Effectiveness of smart charging of electric vehicles under power limitations

• Published in: International journal of energy research Vol. 38; no. 3; pp. 404 - 414
• Main Authors: Lindgren, Juuso, Niemi, Rami, Lund, Peter D.
• Format: Journal Article
• Language: English
• Published: Chichester Blackwell Publishing Ltd 10.03.2014; Wiley; John Wiley & Sons, Inc
• Subjects: Applied sciences; Automobiles; Automotive engineering; batteries; Charging; Direct energy conversion and energy accumulation; Electric batteries; Electric power generation; Electric vehicles; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Energy; Exact sciences and technology; Fuel consumption; Mathematical models; plug-in hybrid electric vehicles; power grids; smart control; smart grids; Strategy; smart grids; Electric energy transportation; Electrical network; electric vehicles; batteries; Battery; plug-in hybrid electric vehicles; power grids; smart control; Smart grid
• ISSN: 0363-907X; 1099-114X
• DOI: 10.1002/er.3130

SUMMARY This article investigates charging strategies for plug‐in hybrid electric vehicles (PHEV) as part of the energy system. The objective was to increase the combined all‐electric mileage (total distance driven using only the traction batteries in each PHEV) when the total charging power at each workplace is subject to severe limitations imposed by the energy system. In order to allocate this power optimally, different input variables, such as state‐of‐charge, battery size, travel distance, and parking time, were considered. The required vehicle mobility was generated using a novel agent‐based model that describes the spatiotemporal movement of individual PHEVs. The results show that, in the case of Helsinki (Finland), smart control strategies could lead to an increase of over 5% in the all‐electric mileage compared to a no‐control strategy. With a high prediction error, or with a particularly small or large battery, the benefits of smart charging fade off. Smart PHEV charging strategies, when applied to the optimal allocation of limited charging power between the cars of a vehicle fleet, seem counterintuitively to provide only a modest increase in the all‐electric mileage. A simple charging strategy based on allocating power to PHEVs equally could thus perform sufficiently well. This finding may be important for the future planning of smart grids as limiting the charging power of larger PHEV fleets will sometimes be necessary as a result of grid restrictions. Copyright © 2013 John Wiley & Sons, Ltd. The effectiveness of electric vehicle battery charging strategies under power limitations was investigated by constraining the available charging power for groups of plugged‐in vehicles. Power to vehicles was allocated based on vehicle‐specific parameters such as the state‐of‐charge. The results show that only modest increases in total electric mileage were achieved through smart charging strategies. This indicates that large electric vehicle fleets could be incorporated to, e.g. smart‐grid schemes.