Computing an Upper Bound for Charging/Discharging Patterns of In-Vehicle Batteries towards Cooperative Transportation-Energy Management

Abstract

The purpose of our research is to establish a novel design of cooperative management system for transportation and energy in a distinct: Electric-Vehicle (EV) sharing and electric-power distribution. A mathematical model of distribution voltage profile, called the ODE (Ordinary Differential Equation) model, plays a central role in this study. An approximate solution of the ODE model for a single straight-line feeder is derived in literature. In this paper, based on the ODE model and its approximate solution, we propose a method for computing an upper bound for charging/discharging patterns of in-vehicle batteries so that the amplitude of distribution voltage at the end point of the feeder can be bounded at its pre-defined acceptable value. The method is computationally simple and easy to implementation, and is therefore utilized for distribution voltage support as a key function of the cooperative management. Effectiveness of the proposed method is established with numerical simulations based on a combination of a practical grid model and synthetic operational data on EVs in a sharing service.