A DREAM COMES THROUGH FOR THE AGORIA SOLAR TEAM
After 7 exhausting racing days, the AGORIA SOLAR team took home the World Cup of the Bridgestone Solar Race 2019 last weekend. On the last racing days it became clear that it would be a neck to neck race. On the penultimate day of racing, the team was able to close the 43-minute time gap thanks to a clever racing strategy. With only 2 minutes and 27 seconds to go, they started the last day of the race and took first place about 250 km before the finish. The TEP 75 DC-DC converter from Traco Power was a key component for winning this prestigeous race!
The full story told by the engineering team of the Agoria Solar Team:
Introduction
The Agoria Solar Team is a student team that consists of twenty students. We all share the passion and motivation to build the winning solar car of the Bridgestone World Solar Challenge (BWSC) 2019. The BWSC is a solar race that spans 3021 km through the Australian outback. The cars are aloud to drive between 8am and 17pm with 9 obligated control stops. The average speed is about 80km/h and the only source of energy aloud to use is the sun.
We are the eighth Solar Team and we have the opportunity to build on the experience of our predecessors. Their experience mixed with the newest technologies implemented in an reliable way, is the perfect mix to build a winning solar car. The previous solar car of the Belgian team was the result of a good co-operation with companies and the use of their high-end technology. Our previous solar car finished in 3th place out of more than 40 teams!
High voltage system of our race car
In order to have an electrical buffer between the solar panel and the electric motor a 5.3kWh battery pack is used in the car. These are standard 18650 batteries that are placed in series and parallel so that a rather high voltage of 130V is achieved on average.
Most of the components used in the solar car are designed by ourselves because our needs for high efficiency, low weight and functionality are so specific. Something we did not design ourselves because the product did already exist, ready to use, and suited our needs so perfectly is the TEP 75-7212WI-CMF. This is a high-voltage DC/DC convertor from TRACO POWER that steps down our battery voltage to a stable 12V.
With an efficiency of over 91% this convertor is responsible for the whole ‘low-voltage’ system of the solar car. This system is used for data communication outside of the solar car, to power the lights, the steering wheel and much more. This ‘low-voltage’ system is really the beating heart of the solar car and we cannot let it fall out during the race. This is also a big reason why we chose the TEP 75-7212WI-CMF.
The ‘CMF’ part of the TEP 75 is an EMI filter built in the DC/DC convertor. For us, this is worth the extra weight because we cannot afford any noise on our CAN-bus.
Low voltage convertors
In order to power our processors which need a stable 3.3V we use the TRACO POWER TSR 0.5-2433SM. This is a DC/DC convertor that steps down the 12V that powers the car to 3.3V to power the processors. The convertor is a switching DC/DC that provides a higher efficiency than any other type on the market.
The compact design of the multiple layer PCB inside the convertor allows for an efficient use of space. This a way more compact than if we designed it ourselves. Also the build in protections always come in handy when you need them, like the overcurrent protection.