EV-EMCU Electric Vehicle - Economy Mode Control Unit

Transcription

1 EV-EMCU Electric Vehicle - Economy Mode Control Unit Vanessa Baltacioglu Shauntice Diaz Chris Chadman Group 4

2 General Project Description A Overall control module Project to implement Description economy mode in a converted electric vehicle Takes in measurements from the vehicle to calculate optimum power usage Speed, RPM, Current, and Acceleration Governs accelerations according to control unit output to make vehicle more efficient.

3 Overall Diagram Block Diagram

4 Goals & Objectives Extend range by implementing Economy-Mode Minimize power usage by attenuating acceleration to an optimum value Use several microcontrollers to allow data recording, calculations for optimum power usage, vehicle safety features, and USB to serial interfacing Take inputs including current, state of charge, RPMs, MPH, and acceleration USB storage Dash-mounted control switch

5 Specifications & Requirements To increase range by 5-10% 12V auxiliary power supply 144V vehicle power supply 6 electrical sensors inputs 5v power supply for microcontrollers USB for > 90 min data recording

6 Sensors Speed 0 to 70 miles per hour Pulse RPM 0 to 5000 Revolutions Per Minute Pulse Current -500 to 500 Amps Analog State Of Charge 10.5volts Volts (0 to 100%) Analog Potentiometer 0-12Volts Analog Accelerometer ± 2g s (horizontal) Analog

7 Power Distribution 12V System 12V from auxiliary battery is fed to PCB through position 1 of terminal blocks Power then goes to 12 volt 7812 regulator 12V regulator output to switching regulator, current sensor and op-amps on board

8 Power Distribution 5V System Switching regulator Uses electrical switch & a controller to regulator energy transfer rate Higher efficiency, less power wasted Steps VOUT down to 5V Dimension Engineering product fits 3 pin form and doesn t require external capacitors Regulated 5V leaves Switching Regulator Powers accelerometer & the 4 microcontrollers

9 Hardware Design Pulse Inputs Eagle schematic capture and pcb layout editor Recommended as easy-to-use Can learn in one semester Rpm and mph sensors have pulse outputs requires clipping at 5V

10 Hardware Design - Potentiometer Potentiometer input ranges from 0 to 12 v We want range to be 0 to 5 v Voltage divider, capacitor, zener, unity buffer

11 Hardware Design Max3232 RS232 converter for PakTrakr input Takes 5V 2 outputs from Max3232 to PakTrakr μc

12 Hardware Design - Schematic

13 Hardware Design - Board Final board design submitted to board house 3 x 3 in 2 to take advantage of special pricing

14 Hardware Design PCB

15 Microcontroller PIC16F886 Microchip Technologies 28 Pin DIP bit A/D Converters 2 8 bit Timers 2 Analog Comparators 2 Output 10bit PWM Designed for Intelligent Driving System

16 Second Microcontroller PIC16F1823 Microchip Technologies 14 Pin DIP 8 10 bit A/D Converters 3Timers; 2-8 bit 1-16 bit timer 2 Analog Comparators 2 Output 10bit PWM Supports EUSART

17 Data Microcontroller 6 inputs from sensors and potbox through UART communications Output to power microcontroller and computer

18 Software Flowchart

19 PakTrakr Microcontroller

20 Data Microcontroller Data Recording

21 Power Controller 5 sensor inputs Computes optimum acceleration Test Data Peukert s Law Battery Resistance Outputs to safety & data microcontrollers

22 Safety Microcontroller 2 Inputs: Potentiometer, Power microcontroller 1 Output: motor controller Acts like typical a comparator Prevents runaway acceleration

23 Software Flowchart

24 Physics Relate Electric Power to Mechanical Power Find Minimum Acceleration for Economy Mode Minimize Electric Power Loss through Heat by Limiting Current / Acceleration Find Power Needed for Acceleration P in = VI in = v v 3 + vma + vmg*sin(θ) P r Current as a Function of Acceleration and Velocity I = [220.46v v ,789v*sinθ va] / V Max Current ~ 350 A; Attenuate Potentiometer as % of I Test Values P a

25 Physics

26 Physics Motor RPM Tire Speed V tire (mph) 1st gear 2nd gear 3rd gear 4th gear 5th gear m/s RPM Hertz Power(steadyV) , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,652.14

27 Power Usage Minimum power needed to overcome frictional forces at constant velocity P = V*I = v v3 + vma + vmg*sin(θ) Power loss due to heat calculated from experimental results Minimum Current vs. Speed (Theoretical) Current (Amps) Speed (mph)

28 Maximum Acceleration Acceleration attenuated dynamically as a function of velocity Less acceleration for higher velocities Optimum acceleration vs. safe/useful acceleration Acceleration vs. Speed (Preliminary) Acceleration (mph/s) Speed (mph)

29 Physics Internal Battery Resistance EV12A- AGM; R i = 3.2mΩ Full Power VI = 144V*350A = 50.4 kw Power 350A = 4.7 kw; 9.5% Temperature Effects

30 Testing Drive vehicle at 5 mph Slowly increase to 55 mph, increasing by 5 mph at a time Continue driving until state of charge reaches 20% Repeat process with EV-EMCU turned ON

31 What is Working? Safety controller Data recorder Can store four analog inputs on computer Timers not working PakTrakr will be completed in 2 days

32 Thank you for Listening