Energy-Efficient Thermal Comfort Management Using Infrared Panel Heating in an Electric Minibus

Operating in cold environments, electric vehicles (EVs) suffer from significant driving range reduction due to the high energy demand of cabin heating. To mitigate this effect, an integrated passenger cabin thermal comfort control strategy is developed for an electric minibus, which combines positive temperature coefficient (PTC) heater-based central heating (a conventional HVAC system) with local/distributed radiative heating utilizing infrared panels (IRPs). The control framework employs a hierarchical structure, where supervisory high-level thermal comfort controller optimally coordinates cabin air temperature setpoint and the IRP temperature reference of each occupied seat, achieved at the lower level by respective feedback controllers. The thermal comfort is quantified via so-called equivalent temperature feedback, capturing both convective and radiative heating contributions and accounting for the non-uniform thermal perception of different passenger body regions. The optimal cabin air setpoints, minimizing overall power consumption, are determined offline from extensive high-fidelity simulations for different minibus occupancy and a range of aggregated equivalent temperature operating points. Simulation results indicate that relatively fast dynamics of IRPs and their local heating contribution combined with the centralized HVAC system can significantly improve the passenger thermal comfort while reducing the battery energy consumption for both stationary and transient (heat-up) conditions.