Group 5: Nick PapernoPatrick Taylor David YeungAndrew Bridges

Introduction Industries are becoming more focused on saving nonrenewable resources There are two main ways of accomplishing this: Use nonrenewable resources in a more efficient manner Focus on using renewable resources Our project focuses on applying these principles to an electric golf cart

Objectives & Goals Allows Driver to change modes of operation from Display Displays Current Speed, Current Battery Charge, Current Mode of Operation, and Distance travelled Can be charged by Solar Power from Solar Panels attached to the roof Must implement a power control and saving system on an electric golf cart Must have a power efficiency mode Must have a high performance mode

Specifications and Requirements Must have 6, 6V flooded lead acid batteries Will go into a power saving mode at 15% charge remaining The HUD must display the charge remaining within a 3% accuracy The HUD must display the range remaining within a 0.5 mile accuracy The HUD must display the power usage of all components in the vehicle to a 3% accuracy

Project Block Diagram

Primary System Block Diagram Speed Controller T, A

Secondary Block Diagram

Battery consideration Li-ion  Light weight, high energy density, consistent discharge voltage  High cost NiCd  Moderate energy density, consistent discharge voltage  Lower cell voltage per cell Lead Acid  Low cost, most battery found in golf carts  Lower energy efficiency, high weight

Energy Density vs. Power density

Cell voltage vs. Discharge

Peukert’s Equation :

Battery TypeApproximate Peukert Number Cost Per BatteryCost To Change 6V AGM 1.08 $329$1974 6V gel cell1.12$269$1614 6V wet Cell1.2$159$0 Battery Comparison

Resister vs. PWM speed control PWM speed controllers are programmable and can support regenerative breaking.

PWM controllers considered. Altrax 8434 Programmable via RS232 Integrated anodized heat sink Fully encapsulated epoxy fill Operating temperature -25ᵒC to 75ᵒC Automatic shutdown at 95ᵒC Adjustable via Controller Pro software allows  Armature current limit  Throttle acceleration

PWM controllers considered cont. TPM400 Regenerative breaking Fully programmable with the Navitas PC Probit programming package Resistive or voltage throttle input Battery over-discharge protection  Current limiting  Thermal limiting

Speed controller Comparison TypeVariable current control Voltage and current monitoring ProgrammableRegenerative breaking Cost Alltrax 8434 Yes No$387 TPM 400 yes Yes $695

Implementing Speed controller

Testing the golf cart

Problems encountered When donated the golf cart did not run (Fixed) Right rear breaks were locked (Fixed)

Solar Panel System Needs to be able to charge 36 V battery bank. Will be attached to the roof of the golf cart Must be able to endure Elements and Floridian Humidity Solar Panel System must have a kill-switch system Must try to optimize charge System must not drain the batteries Temperature Coefficient is -0.5 %/°C and is for 80°F or 27°C

Solar Panel Setup Will have 2 Polycrystalline Solar Panels connected in series Will use a single Pulse Width Modulation Charge Controller System will be connected in parallel to the Battery Bank Will have User on and off switch

Solar Panel Two GEPV-185 MCB-001 Connected in Series Relativity cheap for the amount of Voltage and Wattage ManufacturerGeneral Electric Model NumberGEPV-185 MCB-001 Cell TypePolycrystalline Power Rating185 W Open Circuit Voltage32.2 V Short Circuit Current7.8 A Voltage at Pmax25.6 V Current at P max7.2 A Efficiency12.70% Power Tolerance-5.00% ~ 5.00% Max. Series Fuse15 A Vmax1000 V Dimensions (HxWxD)38.6"x58.5"x1.4" Weight39 lbs Price$ Additional Notes Weight18.1 lb (8.2 kg) Weight (Wind) Bearing Potential50 lbs/ft^2 (125 mph) Hailstone Impact 50 mph (25 80 kph)

Solar Panel

Solar Power Charge Controller Will use Pulse Width Modulation (PWD) charge controller Cheaper price High Efficiency Switches off power to the batteries when batteries are full Prevents power being drained from the batteries

