State-of-the-Art Wireless Charging Systems for E-Bikes: Technologies and Applications

Several advancements were made in wireless charging for e-transportation however, the knowledge acquired in the context of wireless charging of electric cars are not sufficient to apply to electric bicycle (e-bikes). Therefore, this paper reviewed state-of-the-art wireless charging technologies with a special emphasis on e-bike charging. A comparative analysis of different kinds of wireless charging techniques is also presented to provide a clear understanding and guidelines to choose the best suitable technology for implementation in e-bikes. In addition, current issues, challenges, and future research scopes are identified where necessary modifications need to be done before implementing the technology for e-bikes.

I. Introduction

Transportation electrification is one of the potential solutions to mitigate environmental pollution and deal with the exponentially increasing fossil fuel price. However, the wide adoption of electric vehicles (EVs) is primarily bottlenecked by the high initial cost and the anxiety of accepting the new technology. Regarding these, electric bicycles (e-bikes) are the most convenient among EVs due to their low cost and maintenance, and their suitability to operate in crowded environments. As a result, the market share of e-bikes is increasing at a much faster rate especially in the developing countries and countries with high population density. Successful penetration of e-bikes in the market will act as a positive catalyst for the wide adoption of EVs due to the increasing confidence and acceptability of e-transportation [1]. The wireless charging system (WCS) provides significant advantages in the form of simplicity, convenience, reliability, and user-friendliness compared to the wired charging system which will aid the acceptance of e-bikes [2]. Broadly, wireless charging systems are two types namely, stationary and in-motion charging [3]- [5]. The stationary charging system is cheaper and more efficient wherein in-motion charging also helps to reduce the bulky batteries and enhance driving range by frequent top-up charging [6]. Existing wireless charging technologies have several limitations and disadvantages such as low efficiency, limited power transfer capability, misalignment concerns, and health impact and safety issues with electromagnetic interferences (EMI). Despite few review studies available in the literature, they focused on the WCS for EVs in general or primarily on electric cars. None of the studies highlighted the specific research gaps for the WCS of e-bikes. Weight, physical stability, cost, and maintaining minimum air gap is some of the important factors to be considered while designing WCS for e-bikes. Therefore, it is worthwhile to review the prominent developments in WCS to provide a guideline towards developing the best WCS for e-bikes.