Project Group 15 Keith Walls - EE Imran Ali - CpE Travis Comer - - PowerPoint PPT Presentation

The Tohoku Relief Project Group 15 Keith Walls - EE Imran Ali - CpE Travis Comer - EE WCF Funded Mentor – Marcus Ledet

List of Sponsors  Workforce Central Florida  Monetary Funding Of The Project  S&C Electric Company  Advising And Quality Check  Petra Solar  Donated Solar Panels  C&S Companies  Advising And Printing  Progress Energy  Invitation To Symposium

Motivation  Rolling blackouts were a big problem for Japanese universities after the 2011 Tsunami  Waseda University, in Shinjuku, Tokyo reached out to the UCF IEEE chapter to design a green power generation system to power the basic classroom essentials when a blackout occurred.

Tohoku Region

Goals and Objectives  Simultaneous solar and wind power generation  AC and DC power output  Off-Grid laptop and projector power  High efficiency  Portable/semi-modular design  System status and performance screen

Output Power Specifications  120VAC at 60Hz  Supplied through typical home receptacle  12VDC  Supplied through typical automotive cigarette lighter receptacle  5VDC  Supplied through USB connection

Power Storage Specifications  Estimate the max draw of a laptop and a projector at 600W  Battery capacity of at least 25Ah is necessary  Simple charge cycle implementation  Safe  Large cycle life

Input Power Specifications  Recharge the battery in less than 2 hours using simultaneously generated solar and wind energy  Average of 100W solar energy  Average of 200W wind energy

Overall Block Diagram Power Generation: Travis Power Storage: Keith Power System Monitoring: Imran

Design Concept

Solar Panels  Make/Model - BP SX3200  Cell type - Multicrystaline  Max power output – 200W  Max power voltage – 24.5V  Max power Current – 8.16A  Donated

Wind Turbine  Sunforce 45444  Cut-in wind speed – 4.5MPH  Max power output – 450W  Max Power Voltage – 15V  Max Power Current – 30A

Average Power Output  Average Tohoku Region Wind Speed:  15 kmh ≈ 9 mph  Average Wind Power Output ≈ 200W

Battery Chemistries  Lead acid vs. Lithium ion vs. Nickel-metal hydride  NiMH batteries have a complex charging cycle  Li-ion batteries have safety concerns and are expensive  The Lead acid battery was chosen due to it’s simple charging cycle, safety, and low cost

Battery Construction  AGM vs. Gel Cell vs. Flooded cell  Electrolyte evaporates easily and can be spilled in flooded cell batteries  Gel cell batteries usually have a higher cost and internal resistance, but a higher cycle life than comparable AGM batteries  The AGM battery was chosen due to it’s durability, lower internal resistance, and lower cost

Battery Comparison Battery` Capacity (Ah) Weight (lbs) Price UPG UB12550 55 38.5 $199.00 Optima D51 38 26 $158.07 Concord PVX340-T 34 25 $177.00 Data Safe NPX-150R 40 34.2 $161.99

Inverter  Pure sine wave vs. modified sine wave.  Pure sine wave needed for grid tie applications and use with sensitive equipment  Similar efficiencies (~90%)  Pure sine wave inverters often cost more than 3 times that of a comparable modified sine wave inverter  The modified sine wave inverter was chosen due to the lack of benefits of a pure sine wave inverter for our application

Inverter Comparison Temperature Short Circuit Low Battery Protection Protection Protection Protection Efficiency Soft Start Overload USB Port Price ($) Rating Power Peak Vector VEC043B 750 90 X X X X X 64.99 Wagan 2016-6 700 90 X X X X X 60.15 Pyle PINV3 800 90 X X X 44.99 Power Bright PW900 900 90 X X X X 64.44

Inverter Connections

Electronics Enclosure  Contain the battery, charge controllers, sensors, microcontroller, and display  Externally accessible power outlets  Approximate 11” x 24” x 24” external dimensions

