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OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
OPTIMIZING ENERGY  PRODUCTION WITH A LOW/INTERMITTENT WIND  RESOURCE
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OPTIMIZING ENERGY PRODUCTION WITH A LOW/INTERMITTENT WIND RESOURCE

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Design of power electronics for a small (100 watt peak) wind turbine

Design of power electronics for a small (100 watt peak) wind turbine

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  • 1. DESIGN AND DEVELOPMENT OF MAXIMUM POWER POINT TRACKING [MPPT]/LOAD CONTROL ELECTRONICS FOR A SMALL (40 WATTS@ 15 MPH) WIND TURBINE-OPTIMIZING ENERGYPRODUCTION WITH A LOW/INTERMITTENT WIND RESOURCE A SENIOR PROJECT SUBMITTED TO THE DEPARTMENT OF ELECTRONICS ENGINEERING TECHNOLOGYOF THE SCHOOL OF ENGINEERING, TECHNOLOGY, AND MANAGEMENT AT THE OREGON INSTITUTE OF TECHNOLOGY IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF BACHELOR OF SCIENCE IN RENEWABLE ENERGY ENGINEERING David Parker © JUN 2009
  • 2. ABSTRACTIn order to extract the most energy from renewable energy sources attention must befocused on the efficiency of the power conversion of this energy. Up until recently,only solar photovoltaic systems have had significant design efforts in insuring thatthe maximum power at any given moment is extracted and converted to electricalenergy. The principal is called maximum power point tracking [MPPT]. I propose to build a small vertical axis wind turbine based on a design by EdLenz and direct couple this to a Axial Flux Permanent Magnet [AFPM] generator.The output of the 3-phase AFPM generator will feed power/control electronics thatwill rectify and filter the AC output, perform DC-DC conversion to insure properoutput voltage (14 volts here), perform MPPT to insure maximum power output, andshutdown the turbine in case of a high wind/over-speed condition. 3
  • 3. ACKNOWLEDGEMENTSFirst, I would like to acknowledge the VAWT design of Ed Lenz(windstuffnow.com). My turbine is based on his design. I want to thank Kevin andAndrea Noonan at FLN-MAR Rubber & Plastics, Inc. for the fabrication of theplastic wing ribs and stringers. Many thanks go to Al Stucky, Matt Stucky, KennyAro, and many others at Mass Precision, Inc. MASS Precision fabricated the rotoraxle, rotor struts, pole mount adapter, and pre-shaped the aluminum skin for thewings of the turbine. Both the above named companies donated (free of charge) thelabor involved in fabricating these parts. Thanks also go to Steve Drake for hisvaluable help in riveting the wings and the overall assembly and balancing of theturbine. Finally, I want to thank W Stephen Woodward for his design idea (Solar-array controller needs no multiplier to maximize power) published in the Decemberissue of EDN. The MPPT circuit is based on this design idea. 4
  • 4. TABLE OF CONTENTSINTRODUCTION.................................................................................................................................6BACKGROUND ON WIND TURBINES/POWER GENERATION...........................................7 . THE WIND TURBINE..........................................................................................................................8 . THE ALTERNATOR/GENERATOR ....................................................................................................10 . COMBINED CHARACTERISTICS OF THE W IND TURBINE & GENERATOR ......................................11 . MAXIMUM POWER POINT TRACKING ............................................................................................12DETAILED PROJECT DESCRIPTION ........................................................................................13 . MECHANICAL DESIGN/CONSTRUCTION .........................................................................................13 . ELECTRICAL DESIGN/CONSTRUCTION ...........................................................................................17 . .The Rectifier .............................................................................................................................17 . .The Overspeed/Overvoltage shutdown circuit .......................................................................18 . .The DC-DC Converter.............................................................................................................18 . .The Maximum Power Point Tracking circuit .........................................................................19 . .Circuit Construction ................................................................................................................20TESTING METHODOLOGY AND RESULTS ............................................................................22 . RESULTS SUMMARY ........................................................................................................................22 . DISCUSSION .....................................................................................................................................22CONCLUSIONS .................................................................................................................................25PROJECT TIMELINE ......................................................................................................................26APPENDIX A: AFPM GENERATOR SPECIFICATIONS........................................................28APPENDIX B: DESIGN CALCULATIONS..................................................................................34APPENDIX C: MECHANICAL DRAWINGS ..............................................................................43APPENDIX D: ELECTRICAL SCHEMATICS ...........................................................................52APPENDIX E: PCB LAYOUT .........................................................................................................55APPENDIX F: PCB BOM .................................................................................................................56APPENDIX G: SIMULATION.........................................................................................................60APPENDIX H: TURBINE PHOTOS ..............................................................................................61BIBLIOGRAPHY ...............................................................................................................................64 5
