Wolverines Don’t Usually Run This Fast

The wolverine is a powerful animal that can run as fast as 30 miles per hour (mph). However, some wolverines can go much faster. Michigan Electric Racing (MER) is a student-run team at the University of Michigan, home of the Wolverines. The team’s mission is to design, build, test, and finance a high-performance, all-electric Formula-style race car that accelerates from 0–60 mph in just over 4 seconds. The team competes at Formula SAE competitions each summer against teams from all over the world. This intense design and build project allow students from around the university to engage in real-world engineering. It challenges them to further their classroom education on a student-run team.

Challenge: Build a Faster, More Powerful Electric Vehicle

The team, founded in 2011 as the Michigan Hybrid Racing team, moved from hybrid vehicles to full electric in 2019 in response to trends in the automotive industry. Many carmakers are turning to electric vehicles to help them address consumer demands for better fuel efficiency and cars that have less environmental impact.

MER includes the following divisions:

• Vehicle Dynamics and Chassis is responsible for all vehicle dynamics components of the car. They design and tune the chassis and suspension.

• Drivetrain is responsible for delivering mechanical power to the ground from the motors. They conduct vehicle simulations and design and manufacture gearboxes, corners, and the cooling system.

• Aerodynamics is responsible for all vehicle aerodynamics and body panels. They design and manufacture the front, rear, and side wings; undertray; nose cone; and side panels. 

• Ergonomics is responsible for any component the driver interacts with on the car. They design and manufacture components such as the seat, steering wheel, and pedal box.

• Controls is responsible for all low-voltage wiring and vehicle software. They design the software and vehicle dynamics programs that make the car drive. Controls is also responsible for the data logging system to tune the performance of the car.

• Powertrain is responsible for power delivery to the motors and most of the safety systems. This includes designing and manufacturing a custom battery pack, battery, high-voltage safety systems, and custom motor inverters.

Solution: Testing at Keysight’s Automotive Customer Center

MER consists of about 50 students and one faculty advisor. About half the students study electrical engineering, while the rest come mainly from mechanical engineering. Keysight provided technical support and electronic test instrumentation to the Controls and Powertrain divisions to help them design and optimize battery algorithm, battery-pack safety features, and motor controller performance.

Keysight’s Automotive Customer Center in Novi, Michigan, partnered with the Powertrain lead engineer, Spencer Hansen, a fourth-year electrical engineering student at the university. Hansen’s Powertrain division is responsible for designing and manufacturing the custom battery pack and motor controllers for the MER race car. “Keysight’s equipment has allowed us to collect our team’s most accurate battery data ever, which has been invaluable in designing the cooling of our car’s battery pack,” he said.

Each year, the team starts with the prior year’s electrical drive system and tries to make it more efficient, more powerful, and faster. Team members use actual data from the previous year and compare it to recent design simulations to create the improved battery design. Hansen wanted to test the 18650 lithium-ion cells members planned to use in their next-generation battery back for the 2020 season (MER 20 race car). The team needed an easy way to measure discharge curves and battery temperatures under various operating conditions with something that could dissipate more than 30 amps at normal lithium cell voltages.