Variable-Performance Proportional-Type Angle-Filtering System for Motor Drives

Abstract

This brief proposes a proportional-type angle filter with the variable feedback gain mechanism for motor drives using the encoder for angle feedback. In this case, the angle measurement suffers from discontinuity that has to be made continuous through low-pass filters and observers. There are three features. The first designs a real-time feedback gain update rule to improve the closed-loop filtering performance by magnifying the feedback gain in transient periods. The second introduces the disturbance observer (DOB) in the resultant proportional-type feedback filter for enhanced disturbance attenuation against the speed variations. The third proves the useful properties of the filtering error convergence and performance recovery by investigating the filtering error dynamics. A prototype 500-W permanent-magnet synchronous motor (PMSM) drive system validates the practical advantages of the proposed technique.