Traction and Charging Systems for an Electric Motorcycle

Abstract

With the current mobility paradigm, it is proven that excessive energy consumption and low energy efficiency are harming the planet and deteriorating human life conditions. Therefore it is required to substitute Internal Combustion Engines (ICEs) for electric motors and consequently shift gradually to fully electric vehicle (EV) fleets. The electrification of mobility is one of the most researched topics in all technology fields. These efforts put society closer to achieve energy sustainability and reduce the negative human impact on the environment. With this, low energy consumption vehicles such as electric motorcycles (EMs) are a very viable solution to reduce energy consumption. Due to their low power and weight, EMs have high energy efficiency and are optimized for urban transit. In this context, it becomes necessary to develop systems and prototypes common to any EV. Therefore the focus of this thesis is to implement motor traction and battery charging systems for an EM.One of the most important characteristics of an electric traction system is the possibility of applying regenerative braking. Regenerative braking converts the mechanical energy, otherwise dissipated by conventional brakes, into reusable energy that is sent back to the batteries. This process occurs due to the operation of the traction system's power converter and improves greatly the energy efficiency of the EV. Besides, is proposed that the traction system's input is a hand accelerator that can control the motor speed/torque.The charging system acts as an interface between the power grid and the motorcycle system. In applications such as EV charging, it is important to ensure power quality in order to maintain the developed system and the power grid healthy. With this, the first stage of the charger is AC-DC rectification and besides regulating the DC-link voltage should also act as a Power Factor Corrector (PFC) and compensate current harmonics. Secondly, the charger system should be able to regulate and control the charging process by maintaining a constant current, voltage, or temperature. The charger should also ensure the battery's safety, and offer the possibility of regulating the charging speed. This document, details the development of traction and charger systems from the state of the art research and topologies presentation, to the computational simulations, and respective experimental tests/validation.