“ DESIGN AND DEVELOPMENT OF A

MARINE CURRENT ENERGY CONVERSION SYSTEM USING

HYBRID VERTICAL AXIS TURBINE ”

MD. JAHANGIR ALAMMASTER OF ENGINEERING

FACULTY OF ENGINEERING AND APPLIED SCIENCE

MEMORIAL UNIVERSITY OF NEWFOUNDLAND (MUN)

ST.JOHN’S, NL, A1B3X5, CANADA.

Agenda

� Ocean Currents

� Marine Current Energy Conversion System

� Thesis Objective

� Prototype Design

� Flume Tank Test and Test Results

� Experimental Energy Conversion System

� Conclusions

Agenda

1

Ocean/Marine Currents

Horizontal movement of the Ocean water known as Ocean

currents.

Mainly three types-

I. Tidal Currents

II. Wind driven Currents

III. Gradient (Density) Currents

Estimated total power = 5,000 GW

Power density may be up to 15kW/m2

Fig: Labrador Current

Ocean Currents

2

Tidal Currents

� Vertical rise and fall of the water

known as Tides

� Due to the gravitational attraction

of the moon and sun

� Tidal Cycle of 12.5 Hours

Fig: Tides (due to Gravitational Attraction)

Ocean Currents

3

Gulf Stream +THC or Great Conveyor Belt

Ocean Currents

4

North Atlantic current (Near St. John’s)

0.07Near Bottom

0.11280

0.13245

0.14620

Average Water Flow (m/s)Water Depth (m)

Table: Ocean Current Speeds (for different depths)

at different areas of St. John’s, NL

Ocean Currents

5

Marine Current Energy Conversion System

Electrical Conversion

Figure: Marine Current Energy Conversion System (MCECS)

Turbine Gearbox Generator

Power Electronic

Converter Battery

Mechanical Conversion

6

MCECS

� Design and Development of a low cut-in speed

turbine for SEAformatics pods.

� System testing in a deep sea condition.

� Design and Development of Signal Condition

circuits for the generated power.

� Maximum Power Point Tracker development for

the designed conversion system.

Thesis Objective(As a part of ONSFI Project)

7

Ocean Current Turbines

Types of Turbine:

(According to OREG)

I. Vertical Axis Turbines

II. Horizontal Axis Turbines

III. Reciprocating Hydrofoils

Fig. I: Vertical Axis Fig. II: Horizontal Axis

Fig. III: Reciprocating Hydrofoils

Turbines

8

Commercial Application

Fig: Vertical axis (Blue Energy)

Fig: Horizontal axis (MCT Ltd.)

Fig: Reciprocating Hydrofoil

(Engineering Business Ltd.)

Turbines

** High cut-in speed

9

** Turbine Rotation

Vertical Axis Turbines

Vertical-axis turbines are a type of turbine

where the main rotor shaft runs vertically.

Types:

1. Savonius Type (Drag Type)

2. Darrieus Type (Lift Type)

I. Egg Beater Type

II. H-Type

Gorlov, Squirrel cage etc.

[ Turbine rotation is irrespective to the direction

of fluid flow]

(1) Savonius type

(2) Darrieus type

i. H-Typei. Egg Beater Type

Turbines

10

Comparison

Savonius Type:

Adv.: High Starting Torque

Dis.: Low Tip Speed Ratio (TSR ≈<1), Low Efficiency

Darrieus Type:

Adv.: High TSR (>1), High Efficiency

Dis.: Low start-up characteristics

TSR (λ) = (Blade Tip Speed/ Water Speed)= (ωR/V)

Turbines

11

Advantages of a Hybrid Turbine Design

� Flexibility to meet specific design criteria

� Knowledge of conventional rotors

� Simple in structure

� Easy to build

Turbines

12

Prototype Design

Possible Combinations

Fig: Type A Fig: Type B

14

Prototype Design

Selected Prototype

Fig: Hybrid Model (CAD View) Fig: Hybrid Model (Final product)

Prototype Design

15Solidity Ratio: ((No. of Blades * Chord Length)/Rotor dia.)

