Transcript Electrical System Overview

Solar Car Electrical
System Overview
Basic System Diagram
Solar
Array
Maximum
PowerPoint
Trackers
CAN Bus 1
HV Bus
Battery
Motor
Motor
Controller
DC/DC
Converter
Battery
Management
System
CAN Bus 2
Vehicle Control and
Data Acquisition
Computer
Telemetry
Radio
Driver
Display
LV Bus
Rear View
Camera
Lights
Solar Array
• 6m2 SunPower B30 monocrystalline silicon
cells
• Split into 4 sub-arrays
• Specialist encapsulation, increasing efficiency
by ~4%
• 22% efficient overall
• 1.3kW measured max power output
• Value: £22,500
Maximum PowerPoint Trackers
• Also known as MPPTs
• Built to custom specification by
Drivetek
• Essentially a DC/DC converter,
converting array voltage to HV bus
voltage
• 98% efficient
• 4 MPPTs, one to interface with each of
the sub-arrays of solar cells
Motor & Motor Controller
• 1.8kW CSIRO 3-phase brushless DC
hub motor
• 98% efficient
• 4kW peak power
• Custom designed hub, machined by
Cambridge Precision
• Value: £18,000
• Motor Controller: Tritium
Wavesculptor
• Value: £5,500
Battery
• LiFePO4 chemistry
• Limited by World Solar Challenge regulations
to 40kgs
• Capacity of over 4kWhr
• 125V nominal
• Custom BMS with CAN interface module
Control and Data Acquisition
• Entire solution provided by
National Instruments CompactRIO
• Interfaces with CAN busses
• Driver inputs and vehicle
instrumentation connected directly
to modules
• Telemetry radio connected to serial
output port
Control and Data Acquisition
• High-speed control loop run in FPGA,
providing fast, reliable response to driver
inputs
• Background loop run in Real-Time Controller
•
•
•
•
Sets maximum allowable currents
Determines preferred speed for cruise control
Logs all data
Selects data to be transmitted over telemetry, to
minimise power consumption