Project

# Title Team Members TA Documents Sponsor
9 Ethernet Interface for Hardware Data Routing
 Hendrik Dewald
John Alaimo
Satyam Shah
 appendix0.pdf
design_document0.pdf
final_paper0.pdf
presentation0.pdf
proposal0.pdf
In this project, we hope to create an interface for multiple components, like LED arrays, motor controllers, sensors, and servos. The hope is that a single computer can interface with multiple devices using only its Ethernet port, a switch, and our hardware router blocks. They would be reachable through the switch, as each device can be differentiated by MAC address, and the device-side microcontroller would receive instructions and send data through Ethernet that would make use of 3 digital inputs, 3 analog inputs, 3 digital outputs, and 3 analog outputs. With these hardware routers, a 5V power hub, and a routed external power supply, the routers could control any of a multitude of devices, all from a single computer.

Active Cell Balancing for Solar Vehicle Battery Pack

Tara D'Souza, John Han, Rohan Kamatar

Featured Project

# Problem

Illini Solar Car (ISC) utilizes lithium ion battery packs with 28 series modules of 15 parallel cells each. In order to ensure safe operation, each battery cell must remain in its safe voltage operating range (2.5 - 4.2 V). Currently, all modules charge and discharge simultaneously. If any single module reaches 4.2V while charging, or 2.5V while discharging, the car must stop charging or discharging, respectively. During normal use, it is natural for the modules to become unbalanced. As the pack grows more unbalanced, the capacity of the entire battery pack decreases as it can only charge and discharge to the range of the lowest capacity module. An actively balanced battery box would ensure that we utilize all possible charge during the race, up to 5% more charge based on previous calculations.

# Solution Overview

We will implement active balancing which will redistribute charge in order to fully utilize the capacity of every module. This system will be verified within a test battery box so that it can be incorporated into future solar vehicles.

Solution Components:

- Test Battery Box (Hardware): The test battery box provides an interface to test new battery management circuitry and active balancing.

- Battery Sensors (Hardware): The current battery sensors for ISC do not include hardware necessary for active balancing. The revised PCB will include the active balancing components proposed below while also including voltage and temperature sensing for each cell.

- Active Balancing Circuit (Hardware): The active balancing circuit includes a switching regulator IC, transformers, and the cell voltage monitors.

- BMS Test firmware (Software): The Battery Management System requires new firmware to control and test active balancing.

# Criterion for Success

- Charge can be redistributed from one module to another during discharge and charge, to be demonstrated by collected data of cell voltages over time.

- BMS can control balancing.

- The battery pack should always be kept within safe operating conditions.

- Test battery box provides a safe and usable platform for future tests.