Design Equations & Parameters

( )dPsdPss

3)CA-A(CAVρ0.5P +×××=

Mechanical Power Output

of Hybrid Turbine,

V

ωRd=λ

Tip Speed Ratio (TSR),

(I)

(II)

Prototype Design

NACA 0015

4

0.40

1m

1m

1m2

100mm

Airfoil Section

Number of Blades

Solidity Ratio [3]

Rotor diameter (Dd)

Rotor Height (Hd)

Swept area (Ad)

Chord length (C)

Darrieus Rotor

400mm

130mm

20mm

200mm

0.298

0.08m2

Rotor Height (Hs)

Nominal diameter of the

paddles (di)

Diameter of the shaft (a)

Rotor diameter (Ds)

Overlap ratio (β)

Swept area (As)

Savonius Rotor

Solidity Ratio: ((No. of Blades * Chord Length)/Rotor dia.)16

Working Principle (Hydrodynamics)

Counter clock

VRα

ωRd

V= Water Speed

X

Y

900

00

2700

1800

α

ө

V

2cos21V

RV λθλ ++=

+= −

λθ

θα

cos

sintan 1

17

Prototype Design

Flume Tank

Fig: Flume Tank (MI)

8m wide x 4m deep x 22.25m long

Flume Tank Test

18Fig: Turbine With Frame

Test Setup

Flume Tank Test

19

Gear-tooth

Sensor

Gear-tooth

Load CellMagnetic Particle

Brake

Torque Arm

Submerged

Turbine

Fig: Submerged Turbine

Fig: Torque and Speed Measurement

Fig: DAQ board and Data Collection Terminal

Test results

Savonius Test Results

Fig: Two-Stage Savonius

Test Results

21

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

2.2

Water Speed,V (m/s)

Po

wer

ou

tpu

t, P

(W

)

Fig: Power (P) vs. Water Speed (V)

H-Darrieus Test Results

0 0.1 0.2 0.3 0.4 0.5 0.60

2

4

6

8

10

12

14

Water Speed,V (m/s)

Po

wer

ou

tpu

t, P

(W

att

)

Fig: Power (P) vs. Water Speed (V)

Test Results

22

2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3 3.10

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.1

0.11

0.12

0.13

0.14

TSR

Po

wer

Co

eff

icie

nt

(Cp

)

0.3

0.4

0.5

0.6

V ( m / s )

H-Darrieus Test Results

Fig: Power Coefficient vs. TSR (λ) for H-Darrieus

Maximum Cp = 0.1248 @ 0.6m/s, when, TSR = 2.67

Maximum TSR = 3.09 @0.4m/s, when Cp = 0.012

Test Results

23

Hybrid Test Results (P vs. V)

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.80

2

4

6

8

10

12

14

16

18

20

22

Water Speed,V (m/s)

Po

wer

ou

tpu

t, P

(W

att

)

Hybrid

Savonius

Darrieus

Fig: Power (P) vs. Water Speed (V) for Hybrid Turbine

Test Results

24

VIDEO

Hybrid Test Results (P vs. ω)

1.5 2 2.5 3 3.5 4 4.50

2

4

6

8

10

12

14

16

18

20

22

Turbine Speed (rad/s)

Po

wer

(W

att

)

0.3

0.4

0.5

0.6

0.7

0.8

V ( m / s)

Fig: Power vs. Turbine Speed (ω) for Hybrid Turbine

Test Results

25

Hybrid Test Results (CP vs. λ)

2.5 2.6 2.7 2.8 2.9 3 3.10

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

TSR

Po

wer

Co

eff

icie

nt

(Cp

)

0.3

0.4

0.5

0.6

0.7

0.8

V ( m / s )

