Transmotor Based Electric Bicycle with Independent Pedal Speed/Torque Control

Abstract

In this paper, an electric bicycle based on a dual mechanical port machine (also referred to as the 3-member transmotor), is proposed. By using the transmotor, the user is able to achieve independent control of torque and speed for pedaling and for bicycle propulsion. In other words, the user is able to pedal at the torque and speed of his/her own choosing, whilst maintaining complete and independent control of total bicycle propulsion. This is a feature that is not found in any of the e-bikes currently available in the market. A possible architecture for this model was looked at where a motor and generator were connected in series. An alternative and more integrated solution to this model was discussed in the form of the 3-member transmotor. A detailed description of the power balance equations for the transmotor and the various operating modes it offers is discussed. A study of the existing electric bicycle technologies and their shortcomings is given in this thesis, after which a model for an electric bicycle has been developed based on the transmotor and the series motor-generator models. The performance of the proposed systems and its comparisons with existing models is also presented after simulation in MATLAB.