  • 5. IntroductionAt present, small wind turbines used for RV use or remote 12V power typicallydo not have Maximum Power Point (MPPT) electronics. They may have a 12volt charge controller to insure that the battery does not get over-charged, butlittle control beyond that. My goal is to develop a smart DC-DC converter/windturbine controller that: 1. Rectifies the 3-phase AC output of the generator. 2. Shutdowns the turbine in case of high wind/overspeed conditions. 3. Performs DC-DC conversion to insure proper voltage output regardless of rectified turbine input voltage. 4. Performs Maximum Power Point Tracking (MPPT) to insure optimum power output.I propose to do this by building a small, 2 1/2 ft by 3 1/3 ft Vertical Axis WindTurbine based on Ed Lenz’s design that appeared in the July 2007 issue ofPopular Science. This turbine has a published efficiency of 41%. Using analternator with an efficiency of ~ 80% should yield an output of ~ 40 watts @ 15mph.I will locate an off-the-shelf Axial Flux Permanent Magnet generator (AFPM) forthis turbine. Linear Tech has a part (LTC3780) that can be used in a buck/boostDC-DC converter. They advertise efficiencies of 95-98% with input voltages of6-30VDC. I will control the output power of this regulator by adjusting theoutput voltage to the battery using an analog Maximum Power Point Trackingcircuit that consumes less than 2 or 3 milliwatts of power. I plan on using lowvoltage drop Schottky type diodes (SBR diodes from Diodes, Inc.) in the passiverectifier on the output of the alternator. These diodes have ½ the typical voltagedrop (and ¼ the power loss) of a typical rectifier. This design will allow the windturbine to have some usable output when other non-regulated DC wind turbinesare not producing any usable voltage.By adding control electronics to the wind turbine, this may allow one to slightlyundersize or oversize the alternator in order to optimize either low wind energyproduction or maximum high wind power.The turbine design specifications are shown in Table 1. 6
  • 6. Table 1: Wind Turbine Design SpecificationsBackground on Wind Turbines/Power generationAlmost all commercial wind turbines are Horizontal Axis Wind Turbines(HAWTs). Their axis of rotation is parallel to the ground (horizontal) and airflows through the blades only once. Another name used is “axial flow” for thistype of wind turbine. The other type of wind turbine is the Vertical Axis WindTurbine (VAWT). VAWTs are also called “cross-flow” because the wind passesthrough the blades twice- once on the upwind side and again on the downwindside.One of the advantages of the VAWT is that there is no need for a yaw control- acontrol needed by HAWTs to insure that the blades are perpendicular to the winddirection. Another advantage is that VAWTs operate at much lower Tip SpeedRatios (TSR) compared to HAWTs. The TSR is the ratio of the tip speed dividedby the undisturbed wind velocity. For HAWTs, this value is typically between 6and 20. The VAWT to be used here (Lenz turbine) has a TSR of 0.8 to 1.2. At 15 7
  • 7. mph wind velocity the fully loaded rpm of this turbine should be ~ 134. At thisrpm, the turbine should generate little audible noise and allow potentially longerlife from the support bearings.Both HAWTs and VAWTs are limited in the amount of power they can extractfrom the wind. This limit is called the Betz limit after Albert Betz showed in1928 that the maximum fraction of the power in the wind that can theoreticallybe extracted is 16/27 (59.3%) [1]. The Betz limit can be briefly explained asfollows: If a wind turbine captured 100% of the wind energy flowing through itsrotor area, the air on the trailing side of the rotor would be still. Therefore, thewind would stop flowing through the wind turbine rotor. If 0% of the energyavailable in the wind is captured the wind would have the same energy on thetrailing side of the rotor as it did on the leading side. This logic shows that youcan capture some of the wind’s energy, but not all of it. How much energy is inthe wind?.The Wind TurbineThe power in the wind is directly related to its kinetic energy. We all know that: 1 KE = mV 2 2where m is the mass in kg and V is the velocity in m/s [2]. We also know that themass of air moving (through a rotor) is the air density times the volume of airflowing per second. This is also equal to the air density x the area x the velocity.Therefore: mair = !air AVWe plug this into the above KE formula and we get: 1 P= ! AV 3 2where P is the power in watts, ρ is the air density in Kg/m3, A is the swept area ofthe turbine rotor in m2, and V is the velocity of the wind in m/s [3]. With a designswept rotor area of 8.33 ft2 (0.774 m2)and a wind velocity of 15 mph (6.7 m/s) thepotential wind power available is 139 watts. With a published wind turbineefficiency (Cp) of .41 , this should yield ~57 watts (mechanical power) availableto the generator [4].For a wind turbine where the pitch of the blades is fixed, such as the Lenz turbine,there is an optimum, constant TSR that will maximize mechanical power output[6][8]. Figure 1 shows a typical turbine efficiency (Cp) versus TSR (λ) curve fora fixed blade turbine with a constant field generator. 8
  • 8. Figure 1: The variation of turbine efficiency with TSR (λ) [8].If our goal is to design a control circuit that optimizes the power output of thewind turbine, then we need a circuit that allows the turbine rotor rpm to changewith wind speed. Figure 2 is a graph of turbine power versus rotor rpm for threedifferent wind speeds. Figure 2: The variation of turbine power with rotor rpm and wind speed [8]. 9
  • 9. It is clear from the above two figures that we need to allow the turbine rotor rpmto vary in order to maximize power output with variable wind speeds. But theabove two figures represent only one zone of operation of a wind turbine. Let’sstep back and take a look at all the zones.The power output of a turbine can be divided into four operational areas or windzones [9]. Please refer to Figure 3. Figure 3: Turbine power versus wind velocity [9].The zones in Figure 3 for this turbine can be defined as:Zone I -Turbine rotor does not turn (not enough wind)Zone II-Turbine works @ optimum TSR for best power/efficiency (45-180rpm or5-20 mph)Zone III-Turbine power limited by maximum generator power (180-240 rpm or20-27 mph)Zone IV-Turbine rotor is stopped/slowed down to avoid damage due to highwinds (>240 rpm or >27mph)The reader can deduce that Figures 1 and 2 refer to zone II above. This area ofoperation clearly needs some type of active control in order to maximize poweroutput. However, the turbine/generator combination may further complicate thepower output characteristic in this zone. Let’s explore this characteristic in thenext sections..The Alternator/GeneratorThe alternator I chose is a Axial Flux Permanent Magnet generator (AFPM) madeby SEO YOUNG TECH. CO., LTD (see Appendix A). This unit is a three phase, 10
