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Part 2: Computerizing Public Sector Industries International audience An important application of computers from the 1950s and onwards has been for designing and operating complex infrastructural systems like air traffic, telephony, railways, and electricity. This paper tells the story about how computers from the 1950s and onwards became an important tool for designing and operating the Swedish power grid. It describes two phases of this development. In the 1950s and 1960s, computers were used for making complicated calculations for designing power grids in a reliable way and optimizing the use of the different power plants. In a second phase starting in the late 1960s, computer systems were developed for real time monitoring supporting human control of the power grid. The paper analyzes by whom and for what purposes computers became tools for controlling electricity flows. In the conclusion, it also discusses the wider implications of computers for the development of the Swedish power system. Document type: Part of book or chapter of book

Abstract

International audience; Electric Vehicles (EVs) will be in a near future a non-negligible part of the world's car fleet. Nevertheless, a dense network of Fast Charging Stations (FCS) on highways is needed to enable EVs to be competitive with Internal Combustion Engine (ICE) vehicles for long distances. FCS require high power from the grid to charge EVs in less than 30 minutes. Such high power will generate negative impacts on the power grid and will necessitate high investment costs for grid connection. A Battery Electric Storage System (BESS) inside the FCS could alleviate those negative impacts. The presence of a BESS then permits to offer grid services and to increase the profits of the FCS operator. However, the deployment of grid services with BESS is often faced to concerns on additional battery degradation. In this paper, we propose a FCS model including grid services and a study of battery degradation under different circumstances, and an economic comparison is done with the net present value.

Abstract

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.