Efficient Electric School Bus Operations: Simulation-Based Auxiliary Load Analysis 2024-01-2404

The study emphasizes transitioning school buses from diesel to electric to mitigate their environmental impact, addressing challenges like limited driving range through predictive models. This research introduces a comprehensive control-oriented model for estimating auxiliary loads in electric school buses. It begins by developing a transient thermal model capturing cabin behavior, divided into passenger and driver zones. Integrated with a control-oriented HVAC model, it estimates heating and cooling loads for desired cabin temperatures under various conditions. Real-world operational data from school bus specifications enhance the model’s practicality. The models are calibrated using experimental cabin-HVAC data, resulting in a remarkable overall Root Mean Square Error (RMSE) of 2.35°C and 1.88°C between experimental and simulated cabin temperatures. A lateral powertrain model has been developed that encompasses vehicle dynamics, electric machinery, transmission, and electrical loads, crucial for holistic analysis. The model also estimates the battery pack’s state-of-charge (SOC), vital for e-bus operations. The paper demonstrates the powertrain model with and without thermal load characterization to precisely estimate the battery SOC. This implies a foundational tool for thermal load management by accurately characterizing load peaks and enhancing the drive range through different control-oriented strategies. This research is pivotal for advancing sustainable transportation through optimized e-bus emissions, enhanced vehicle performance, and improved public transit quality.