Hardware-in-the-Loop Implementation and Validation of a Closed-Loop Thermal Management System for High-Power EV Converters

This paper presents the design, hardware-in-the-loop (HiL) implementation and experimental validation of a closed-loop thermal management system (TMS) that employs a Texas Instruments C2000 LAUNCHXL-F28379D microcontroller integrated with MATLAB/Simulink real-time controller development. The developed TMS consists of a radiator with fixed fan cooling, a DC pump actuated through a pulse-width modulation (PWM) signal, a Hall-effect-based flow sensor, a heatsink temperature sensor and two negative temperature coefficient (NTC) water temperature sensors to measure the inlet and outlet coolant temperatures on either side of the heatsink. In order to make the sensor outputs compatible with the analog-to-digital converters (ADCs) of the microcontroller, a hardware scaling board is designed, while the PWM output of the microcontroller is utilized through a hardware interface to switch a 12 V DC PWM signal for the pump. For the flow control loop, open-loop experimental measurements are employed to derive a third-order state-space mathematical model of the TMS, where a high coefficient of determination between the real-time system and the mathematical model demonstrates the acceptable accuracy of the developed model. The identified third-order model is reduced to a second-order representation by removing a near-canceling pole–zero pair, while accounting for input delay, flow offset and pump duty cycle scaling. For the closed-loop heatsink temperature control, a practical control framework is adjusted iteratively since the ambient temperature influence and thermal disturbances make the extraction of a sufficiently reliable mathematical model less practical for controller tuning. The experimental results verify stable heatsink temperature regulation with low steady-state error, although with slower dynamics as expected due to the thermal inertia of the system. In this work, the developed HiL-based TMS provides a practical platform for the implementation and validation of real-time thermal control strategies.