Necessary Solar Charge Controller Features  Maximum Power Point Tracking (MPPT) to maximize efficiency  Charge cycle compatible with 12V lead- acid batteries  Sleep mode for night time hours

Solar Charge Controller IC Comparison  TI SM72442  Perturb and observe MPPT method  Requires interfacing with an H bridge driver through four PWM gate drive signals which will then control the MOSFETs in a buck/boost converter  TI BQ24650  Constant Voltage MPPT method  Directly controls buck converter to regulate the charge voltage

MPPT Method Comparison  Perturb and observe  Measures voltage and calculates dp/dv  If the slope is positive, the algorithm knows it adjusted in the correct direction.  If the slope is negative, the algorithm knows it adjusted too far and needs to go back.

MPPT Method Comparison  Constant voltage  Drawing current from PV panels causes panel voltage to drop  The algorithm constantly adjusts the charging current to keep the panel voltage at the max power point voltage, which has a linear relationship to the panel’s easily measured open circuit voltage

Solar Charge Controller  TI BQ24650 was chosen  Simpler implementation – only one IC  Has capability to implement PV panel temp at a later time  Evaluation board available

Solar Charge Controller Schematic

Charge Controller Connection

Microcontroller  Monitor Power Usage  Monitor Power Generation  Monitor Battery Voltage  Display all data on a easy to read screen

Microcontroller  ADC’s needed  2 current sensors  1 battery voltage  1 GPIO for screen (serial connection)  Low power usage  At least 1KB memory

Microcontroller Comparison MSP430G2231 ATmega2560 Operating Voltage 1.8 Volts 5 Volts Flash Memory 2 KB 256 KB ADC 8 16 GPIO 10 54 Price Free $59.95  MSP430G2231 Chosen

Functions Functions Description Void getValues() Get values from ADC which will be converted into its appropriate real time values Void Buttonpressed() Determines which option to send to the display when the button is pressed Void Transmit() Main Transmit function which calls TXString(char* string) or InttoDisplay(int number) Void InttoDisplay(int number) Transmits number over serial to display Void TXString(char* string) Transmits String over serial to display

Display  Functional/ Easy to use display  Button will toggle through options  Display will be updated upon button being pressed.

Display Comparison Sparkfun SerLCD uLCD-144(SGC) 16 x 2 Voltage 5 Volts 3.2 Volts User Experience Simple Display Complex Display Outdoor Environment Easier to read Light intensity can affect display Price $29.99 $55.99

Voltage Regulators  Using linear regulators  UA78M33 & UA7805  Planning to change these to switching regulators for max efficiency  Total of 3 regulators used  5V regulator for LCD  5V regulator for current sensor  3.3V regulator for microcontroller

Current Sensing  Measure the current going into and out of the system for power calculations  Must be able to handle a maximum of 60 amps  Must have high sensitivity for accurate calculations

ACS758xCB Vs. CS100A ACS758xCB CS100A Peak Current 100 A 100 A Current Direction Unidirectional Bidirectional Current Sensitivity 40 mV/A 20 mV/A Ease of Use Need to be mounted Already on a PCB with 4 oz Copper Input Voltage 3-5.5 V 3-5.5 V Price $7.00 $14.99

Power Monitor Schematic

Power Monitor PCB Layout

3D View of Power Monitor PCB

Power Connection Schematic

Budget Part Budgeted Price Amount Spent Solar Cells Donated Donated Wind Turbine $850.00 $729.44 Battery $160.00 $137.99 LCD Screen $30.00 $28.68 MSP430 $10.00 $0.00 Current Sensors $100.00 $92.57 PCB's $150.00 $70.80 Enclosure $150.00 $112.68 Charge Controllers $90.00 $429.08 Mirrors $70.00 $0.00 AC - DC Converter $80.00 $70.43 Telescoping Tripod Stand $130.00 $113.35 Miscellaneous Hardware $100.00 $20.00 Total $1,920.00 $1,805.02 $114.98 Remaining

Distribution of Work

Questions?