Unical Reparto Corse

Unical Reparto Corse is the racing team of the University of Calabria, founded in 2005 by Professor Maurizio Muzzupappa, the Faculty Advisor who supports and guides students from the initial idea to the project's completion.

According to an organizational chart, the team is divided into groups each specialized in a specific aspect of the project, but interdependent and crucial to each other, as collaboration is essential for the project's overall success: designs and construct a Formula SAE racing car to participate in international competitions, usually hosted at renowned F1 circuits.

In particular, the entire competition consists of both static and dynamic events. Among the static events, after the Technical Inspection, where compliance with the project specifications required is checked, there are the Cost and Manufacturing Event to assess the team's comprehension of the manufacturing procedures for building a prototype, the Business Presentation Event to formulate and present a thorough business model and the Engineering Design Event to judge the engineering process and effort exerted by the students.

The dynamic events consist of an Acceleration Event to measure the vehicle's speed, a Skidpad Event to evaluate maneuverability and lateral grip, an Autocross Event which is a timed race on a twisting course, and the Endurance and Efficiency Event, a long-duration race that tests the vehicle's durability and reliability over a 22 km distance.

After the great result achieved: 3rd place overall at Formula SAE Italy in the 2022 season, the team decided to take on a new challenge: designing, building, and competing with its new and first Formula Student Electric car. Therefore, there was a need to have high-quality custom circuits and PCBs necessary for the vehicle's realization, and we believe that PCBWay is the best ally.

Examples of the boards we have designed are: BSPD, PDM, BMS SHIELD, BMS SLAVE, HV INDICATOR, TSAL LV, TSAL DCLINK, TSAL TSAC, TSAL LIGHT, TSMP, BRAKE LIGHT

BSPD

The BSPD (Brake System Plausibility Device) fulfills the function of controlling the amount of power transferred to the electric motor and at the same time the pressure exerted on the brake pedal, to detect a possible condition of implausibility, which occurs when the pressure sensor, positioned on the brake pedal, measures a pressure greater than 30bar while the power transferred to the engine is greater than 5kW. Under such conditions, the BSPD must open the shutdown circuit (SDC). The designed BSPD is equipped with three connectors for communication with other vehicle components: one transfers values from the brake pressure and current sensors, another supplies power from the LV Battery to onboard electrical components, and the third provides output to the SDC.

PDM

The Power Distribution Module is an intelligent circuit responsible for managing low-voltage electrical loads, such as sensors, water pumps, and fans, using solid-state relays controlled by a microcontroller. It communicates via CANBUS with the Vehicle Control Unit, which toggles the load on or off and receives feedback regarding the current consumption as well as information about the PDM's status. It is based on solid-state power relays, the Profets.

BMS SHIELD

A custom expansion board for the microcontroller evaluation board was developed by the team in order to integrate the components for the SDC powerstage, the activation logic with MOSFET for the AIRs control, transceivers for CAN communication and PCB connectors. In fact, the evaluation board comes with pin headers, that are good for testing and rapid prototype purpose, but they not offers a reliable electrical and mechanical connection for the external wires from and to the BMS.

HV INDICATOR

The voltage indicator, mandated by the regulations, activates whenever the voltage exceeds 60 VDC. It is required to be powered directly and exclusively by the TS on the vehicle side of the AIRs. Furthermore, it is necessary for it to be a hard-wired electronic system, devoid of software control, with the capability to remain operational even if the accumulator is removed from the vehicle or disconnected from the LVS. Therefore, a DC-DC Flyback converter should be integrated to provide isolated low voltage to both the logic and the indicator.

TSAL

The TSAL (Tractive System Active Light) is a signaling device that indicates the presence of a dangerous voltage in the Tractive System. Its basic function is to indicate, through a flashing red light, the presence of a voltage higher than 60 V DC in the Tractive System and, through a steady green light, the absence of dangerous voltages. The device is partitioned into three distinct boards, each situated within its designated circuit enclosure for measurements, as mandated by regulations. More precisely, two boards are allocated for high voltage measurements in the TSAC and DC-LINK. The first will contain the voltage detection circuit post-AIR within the TSAC, an isolated DC-DC converter, an LDO, and the circuit for detecting the mechanical state of the relays. The second will contain the voltage detection circuit for the DC-link, an isolated DC-DC converter, and an LDO. The third LOW VOLTAGE board is tasked with identifying any irregularities in the signals generated by the HV boards and managing the logic associated with these signals. This board will be positioned outside the LV case and will contain all the signal processing logic generated by the various detection circuits. It includes an LDO, a timer circuit, a latch, and finally, the logic circuitry.

BMS SLAVE

The master-slave configuration of the Battery Management System (BMS) involves a main controller, known as the master, that coordinates various control devices, called slaves, to optimize system performance and ensure safety. A custom PCB for the BMS slave IC is designed by the team, following the hardware design guideline document, layout recommendation for the battery cell controller, and the design of the evaluation board provided by NXP. The slave is composed of two boards connected with an unshielded twisted pair: the first is used to connect the cell terminal and the NTC sensor with a soldering pad and is fixed on the battery pack segment, while the second is the BMS slave itself. The second board contains the NXP IC and the components needed for ESD protection, cell voltage and temperature measurement (low-pass filters and pull-up resistor), balancing (resistor), and TPL communication.

TSMP

The TSMP (Tractive System Master Points) are key control points for the vehicle's tractive system, and these points are essential for ensuring the safety and control of the vehicle's high-voltage electrical system. We chose to design a PCB instead of using panel-mounted power resistors because the printed circuit board offers many advantages, one of which is reducing bulkiness. According to the regulations, appropriate resistors were selected corresponding to the voltage provided by the battery pack, which in our case is 453.6 [V], resulting in 15kΩ. Furthermore, they are required to feature 2 output connectors, specifically banana jacks (TS+, TS-). Following this, the resistor selection process took into consideration not only their nominal value and voltage rating but also their power dissipation characteristics.

BRAKE LIGHT

On this PCB, there are the LEDs and the brake light, which must activate every time a braking action occurs.

At last, we would like to extend our gratitude to PCBWay for their support and the opportunity to assist us with our project.