  • 10. 20 pole generator with a wye connected output. The no load rectified outputvoltage versus rpm is given in Figure 4 below. Figure 4: AFPM generator rectified DC voltage vs. rpm.If we terminate the generator with a load resistance equal to the source resistanceof the generator, this should give us the maximum electrical power output. Doingthis will drop the output voltage to ½ it’s no load value. Let’s look at thecombined output characteristic vs. rpm of the turbine/generator next..Combined Characteristics of the Wind Turbine & GeneratorOne can calculate the power output of the turbine vs. rotor rpm based on what wehave covered so far. Recall that turbine power is proportional to the cube of windspeed. For this turbine, this means that turbine power is proportional to the cubeof the rotor rpm (@ optimum TSR). For the generator, Voltage output isproportional to rpm (See Figure 4). This means that generator power isproportional to the square of the rpm because: E2 P= R 11
  • 11. Figure 5 illustrated the relationship between turbine mechanical power outputand generator mechanical power input. See Appendix B for these designcalculations. This also corresponds to zone II in Figure 3. Figure 5From this Figure one can see that below ~ 150 rpm, the generator requires moremechanical input power than what is available from the turbine. If one were toterminate the generator with its ideal load, this would be too much load for theturbine. In order to address this issue, we need a method of controlling theturbine that will automatically adjust or limit the generator output to match theavailable turbine input power. The general description of the technique to do thisis called Maximum (or sometimes Peak) Power Point Tracking (MPPT) [6] [7] [8][9] [10]..Maximum Power Point TrackingMPPT has wide use in many different applications. Besides optimizing powerversus loading of fixed pitch wind turbines its most popular use is forphotovoltaics. It can also be used for small pelton wheel (impulse) water turbines[6]. 12
  • 12. The most popular technique for implementing MPPT is the “perturb and observe”algorithm. This algorithm periodically “bumps” or perturbs the load voltage, andobserves the change in power of the source-the turbine/generator in this case- andcalculates the phase relationship between load power and generator power asfeedback to “climb the hill” of the current vs. voltage curve to the optimum powerpoint. A typical torque vs. rpm curve for a fixed pitch wind turbine is shown inFigure 6 [6]. Figure 6: Torque vs. rpm with dither for MPPT [6].The circuit I chose to implement was found in a “Design Idea” article in EDN byW Stephen Woodward [7]. The only change I made to this circuit was to changethe dither rate from 100 Hz to 10 Hz to allow for the slower inertial time constantof the generator.Detailed Project Description.Mechanical Design/ConstructionIn Ed Lenz’s turbine, the wing ribs were made of ¾ inch plywood while the rotoraxle was made of iron. Iron straps that were welded to the axle supported thewings. The AFPM generator was a homemade unit that was integral to the rotor. 13
  • 13. The turbine was supported by two pillow block bearings. Plans for this turbinecan be found at windstuffnow.com. Please see Figure 7 below.For my turbine, I decided to use an off-the-shelf AFPM generator made by SEOYOUNG TECH. CO., LTD (see Appendix A). Because the bearings are integralto the design of the generator I did not have to be concerned with an upperbearing on the turbine rotor. However, this made balancing the turbine moredifficult because the 40-inch long axle would amplify any error in the rotor axleface. Please refer to Figure 8 below. I used 5052 alloy aluminum for the rotor axle and wing struts. I chose marinegrade plastic for the wing ribs and stringers. The wing covering specified in theoriginal design was .025” aluminum. I used .032” because that is what thefabricator had on hand. Aluminum rivets were used to attach the wing coveringto the plastic ribs. I used VectorWorks (CAD) to design the rotor axle, the twowing struts, and the pole mount adapter. Please see Appendix C for themechanical drawings. Since the generator face had mounting holes for eight M8bolts, I used these eight bolts for mounting the lower wing strut and the rotor axleto the generator. I also used eight M8 bolts (and nuts) to attach the top wing strutto the top of the rotor axle. The wing struts are used to support the three wings.Each wing is attached to the struts with six M6 bolts and nuts. All nuts and boltsare stainless steel. The expected life of the turbine rotor assembly is at least 20years.The original Lenz turbine had a rotor diameter of 3 ft and a rotor height of 4 ft.Because the generator a chose was rated @ 140 rpm (see Appendix A), I scaleddown the rotor diameter slightly in order to increase the nominal turbine rpm in a15 mph wind from 122 rpm to ~135 rpm. With a design TSR of 0.8, the optimumrotor diameter is 30 inches. With a rotor height of 40 inches, the mechanicalpower output of the turbine –based on a Cp of 0.41- should be 57 watts (seeFigure 10). The wings were also scaled down per the scaling recommendationsby Ed Lenz at windstuffnow.com. The final turbine rotor size is 30 inches indiameter by 40 inches in height. 14
  • 14. Figure 7:Lenz Turbine Figure 8: Design Turbine 15
  • 15. Figure 9: Overall block diagram of turbineFigure 10: Overall turbine efficiency 16
