Green Team Twente: The hydrogen racers

Blog by Green Team Twente.

Introduction

Green Team Twente is a student team building a car powered by hydrogen. The team consists of 31 enthusiastic students from different disciplines of the University of Twente and Saxion. Since 2011, we have been building cars that are powered by hydrogen, but two years ago we switched competitions. Where we used to compete in the Shell Eco Marathon, which is an endurance-focused race we now participate in Formula Student races. Participating in this competition requires building a new racecar every year. This year, we will be racing in the Netherlands and France.

Currently, we are the only team in the Formula Student that drives on hydrogen. By building a racecar powered by hydrogen we aim to prove the potential of hydrogen and accelerate the energy transition towards zero emission. A short-term goal is to convince other teams to switch to hydrogen and start a hydrogen competition within Formula Student, but on the long term we aim to also be an example for other industries and make a difference in the energy transition.

Last year, Green Team Twente managed to design and build a driving Formula Student car for the first time! This car contained custom-designed PCBs, manufactured by Eurocircuits. This year’s task is to improve and   of last year to facilitate the hydrogen setup inside the car itself.

BSPD

The Brake System Plausibility Device is an integral PCB built for the safety of the driver. This PCB checks if hard braking occurs while power is being delivered to the electromotors, making sure the car will shut down when the driver wants to make an emergency stop, or when the brake line disconnects. While this PCB has a defined function as per the Formula Student rules, it was changed quite a bit this year. With the basis that was laid last year, this year the BSPD’s size more than halved due to the removal of test signal circuitry.

TSAC Safety Circuit (TSC)

The Left TSAC of our car houses both the Insulation Insulation Monitoring Device (IMD) and Accumulator Measurement System (AMS). Both components need to be able to open the Shutdown Circuit (SDC) whenever an electrical unsafe scenario is detected. The PCB designed to facilitate this logic is called the TSAC Safety Circuit (TSC).

The TSC incorporates logic to detect unsafe status inputs from the IMD and AMS. If detected, it triggers a latch to open the SDC. It is crucial that this logic relies on non-programmable logic. Additionally, the TSC obtains CAN information from both the IMD and AMS and forwards this to the electronic control unit (ECU). Consequently, status signals are transmitted to the ECU to activate error LEDs if either device presents issues.

The primary change compared to last year is the modification in how the error indication signals are forwarded to the ECU. Instead of powering the status LEDs directly from the TSC, a status signal is now transmitted to the ECU. This guarantees that the LEDs remain illuminated even if the TSC is disconnected, ensuring full compliance with FS regulations.

What’s next?

With the quick check and confirmation times of the Eurocircuits engineers, these PCBs could be ordered within a few working days after finishing the design. We will be making more orders this year with the end goal of powering our high-voltage electronic systems inside the first-ever Formula Student car powered by a self-build hydrogen system!