Bring your product to market on time and within budget – join the Eurocircuits Community
Hanze Racing Division, HARD, is a student racing team from Groningen. They are currently working on their first driverless, electric race car, with a group of 40 students, and are planning to race at the Formula Student in the summer of 2023. Formula Student is a motorsport design competition where different student teams compete. In previous years, HARD has worked on combustion engine cars, but they decided to start working on an electric car. To realise this, there is a complex electrical system, which requires different PCB’s.
The most important and the first part on the electrical systems are the rules given by Formula Student. It is key to get to know these rules and know what your system is required to do. These rules specify the safety requirements and the restrictions for the car. When this is done, the schematics can be drawn, and the required component will be selected.
Next up is simulating the PCB’s. By running simulations of the PCB’s, most of the errors can be found before ordering the PCB. This saves a lot of money, effort, and time. When the simulations are successful, designing the PCB can start. There are some extra rules concerning electrostatic discharge (EDS) and ground connections to ensure the safety of the car.
When the design is ready, another member of the team will review the design to see if he can find any errors that the designer might have missed. If the review is successful, the chance of running into issues with the PCB has come down enough to compose a bill of materials and order the PCB at Eurocircuits. When the PCB has arrived, it will be soldered and then tested by the students. If during testing any issues arrive, they will try to figure out where the mistake was made and try to fix it. If the testing is successful, the PCB is ready to be used in the race car!
A very important part of the electrical system is the shutdown circuit. If something happens that isn’t supposed to happen, the shutdown circuit will get notified and shut down the vehicle. To make this shutdown circuit, we make use of different sensors, switches, and PCB’s.
To start the electrical system there is a low voltage (LV) battery. This will supply the shutdown circuit with the necessary current. The first block in the circuit is the LVMS, or Low voltage master switch. This is a physical switch on the side of the car that is turned on when starting the vehicle to allow the current to flow to the rest of the shutdown circuit and the rest of the low voltage system.
The second block is the BSPD, or Brake System Plausibility Device. This device monitors faults in the braking system. If braking goes wrong, it will automatically shut down the circuit. After that, you can see the IMD, or Insulation monitoring device, and the AMS, Accumulator management system. The IMD continuously checks if the value of the insulation resistance falls below a response level. If so, the system will shut down. The AMS checks if anything is wrong with the cells of the accumulator container, and again, if anything is wrong it will shut down the system.
On the car are three shutdown buttons. These are physical emergency buttons that can be pushed by people around or inside the car to shut down the circuit. There is one button inside the cockpit and one on the left and right side of the car.
AS and RES, Autonomous system, and Remote emergency system, are systems that come from the driverless systems of the car. If anything goes wrong in the driverless systems, these PCB’s will get that feedback and are able to shut down the entire vehicle.
If the car crashes and thus decelerates at an abnormal amount the Inertia switch will get activated and it will shut off the systems. BOTS, or Brake over-travel switch, will get activated when the brake paddle breaks. There is a switch behind the brake paddle, which it can’t reach when fully intact. When broken the brake paddle will exceed the regular travel distance and activate the switch.
TSMS, or Tractive system master switch, is a switch that needs to be turned on when starting the car to allow the current to flow through the rest of the circuit. The AIR Coils, or the Accumulator isolation relay coils, check if there is current flowing in its coils. If so, it will activate the high voltage systems and if not, the systems get deactivated.
The Activation logic is related to the start button inside of the cockpit.
For more information, please visit the Hanze Racing Division website.
Be the first to read all about our news and information. Follow us on