Course Overview

COVID-19 Instructions for ECE 445 Senior Design

We require everyone who uses the 445 lab in ECEB to adhere to the following lab policies regarding COVID-19.

  • You must wear a mask at all times while in the lab.
  • You must clean and disinfect your workstation when you are finished with it.
  • Welcome!

    Welcome to ECE 445! If you've looked at the course Calendar, you've probably already noticed that this class is quite different from most other classes in the department. The class only meets as a whole for the first few weeks of the semester. During these lectures you will meet the Course Staff, learn about specific assignments, requirements, and resources for the course, and have a chance to meet other students to share ideas and form teams. These are some of the most important weeks for the class since the decisions you make during this time will determine what you'll get out of this class and, in many ways, how much you'll enjoy it.

    Outside of lecture, you are expected to be working on your own to develop ideas and form teams. You are also expected to actively participate on the web board to exchange ideas, receive feedback from course staff, and eventually get your project idea approved. Once your team has a project approved, you will be assigned a TA, with whom you will have weekly meetings. Think of your TA as a project manager. Keep in mind that they are not there to do the work for you. Rather, they are there to keep you on track, point you towards resources (both within and outside of the department), and evaluate the result of your efforts.

    Expectations and Requirements

    We have high expectations for students participating in ECE 445. You are soon to be alumni of one of the top ECE departments of the world. Our alumni hold themselves to high technical and professional standards of conduct. In general, projects are expected to be safe, ethical, and have a level of design complexity commensurate with the rigor of the ECE Illinois curriculum. Requirements for specific assignments due throughout the semester can be found by looking through the Grading Scheme for the course. Please read through this documentation well before each assignment is due. Specific due dates can be found on the course Calendar.

    Below are a few words of wisdom to keep in mind throughout the semester to increase your enjoyment and success in the course:

    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.