P14421: Smart PV Panel Bobby Jones: Team Leader Sean Kitko Alicia Oswald Danielle Howe Chris...
-
Upload
tyrell-laflin -
Category
Documents
-
view
216 -
download
1
Transcript of P14421: Smart PV Panel Bobby Jones: Team Leader Sean Kitko Alicia Oswald Danielle Howe Chris...
P14421: Smart PV PanelBobby Jones: Team LeaderSean KitkoAlicia OswaldDanielle HoweChris Torbitt
AGENDA
•Background•Heat Analysis•Power Electronics•Controller•Sensors•Ink Research•BOM•Schedule
BACKGROUND
•Advance Power Systems▫Jasper Ball▫Atlanta, GA
•Snow reduces power output of PV panels•Develop method to prevent snow from
accumulating in the first place▫Apply current to conductive, heating ink▫Keep temperature of panel surface above
freezing▫Sense presence of snow
PROJECT BACKGROUND
Needs List
Engineering Requirements
PROOF OF CONCEPT
POC ENERGY USAGE ANALYSIS
Final finding to melt one year worth of snow: 48,502,500J
E msh (mCpT)g (mCpT)sVariables
Name Units ValueCps specific heat capacity of snow j/(kg*K) 2090Cpg specific heat of tempered glass j/(kg*K) 720h heat fusion of snow* J/kg 334000ρs average density of new snow kg/m^3 60 average snowfall annually rocherster m 2.344
ρg average density of tempered glass kg/m^3 2440
T (°C)Tig -5Tfg 5Tis -5Tfs 0
*For snow, use the parameter of ice
Need to determine total energy needed to heat panel and melt snow over the period of a year:
POC POWER REQUIRMENT
•The Data:▫TMY3 (Typical Meteorological Year)▫Hourly data taken from 1961-1990 and
1991-2005▫Takes the month that is closest to the
average
•Calculations make use of the direct and the diffuse beams from sunlight in Rochester, NY taken from this data
POC POWER REQUIRMENT con’t•Assumptions:
▫Latitude: 43.12° (Rochester, NY)▫Local Longitude: 77.63°▫Local Time Meridian: 75°▫PV efficiency of 20%▫A directly facing south panel▫Use tilt angles 10°-35° in steps of 5°▫Reflected off grass in summer (ρ=0.2)▫Reflected off snow in winter (ρ=0.8)
POC POWER REQUIRMENT con’t•Equations:
▫Convert civil time to solar time
▫Calculate Solar Declination Angle
POC POWER REQUIRMENT con’t
• Calculate Solar Altitude Angle
• Calculate Solar Azimuth Angle
POC POWER REQUIRMENT con’t
• Calculate Direct Beam on the panel:
• Calculate Diffuse
• Calculate Reflected
POC POWER REQUIRMENT con’t•Calculation done for every hour of the
day. •Then added together to get the amount of
solar flux available in a given year at different tilt angles. These fluxes were averaged giving: 291,113 Wh/m2
• Restricted to 10% of annual power: 29,111 Wh/m2
Energy Conclusion
•Yes! 48,502,500J<104,800,822•Next steps:
▫Model in ANSYS Model different ink layouts for feasibility
Power Electronics
•Battery•Charging System•Supplying Power to Ink
Choosing the Battery•Battery Type has to first be chosen
“Batteries and Charge Control for Stand-Alone Photovoltaic Systems : Fundamentals and Applications” , James P. Dunlop
Battery Capacity• How much energy is stored in the battery measured in
ampere hours
• Ah will provide ‘X’ amps of current for ‘Y’ hrs
• From previous calculation we assume the total amount of power that we can use is 29,000 Wh/m2 , are prototype is 3’x5’ (0.92m x 1.525m)
• Therefore the total power used in a year can be about 40,600Wh
Battery Capacity
• Assuming snowfall for 240hrs a year the average amount of power of the device will be 170W (40,600Wh/240h)
• Therefore Ah = (170W*4h)/ 12V = 56Ah
• To increase battery performance and life the battery should not be consistently discharged below 60% capacity so to be safe the battery capacity should be about 90Ah
(V) Voltageattery
(Hrs) TimeRun * (W) WattageDevice
BAh
Battery Options•Trojan Deep-Cycle AGM Battery can be used•31-AGM could all be options with 5hr rate-
capacity of 82Ah•Can be purchased from civicsolar for $270
Battery Chargers
•Controls incoming charge of the battery•AGM batteries are INTOLERANT to
overcharge•Standard Solar Chargers or MPPT
(Maximum power point tracking) charger•MPPT chargers are much more efficient•Standard chargers can lose between 20-
60% of the rated solar panel wattage
Choosing a Battery Charger• Charger needs to be able to handle rated watt, voltage,
and current rating of PV panel (charging source)• Charging source is still being determined (Full Panel or
select number of cells)• For now we can base the charger choice off a SBM
solar 150W panel with the following specs:
Possible MPPT Charge Controller• Morningstar SunSaver 15 Amp MPPT Solar
Charge Controller ($225)
