By Dr. Timothy Han, President and Sr. Director of Technology, SemiQ

The 2024-5 Formula SAE racing season is now complete, and we’re delighted to say SemiQ technology played a role in the development and racing of the University of California Santa Barbara Racing Team – better known as Gaucho Racing.

Gaucho Racing’s car was developed for the Formula SAE Electric event, which took place in Michigan this June, with the team also competing in regional/showcase events along the way. This year, SemiQ donated GCMX020A120B2B1P half-bridge MOSFET modules to the team, which played a critical role in the car’s powertrain.

The competition (and its European counterpart, Formula Student) plays a vital role in developing engineers and readying them for leaving university. If we look at those that have entered motor racing itself, we can list racing drivers such as David Brabham, and countless engineers: notably James Allison, the World Championship-winning Mercedes F1 team’s Chief Technical Officer; but also people like Jeff Braun and Craig Hampson, both exceptional IndyCar engineers. And for those not wanting to enter motorsport, the competition also does a spectacular job in preparing these talented engineers too.

“These programs teach you to think on your feet, to work on a system with other people, and to know how to sell / back up your decisions….  I have cohorts from my era who work in automotive, aviation, aerospace, Google, etc… and they all benefited from the experience.” This quote comes from a Formula SAE founder and is one of my favorites from the countless online surveys and Subreddits of Formula SAE and Formula Student alumni. It perfectly sums up the skills the competition provides.

These skills were certainly evident in the Gaucho Racing Team with the dedication they showed to create an innovative, efficient electric vehicle. We at SemiQ are so proud to have played even a small role in their journey. This pride was doubled on seeing Gaucho take third in their first race: November’s SoCal Shootout at the Willow Springs Kart Circuit.

Team Gaucho

While this is SemiQ’s first foray into Formula SAE, the 2024–25 Formula SAE season marked the second year of Gaucho Racing’s entry into the electric category. With it being their second run, the team’s ambition was to improve, and power electronics was a key focus of this – especially in relation to the front-wheel hub motors.

The motor controller project was aimed at developing a compact, lightweight, and efficient traction inverter for the two AMK DD5 motors driving the front wheels of the GR25 vehicle. An Emrax 228 motor was also used to drive the two rear wheels. These controllers had to meet both electrical performance demands and packaging constraints while conforming to FSAE safety and design regulations.

At the system level, the design team selected a two-level inverter topology. This choice reflects a practical trade-off between complexity and performance: while three-level or resonant inverters can offer smoother drive characteristics or higher efficiency, the two-level design minimized component count, reduced PCB area, and simplified control – appropriate for the sub-100A current class of the application.

Switching was handled by SiC MOSFETs, selected over silicon devices and IGBTs for their faster switching performance and lower losses at the target 40 kHz frequency. The use of SemiQ GCMX020A120B2B1P half-bridge modules in particular enabled high-speed switching and high voltage operation with sufficient thermal and current headroom.

The power stage was based on three of these SiC half-bridge modules, press-fit into a PCB with 2oz copper layers. This eliminated the need for external busbars and reduced parasitic inductance. Ceramic capacitors were placed close to the FET pins to mitigate voltage overshoot and ringing due to high di/dt transients. Each module supports continuous current up to 89 A (at 65°C case temperature) and peak current up to 250 A, which exceeds the continuous and transient demands of Gaucho Racing’s motors and allowed for thermal margin that ensured compliance with FSAE reliability requirements.

Of course, thermal management is vital, and this was achieved via a custom CNC-machined aluminium cold plate, shared between two inverters. The cold plate featured embedded mounting hardware and meandering fins to improve surface area and fluid contact. This design enabled compact packaging and high heat dissipation, supporting up to 1,863 W of peak thermal load per pair of inverters.

As these engineers come into the real world, they will need to work with constraints and the ability to optimize for countless criteria is a hugely important skill that every engineer needs to master. The team demonstrated they could do this in spades, making well-reasoned technical choices aimed at balancing performance, cost, manufacturability, and compliance within the constraints of a student-built electric race car.

In this case (the motor controllers and their power stages), the design highlights Gaucho Racing’s practical considerations, with the team selecting inverter topology, thermal design, and noise mitigation strategies appropriate to high-speed, high-switching environments.

If this team is anything to go by, there are about to be many very talented engineers entering the job market and we can’t wait to see what they can do.