  • 16. .Electrical Design/ConstructionThere are four functions implemented in the electronics. These functions are: 1. Rectification 2. Overspeed/Overvoltage shutdown 3. DC to DC Conversion 4. Maximum Power Point TrackingThese functions are shown in Figure 9. Please note that three of the four circuitfunctions were simulated in LTSpice (The MPPT circuit was not simulated).Before looking at these we need to look at the expected efficiency of thecomponents that make up the turbine. Referring to Figure 10 and recalling ourprevious analysis of the total power in the wind we know that with this turbinerotor size, there is 139 watts available in a 15 mph wind. Based on Ed Lenz’spublished efficiency of the turbine (Cp of 0.41) we have 57 watts of mechanicalpower from the turbine rotor. If we assume that the generator has an efficiency of80%, then we have 45 watts going to the rectifier. Using Super Barrier Rectifier(SBR) diodes should provide us with an efficiency of 95%. The Linear TechLTC3780 DC-DC Converter has a nominal conversion efficiency of 95%. Thisgives us 41 watts of power to the load.Let’s examine the four functions of the electronics and their implementation. Asimplified schematic showing only the rectifier and the DC-DC converter isshown in Figure 11. The brake switch simply shorts out the generator, causingthe turbine rotor to slow down or stop. This switch is used when performingmaintenance or in high wind conditions to shutdown the turbine. Figure 11: Simplified electronics schematic..The RectifierThe purpose of the rectifier is to convert or rectify the three phase AC output ofthe generator to DC. Please refer to schematic 1 in Appendix D. I implemented a 17
  • 17. three phase, two way, six-pulse topology using 6 SBR2060CT low forwardvoltage drop diodes. The typical voltage drop of these diodes at nominal outputpower (~40 watts @ 15mph) is less than 0.4 VDC. For higher efficiencies, anactive rectifier topology could be used, i.e., Hall-Effect or opto-isolator sensorsmounted on the generator shaft that switch Power MOSFETs or IGBJTs at thezero crossing of each phase’s output...The Overspeed/Overvoltage shutdown circuitThe overspeed/overvoltage shutdown circuit can be seen on schematic 1 inAppendix D. The key simulation parameters for this circuit are shown inAppendix E. The main circuit elements are linear regulator U1, dual op-amp U2,555 timer U3, and power MOSFET switch Q1. Conn2 is used to connect to a 0.5ohm, 300-watt diversion load resistor (not shown). U1 uses +Vout (which isconnected to a 12V 18ah lead acid battery) to supply a regulated 5.9VDC to thecircuit. U2a is a comparator that senses the rectifier output voltage. When therectifier output voltage exceeds 24 VDC, Zener diode D7 begins to conduct.When rectifier output voltage exceeds 32 VDC,U2a will see 6VDC on pin 2 , itsoutput goes low, triggering timer U3. Timer U3 output goes high and switch Q1conducts. This puts the 0.5-ohm, 300-watt resistor across the rectifier output.This causes high currents in the generator, slowing down the turbine, andlowering rectifier output voltage to a few volts or so. Also, when Timer U3’soutput goes high, this causes U2b output to go low (RUN3780), shutting downthe LTC3780 DC-DC converter (see schematic 2).The timer output resets after about 1 minute. Please note that comparator U2a has4V of hysteresis, which should prevent false triggering. In simulation, switch Q1never sees more than about 14A or so because of the internal resistance of thegenerator. And that current drops very quickly. Nevertheless, I sized thediversion load resistor to handle up to 2 kW for 2-3 seconds. Please note that thepeak current rating for Q1 is 150A and the peak current rating of each of therectifiers (D1-D6) is 80A. So we have plenty of design margin here. Resistor R1is a current sense resistor that is used in the MPPT circuit...The DC-DC ConverterPlease refer to schematic 2 in Appendix D. A simplified schematic is shown inFigure 12 below. The DC-DC Converter uses Linear Tech’s LTC3780 chip. Thiscircuit is unique in that it allows the use of a single inductor while allowing Vin tobe below, above , or equal to Vout. It also boasts typical conversion efficienciesof 95%. However, you do pay for these benefits with increased circuitcomplexity. The circuit uses 4 MOSFET output switches and 4 Schottky diode 18
  • 18. rectifiers. This circuit allows the rectifier output to vary between 5VDC and 30VDC while supplying a constant 14.2 VDC output to the battery/load. Pleaserefer to Linear Technology’s application notes for more information on circuitoperation. Design calculations for this application are found in Appendix B.Please note that the circuit is designed for 200kHz operation and output increasedto 14V @ 8 amps. Figure 12: Simplified DC-DC converter circuit..The Maximum Power Point Tracking circuitAfter significant research on peak power tracking circuits implemented withmicro-controllers ([8] [10]), I decided to try a technique where no programmingwas required. Dr. W Stephen Woodward has published two techniques that donot use a micro-controller [6] [7]. I decided to use the second technique using theLTC3780 DC-DC Converter. The converter in [7], an LTM4607 is in a LGApackage and is beyond my soldering abilities. That is why I chose the 24-pinLTC3780. The unique idea in this circuit is how it calculates the instantaneouschange in power after perturbing the input voltage. It uses the logarithmicbehavior of transistor junctions to calculate the change in power.The basic idea of peak power tracking in this circuit is to match the output powerof the DC-DC converter to the output of the turbine-generator combination. Thepeak power tracking circuit does this by reducing the output voltage set point ofthe converter until power matching occurs. If the tracking circuit allows the 19
  • 19. output voltage to go to the programmed set point (14.2VDC here) of theconverter, then, at that point, peak power tracking is disabled and the maximumallowed output voltage –and maximum power if the loading is appropriate-occurs. This is where the turbine would be operating in zone 3 of Figure 3. For adescription on MPPT circuit operation please refer to [7]. Figure 13 shows theMPPT circuit with the one capacitor changed from 0.01uF to 0.1uF. This slowsthe dither rate from 100 Hz to 10Hz. Although the circuit was designed for asolar-panel input, it should work well with the rectified turbine/generator input. Figure 13: MPPT circuit [7]..Circuit ConstructionThe low frequency rectifier and the Overspeed/overvoltage shutdown circuit wereplaced on one two-layer printed circuit board (PCB) 3 inches wide by 5 incheslong. The high frequency DC-DC converter and the MPPT circuits are placed onone four-layer PCB 4 inches wide by 5 inches long. I believe that by physicallyseparating the high frequency DC-DC converter from the rectifier and theoverspeed/overvoltage shutdown circuit should improve the noise immunity of 20
