Managing electric vehicles with renewable generation through energy storage and smart grid principles

Abstract

Electric vehicles (EVs) are the most comprehensive method of sustainable transportation because they are environmentally friendly, quiet and low maintenance. However, they suffer from low usability because of the limited distance that can be covered on a single charge, which limits the freedom of transportation. Further, the charging process to restore the initial driving range is relatively long compared with conventional solutions. The only proposed way to improve the distance on a charge is to install a large energy storage system (ESS), which takes up more space, thereby limiting the usability of space by passengers and increasing the weight of the EV. The increased weight and size of the EV also negatively affect the distance range. In addition, the larger size of the battery, which is the main component of the ESS, requires a longer charging time. The current solution for fast charging requires more time than traditional refuelling techniques. This study aims to design, develop and analyse a novel approach for improving the energy consumption of EVs using optimisation techniques. In the first phase of the study, detailed analysis is conducted of the existing systems of EVs to determine which areas can be improved. The outcome of this investigation is used to determine presented loading profile of the various loads in EVs and determine the way to characterise them. These results are applied to design the new architecture for the loads to improve the connectivity of the various components of EVs and introduce interaction between loads. The developed architecture has centralised topology with separated control bus for the safety systems to satisfy the ISO 26262 safety standard. The newly developed system considers various loading requests at the same time to supply the load. The control algorithm schedules the power supply to the selected loads or, in some cases, clips the load request to decrease the momentary energy consumption. To achieve better optimisation, the thermal energy generation is analysed because it has a significant effect on the electric energy consumption in the heating elements. The second part of the developed approach is deep integration of loads with the overall energy flow in EVs. As a result, the recuperated energy in the propulsion system can be transferred to the components of the ESS and to supply the auxiliary loads on demand. The xviii generation units are combined with a photovoltaic system to improve the generation capability of the architecture. One of the key aims of this research is the simulation and experimental study of the developed architecture to identify weak spots in the solution and compare its performance with existing solutions under various solutions that go beyond traditional driving cycles