Multiple Observers-Based Demagnetization Fault Detection With Inductance Mismatch Impacts Eliminated for PMSMs

Abstract

This paper proposes to use multiple sliding mode (SM) observers to accurately detect demagnetization fault (DF) for permanent magnet synchronous motors (PMSM). First, relying on the properties of the PMSM, three sequential SM observers including a flux linkage observer (FLO), a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">q</i> -axis inductance observer (QIO) and a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</i> -axis inductance observer (DIO) are developed, with their stability discussed. Second, the estimation errors of the proposed SM observers are analyzed, and on this basis, the accurate flux linkage that eliminates the negative impacts of inductance mismatch is calculated. Then, the calculated flux linkage is used to determine whether an DF occurs. Finally, comparative experiment is conducted on two PMSM prototypes to validate the proposed flux linkage estimation and DF detection techniques.