  • 20. the latter circuits. Photographs of the two PCB’s are shown in Figures 14 and 15.The PCB layout for these boards can be found in Appendix E.There are five common connections between the schematic 1 PCB and theschematic 2 PCB. These are :+Vrect Positive terminal output of the rectifier-Vrect Negative terminal output of the rectifier+Vout Positive terminal output of the DC-DC ConverterGnd Common (ground) of both PCBsRUN3780 To Run pin of LTC3780 converter (enables output)I chose Advanced Circuits (http://www.4pcb.com/) located in Aurora, Coloradofor building these prototype boards. The software they provide for free –PCBARTIST- I found to be a useful tool for schematic capture and PCB layout. TheBill of Material (BOM) for both boards is in Appendix F. Figure 14: Rectifier &/Overspeed/overvoltage shutdown circuit board 21
  • 21. Figure 15: DC-DC Converter & MPPT circuit boardTesting methodology and results.results summary  Recorded a maximum output of 56 watts with sustained wind speeds of >30 mph.  Rectifier circuit functions per design  Overspeed/overvoltage circuit functions per design  DC-DC converter functions per design  Standby circuit current less than 0.25 mAUnable to obtain the Turbine Power vs. Wind speed curve because of a faultysensor (Analog module).MPPT circuit did NOT appear to be functioning..discussionI hoped to provide an actual Power vs. Wind speed curve of the turbine tocompare with the expected performance shown in Figure 5. However, I was 22
  • 22. unable to correct a problem with one of the sensors used to record the outputcurrent to the battery. For my test methodology, I employed a data logger fromOnset Computer Corp., model H22-001. I used three smart sensors that measuredwind speed, temperature & relative humidity, and barometric pressure. Please seeFigure 16. I also purchased a Flexsmart analog module that has 2 input voltagechannels. One channel monitored the output (+Vout) of the DC-DC converter,which supplied charging current to an 18ah 12V lead aid battery. The otherchannel of the analog module was connected to a Hawkeye 970LCA currenttransducer. My intent was to monitor the DC output current and voltage of theelectronics while also monitoring the meteorological data at the site. The turbinewas mounted on a 24-foot tower using a kit purchased from SouthwestWindpower, Inc. It was sited on a south-facing ridge behind the RV park inWilsonville, Oregon. With the right wind conditions, I had hoped to add a 75-100watt load on the battery, which would allow the turbine to output up to 100 watts.My plans also included monitoring the three-phase output power of the generatorand the DC output power from the rectifier. Unfortunately, I simply ran out oftime. Please refer to the Project Timeline at the end of this paper.The current sensor problem involved an analog input module. The secondchannel of the module did not appear to be working. Another module wasordered but was not received before the tower and turbine were taken down.The general rule of thumb about how there will be no wind for two weeksfollowing the installation of a wind turbine did seem to hold. The site recorded amaximum wind speed of 10.22 mph in the 12 days following installation at thesite. During this time, I did observe the turbine spinning very easily in the lowwinds. I observed the DC-DC converter turn-on and saw output power go up to 2or 3 watts. Unfortunately, this would usually slow down/stall the turbine. Thishappened numerous times. This behavior is consistent with the MPPT circuitNOT limiting the output power-the circuit did not appear to be functioning. It ispossible that either of the two CMOS chips used in the circuit was defective. Or Icould have made a layout error when designing the circuit. Clearly, furtherinvestigation will be required to find and correct this issue.Approximately two weeks after installation of the turbine, on June 4th, athunderstorm blew through the area. During the storm, the logger recordedsustained winds of over 30mph. I had connected a Fluke DMM to record the peakcurrent into the battery. It recorded 4.00 amps. I also observed that the turbinewas spinning very rapidly, then would slow down abruptly and remain turningslowly for about one minute. This happened twice during the storm. Thisbehavior is consistent with the tripping of the overspeed/overvoltage circuit. 23
  • 23. On June 6th, water managed to enter the electronic enclosure. I had failed to sealthe screw holes that were used to mount the 300-watt diversion load resistor. Thiswater damaged the Overspeed/overvoltage shutdown circuit- which causedspurious and random turbine shutdowns to occur very frequently from that point. Figure 16: Turbine with wind sensor on guyed tower 24
  • 24. ConclusionsA small vertical axis wind turbine was built based on Ed Lenz’s design. Theturbine itself is very sensitive to low winds. It is so sensitive that it will startrotating BEFORE the anemometer starts turning. The bearings in the generatorare very good, low friction bearings. I remain convinced that the turbine willserve as an excellent test platform for characterization and performance of windturbine control electronics, including peak power tracking.Three of the four circuits did appear to function as designed. In particular, therewere significant challenges in building the Overspeed/overvoltage shutdowncircuit and the DC-DC converter because they employed surface mount devices(SMD). The MPPT circuit did not work. Given the time and opportunity, I hopeto resolve this and obtain power vs. wind curves of the turbine, with and withoutpeak power tracking, in order to better quantify the promised improvement withMPPT. Perhaps I may also explore implementing the MPPT with a micro-controller. The advantage of using a micro-controller is that one can tailor oradjust the MPPT algorithm to the specific application. The disadvantage of thismethod is the extra time needed to learn how to program the controller.There are several lessons I learned from this project. I became more proficientwith several tools including Maple (math software), VectorWorks (CAD), PCBArtist (schematic capture and layout), and LTSpice (circuit simulation). I learnedhow to solder SMD’s. I learned how difficult it can be to layout a DC-DCconverter. Attention must be paid to where the high frequency, high current pathsare in the circuit as well as circuit elements that need to have good noiseimmunity. And I learned how time consuming a project of this magnitude can bewhile going to school full-time. My advice to others would be to limit the scopeof your project as much as possible and to have a partner in your research project.It is my sincere hope that other students and researchers in their pursuit ofharvesting the most energy possible from renewable energy sources will use thispaper as a reference. 25
