Position Sensorless Control of the PMSM in a Wide Speed Range

Position Sensorless Control of the PMSM in a Wide Speed Range

Brouwer, J. (TU Delft Electrical Engineering, Mathematics and Computer Science)

Dong, J. (mentor)
Bauer, P. (graduation committee)
Lekic, A. (graduation committee)

Delft University of Technology

2020-09-16

Due to its high torque density, excellent efficiency and ease of control, the Permanent Magnet Synchronous Machine has found its use more and more in today’s world. To power these machines however, the position of the rotor magnets is required to be able to inject currents which generate the desired torque and speed. This magnet position is traditionally obtained by the use of an expensive shaft encoder which introduces an extra failure mode to the drive set-up. In this thesis, the process of designing a control scheme which uses position observers instead of an encoder is worked out from theory till lab verification. First, the basic magnetic and electromechanical working principles of the used machines are described. This is followed by building the models for these machines and verifying these in the lab. These models will form the backbone of the position estimation algorithm. Moving on, the principles of Field Oriented Control and Space Vector Pulse Width Modulation are covered together with the design of the speed and current controllers. Using this control scheme combined with the machine models, a controller without an encoder is designed. The design of this sensorless controller is carried out for both back-EMF observers as for a reduced-order flux-observer. Algebraic derivations for both the observers themselves and for the phase locked loops used for obtaining the estimated speed are provided; these derivations are then used for tuning the performance of these observers. This performance is verified by intensive simulation and lab-testing. The results of the different observers are compared, analyzed and used to improve the controller. The result is a sensorless control scheme which can drive the permanent magnet machine from 0 to 39 rpm in open-loop and from 39 to 6000 rpm in closed-loop mode.

Permanent Magnet Machine
Sensorless
Control
observer
back-EMF
Flux

http://resolver.tudelft.nl/uuid:d8078a05-bcfd-469e-9c71-a87b4b7edcc5

Student theses

master thesis

© 2020 J. Brouwer