Predictive Current Control vs. PI Control for Surface Mounted Permanent Magnet Machines

Abstract

This article presents a comparative study of a standard PI controller with three more advanced predictive current control schemes, applied to a surface mounted permanent magnet synchronous machine fed by a two-level voltage source inverter. The three predictive current controllers are: finite-set model based predictive control, deadbeat control, and a combination of both previous algorithms. Key performance indicators concerning control- and voltage quality, dynamic performance and parameter sensitivity, enable a quantitative comparison of the four controllers. The indicators are not only obtained from simulation results, they are also experimentally validated on a 4 kW axial flux permanent magnet synchronous machine with yokeless and segmented armature topology. A general conclusion is that the PI controller excels when it comes to control quality: only the deadbeat controller can compete with its low torque ripple. The predictive controllers on the other hand show superior dynamic performance.