  • 25. Project TimelineMay 2008Project scope defined. Decided to build a small wind turbine with a focus on theload/control electronicsAugust 2008Purchased generator for turbine. Turbine size now set. Also found twocompanies interested in fabrication of the turbine. The fabricator for the plasticwing ribs and stringers is:FLN-MAR Rubber & Plastics, Inc.102 Cabot Street, Suite 8Holyoke, MA 01040The fabricator of the aluminum rotor axle, wing struts, pole mount adapter, andthe aluminum skin for the wings is:MASS Precision, Inc.2110 Oakland Rd.San Jose, CA 95131November 2008Completed mechanical design of turbine. Turbine parts designed withVectorWorks (CAD) software.December 2008Turbine assembled and balanced. Will turn in the slightest breeze.Started research on MPPT/Control electronics for wind turbines.February 2009 26
  • 26. Decided on design of rectifier, MPPT, & DC-DC converter. Started design ofOverspeed/overvoltage shutdown circuit. Ordered and received components forwind turbine tower.March 2009Completed design of rectifier & overspeed/overvoltage shutdown circuit.April 2009Completed design of DC-DC converter & MPPT circuit. Completed PCB layoutof both boards. Started enclosure design.May 22, 2009Completed and tested PCBs (except for MPPT). Completed enclosure design andassembly. Assembled turbine. Erected tower. Turbine up & flying withmeteorological sensors attached to data logger. Ordered Voltage and currentsensors from Onset Computer. No significant wind until June 4th. Still unable tolog output power of turbine- can record manually only.June 4, 2009Thunderstorm generates sustained winds of > 30 mph. Recorded peak poweroutput to battery of 56 watts. No load on battery at this time. Turbine didshutdown on overspeed condition twice during storm.June 6, 2009Shutdown circuit is triggered spontaneously and randomly without reason. Notedthat water entered the enclosure and got both PCBs wet. Theorize that this waterdamaged the high impedance CMOS chips that control the overspeed shutdowncircuit. Verified that rectifier and DC-DC converter circuits still working.June 8, 2009Shutdown turbine, disassembled tower and turbine. 27
  • 27. Appendix A: AFPM generator specifications 28
  • 28. SEO YOUNG TECH. CO., LTD. Renewable Energy DevicesModel-SYG-A208-100-140 AFPMG For VAWT and HAWT ! ! ! ! ! No. Parameter Symbol units ! 1 Rectified DC Voltage E V 12 2 Gen. Output Voltage ! ! AC (3Phase) 3 Rotor ! ! Permanent magnet type (outer rotor) 4 Stator ! ! Coreless type 5 Rectifier loss ! ! Included 6 Output Power Po W 96 (14V@112W) 7 Rated speed w rpm 140 8 Speed Constant KE V/krpm 152 9 Resistance (Line-Line) RT ! 1.24 10 Inductance (Line-Line) L mH 18.4 11 Rotor Inertia J Kg-m2 0.038 12 Electrical Time Constant "# ms 14.84 o 13 Maximum Winding Temperature CMax C 130 14 Number of Phase - - 3 15 Number of Pole - - 20 16 Winding type - - Wye 17 Magnet Material - - NdFeB 15 Gen. Weight WM Kg 8.5 16 Gen. Diameter MD mm 245 17 Gen. Length ML mm 56 18 Housing Material - - Aluminum 19 Shaft. Diameter MD mm 30 20 Bearing - - Ball APLICATION – Small Wind Turbine, Hydro Power, etc. ! SEOYOUNG TECH Co., Ltd. #407, Kumi College Venture Business Center, Bugok-dong, Kumi City, Kyungbuk, Korea 730-711 Tel: +82-54-442-4040 Fax: +82-54-442-4060 e-mail: load927@evsmotor.co.kr or load927@hotmail.com www.evsmotor.co.kr
  • 29. SEO YOUNG TECH. CO., LTD. Renewable Energy Devices No-Load 48 44 Rectifier DC Voltage [ V ] 40 36 32 28 24 20 16 12 8 4 0 0 30 60 90 120 150 180 210 240 ! [rpm] ! Load@140rpm 24 21 Rectifier DC Voltage [ V ] 18 15 12 9 6 3 0 0 1 2 3 4 5 6 7 8 9 10 DC Current [ A ] ! !SEOYOUNG TECH Co., Ltd.#407, Kumi College Venture Business Center,Bugok-dong, Kumi City, Kyungbuk, Korea 730-711Tel: +82-54-442-4040 Fax: +82-54-442-4060e-mail: load927@evsmotor.co.kr or load927@hotmail.comwww.evsmotor.co.kr
  • 30. SEO YOUNG TECH. CO., LTD. Renewable Energy Devices ! ! ! ! !SEOYOUNG TECH Co., Ltd.#407, Kumi College Venture Business Center,Bugok-dong, Kumi City, Kyungbuk, Korea 730-711Tel: +82-54-442-4040 Fax: +82-54-442-4060e-mail: load927@evsmotor.co.kr or load927@hotmail.comwww.evsmotor.co.kr
  • 31. SEO YOUNG TECH. CO., LTD. Renewable Energy Devices ! ! ! ! ! ! ! ! !SEOYOUNG TECH Co., Ltd.#407, Kumi College Venture Business Center,Bugok-dong, Kumi City, Kyungbuk, Korea 730-711Tel: +82-54-442-4040 Fax: +82-54-442-4060e-mail: load927@evsmotor.co.kr or load927@hotmail.comwww.evsmotor.co.kr
  • 32. SEO YOUNG TECH. CO., LTD. Renewable Energy Devices Outer Face Blade Fixing W ires ! ! !SEOYOUNG TECH Co., Ltd.#407, Kumi College Venture Business Center,Bugok-dong, Kumi City, Kyungbuk, Korea 730-711Tel: +82-54-442-4040 Fax: +82-54-442-4060e-mail: load927@evsmotor.co.kr or load927@hotmail.comwww.evsmotor.co.kr
  • 33. Appendix B: Design Calculations 34
  • 34. David ParkerOct. 9, 2008Revised Feb 10, 2009Senior Project : Vertical Axis Wind TurbineBasic Electrical characterisitics of Generator:@ 140 rpm, 3 phase, Y connection:(Vrms=Vdc/1.3)O restart;O Pgen d Vdc$Idc; Pgen := Vdc Idc (1)Vdc d 14 = 14 Idc d 8 = 8 PF d 0.9 = 0.9O Pgen ; 112 (2) PgenO Iline d ; Vdc $PF$ 3 1.3 Iline := 3.851851852 3 (3)O evalf 5 (3) 6.6719 (4)Basic Electrical characterisitics of Generator:@ 180 rpm, 3 phase, Y connection:O restart;O Pgen d Vdc$Idc; Pgen := Vdc Idc (5)Vdc d 18 = 18 Idc d 6.222 = 6.222 PF d 0.9 = 0.9O Pgen ; 111.996 (6) PgenO Iline d ; Vdc $PF$ 3 1.3 Iline := 2.995777777 3 (7)O evalf 5 (7) 5.1890 (8)Calculation of voltage drop in 25 ft of wire[12AWG] (from generator to Converter):
