Introduction

The team of Electric Arrow was formed by former members of the Formula Student Team Tenfore Road Arrow in October 2018.

They decided to make this great project come true after years of work and experience on the first project, and now they have a desire to go one step further and move the borders of the past success.

This is the first Serbian electric formula team, and one of the first in the region, formed by students from 10 different faculties of Belgrade University.

Although the team was established in 2018, members of the Tenfore Road Arrow team developed a preliminary design of electric vehicle two years earlier, which won the third place in class II in the competition in Italy.

Now they want to design the new one, which will be much more complex and with much more innovation.

The Project

Their task is, to develop and construct a prototype electric racing car for unprofessional autocross or sprint racing in less than two years.

Electric arrow will compete in the e-formula class with more than two hundred student teams from around the world.

The team’s success is to construct a race car that, besides being fast, manageable and reliable, has an optimal price / quality ratio.

Using innovations and the most advanced technologies, the race car of this team will fulfill the high standards of the Formula Student Competition.

With this project we raise ecological awareness and encourage the application of knowledge in the light of sustainable development.

The most numerous members of this team are students of the Faculty of Electrical Engineering and Faculty of Mechanical Engineering.

These have shown their readiness to successfully deal with the numerous engineering challenges that have been faced with them in the Tenfore Road Arrow team so far.

It is also an excellent opportunity for all of them to use knowledge gained on the faculties and apply in solving one of the most complex tasks that students can meet during the course of their studies.

As this project is still developing, team members, through numerous educations and seminars linked to the use of software packages for modeling, preparing technical documentation, and learning rules and their importance, are preparing for competitions that are waiting for them.

Electric vehicle project is a 2 year project, as this year the team will compete in class II in UK and in Italy, and produce the vehicle for next season.

Both the electric and combustion team collaborate, and they will share the same telemetry and data logging board, sensor acquisition nodes as well the display.

This way they will not just save the money but also the time that is needed to design new concept.

Nikola Novaković – Project leader of the team Electric Arrow.

“The Tractive system accumulator gives 600 VDC on its output. It has a capacity of 7.7 kWh and it consists from 5 smaller segments.

In total it has 700 Li-ion cells in a 140s5p configuration.

Every segment has two BMS Slave (Battery Management System) boards which monitor the state of the cells. They measure voltage and temperature of the cells.

All 10 of these PCBs send data via a serial communications line which ends to a Master BMS.

This board is practically a microcontroller which is the brain of the accumulator. It has an integrated MCU chip (like the ones on our telemetry units).

The Low Voltage accumulator gives a 12 and 24 VDC voltage on its output. Designed in the same way as the HV Accumulator, the accumulator is built using Li-ion cells in a 4s8p configuration.

It also has its own Low Voltage BMS board.

Because the Inverters of the Tractive System demand a 24 V supply the accumulator has a 12/24 VDC converter using a boost converter.

All actions regarding the handling of the Tractive System, such as current and voltage measurements, safety circuit, pre-charge, discharge, visual and sound signalization of the TS state are done on a special board which we named TSMD (Tractive System Management Device).

Creating this board will be a real accomplishment because it has to sustains 600 Volts and currents up to 100 A.

To make matter even more difficult, the board features both HV and LV systems which are galvanically separated.

Whats Next

We are still planning on how to implement our ECU (Electronic Control Unit) which will command the whole vehicle.

So far it is most likely that we will use a powerful MCU with Simulink programming capabilities which will be plugged in our shield board.

The telemetry will be the same as that in our combustion vehicle which was proven to be very reliable in terms of durability, flow rate and accuracy last year.

The same goes for our LCD Display, with minor software changes regarding what information will be displayed.

As we consider the lithium battery pack the most critical part of an electric vehicle, we set our main goal for this season to design and properly test high voltage battery pack.

We want to manufacture and test our custom made Battery Management System for both our high voltage battery pack and low voltage battery.”

For the 2018/2019 season, it is planned to present the conceptual design of the vehicle, which will have significant improvements in relation to the 2016 version.

System design and development is currently underway, and component testing will follow shortly thereafter.

Going to a large European competition to compete in Class II will be an introduction to the design and testing phase, for the 2020 season.

As one step closer to that, the team of Electric Arrow has already qualified for the prestigious competition held in the United Kingdom on the famous Silverstone track.

Thanks to Eurocircuits

We are so grateful that Eurocircuits saw our potential back in 2017, and still believe in our ideas and desire to give our 100% in every moment of creating process.

Our last year attempt to design a PDU (Power Distribution Unit) as a PCB with relays and fuses on it proved to be a total success.

The board resisted high currents and temperatures with ease with no noticeable heating thanks to Eurocircuits quality printing and our designing skills.

For more information please visit the Tenfore Road Arrow – Electric Arrow website.