Energy Consumption of In-Vehicle Communication in Electric Vehicles : A comparison between CAN, Ethernet and EEE

Abstract: As a step towards decreasing the greenhouse gas emissions caused by the transport sector, electrical vehicles (EVs) have become more and more popular. Two major problem areas the EV industry is currently facing are range limitations, i.e. being restricted by the capacity of the battery, as well as a demand for higher bandwidth as the in-vehicle communication increases. In this thesis, an attempt is made to address these problem areas by examining the energy consumption required by Controller Area Network (CAN) and Ethernet. In addition, the effects of Energy-Efficient Ethernet (EEE) are reviewed. The protocols are examined by performing a theoretical analysis over CAN, Ethernet and EEE, physical tests over CAN and Ethernet, as well as simulations of EEE. The results show that Ethernet requires 2.5 to four times more energy than CAN in theory, and 4.5 to six times more based on physical measurements. The energy consumption of EEE depends on usage, ranging from energy levels of 40 \% less than CAN when idle, and up to equal amounts as regular Ethernet at high utilisation. By taking full advantage of the traits of Time-Sensitive Networking, EEE has the potential of significantly decreasing the amount of energy consumed compared to standard Ethernet while still providing a much higher bandwidth than CAN, at the cost of introducing short delays. This thesis provides insight into the behaviour of a transmitter for each of the three protocols, discusses the energy implications of replacing CAN with Ethernet and highlights the importance of understanding how to use Ethernet and EEE efficiently.