  • 35. Rperft d 0.00162 = 0.00162 Irms d 5.1890 = 5.1890 L d 25 = 25O Vdrop d L$Irms$Rperft; Vdrop := 0.210154500 (9) VdropO lineloss d ; Vdc 1.3 lineloss := 0.01517782500 (10)O
  • 36. David ParkerSept. 25, 2008Oct. 23, 2008-updated rotor height from 36" to 40" (~1.00m)Dec. 23, 2008-added Turbine solidity calculationSenior Project : Vertical Axis Wind TurbineM atching the Turbine output with the required AFPM generator input powerO restart;Power from the turbine rotor: 1O Pturbine d $! $A $V 3 $C ; 2 air rotor wind p 1 3 Pturbine := ! air Arotor Vwind Cp (1) 2O Arotor d Diameterrotor $Heightrotor ; Arotor := Diameterrotor Heightrotor (2) RPMturbine$Diameterrotor $evalf "O Vwind d ; TSR$60 0.05235987757 RPMturbine Diameterrotor Vwind := (3) TSRO Pturbine; 4 3 0.00007177378865 ! air Diameterrotor Heightrotor RPMturbine Cp (4) TSR 3O! air d 1.21 Heightrotor Diameterrotor TSR d 0.8 = Cp d 0.41 == 1.21 d 1.00 d 0.762 800.00 # 10 - 3 410.00 # 10 - 3 = 1.00 = 762.00 # 10 - 3KChord d 0.309 Nwings d 3 = -3 3.00= 309.00 # 10O PlotPturb d plot Pturbine, RPMturbine = 0 ..180, color = red :M echanical Power required into the AFPM generator:O EoutDC d 0.1$RPMturbine; (5)
  • 37. EoutDC := 0.1 RPMturbine (5) 2 EoutDC 1O Pgen K input d $ ; Rload !gen 2 0.01 RPMturbine Pgen K input := (6) Rload !genRload d 3.50 = 3.50 !gen d 0.8 = 800.00 # 10 - 3O PlotPgen d plot Pgen K input , RPMturbine = 0 ..180, color = green :O plots display PlotPturb, PlotPgen ; Wind Turbine & Generator Power vs RPM 140 120 100 80 P 60 40 20 0 0 20 40 60 80 100 120 140 160 180 RPMturbine Turbine GeneratorTurbine solidity calculation:O Arotor ; 0.76200 (7)
  • 38. Nwings $KChordO Sd ; Diameterrotor S := 1.216535433 (8)O
  • 39. David ParkerSenior Project-Vertical Axis Wind Turbine withM ax. Power Point ElectronicsDC-DC Converter Calculations:Chosen controller: Linear Technology LTC3780 Buck-Boost regulatorDesign input range: 7-30 VDCDesign output: 14 VDCDesign current output: 8 Amps (buck), 3 Amps (boost)Jan. 31, 2009Frequency set @ 200Khz by leaving pins 10 & 11 open.Burst mode is active in boost operation and the skip cycle mode is active in buckoperation by leaving pin 9 open (floating).O restart;Vinmin d 7 Vinmax d 30 Vout d 14 = Ioutbuck d 8 = Ioutboost d 3 == 7.00 = 30.00 14.00 8.00 3.00freq d 200000 = !I d .32 = Cout d 374E-6 = RDSon d .0068 = Crss d 285E-12 L 3 -6 -3200.00 # 10 320.00 # 10 - 3 374.00 # 10 = 6.80 # 10 = 285.00 # 10 - 12 2 Vinmin $ Vout K VinminO Lboost d ; freq$Ioutboost $!IL$Vout 2 9.11 # 10 - 6 (1) Vout$ Vinmax K VoutO Lbuck d ; freq$Ioutbuck$!IL$Vinmax 1.46 # 10 - 5 (2)Inductor value based on worst case (buck)- will choose 15 uHCoilcraft SER2915H-153KL1 $4.55 2$0.160$VinminO Rsenseboost d ; 2$Ioutboost $Vout$!IL$Vinmin Rsenseboost := 0.01190476190 (3) 2$0.130O Rsensebuck d ; 2$Ioutbuck K !IL Rsensebuck := 0.01658163265 (4)Rsense value based on worst case (boost)- will choose 12 milliohm (2 ! 25m" 0.5W) (5)
  • 40. Vout 2$VoutO IinputRMS d Ioutbuck$ $ K1 ; 2$Vout Vout IinputRMS := 4 (5) Ioutboost $ Vout K VinminO CapRippleboost d ; Cout$Vout$freq CapRippleboost := 0.02005347594 (6) Ioutbuck$ Vinmax K VoutO CapRipplebuck d ; Cout$Vinmax $freqCout will be:(1) 330 uF 25V bulk cap(2) 22 uF 25V Ceramic capCin will be:(1) 22 uF 50V Ceramic cap(2) 3.3 uF 50V ceramic cap CapRipplebuck := 0.05704099820 (7)Power M OSFET calculations (Fairchild FDD8453LZ): 2 VoutO PowerMOSAboost d $Ioutboost $1.5$RDSon; Vinmin PowerMOSAboost := 0.36720 (8) Vinmax K Vout 2O PowerMOSBbuck d $Ioutbuck$1.5$RDSon; Vinmax PowerMOSBbuck := 0.3481600000 (9) Vout K Vinmin $Vout Ioutboost $Ioutboost $1.5$RDSon C 1.7$Vout 3 $ 2O PowerMOSCboost d 2 Vinmin Vinmin $Crss $freq; PowerMOSCboost := 0.2975544000 (10) Vinmin Vout 2O PowerMOSDboost d $ $Ioutboost $1.5$RDSon; Vout Vinmin PowerMOSDboost := 0.1836000000 (11)Schottky diodes should be rated @ 3-4 ampsRecommend Diodes, Inc. model B340LAFeedback resistors R1 & R2 (12)
  • 41. R2O Vsetout d 0.8$ 1 C ; R1 0.8 R2 Vsetout := 0.8 C (12) R1O R2 d 100E3; R1 d 6.00E3; R2 := 1.00 105 R1 := 6000. (13)O Vsetout; 14.13333334 (14)Note: R1 will be a 7.2K resistor in parallel with a 36K resistor from the M PPT circuit.CA & CB bootstrap caps CA$VINTVccO qGate d ; 100 1 qGate := C V (15) 100 A INTVccO CA d 0.33EK6 : VINTVcc d 6 :O qGate; 1.980000000 10-8 (16)qGate is the gate charge of the M OSFET.Will use 0.33 uF X5R caps for CA and CB.For soft-start cap (Css) will use .68 uF capStart up time (seconds) will be:O Tirmp d 1.5$.68; Tirmp := 1.020 (17)O
  • 42. Appendix C: Mechanical Drawings 43
  • 43. 1 2 VECTORWORKS EDUCATIONAL VERSION 3A A TitleB B Turbine rotor axle +struts Drawing Number Drawn By Date 9 David Parker 11/16/2008 CAD File Name Turbine rotor axle+struts 1 2 VECTORWORKS EDUCATIONAL VERSION 3
  • 44. 1 2 VECTORWORKS EDUCATIONAL VERSION 3A A MATERIAL: 5052 OR 6061 ALUMINUM 3.175cm 3.81cm +0.2cm 101.6cm 0cm 100.33cm 0.635cm TitleB B Turbine rotor axle Drawing Number Drawn By Date 2 David Parker 11/09/2008 CAD File Name Turbine rotor axle 1 2 VECTORWORKS EDUCATIONAL VERSION 3
  • 45. 1 2 VECTORWORKS EDUCATIONAL VERSION 3 General Notes 1.The mounting holes match the M8 threadedA -0.017cm mounting holes on A 9.8cm-0.035cm the top of the generator. (See 4c +0.04cm generator m 0.8cm 0cm drawings-SYG-A2 08-100-140). TitleB B Turbine rotor axle end flange Drawing Number Drawn By Date 3 David Parker 11/09/2008 CAD File Name Turbine rotor axle3 1 2 VECTORWORKS EDUCATIONAL VERSION 3
  • 46. 1 2 VECTORWORKS EDUCATIONAL VERSION 3 General Notes 1.Tube is centered on center of flange. 0.635cmA A 3.175cm 3.81cm 9.8cm 2.995cm TitleB B Turbine rotor axle (close up) Drawing Number Drawn By Date 5 David Parker 11/09/2008 CAD File Name Turbine rotor axle5 1 2 VECTORWORKS EDUCATIONAL VERSION 3
  • 47. 1 2 VECTORWORKS EDUCATIONAL VERSION 3 General Notes 1.This strut has a thickness of 0.476cm (3/16 inch). One strut 38.1cm±0.05cm 41.91cm mounts on each end of the rotor axle. The 8 mounting holes are 34.29cm 120 degreesA center to center identical (8 mm dia.) and match A the mounting holes on the rotor axle flange for M8 mounting bolts. 43 .18 cm m 8c MATERIAL: 5052 OR 6061 ALUMINUM 3.1 7.62cm Radius TitleB B Turbine rotor wing strut (2 required) Drawing Number Drawn By Date 6 David Parker 11/15/2008 CAD File Name Turbine rotor wing strut 1 2 VECTORWORKS EDUCATIONAL VERSION 3
