Optimal Design of Charging Infrastructure and Battery Sizing for Electric Bus based Public Transportation System

Electrification of public transportation systems can significantly reduce the tail-pipe emissions from the vehicle fleet, thus helping alleviate emission concerns and contributing to global efforts towards sustainability. Climate goals and increasing regulatory restrictions on internal combustion engine-based buses in urban spaces are gradually leading to the widespread adoption of electric buses (EBs), which are both emission-free and quieter than conventional buses. Nevertheless, incorporating EBs presents significant challenges for the transportation sector and the power distribution utilities. Factors such as battery capacity, associated charging facilities and their impact on the distribution network must be analyzed thoroughly to ensure the smooth adoption of the EB ecosystem. This paper introduces a comprehensive mathematical model for optimal charging infrastructure design, and battery sizing for EB-based public transport systems in urban setups, including the charger power rating and the number of chargers required to cater charging demands of EBs. The operational schedule of the EBs on all the constituent routes, their per-kilometre energy consumption and on-route (opportunity) charging at the terminal stations have been incorporated into the model. The model has been implemented on a real-life public transit system in a city in India to validate its effectiveness and practicality. The obtained results are able to fulfil all the operational constraints of the considered problem while minimizing the incurred capital cost, which is expected to benefit the concerned stakeholders in making informed decisions on the investment opportunities and technical configuration of the transit system.