Comprehensive Investigation of the Resolver’s Eccentricity Effect on the Field-Oriented Control of PMSM
MohammadSadegh KhajueeZadeh, Mahdi Emadaleslami, Farid Tootoonchian, Ahmad Daniar, Matthew C. Gardner, Bilal Akin
Abstract
Accurate position feedback from a resolver is highly critical for high-performance field-oriented control (FOC) drives, and eccentricity in resolvers negatively affects the drive performance. The current unbalance intensity (CUI) of permanent magnet synchronous motors (PMSMs) is a known criterion to evaluate drive stability and can be caused by position feedback error. In this article, the eccentric resolver operation is comprehensively investigated, and the corresponding CUI is analytically evaluated. Accordingly, the error limit is defined for an acceptable operation under eccentricity without derating the motor control. For this purpose, the relationship between the: 1) resolver’s physical geometry; 2) magnitude and the angle of the stator current; and 3) resolver accuracy are presented through surrogate modeling. Using the proposed analytical current model, the resolver geometry is updated in order to improve the eccentricity tolerance and accuracy and lower the CUI. An optimized rotor design is built, and its accuracy and effect on CUI mitigation are experimentally verified.