  • 48. 1 2 VECTORWORKS EDUCATIONAL VERSION 3A A General Notes 1.Three thru-holes 6mm in diameter for M6 bolts. TitleB B Turbine rotor wing strut (2 required) Drawing Number Drawn By Date 7 David Parker 11/15/2008 CAD File Name Turbine rotor wing strut 1 2 VECTORWORKS EDUCATIONAL VERSION 3
  • 49. 1 2 VECTORWORKS EDUCATIONAL VERSION 3 0.635cm 1.27cm 8cm±0.03cmA A 8cm TitleB B Turbine pole mount Drawing Number Drawn By Date 11 David Parker 11/20/2008 CAD File Name Turbine pole mount 1 2 VECTORWORKS EDUCATIONAL VERSION 3
  • 50. 1 2 VECTORWORKS EDUCATIONAL VERSION 3 3.1cm 3.9cm 5cmA 2.4cm A 5cm 5.6cm±0.03cm TitleB B Turbine pole mount3 Drawing Number Drawn By Date 12 David Parker 11/22/2008 CAD File Name Turbine pole mount3 1 2 VECTORWORKS EDUCATIONAL VERSION 3
  • 51. Appendix D: Electrical SchematicsSchematic 1 shows the three phase, two way, six pulse rectifier and the turbineoverspeed circuit.Schematic 2 shows the DC-DC Converter and the Maximum Power PointTracking circuit. 52
  • 52. Appendix E: PCB Layout 55
  • 53. Appendix F: PCB BOM 56
  • 54. Name Component Package Value Manuf Distrib Distrib Part No QtyC1 CAP_1u DSC Arcotronics Mouser 80-R82CC4100JB60J 1C2 CAP_4.7u DSC TDK Mouser 810-FK20Y5V1H475Z 1C3 CAP_ELECT100u DSC Vishay/Sprague Mouser 1C4 CAP_.01u DSC Xicon Mouser 140-PF1H103K 1C5 CAP_ELECT100u DSC Vishay/Sprague Mouser 1C6 CAP_2000p DSC Xicon Mouser 140-PF2A202K 1CONN1 KOBICONN3 USER 1CONN2 KOBICONN2 USER 1D1 SBR2060CT DSC 1D2 SBR2060CT DSC 1D3 SBR2060CT DSC 1D4 SBR2060CT DSC 1D5 SBR2060CT DSC 1D6 SBR2060CT DSC 1D7 1N4749A DSC Vishay Mouser 78-1N4749A 1Q1 FBP5800 NMOS DSC Fairchild Mouser 512-FDP5800 1R1 R1.0W DSC 1R2 R 0.25W 5% MCF 120K 0.500 R 121K 1R3 R 0.25W 5% MCF 33K R 0.500 33K 1R4 R 0.25W 5% MCF 1.0KR 0.500 1.0K 1R5 R 0.25W 5% MCF 1.0KR 0.500 1.0K 1R6 R 0.25W 5% MCF 1.0M 0.500 R 1.0M 1R7 R 0.25W 5% MCF 470K 0.500 R 499K 1R8 R 0.25W 5% MCF 1.0M 0.500 R 1.0M 1R9 R 0.25W 5% MCF 5.1KR 0.500 5.1K 1R10 R 0.25W 5% MCF 100K 0.500 R 100K 1R12 R 0.25W 5% MCF 5.1KR 0.500 5.1K 1R13 R 0.25W 5% MCF 51K R 0.500 51K 1U1 LT3010EMS8E SM 1U2 LMC6062IN DIP8 1U3 ICM7555 DIP8 1
  • 55. Name Component Package Value Manuf Distrib Distrib Part No QtyC1 CAP_0.1u DSC Evox Rifa Mouser 80-MMK5104J50J01TR18 1C2 CAP_1500p DSC AVX Mouser 581-BQ014D0152J 1C3 CAP_WIMA_1u DSC WIMA Mouser 505-MKS21/50/10 1C4 CAP_.01u DSC Xicon Mouser 140-PF1H103K 1C5 CAP_100p DSC WIMA Mouser 505-FKP2100/100/2.5 1C6 CAP_ELECT10u DSC Xicon Mouser 140-ESRL50V10-RC 1C7 CAP_ELECT22u DSC Xicon Mouser 140-ESRL50V22-RC 1C8 CAP_ELECT4.7u DSC Xicon Mouser 140-ESRL50V4.7-RC 1C9 CAP_ELECT330u DSC Xicon Mouser 140-ESRL25V330-RC 1C10 CAP_ELECT47u DSC Vishay Mouser 75-94SC476X0025FBP 1C11 CAP_ELECT47u DSC Vishay Mouser 75-94SC476X0025FBP 1C12 CAP_.33u DSC Xicon Mouser 140-PF1H334K 1C13 CAP_.33u DSC Xicon Mouser 140-PF1H334K 1C14 CAP_0.1u DSC Evox Rifa Mouser 80-MMK5104J50J01TR18 1C15 CAP_.OO1u DSC Nichicon Mouser 647-QYXX1H102JTP3TA 1C16 CAP_.56u DSC AVX Mouser 581-BQ074D0564J 1C17 CAP_100p DSC WIMA Mouser 505-FKP2100/100/2.5 1C18 CAP_100p DSC WIMA Mouser 505-FKP2100/100/2.5 1C19 CAP_.01u DSC Xicon Mouser 140-PF1H103K 1CONN2 KOBICONN2 USER 1D1 1N5819 DSC On Semiconductor Mouser 863-1N5819RLG 1D2 1N5819 DSC On Semiconductor Mouser 863-1N5819RLG 1D3 1N5822 DSC Vishay Mouser 625-1N5822-E3 1D4 1N5822 DSC Vishay Mouser 625-1N5822-E3 1L1 L_15uH DSC 1Q1 2N4401 DSC Fairchild Mouser 512-2N4401BU 1Q2 2N4401 DSC Fairchild Mouser 512-2N4401BU 1QA FDD8453 DSC Fairchild Mouser 512-FDD8453LZ 1QB FDD8453 DSC Fairchild Mouser 512-FDD8453LZ 1QC FDD8453 DSC Fairchild Mouser 512-FDD8453LZ 1QD FDD8453 DSC Fairchild Mouser 512-FDD8453LZ 1R20 R 0.25W 5% MCF 2000.500 R 200 1R21 R 0.25W 5% MCF 470K R 0.500 499K 1R22 R 0.25W 5% MCF 1.0M R 0.500 1.0M 1R23 R 0.25W 5% MCF 1.0M R 0.500 1.0M 1
  • 56. R24 R 0.25W 5% MCF 470K R 0.500 499K 1R25 R 0.25W 5% MCF 470K R 0.500 499K 1R26 R 0.25W 5% MCF 470K R 0.500 499K 1R27 R 0.25W 5% MCF 1.0K R 0.500 1.0K 1R28 R 0.25W 5% MCF 36K0.500 R 36K 1R29 R 0.25W 5% MCF 7.5K R 0.500 7.15K 1R30 R 0.25W 5% MCF 100K R 0.500 100K 1R31 R 0.25W 5% MCF 10 0.500 R 10 1R32 R 0.25W 5% MCF 100K R 0.500 100K 1R33 R1.0W DSC 1R34 R1.0W DSC 1R35 R 0.25W 5% MCF 1000.500 R 100 1R36 R 0.25W 5% MCF 1000.500 R 100 1R37 R 0.25W 5% MCF 100K R 0.500 100K 1U1 LMC6064IN DIP14 1U2 74VHC4053N DIP16 1U3 LTC3780EG SM 1
  • 57. Appendix G: SimulationThe following figure shows a LTspice simulation of the turbineOverspeed/overvoltage circuit: 60
  • 58. Appendix H: Turbine photos Turbine right after initial assembly and balancing Electronics enclosure and base of tower 61
  • 59. Open electronics enclosure with diversion load resistor Disassembled turbine 62
  • 60. Turbine up and flying 63
  • 61. Bibliography[1] Boyle, Godfrey. Renewable Energy Power for a Sustainable Future(2nd Edition).Oxford, United Kingdom: Oxford University Press, 2004.[2] Halliday,David, Robert Resnick, Jearl Walker. Fundamentals ofPhysics (7th Edition). New Jersey: John Wiley & Sons, 2005.[3] Masters, Gilbert M. Renewable and Efficient Electric Power Systems.New Jersey: John Wiley & Sons, 2004.[4] Lenz, Ed. Lenz2 Turbine. 2007. 17 Mar. 2009.http://www.windstuffnow.com/main/lenz2_turbine.htm[5] Nilsson, K.,E. Segergren, M. Leijon. “Simulation of Direct DriveGenerators Designed for Underwater Vertical Axis Turbines”. Division forElectricity and Lightning Research Uppsala University, SwedenFifth European Wave Energy Conference. Cork, Ireland: 17-20 September2003[6] Woodward, W Stephen. “Maximum-Power-Point-Tracking Solar Battery Charger.” Electronic Design. 14 Sep. 1998. 7 Jan.2009.http://electronicdesign.com/Articles/Print.cfm?ArticleID=6262[7] Woodward, W Stephen. “Solar-array controller needsno multiplier to maximize power.” EDN. 5 Dec. 2008. 7 Jan. 2009.http://www.edn.com/contents/images/6619019.pdf[8] Gitano, Horizon, Soib Taib, and Mohammad Khdeir. “Design andTesting of a Low Cost Peak-Power Tracking Controller for a Fixed Blade1.2 kVA Wind Turbine.” Electrical Power Quality and Utilisation, JournalVol. XIV, No. 1, 2008[9] Vergauwe, Jan, André Martinez and Alberto Ribas. “Optimization of aWind Turbine using Permanent Magnet Synchronous Generator (PMSG).”INTERNATIONAL CONFERENCE ON RENEWABLE ENERGIES ANDPOWER QUALITY. 7 April, 2006. 10 Jan. 2009.http://www.icrepq.com/icrepq06/214-vergauwe.pdf 64
  • 62. [10] Charais, John. Maximum Power Solar Converter. 2008. 8 Jan. 2009.http://www.microchip.com/ 65

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