One of the main goals of Poly eRacing team is to accelerate the development and improve technology related to electric cars. This is the reason the team, at its begining, decided to share all of its electrical circuits designs, even though Formula SAE is a design competition. Hence, we are publishing here the design files of all the electrical circuits developped and used in 2016 competitions under GNU GPL v3.
If you want to encourage us on keeping publishing our designs, let us know by sending us an small thank you email. If you also want to share your knowledge, feel free to send us some of your designs or comments on our designs so we can also learn from you.

BMS

BMSafe (original project name) is a multi-chemistry battery management system designed for safety critical systems like EVs. It uses a master/slave topology communicating via a high speed CAN link. PCBs are designed in Eagle, code is written in C, IDE used is CodeWarrior, and ICs are Freescale and Linear.

Features:
  • up to 12 cells per slave module
  • 12 thermistors inputs per slave (for temperature measurement)
  • Isolated High Speed CAN 2.0 Communication
  • Passive balancing auxiliary circuit
  • Cell voltage range: 0 to 5V
  • Easy slave connectivity (daisy-chain)
  • Accumulator isolation relay control
  • Compatible with Brusa NLG5 chargers (CAN controlled charging)
  • Many security features and plausibility checks
  • Slaves are directly powered by the cells
  • Master can be powered by an external voltage source from 7 to 36V

Archive

HVS

The High Voltage Systems (HVS) is the interface between the high voltage and low voltage in the vehicle. It is used to ensure safety from the high-voltage battery and to supply power to low voltage systems of the car.

Features:
  • TI TM4C MCU
  • CAN Bus Communication
  • Modular Design – Main Board and Subsystems Board
  • Insulation Monitoring Device Interface (Bender IR155-3204)
  • 250W 24VDC Output DCDC Converter and Monitoring Interface
  • Precharge and Discharge Circuits
  • Temperature Sensing Interface
  • LV Electrical Load Control and Monitoring (Voltage and Current)

HVS Main PDF HVS Sub PDF Archive

TCS

The Traction Control System circuit (TCS) interfaces the acceleration and brake pedal and connects by CAN with the motor drive to send torque commands.

Features:
  • CAN communication interface
  • Multiple available inputs (current transducer, speed sensor, …)
  • Redundancy (multiple sensors) and plausibility checks (pedal and accel positions)
  • Brake System Plausibility device (hardware)
  • Interface with the Bamocar D3 drive

Archive

Dash

The dashboard is a module designed to communicate relevant informations to the driver, such as the state of charge of the batteries, the speed of the car and any errors that might occur in the system, while allowing him to activate certain functions such as traction control. Moreover, this module will gather various relevant informations about the different modules present in the car by listening on the CAN (Controller Area Network) communication. It will then send this information to the team through Wi-Fi to analyse the car’s performance in order to fine tune various parameters, improve design or driving techniques. In addition to gathering and sending relevant messages received over CAN, the dashboard also collects data by itself. Indeed, a GPS (Global Positioning System) as well as an accelerometer and a gyroscope have been installed on the PCB (Printed Circuit Board). A speed sensor also hooked to the front wheels also provides useful information about the car. Finally, an SD card (Secure Digital) enables data logging, preventing any loss of data. This compact system is packed with functionality and will greatly improve our team’s ability to tweak the performance of our car and guide future design.

Dash PDF Archive