In this thesis, the development of software for controlling an active rectifier is presented. The aim was to use an electric bicycle as an energy source for a microgrid. The objective was also to develop the software so it could simulate riding a bicycle outdoors while the bicycle is mounted on a stand. To accomplish that, we used field oriented control (FOC).
We used FOC to control the permanent magnet synchronous motor (PMSM), that is part of the electric bicycle, as a generator. Necessary changes to the FOC algorithm were made to control the PMSM, and we eliminated the need for a position sensor by implementing a rotor position estimation algorithm. To simulate riding outdoors, we also added a torque function that is dependant of bicycle speed.
Because of the gear ratios on the bicycle, we implemented additional protections alongside the existing FOC protections to adhere to selected microgrid requirements. This was necessary because a user can propel the bicycle to produce back-EMF voltages outside the microgrid's required range for safe operation. To rectify this, we implemented two back-EMF voltage protections that solve the issue.
Finally, we measured the efficiency of the active rectifier, tested the implemented voltage protections, and conducted a user study in which participants selected, from a set of torque functions, the one that best represents riding a bicycle outdoors.
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