New Generalized D-State-Observers for Sensorless Drive of Permanent-Magnet Synchronous Motors: —Impact of Rotor Flux Harmonics to Fundamental Component Estimate—@@@—回転子磁束高調波成分の同基本波成分推定値への影響—

This paper proposes new generalized D-state-observers as new minimum-order flux state-observers for sensorless drive of permanent-magnet synchronous motors. The proposed generalized D-state-observers, which are established by a new approach using filters in the D-module, contain the conventional D-state-observer as a special case, and the associated observer gain also contains the conventional one for the conventional D-state-observer as a special case. Consequently, The proposed generalized D-state-observers provide designers with higher degree of design flexibility. In addition, for the generalized D-state-observers, this paper presents a new analysis about estimation error of rotor flux fundamental component due to rotor flux harmonics originating from non-sinusoidal magnetization, which has been remaining as an unsolved problem so far. It is analytically shown and verified by numerical experiments that harmonics appear on the flux estimate in a similar manner to the original rotor flux harmonics from viewpoints of rotor phase error. The proposed generalized D-state-observer to estimate rotor flux using stator voltage and current is described as