Online estimation of inductances of permanent magnet synchronous machines based on current derivative measurements

This paper proposes a novel technique to estimate online the inductances of a Permanent Magnet Synchronous Machine (PMSM) based on the measurement of the current derivatives excited by two active-voltage vectors and one zero-voltage vector within a PWM cycle. The d- and q-axes inductances of PMSMs are calculated during normal operation of the drive system. The influence of the magnetic saturation effect on the machine's inductances is also considered by the proposed estimation method. The full system simulation and experiment were implemented to verify the effectiveness and robustness of the proposed method.