Power used from possible 150W:Power= PV Panel Power * EfficiencyPower = 150W * 97.5%Power=146.25
Charge Current = Power/Battery VoltageCharge Current = 146.25W/12VCharge Current =12.2A
Charging Time = Battery Ah / Charge Current
= 100Ah/ (12.2A)Charging Time = 8.2 hrs
Possible Standard Charge Controller• Morningstar SS-20L 20 Amp PWM Solar Charge
Controllers w/LVD ($78)
Power used from possible 150W:Power = Voltage *Charge
CurrentPower = 12V *8APower = 96W about 66%
efficient
Charging Time = Battery Ah / Charge Current
= 100Ah/ (8A)Charging Time = 12.5 hrs
Battery
Regulating Circuit
Rtrace1
Rtrace2
Rtrace3
Rtrace4
Ink Power Supply
RTotal
I out
TotalR
PowerI
Ink)Heat toNeeded (out
POC CONTROL SYSTEM
• Atmel's ATMega328P 8-Bit Processor in 28 pin DIP package with in system programmable flash
Features:•32K of program space•23 programmable I/O lines 6 of which are channels for the 10-bit ADC. •Runs up to 20MHz with external crystal. •Package can be programmed in circuit. •1.8V to 5V operating voltage•External and Internal Interrupt Sources•Temperature Range: -40C to 85C•Power Consumption at 1MHz, 1.8V, 25C
–Active Mode: 0.2mA–Power-down Mode: 0.1μA–Power-save Mode: 0.75μA (Including 32kHz RTC)
POC CONTROL SYSTEM Con’t
POC CONTROL SYSTEM Con’tControl System Pseudocode
• Reset• Enable global interrupts on interrupt input pins 4 and 5• Define interrupt on pin 4 or 5 for a rising edge signal from
sensor conditioning logic for inputs from temperature/proximity/moisture etc sensors
• Enter Sleep Mode• Rising edge?
Yes: o Go to ISR (Interrupt Service Routine) if rising edge is triggeredo Run specified program based on polled sensor values
No: o Continue to sleep
POC SENSOR RESEARCH Snow will be sensed by monitoring 5 sensors
Ambient temperature Panel temperature Precipitation Ambient light Motion/Proximity
Use of all 5 sensors would allow for sufficient redundancy to ensure proper operation.
POC SENSOR RESEARCH con’tAmbient temperature
Will be used in combination with panel temperature
If ambient temperature >~5◦C, then operation should not be necessary.
Achieved with basic temperature sensor:
Analog Devices TMP36
POC SENSOR RESEARCH con’tPanel temperature
Will be used in combination with ambient temperature
If ambient temperature >~1◦C, then operation should not be necessary.
Achieved with basic thermocouple/thermistor:
Omega 5LRTC series, type T thermocouple
Spectrum Sensors & Controls RT24 Surface Temperature Sensor
POC SENSOR RESEARCH con’tPrecipitation
Most difficult/most expensive to implement
Operates by applying a small amount of power to a small heater, and then looking for water
Automatically operates only at specific temperature range.
ETI CIT-1 Snow Sensor
POC SENSOR RESEARCH con’tAmbient light
Small photocell Will allow for optimized
operation (operation will shut down after an extended period in low-light environment).
Intersil ISL29101
POC SENSOR RESEARCH con’tMotion/Proximity
Transmissive infrared or ultrasonic sensor
Will provide some estimation of how much/fast it is snowing (allowing for operation optimization)
Omron E4E2 Ultrasonic Sensor
Chamberlain IR 801CB garage door safety sensors (or something similar).
POC INK RESEARCH•Brinkman Lab Testing 10/24/2013
▫The point of the test was to obtain the appropriate parameters to use on the pulseforge for the curing process.
▫Tested a copper based ink usually used on paper
▫Wanted to see how the ink would be effected by putting it on glass
POC INK RESEARCH con’t▫Setup:
Ink was placed at the top of a screen with the glass below.
POC INK RESEARCH con’t Ink was then spread across the screen with
two passes. The screen gave the following pattern on the glass
POC INK RESEARCH con’t The pattern was then covered with paper so
only two lines on a trace were exposed. This was done so different parameters could be tested for the pulseforge two lines at a time.
POC INK RESEARCH con’t Eight trials were done at different parameters. (1
to 8 right to left) Conclusion: This copper based ink is coming off
the glass Next Step: Find a different ink that is adhesive to
glass
12345678
BILL OF MATERIALS
TEST PLAN OUTLINE• Test Ink
▫Verify heat dispersion, and ink durability• Test Control System
▫Verify appropriate output signal and system response
• Test Battery▫Verify battery life/performance and response to cold
• Test Power/Charging Electronics▫Verify power output and charging capabilities
• Test Sensors▫Test different sensing options
• System Integration Test▫Verify all subsystems operate together
SCHEDULE