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The increasing demand for electric vehicles, due to advantages such as higher energy efficiency, lower fuel costs, and less vehicle maintenance, is expected to drive the need for electric vehicle charging infrastructure. Due to their reduced size and weight, high power and scalable compact solid state transformers (SST) are growing in popularity. This study presents the total loss analysis and control design for a direct grid connected single-phase SST for a fast charging station. A control strategy to achieve robust current control, DC voltage and power balancing, and power loss minimization (PLM) is implemented for this system. Detailed analyses and simulation results obtained from MATLAB/Simulink are given to prove the effectiveness of the proposed control techniques.
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Joint Optimization of Autonomous Electric Vehicle Fleet Operations and Charging Station Siting
Charging infrastructure is the coupling link between power and transportation networks, thus determining charging station siting is necessary for planning of power and transportation systems. While previous works have either optimized for charging station siting given historic travel behavior, or optimized fleet routing and charging given an assumed placement of the stations, this paper introduces a linear program that optimizes for station siting and macroscopic fleet operations in a joint fashion. Given an electricity retail rate and a set of travel demand requests, the optimization minimizes total cost for an autonomous EV fleet comprising of travel costs, station procurement costs, fleet procurement costs, and electricity costs, including demand charges. Specifically, the optimization returns the number of charging plugs for each charging rate (e.g., Level 2, DC fast charging) at each candidate location, as well as the optimal routing and charging of the fleet. From a case-study of an electric vehicle fleet operating in San Francisco, our results show that, albeit with range limitations, small EVs with low procurement costs and high energy efficiencies are the most cost-effective in terms of total ownership costs. Furthermore, the optimal siting of charging stations is more spatially distributed than the current siting of stations, consisting mainly of high-power Level 2 AC stations (16.8 kW) with a small share of DC fast charging stations and no standard 7.7kW Level 2 stations. Optimal siting reduces the total costs, empty vehicle travel, and peak charging load by up to 10%.
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- Award ID(s):
- 1837135
- PAR ID:
- 10317909
- Date Published:
- Journal Name:
- 2021 IEEE International Intelligent Transportation Systems Conference (ITSC)
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1109/ITSC48978.2021.9565089
