System for Motor Control in a Solar Powered Electric Race Car Jay Oatts Duncan Thompson Pavel Rybakov Alex Jenkins Ed Kfir Monday November 1, 2010 Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Project Overview Design motor controlling system for solar- powered race car to participate in 2011 World Solar Challenge in Australia Modular design for efficient portability to solar racer and integration with full electronics system Expected cost of replication for Solar Jackets is approximately $550 Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Technical Objectives Design test bench and implement safety mechanisms Test functionality of motor controller and motor (donated items) Operate motor controller via single-board computer program and discrete controls Output vital data from motor controller to driver via LCD screen Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Current Status Test bench construction complete Motor controller and motor functional (only one of each) Operation in discrete (human interface) and serial (computer interface) confirmed Safety systems installed Semi-full systems test passed (SBC and LCD excluded) Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Latest Test Run Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Modular Design Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Modular Design Power Source Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Modular Design Power Source Motor Controller Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Modular Design Power Source Motor Controller Motor Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Modular Design Power Source Motor Controller Motor Discrete Controls Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Modular Design Power Source Motor Controller Motor Discrete Controls SBC Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Modular Design Power Source Motor Controller Motor Discrete Controls SBC Driver Display Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Power Source - Batteries 8 x 12V series connection 96V effective Wiring – AWG-4 Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Power Source - Fuse 250V / 150A rated fuse and holder Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Power Source – Main Power Cutoff 48V/96V blowout 1000A Keyed access Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Power Source – Power Relay Contactor – 900V / 500A (cont.) / 2000A (cutoff) Power Resistor – 100Ω/200W Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Motor Controller - Connections Battery Terminals Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Motor Controller - Connections Battery Terminals Motor 3-Phase Power Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Motor Controller - Connections Battery Terminals Motor 3-Phase Power Motor Sense (15 pin) Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Motor Controller - Connections Battery Terminals Motor 3-Phase Power Motor Sense (15 pin) Discrete/Serial Controls (25 pin) Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Motor Controller - Connections Battery Terminals Motor 3-Phase Power Motor Sense (15 pin) Discrete/Serial Controls (25 pin) Fan Power Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Motor Controller - Connections Battery Terminals Motor 3-Phase Power Motor Sense (15 pin) Discrete/Serial Controls (25 pin) Fan Power Fans (2 x 24V) Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Motor Controller - Communication Split from 25 pin controls cable Serial-USB for computer Hyperterminal program Serial syntax – Commands (same as discrete + program/operate mode + hard reset) XX! – Queries XX? (RAM) XX> (EEPROM) – Assignments XX=# (RAM) XX<# (EEPROM) – (*Must be in programming mode) Solar Jackets – Motor Controller GroupECE 4007L01 – ws3 Note: XX implies register hexadecimal number for RAM/EEPROM or command number. # implies decimal value to be assigned to the register

