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

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.