Johannes Karlsson, Electrical engineering

Johannes Karlsson is a PhD student in the research group Automatic Control, Division of Systems and Control

Discussion leader is Dr. Maria Taljegård, Energy Technology, Chalmers

Main supervisor is Professor Anders Grauers, Division of Systems and Control

Examiner is Professor Torsten Wik, Division of Systems and Control

Abstract

One possible step for reducing humans use of fossil fuel due to transportation is to replace diesel trucks with battery electric ones. This thesis focuses on effective system solutions for battery electric trucks but not the ones which can charge while driving on so called electric roads. The energy distribution diagram is introduced which makes it easy to visualise the daily energy consumption for the trucks full service life in a compact way. The energy distribution diagram is used to investigate which driving patterns that are suitable for cost effective battery electric trucks and the cost is compared to commercial diesel trucks. These analyses are done both for several simple shapes of the energy distribution as well as for a special case of electrification of long-distance line-haul trucks. An investigation about how to select the total power of a charging station with a given demand of charging is also presented. Finally, the charging needed for trucks, the charger utilization and the problems with queuing at chargers along a highway in Sweden is investigated with an agent-based model based on traffic data.

The results indicates that the utilization of the chargers along the investigated highway could be high and at the same time the system will have good ability to resist queues. Regarding the total power of a charging station, it is found that it is not always optimal to meet the maximum charging demand if the goal is to maximize the net income for the charge point operator.

Further on, the battery electric trucks are, in many cases, found to be competitive to the commercial diesel trucks, especially when there is low variation in the daily energy consumption for the trucks. It is useful to find under what circumstance they may be cheaper, as it will be much easier to transition into battery electric trucks in segments in which the total cost of ownership is reduced. Cost-effective solutions for battery electric trucks are therefore highly important to find, and this thesis explores some of the main factors and trade-offs which influence the effectiveness of the whole system.