Motor 3 phase cables connect to attract rotating permanent magnet in sequence Controller sends power to phases relative to desired speed/torque (commutator) Motor sense cable sends information back to controller (Hall effect sensors, temp sensor, connection sense) Mount for support/stability Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Discrete Controls - Switches Enable – Master controller enable (must be on to operate) Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Discrete Controls - Switches Enable – Master controller enable (must be on to operate) Throttle Enable – Phase current enable (drops to zero when disabled, but regen still operational) Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Discrete Controls - Switches Enable – Master controller enable (must be on to operate) Throttle Enable – Phase current enable (drops to zero when disabled, but regen still operational) Direction Switch – Forward or Reverse Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Discrete Controls – Output Signals Brake (Regen) Light – Activates anytime the controller is regenerating power back to batteries (Phase current negative) Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Discrete Controls – Output Signals Brake (Regen) Light – Activates anytime the controller is regenerating power back to batteries (Phase current negative) Reverse Light – Activates when reverse switch set (as long as motor is currently rotating forward) Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Discrete Controls – Output Signals Brake (Regen) Light – Activates anytime the controller is regenerating power back to batteries (Phase current negative) Reverse Light – Activates when reverse switch set (as long as motor is currently rotating forward) Speed Pulse – State change every two consecutive commutations Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Discrete Controls – Pedals Throttle – Analog input (potentiometer for now) to scale throttle from 0-5V Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Discrete Controls – Pedals Throttle – Analog input (potentiometer for now) to scale throttle from 0-5V Regenerative Braking – Same as throttle, but scales amount of regeneration to batteries from motor Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Discrete Controls – Pedals Throttle – Analog input (potentiometer for now) to scale throttle from 0-5V Regenerative Braking – Same as throttle, but scales amount of regeneration to batteries from motor Air Gap – Mentioned in manual, but ultimately unused Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Single Board Computer (SBC) Serial interface cable connects to serial port in place of laptop Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Single Board Computer (SBC) Serial interface cable connects to serial port in place of laptop 1x 10/100 Ethernet, 2x USB2.0 Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Single Board Computer (SBC) Serial interface cable connects to serial port in place of laptop 1x 10/100 Ethernet, 2x USB2.0 Boots Linux in about 3 seconds RS-485 multi-drop network for communication with solar cell switching power supplies Connects and operates LCD driver display Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Driver Display Potential display choice Connects to SBC on either SPI or I2C bus LED backlighting Many colors available Affordable for basic testing Nothing purchased yet and open to feedback Solar Jackets – Motor Controller GroupECE 4007L01 – ws3 F R Cruise Control Speed: RPM Regen: 0% 100% Power Supply: 96.3V / 20.2A Motor Temp: 30°C Controller Temp: 25°C

Acceptance Testing Confirmation of functional motor controller – Connect to 60V power supply at minimal current, measure input/output pin voltages (+5V for signal lines, +24V for fan) Full controls and motor connection – Communication with motor controller, motor rotation, discrete controls operational, fans connected, 870dHz measured rotation (1740 RPM estimated) Battery array connection (full power operation) – Torque vs. speed control testing, safety systems operational, 96.3V measured battery power, 200mA full speed (no-load) current draw Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Current Issues - Motor Motor pole count – Total number of poles not listed in any manuals – Needed to confirm speed calculation from motor controller Torque (phase current) control spiking – Without load, current spikes at turn on to reach max speed and then levels out to nominal current draw – Need to load motor to further test current range Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Current Issues - Controls Regenerative braking lights – Signal every time negative current is recognized by the motor controller (regeneration) – Not an effective sign of actually braking (light can trigger without regen being applied) Throttle/Regen potentiometers (sensitivity) – Current max measured at about half of potentiometer max range – Motor controller registers can modify range and deadband settings to optimize LCD screen choice – Need to decide on LCD screen so information can be viewed continuously from program Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Upcoming Milestones Basic single board computer I/O – November 5, 2010 Basic functional LCD user interface – November 12, 2010 System logic programmed – November 19, 2010 Automatic programmed motor control – December 1, 2010 Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Discussion Regenerative braking lights Torque control spiking (need to load test) Throttle/Regen potentiometers (sensitivity) LCD screen decision Motor pole count Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Motor Controller Interface Cable Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Detailed Full System Solar Jackets – Motor Controller GroupECE 4007L01 – ws3

Cost Analysis PartApproximate Price Littelfuse Slo-Blo Fuse$35 Fuse Holder$55 Kilovac EV-200 Series Contactor$80 Power Resistor$12 Curtis/Albright Battery Disconnect Switch (with recommended extra contacts for 12V line) $90 ($120) 24V Brushless Fan (x2)$20 CPC Fan Connection Plug (and 2 connector pins)$5 TS-7250 SBC (with full duplex RS-485)$150 ($165) AWG-4 Cable (and terminal connectors)$50 TOTAL SUGGESTED COST$542 Solar Jackets – Motor Controller GroupECE 4007L01 – ws3