EV Electrical Systems for Student Teams: An Iterative Design Approach with Practical Lessons

Abstract

The shift toward vehicle electrification has created an urgent need for engineering students to acquire practical knowledge in electric vehicle (EV) systems. While industry and academia offer theoretical instruction, student design teams often lack practical guidance, resulting in preventable errors, safety risks, and incomplete competition vehicles. This thesis addresses that gap by identifying key lessons to learn for building EV electrical systems and offering real-world insights through a case study of the University of Waterloo Alternative Fuels Team (UWAFT) during the EcoCAR 5 competition. The thesis is structured around three primary electrical domains: High Voltage (HV), Low Voltage (LV), and Serial Communication Systems. Each chapter begins with generalized best practices, safety procedures, and design considerations, then explores how UWAFT applied—or struggled to apply— these concepts in practice.

In the HV domain, the thesis covers critical safety mechanisms like Isolation Monitoring Devices (IMDs), Emergency Disconnect Systems (EDS), and Lockout/Tagout (LOTO) procedures. It highlights common student pitfalls such as improper cable terminations and the consequences of electromagnetic interference (EMI).

The LV section details harness design, schematic development, wire selection, and assembly techniques essential for powering 12V components safely and reliably. Emphasis is placed on documentation, modularity, and physical protection of circuits.

In the Serial Communication chapter, the CAN bus protocol is explained in the context of a complex vehicle network involving autonomous driving, propulsion control, and diagnostics. The harness assembly techniques from the LV chapter are expanded upon for the specific case of CAN cables. Finally, UWAFT’s Serial Network Diagram (SND) serves as a practical guide to organizing and troubleshooting communication systems.

Through a combination of foundational theory and applied case study, this thesis equips student teams with a framework for developing safe, functional, and competition-ready EV electrical systems. It also highlights the importance of mentorship, iterative learning, and documentation in engineering education.