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

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 which could generate stress on the power grid and necessitate expensive investments for grid connection. An Electric Storage System (ESS) inside the FCS could mitigate those impacts, and a Battery ESS (BESS) also allows to offer grid services and to maximise the profits of the FCS operator. In this paper, we propose a FCS model including grid services and battery degradation. A trade-off between BESS size and contracted power value is assessed to satisfy the EV needs and to respect the battery state-of-charge limits. Finally, an economic survey is done with the net present value to compare a FCS with BESS (with or without delivery of grid services) and without BESS.

Abstract

The ability to store electrical energy adds several interesting features to a ships distribution network, as silent power, peak shaving and a ride through in case of generator failure. Modern intrinsically safe Li-ion batteries bring these within reach. For this modern lithium battery applications thermal management is vital in achieving a good trade off between maximum lifetime and optimal performance. This article addresses part of the thermal design of a battery storage system, based on commercially available lithium battery technology. During the design process the model assisted in assessment of design choices by checking that battery temperature rise would remain within acceptable levels. The final design is based on eight modules in parallel called PowerBlocks, where each module consists of thirty lithium batteries in series (30×12.8V = 384V; 130Ah) and a three phase converter. The complete battery storage system was modeled thermally, where validation of the model was done in the laboratory. Based on the experimental results from the validation a safe operating area was defined, which marks the thermal boundaries of the system. This study's conclusions indicate that commercially available lithium battery technology can, with good thermal management, be applied to improve the performance of power distribution systems in maritime applications.