DESIGNAND DEVELOPMENTOF A MARINE CURRENT ENERGY CONVERSION SYSTEM USING HYBRID VERTICAL AXIS TURBINE MD. JAHANGIR ALAM MASTER OF ENGINEERING FACULTY OF ENGINEERING AND APPLIED SCIENCE MEMORIAL UNIVERSITY OF NEWFOUNDLAND (MUN) ST.JOHN S, NL, A1B3X5, CANADA.
Agenda Agenda Ocean Currents Marine Current Energy Conversion System Thesis Objective Prototype Design Flume Tank Test and Test Results Experimental Energy Conversion System Conclusions 1
Ocean/Marine Currents Ocean Currents Horizontal movement of the Ocean water known as Ocean currents. Mainly three types- I. TidalCurrents II. Wind driven Currents III. Gradient (Density)Currents Estimated total power = 5,000 GW Power density may be up to 15kW/m 2 Fig: Labrador Current 2
Tidal Currents Ocean Currents Verticalrise and fall of the water known as Tides Due to the gravitationalattraction of the moon and sun Tidal Cycleof 12.5 Hours Fig: Tides (due to Gravitational Attraction) 3
Gulf Stream +THC or Great Conveyor Belt Ocean Currents 4
North Atlantic current (Near St. John s) Ocean Currents Water Depth (m) 20 45 80 Near Bottom Average Water Flow (m/s) 0.146 0.132 0.112 0.07 Table: Ocean Current Speeds (for different depths) at different areas of St. John s, NL 5
Marine Current Energy Conversion System MCECS Turbine Gearbox Generator Power Electronic Converter Battery Mechanical Conversion Electrical Conversion Figure: Marine Current Energy Conversion System (MCECS) 6
Thesis Objective (As a part of ONSFI Project) Design and Development of a low cut-in speed turbine for SEAformatics pods. System testing in a deep seacondition. Design and Development of Signal Condition circuitsfor the generated power. Maximum Power Point Tracker development for the designed conversion system. 7
Ocean Current Turbines Turbines Types of Turbine: (According to OREG) Fig. I: Vertical Axis Fig. II: Horizontal Axis I. Vertical Axis Turbines II. Horizontal Axis Turbines III. Reciprocating Hydrofoils Fig. III: Reciprocating Hydrofoils 8
Commercial Application Turbines Fig: Vertical axis (Blue Energy) ** High cut-in speed ** Turbine Rotation Fig: Reciprocating Hydrofoil (Engineering Business Ltd.) Fig: Horizontal axis (MCT Ltd.) 9
Vertical Axis Turbines 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) (1) Savonius type I. Egg Beater Type II. H-Type Gorlov, Squirrel cage etc. [ Turbine rotation is irrespective to the direction of fluid flow] i. Egg Beater Type (2) Darrieus type i. H-Type 10
Comparison Turbines Savonius Type: Adv.: High Starting Torque Dis.: Low Tip Speed Ratio (TSR <1), Low Efficiency Darrieus Type: Adv.: HighTSR (>1), HighEfficiency Dis.: Low start-up characteristics TSR (λ) = (Blade Tip Speed/ Water Speed)= (ωr/v) 11
Advantages of a Hybrid Turbine Design Turbines Flexibility to meet specific design criteria Knowledge of conventional rotors Simple in structure Easy to build 12
Prototype Design
Possible Combinations Prototype Design Fig: Type A Fig: Type B 14
Selected Prototype Prototype Design Fig: Hybrid Model (CAD View) Solidity Ratio: ((No. of Blades * Chord Length)/Rotor dia.) Fig: Hybrid Model (Final product) 15
Design Equations & Parameters Prototype Design Mechanical PowerOutput of Hybrid Turbine, 3 P = 0.5 ρ V s Ps + ( A C (A -A )C ) Tip Speed Ratio (TSR), λ = ωr d V (II) d s Pd (I) Airfoil Section Number of Blades Solidity Ratio [3] Rotor diameter (D d ) Rotor Height (H d ) Swept area (A d ) Chord length (C) Savonius Rotor Rotor Height (H s ) Nominal diameter of the paddles (d i ) Diameter of the shaft (a) Rotor diameter (D s ) Overlap ratio (β) Swept area (A s ) Darrieus Rotor 400mm 130mm 20mm 200mm 0.298 0.08m 2 NACA 0015 4 0.40 1m 1m 1m 2 100mm Solidity Ratio: ((No. of Blades * Chord Length)/Rotor dia.) 16
Working Principle (Hydrodynamics) Prototype Design V= Water Speed V ωr d α V R Y 180 0 ө 90 0 0 0 X V R = α = V tan 1 1 + 2λ cos θ + λ 2 sin θ cos θ + λ 270 0 α Counter clock 17
Flume Tank Flume Tank Test 8m wide x 4m deep x 22.25m long Fig: Flume Tank (MI) Fig: Turbine With Frame 18
