Real-Time Digital Field-Oriented Control of a Three-Phase Permanent Magnet Synchronous Motor

This paper presents the implementation and evaluation of a digital field-oriented control for a brushless permanent magnet synchronous motor reported in the literature. A digital vector control algorithm based on a field-oriented control is implemented using a TMS320F28379D microcontroller. An internal incremental encoder to sense rotor position is used in this work to adjust stator voltages in terms of amplitude and frequency in order to maintain rotation of the permanent magnet rotor assembly. Current controllers for the d-axis and q-axis are implemented in this work using conventional PI controllers. Experimental results to evaluate the transient performance of the speed controller of PMSM using PI controllers indicate oscillations at low speeds. Further, the performance of the proposal is reported in terms of frequency spectrum and total harmonic distortion for voltages and currents at different rotation speeds. The actual measurements results indicate that the total harmonic distortion of the three-phase voltages at the terminals of the PMSM varies from 112.01% to 31.43%, whilst the stator currents reduce from 85.53 to 40.12% for a rotational speed change from 500 to 1500 rpm.