Implementation of sensorless field oriented motor control in a solar car

Abstract

In this thesis the implementation of Field Oriented Control in the car of the NUON Solar Team will be discussed. The team decided to do research into the possibilities of a custom motor controller, and this thesis covers the beginning of that process. First a comparison between different control methods is made, and sensorless FOC is decided as the method to be used. Then the implementation of FOC is discussed. The Texas Instruments InstaSPIN™ technology has the preference for this implementation. This because it has all the elements of the control embedded in one microcontroller, along with a software estimator which eliminates the use of expensive sensors like a shaft encoder. Also the ease of use and the familiarity of TU Delft staff with this technology played a big part in this decision. With this technology, a simulation set-up was made as a proof of concept, which can also be used to teach the NUON Solar Team members the basics of motor control. After that the connections from the controller to the inverter are discussed, so it can be connected to other inverters in the future. In the controller, a CAN-interface is also implemented, which is essential for using it in the Nuna car. With the information presented in this thesis, the NUON Solar Team can continue the development of a controller. It is recommended to eventually leave the development kits used during this project, and integrate the MCU directly into an inverter. This will allow for well-tuned, efficient control of the motor with a small
footprint.