Fig: Power Coefficient vs. TSR (λ) for Hybrid Turbine

Maximum Cp = 0.1484 @ 0.6m/s, when, TSR = 2.6794

Maximum TSR = 3.1114 @0.5m/s, when Cp = 0.0539

Test Results

26

Experimental Energy Conversion System

Experimental Energy Conversion System

Experimental Conversion System

28

Fig: Experimental Energy Conversion System (MPPT based)

Dummy

Load

Hybrid

Turbine

PM

Generator

Rectifier

DC/DC

Converter BatteryBattery

Charger

User Interface

RS232 Communication

MicrocontrollerPower and Voltage

Calculation & PWM Duty

Cycle Calculation

Current and Voltage

SensingPWM

Control

Signal

LCD Display

Maximum Power Point Tracker (MPPT)

v

PMPP

1

24

0

3

0

+>0>00→4

-<0>03→0

->0<02→0

+<0<00→1

ActiondvdPCase

Experimental Conversion System

MPPT Control

SourceSwitch Mode

Power Supply

MPPT

Algorithm

LoadPIN POUT

Fig. Basic MPPT control blocks

Fig. MPPT Actions (Graphical View of P & O)

Fig. MPPT Actions

29

MPPT Algorithm (Perturbation & Observation)

Experimental Conversion System

Fig: MPPT Flow Chart

30

Experimental Conversion System

Detailed Circuit Diagram

31

� Low cost microcontroller based

� Less complexity

� Easily extendable

� Minimize the size due to less components

Main features

32

Experimental Conversion System

Boost Converter

Microcontroller with

RS232 and LCD Display

Current

Sensor

LOAD

Dummy

Load

Battery 12 V

DC Supply

Laboratory Setup

Experimental Conversion System

33

Test Result (Boost Converter)

Experimental Conversion System

0 1 2 3 4 5 6 7 8 9 100

3

6

9

12

15

18

21

24

27

30

Input Voltage, Vin (V)

Ou

tpu

t V

olt

ag

e,

Vo

ut

(V)

Theoretical

Experimental

Fig: Vout vs. Vin

222 µH MUR815

Diode

IRL 520

MOSFET (Logic level)1300 µF

Fig: Boost Converter

34

Test Result (MPPT)

Experimental Conversion System

** 5 Volt/Div

Vout

PWM Signal

Fig: Oscilloscope shots of PWM Signal and Vout

D)-(1

V V in

out= )( D-1II

inout=&

35

Conclusions

Conclusions

Thesis Contribution

� A simple, low cut-in speed, high TSR, lift type hybrid turbine

has been designed.

� Designed turbine has been built, tested and analyzed in a

real world situation.

� A low cost microcontroller based experimental energy

conversion system has been built and tested.

� A MPPT control algorithm has been tested for the design

conversion system.

37

Future Work and Suggestions

� More water speed data should be collected at other areas of St.John’s.

� A CFD (Computational Fluid Dynamics) analysis should be done before

the actual design and test.

� To get a higher torque at a comparatively low TSR, cambered airfoil (for

example, NACA 4415) can be used.

� A low speed DC PMG can be used to avoid gearbox and rectifier losses.

� More sophisticated MPPT algorithm and digital filtering can be

introduced in the control system.

Conclusions

38

Acknowledgements

Supervisor:

Dr. M. Tariq Iqbal

SEAformatics Group:

Dr. Vlastimil Masek

Dr. Michael Hinchey

Andrew Cook

Paul Bishop

Brian Pretty

Nahidul Islam Khan

Sanjida Moury

39

Publications

� “Design and Development of Hybrid Vertical Axis Turbine”

presented at 22nd CCECE’09, St.John’s, NL, Canada, 03-06

May, 2009, pp.1178-1183.

� “A Low Cut-in Speed Marine Current Turbine” submitted to

Journal of Ocean Technology, 2009.

40

T h a n k s