New power generation – Bath goes electric at Formula Student

Stefano Dallavalle, Team Bath Racing Electric project manager, provides a fascinating account of the Formula Student experience, from assembling a team to the competition weekend.

Team Bath Racing Electric (TBRe) was formed in 2015 by a small group of final year undergraduate students who wanted to see the progression of EV technology at the University. Two years later, a strong team comprising first to final year students successfully competed at the UK Formula Student competition and are currently leading the way as the top UK electric team.

In September 2016, the aim was to increase the core of the team from 10 final year students to a team spanning both the Electrical and Mechanical Engineering departments at the University. It is widely recognised in the automotive industry that the next generation automotive engineer will require electrical and mechanical skills in equal measures, so attracting top students to the project was not difficult.

With a strong team, the next aim was to lock in the design early on and to order the main powertrain components and battery cells to avoid changes further on in the year. The extent of the challenge ahead was intensified from January 2017 with exams and academic hand-ins alongside our TBRe commitments and before we knew it, the competition was upon us.

Mechanically, the car was ready in good time but the time consuming, careful and laborious work of making and assembling all 1,000 parts of the two battery pack sub systems proved a challenge and a previously unknown area for the team. Ultimately, this critical system meant that testing time was extremely limited in the build up to competition. Never the less, with just days to go before Silverstone we successfully tested all sub-systems together and for the first time, TBRe17 moved under its own power. This was a big milestone for the team and a huge confidence boost going into the weekend.

Arriving on the Thursday morning, we quickly set up our pit garage and proceeded to mechanical scrutineering – going through each point on the checklist and slowly but surely ticking off each element. Due to our lack of experience at competition, there were a couple of issues surrounding our safety harness and steering rack – both of which were fixed on the Friday and the first scrutineering stickers were placed on the car.

Alongside mechanical scrutineering, the two battery packs were also assessed by the judges. Aided by full documentation and assembly procedure, both packs were passed by the judges first time without any issues - a huge testament to the fantastic in-house design, manufacture and build of the whole battery system.

The Formula Student weekend is not solely made up of dynamic events. Static design, costing and business judging also took place on the Friday and this gave our engineers a great chance to highlight the innovation and hard work put into the design of the whole vehicle. Our key design features included the battery packs, a custom driver display and energy usage algorithm, carbon fibre wishbones, an in-house battery management system as well as numerous PCB boards throughout the vehicle – all of which were designed by the team.

We successfully finished 20^th for our car design out of a field of over 80 other vehicles and the experience in both costing and business allowed for some of the younger members of the team to present and gain FS experience in the static events. Overall, a strong performance in the statics allowed us to become the top UK electric team.

Moving onto the Saturday, the dynamic events had started and to our frustration, we had not yet passed scrutineering. This meant we missed the acceleration event – an event where we knew we could have performed strongly!

Never the less, we knew electrical scrutineering would be a challenge and with no other UK electrical team passing scrutineering before 2017 we knew that our main focus had to be to pass before thinking about the dynamic events.

Again, due to lack of electrical scrutineering experience there were some issues that needed attention but nothing that couldn’t be fixed. After the most nerve-racking 4 minutes watching the car being soaked in water for the first time during the rain test, TBRe17 passed and received both low and high voltage stickers. Time was now running out on Saturday and we still needed the Tilt, Noise and Brake stickers to allow us to race on the Sunday. There was only time to complete the tilt test so this left us with two stickers still to get on the final day.

Sunday morning saw us sail through the noise and brake test but ongoing issues with the battery management system (BMS) and the danger of cells dropping dangerously under voltage meant that our electrical engineers had to make some last minute software changes to resolve the issue.

With the car successfully passing scrutineering, the whole team were itching to see the car out on track for the endurance event on the Sunday afternoon. The decision was made to run with half power to avoid further battery issues but then, out of our control, there was an issue with our current metre measurements. This was a hardware issue that other teams were also experiencing and could have meant that we missed out on the endurance event. With just 5 minutes to go to get into line for endurance, the scrutineers were happy to let us take TBRe17 out on track.

Even though we only completed 4 laps of the endurance, it was a fantastic moment for the team to see the car competing dynamically. The weekend was a great success and I personally am very much looking forward to seeing the continuing development and success of the team over the coming years especially with the strong 2^nd place finish for TBRe18’s car design in the class 2 event at the competition.