Slide 1

The Electric Golf CartProgress EnergyGroup 5:Nick PapernoPatrick TaylorDavid YeungAndrew Bridges

IntroductionIndustries are becoming more focused on saving nonrenewable resourcesThere are two main ways of accomplishing this:Use nonrenewable resources in a more efficient mannerFocus on using renewable resourcesOur project focuses on applying these principles to an electric golf cart

Objectives & GoalsAllows Driver to change modes of operation from DisplayDisplays Current Speed, Current Battery Charge, and Current Mode of OperationCan be charged by Solar Power from Solar Panels attached to the roofMust implement a power control and saving system on an electric golf cartMust have a power efficiency modeMust have a high performance modeSpecifications and RequirementsMust have 6, 6V flooded lead acid batteriesWill go into a power saving mode at 15% charge remainingThe HUD must display the charge remaining within a 3% accuracyThe HUD must display the power usage of all components in the vehicle to a 3% accuracy

Project Block Diagram

Primary System Block DiagramSpeed ControllerT, A

Secondary Block Diagram

Golf CartBattery considerationLi-ionLight weight, high energy density, consistent discharge voltageHigh costNiCdModerate energy density, consistent discharge voltageLower cell voltage per cellLead AcidLow cost, most battery found in golf cartsLower energy efficiency, high weight

Energy Density vs. Power density

Cell voltage vs. Discharge

Peukerts Equation:

Battery TypeApproximate Peukert NumberCost Per BatteryCost To Change6V AGM1.08$329$19746V gel cell1.12$269$16146V wet Cell1.2$159$0Battery ComparisonResister vs. PWM speed control

PWM speed controllers are programmable and can support regenerative breaking.Pulse Width ModulationPWM signal supplies positive gate voltage to an n-channel power MOSFET which drives the motorMotor on when the PWM signal is high and off when the PWM signal is lowDecrease speed of the golf cartIncreases battery charges length

PWM controllers considered.

Altrax 8434Integrated anodized heat sinkFully encapsulated epoxy fillOperating temperature -25C to 75CAutomatic shutdown at 95CCan not adjust running mode without connecting to a computerAdjustable via Controller Pro software allowsArmature current limitThrottle acceleration

PWM controllers considered cont.

TPM400Regenerative breakingCan not adjust running mode without connecting to a computerResistive or voltage throttle inputBattery over-discharge protectionCurrent limitingThermal limitingPWM controllers considered cont.Complete control over PWM voltage outputCan switch to different modes while the golf cart is running, without connecting to a computerVoltage and current sensing

Stellaris LM3S2965Speed controller ComparisonTypeVariable current controlVoltage and current monitoringChange of mode while runningRegenerative breakingCostAlltrax 8434YesYesNoNo$387TPM 400YesYesNoYes$695StellarisLM3S2965YesYesYesNo$250Implementing Speed controller

Testing the golf cart

Solar PanelSolar Panel SystemNeeds to be able to charge 36 V battery bank.Will be attached to the roof of the golf cartMust be able to endure Elements and Floridian Humidity

Solar Panel System must have a kill-switch systemMust try to optimize chargeSystem must not drain the batteriesTemperature Coefficient is -0.5 %/C and is for 80F or 27C

Solar Panel Setup

Will have 2 Polycrystalline Solar Panels connected in seriesWill use a single Pulse Width Modulation Charge ControllerSystem will be connected in parallel to the Battery Bank

Solar PanelTwo Canadian Solar PV Module 215W B (CS6P-215-B)Connected in SeriesRelativity cheap for the amount of Voltage and WattageManufacturerCanadian SolarModel NumberCS6P-215-PCell TypePoly-CrystallinePower Rating215 WOpen Circuit Voltage36.5 VShort Circuit Current8.01 AVoltage at Pmax44 VCurrent at Pmax29 VEfficiency12%Power Tolerance+5 WVmax1000 VDimensions (HxWxD)64.5x38.7x1.57Weight44.1 lbsPrice$406.35Solar Panel

Solar Power Charge ControllerWill use Pulse Width Modulation (PWD) charge controllerCheaper priceHigh EfficiencySwitches off power to the batteries when batteries are fullPrevents power being drained from the batteriesSolar Power Charge ControllerOne Morningstar TS-45High EfficiencyModerate Price

ManufacturerMorningstarModel NumberTS-45TypePWDMax Battery Current45 ANominal System Voltage12 - 48 VPeak Efficiency99%Max Solar Voltage125 VSelf-Consumption (Controller)