Position Sensorless Control of PMSM at Overall Speed with Extended-EMF Excited by Speed and Signal Injection
Takumi Nimura, Shinji Doki · IEEJ Transactions on Industry Applications · 2020
Extended electromotive force (EEMF) estimation method is a representative method used for position sensorless control of PMSM in the middle/high speed range. EEMF enables position estimation by utilizing back-EMF and the saliency of inductance. The amplitude of EEMF is adjusted to maintain it above a certain voltage by using a signal injection, regardless of the rotor speed. Thus, EEMF can be used as a single position estimator to estimate overall speed range. Based on the validation of a EEMF control performance and a parameter sensitivity analysis, this paper presents a position sensorless control system configured with a single position estimator from startup to middle/high speed. The necessary adjustment parameter and control performance of the actual machine are also presented.