Test Setup Flume Tank Test Magnetic Particle Brake Load Cell Gear-tooth Submerged Turbine Gear-tooth Sensor Torque Arm Fig: Torque and Speed Measurement Fig: Submerged Turbine Fig: DAQ board and Data Collection Terminal 19
Test results
Savonius Test Results Test Results 2.2 2 1.8 Power output, P (W) 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 Fig: Two-Stage Savonius 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Water Speed,V (m/s) Fig: Power (P) vs. Water Speed (V) 21
H-Darrieus Test Results Test Results 14 12 Power output, P (Watt) 10 8 6 4 2 0 0 0.1 0.2 0.3 0.4 0.5 0.6 Water Speed,V (m/s) Fig: Power (P) vs. Water Speed (V) 22
H-Darrieus Test Results Test Results Power Coefficient (Cp) 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3 3.1 TSR V ( m / s ) Fig: Power Coefficient vs. TSR (λ) for H-Darrieus 0.3 0.4 0.5 0.6 Maximum Cp = 0.1248 @ 0.6m/s, when, TSR = 2.67 Maximum TSR = 3.09 @0.4m/s, when Cp = 0.012 23
Hybrid Test Results (P vs. V) Test Results 22 Power output, P (Watt) 20 18 16 14 12 10 8 6 Hybrid Savonius Darrieus 4 2 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 Water Speed,V (m/s) Fig: Power (P) vs. Water Speed (V) for Hybrid Turbine VIDEO 24
Hybrid Test Results (P vs. ω) Test Results Power (Watt) 22 20 18 16 14 12 10 8 V ( m / s) 0.3 0.4 0.5 0.6 0.7 0.8 6 4 2 0 1.5 2 2.5 3 3.5 4 4.5 Turbine Speed (rad/s) Fig: Power vs. Turbine Speed (ω) for Hybrid Turbine 25
Hybrid Test Results (C P vs. λ) Test Results 0.16 Power Coefficient (Cp) 0.14 0.12 0.1 0.08 0.06 0.04 V ( m / s ) 0.3 0.4 0.5 0.6 0.7 0.8 0.02 0 2.5 2.6 2.7 2.8 2.9 3 3.1 TSR 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 26
Experimental Energy Conversion System
Experimental Energy Conversion System Experimental Conversion System Hybrid Turbine PM Generator DC/DC Converter Battery Charger Battery Dummy Load Rectifier PWM Control Signal Current and Voltage Sensing Microcontroller Power and Voltage Calculation & PWM Duty Cycle Calculation RS232 Communication User Interface LCD Display Fig: Experimental Energy Conversion System (MPPT based) 28
Maximum Power Point Tracker (MPPT) Experimental Conversion System Source P IN Switch Mode Power Supply MPPT Algorithm P OUT Load P 0 1 4 MPP 2 0 3 MPPT Control Fig. Basic MPPT control blocks Case dp v Fig. MPPT Actions (Graphical View of P & O) dv Action 0 1 <0 <0 + 2 0 <0 >0-3 0 >0 <0-0 4 >0 >0 + Fig. MPPT Actions 29
MPPT Algorithm (Perturbation & Observation) Experimental Conversion System Fig: MPPT Flow Chart 30
Detailed Circuit Diagram Experimental Conversion System 31
Main features Experimental Conversion System Low cost microcontroller based Lesscomplexity Easily extendable Minimizethe size due to less components 32
Laboratory Setup Experimental Conversion System DC Supply Current Sensor Boost Converter LOAD Dummy Load Microcontroller with RS232 and LCD Display Battery 12 V 33
Test Result (Boost Converter) Experimental Conversion System 222 µh MUR815 Diode 1300 µf IRL 520 MOSFET (Logic level) Fig: Boost Converter Output Voltage, Vout (V) 30 27 24 21 18 15 12 9 6 3 Theoretical Experimental 0 0 1 2 3 4 5 6 7 8 9 10 Input Voltage, Vin (V) Fig: V out vs. V in 34
Test Result (MPPT) Experimental Conversion System PWM Signal V out Fig: Oscilloscope shots of PWM Signal and V out V V = in out & (1-D) I = I ( 1-D) out in ** 5 Volt/Div 35
Conclusions
Thesis Contribution Conclusions A simple, lowcut-in speed, hightsr, lifttype hybrid turbine has been designed. Designed turbine has been built, tested andanalyzed in a real world situation. A low costmicrocontroller based experimental energy conversion system has been built and tested. A MPPT control algorithmhas been tested for the design conversion system. 37
Future Work and Suggestions Conclusions Morewater 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 PMGcan be used to avoid gearbox and rectifier losses. More sophisticated MPPT algorithmand digital filteringcan be introduced in the control system. 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
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