Solar Power Charge Controller One Morningstar TS-60 High Efficiency Moderate Price Data Logging with Display Screen ManufacturerMorningstar Model NumberTS-60 TypePWD Max Battery Current60 A Nominal System Voltage V Peak Efficiency99% Max Solar Voltage125 V Self-Consumption (Controller)<20 mA Self-Consumption (Meter)7.5 mA Dimensions10.3"x5"x2.8" Weight3.5 lbs Cost$ Additional NotesDisplay Screen, Data Logging

Solar Panel Roof Mount Will replace old flimsy roof with new roof to mount solar panels on top Made with treated plywood and metal support beams Will attach to existing support beams Problems Foreseen: Too much weight Slow cart down Columns might not support roof and Solar Panels Solutions: Use light and durable material Add more columns to support weight

Solar Panel Roof Mount

Voltage Regulators Need to have 12V and 5V supply voltage for sensors and controllers LM 2576 switching regulator and LM 7805 linear regulator Originally going to use LM 117HV in place of 7805

LM 2576 Adjustable Switching Regulator Will drop voltage from 36V to 12V Power speed sensor Make easier to reduce voltage to 5V

LM 7805 Linear Regulator Drop voltage from 12V to 5V Power Microcontroller, Display controller, current sensor, and provide voltage for switch

Microcontroller Three controllers for whole system Speed controller Display controller ATmega644

Use AVR Studios 4 and STK500 starter kit to program and run basic tests Uses C programming language Main program will be switch statement Inputs will be located on Port D Outputs will be located on Port B

System Block Diagram

Sensors Three quantities that need to be measured Voltage across the batteries Current output of batteries Speed of golf cart Devices that will be used Voltage divider CSLT6B100 Open-Loop Hall effect sensor Flange Mount Hall effect Sensor

Voltage divider Three resistors 560kΩ 20k Ω 100k Ω Reduces input voltage to 5.29V

CSLT6B100 Open-Loop Hall effect sensor Placed after ignition switch Can sense up to 100A current Gives output voltage

55110 Flange Mount Hall effect Sensor Mounted near axel and connected to display controller Voltage output Durable housing Originally going to use 55100

Modes of Operation Standard ModeHigh Performance Mode Efficient Mode Uses typical golf cart settings before modifications Top speed increases Acceleration increases Battery life decreases Top speed decreases Acceleration decreases Battery life increases Three modes of operation are available to provide a balance between performance and efficiency Buttons in the golf cart will allow the driver to switch between modes of operation

Human Interactive Display: Goals and Objectives Provide the driver with information Speed Charge remaining Distance travelled Current mode of operation Allow the driver to switch modes of operation

Human Interactive Display: Requirements and Specifications Three buttons for modes of operation Display speed in MPH within 5% accuracy Display charge remaining as percentage within 3% accuracy Display charge remaining as time in the format HH:MM within 5 minute accuracy Display distance travelled in miles within 3% accuracy

Human Interactive Display: Inputs to Display Voltage sensors Measure charge remaining Speed sensor Measures speed Also used to calculate distance travelled Three buttons for modes of operation

TMPZ84C00A 8-bit microprocessor Will be connected to the T6963CFG LCD controller for the CFAG160128B-TMI-TZ monitor Converts and transmits inputs to the display

CFAG160128B-TMI-TZ Monitor Graphic LCD LED backlight Number of dots: 160 x 128 Module dimension: mm x mm x 16.5mm Display format Columns: 32, 40, 64, 80 Lines: 2, 4, 6, 8, 10, 14, 16, 20, 24, 28, 32 Programming in assembly

Connecting Components

Potential Problems Connecting components Programming monitor output Mounting to the golf cart Protection from elements

Budget ItemsActual Cost to dateProjected Cost Golf Cart$0 (Donated)$600 Batteries$0 (Donated)$300 Solar Panels(Haven’t Purchased)$700 Solar Panel Controller(Haven’t Purchased)$200 Microchips and Sensors$64.67$150 Circuit Boards(Haven’t Purchased)$60 Human Interactive Displays(Haven’t Purchased)$200 Misc. Material$129.48$250 Total$193.75$2360

Current Progress Sub-SystemCompleted(%) Golf Cart 80 Parts Acquired 60 Sensors 40 Voltage Regulators 40 Microcontrollers 20 Solar Panels 0 Display 0

Plans to Complete Project Have weekly meetings to discuss individual process and the future plans Work on the golf cart every weekend until completion Buy all necessary parts that have not been purchased yet