Energy Management System
Luis Cabrera, CpE
Team Leader, Software Manager
Abstract
Scott Perry, EE
Hardware Manager
Hardware
Josh Shepard, EE
Archivist
Design Requirements
Electric vehicles are leading the way in alternative methods to move away from the
combustion engine. With growing battery technology, electric vehicles are becoming a
financial risk worth taking on the large manufacturing scale. This has triggered a Formula
SAE event specifically tailored for an Electric Vehicle event. Yet batteries are still not fail
proof, and the correct set up is still needed to operate them at the optimum level without
damage to the cells. So an entire Energy Management System (EMS) must be put in place
to control the charging and discharging of the battery pack. This is just as important as
selecting the appropriate batteries themselves. So as participants of the SAE competition a
balancing circuit must be implemented to make the EMS as efficient and safe as possible.
Theory of Operation
An energy management system must be able to store energy and supply the required
amount of power to a load.
The energy management system charges a group of connected cells using analog
and digital circuitry that balances each cell to a specific voltage.
Software
Each cell has an individual circuit that integrates both analog and digital components.
Both types are used to provide a redundancy check. This will include analog circuitry
to ensure correct operation.
The digital circuit holds a PIC that controls the circuit's operation. Sensors will
measure the
current, voltage, and temperature. The PICs are all connected to a main
microcontroller that holds the system logic and stores the measured variables.
Once the group of cells have been charged, it will be able to supply power to a load.
At this point the system can switch to the discharge mode, where the main
microcontroller can control the PICs and regulate the power being drawn.
• 2012-2013 Senior Design Capstone Project • Dr. Tom Hartley, Faculty Advisor • Mr. Gregory A. Lewis, Senior Design Coordinator • Department of Electrical and Computer Engineering • College of Engineering • University of Akron •