 4 2 0 -2 -4

0

1

2

3

4

5

6

7

8

9

10

time (sec)

Electromagne9c torque 5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

Fuel consumpFon calculaFon • Specific fuel oil consump9on (sfoc) calcula9on for the main engine and diesel generator • Typical journey of 7 hours (6 hours sea service, 1 hour maneuvering) • Fuel consump9on calcula9on for the exis9ng configura9on of the examined vessel • Op9miza9on of the exis9ng opera9onal scenario by u9lizing the proposed control system • Calcula9on of fuel consump9on a/er the aforemen9oned op9miza9on

5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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Specific fuel oil consumpFon • • • •

Four main diesel engines (1200 kW) Two sha/ generators (2400 kVA) Three diesel generators (2100 kVA) Calcula9on of the specific fuel oil consump9on using official datasheet

5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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ExisFng operaFonal scenario • Sea opera9on – 1 sha/ generator, 1 diesel generator

SG DG ΜΕ Load % 66.86 73.25 95 .6

Sfoc g/kWh 192.14 173.08

• Maneuvering – 2 sha/ generators, 3 diesel generators

Load % Sfoc g/kWh

SG1

SG2

DG1

DG2

DG3

ΜΕ1

ΜΕ2

4.9

8.3

50

50

51

95.4

95.7

197.23

197.23

196.88

173

173.12

• Total fuel consump9on 3.478.118 gr 5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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Proposed operaFonal scenario • Sea opera9on – 2 sha/ generators Load %

SG1

SG2

ΜΕ1

ME2

71.33

71.33

95.71

95.71

173.12

173.12

Sfoc g/kWh

• Maneuvering – 2 sha/ generators, 1 diesel generator Load % Sfoc g/kWh

SG1

SG2

DG1

ΜΕ1

ΜΕ2

40

40

81.36

98.2

98.2

191.89

174.19

174.19

• Total fuel consump9on 3.375.092 gr 3% reduc9on 5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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Conclusions • Proposing a flexible control system for the sha/ generators in order to achieve: Ø Control of the ac9ve power output Ø Constant dc link voltage Ø Constant grid voltage and frequency Ø Invert power flow : the sha/ generator (8% of the main engine’s power) can provide 50% of the rated speed in emergency opera9on • Improved efficiency of the sha/ generators system from 0.883 to 0.92 • Power factor of the diesel generators improved by 14% , from 0.85 to 0.97 • Reduced fuel consump9on up to 3% according to theore9cal calcula9ons

5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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ACKNOWLEDGMENT THE

WORK PRESENTED IN THIS PAPER HAS BEEN DEVELOPED WITHIN THE

THALES-DEFKALION PROJECT. THIS RESEARCH HAS BEEN COFINANCED BY THE EUROPEAN UNION (EUROPEAN SOCIAL FUND – ESF) AND GREEK NATIONAL FUNDS THROUGH THE OPERATIONAL PROGRAM "EDUCATION AND LIFELONG LEARNING" OF THE NATIONAL STRATEGIC REFERENCE FRAMEWORK (NSRF) - RESEARCH FUNDING PROGRAM: THALES: REINFORCEMENT OF THE INTERDISCIPLINARY AND/OR INTER-INSTITUTIONAL RESEARCH AND INNOVATION.

FRAMEWORK OF THE

Thank you for your anen9on

5th and 6th MARINELIVE Workshops on “Ship Electric Grids” and “Power Management Systems”

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