Thermal Management Strategy for a Formula Student Vehicle: Modelling and Control of the Cooling Loop

This thesis aims to develop a thermal management strategy for a Formula Student vehicle, focusing on controlling the cooling system auxiliaries, specifically pumps and fans. The work is divided into two main stages. First, a thermal model of the existing cooling system is developed in MATLAB Simulink, based on the architecture of the Oxford University Racing 2023 single-seater. The model is then simulated to assess its dynamic behavior and responsiveness. The model’s response is analyzed under different external and operating conditions. Simulations are conducted to establish a reference condition. A maximum cooling scenario is simulated, where the cooling system auxiliaries operate at full power. This provides a baseline in terms of temperature at critical points of the cooling loop and energy consumption from the low-voltage battery pack. The second stage focuses on designing a control strategy. The control variables are associated with the radiator fans and pumps. The control strategy aims to maintain the temperature close to a target value while avoiding excessive cooling of components. Two control strategies are presented. The first is based on PID controllers, chosen for their simplicity and ease of implementation in Simulink. However, PID controllers may exhibit overshoot, which must be managed to avoid excessive temperature fluctuations and potential damage to powertrain components. The second approach utilizes a Model Predictive Controller (MPC), which is better suited for handling MIMO (Multiple Input Multiple Output) dynamic systems and predicting variations. This controller demonstrates greater robustness, but its computational demand is a key consideration for vehicle implementation. The conclusions show that implementing a control strategy that prevents excessive cooling of powertrain components can result in an energy saving of approximately 60%. This, in turn, brings several benefits, such as a lighter battery pack due to the reduced number of cells, and thus contributing to improved vehicle dynamics and lower costs. Additionally, in the context of Formula Student competitions, it can lead to higher scores in both static and dynamic events. A well-structured thermal management strategy ensures safe operation, preventing overheating and unnecessary energy losses, ultimately enhancing the team’s competitive edge.