Grid-Aware On-Route Fast-Charging Infrastructure Planning for Battery Electric Bus with Equity Considerations: A Case Study in South King County

TL;DR

This paper presents a comprehensive planning framework for on-route fast-charging infrastructure for electric buses, integrating power and transit networks, with a focus on cost efficiency and social equity in South King County.

Contribution

It introduces a novel mixed-integer second-order cone programming model that considers grid constraints and fairness, advancing infrastructure planning for electric buses.

Findings

Optimized charging station locations reduce total costs.

Incorporating fairness improves social equity in infrastructure deployment.

The model balances economic and social objectives effectively.

Abstract

The transition from traditional bus fleets to zero-emission ones necessitates the development of effective planning models for battery electric bus (BEB) charging infrastructure. On-route fast charging stations, distinct from on-base charging stations, present unique challenges related to safe operation and power supply capacity, making it difficult to control grid operational costs. This paper establishes a novel framework that integrates the bus route network and power network, which leverages the inter-dependency between both networks to optimize the planning outcomes of on-route BEB charging stations in South King County. The problem is formulated as a mixed-integer second-order cone programming model, aiming to minimize the overall planning cost, which includes investments in charging equipment, power facility, and grid operation. Furthermore, fairness measurements are incorporated into the planning process, allowing for the consideration of both horizontal transit equity and vertical transit equity based on different zone merging criteria within the county's existing census tracts. The results of this planning model offer valuable insights into achieving both economic efficiency and social justice in the design of on-route charging facilities for BEBs in South King County.