Two-line-same-phase AC standstill measurement method for obtaining accurate PMSM d–q-axis inductance values

With their simple structure, good characteristics, small size, low weight, high starting torque, and high power density, permanent magnet synchronous motors (PMSM) are widely used in industry and national projects. However, accurate PMSM d–q-axis inductance values cannot be obtained after dynamic decoupling of the d–q-axis voltages of a PMSM under vector control. To tackle this challenge, this paper proposes a two-line-same-phase AC standstill measurement (TLSP-ACSM) method. To verify the effectiveness of the proposed method, both the motor synthetic magnetomotive force and theoretical error of inductance measurement based on the TLSP-ACSM method are analyzed, followed by experiments to demonstrate the effectiveness of TLSP-ACSM. By comparing the proposed method with another measurement method, it is demonstrated that the relative error of the d-axis and q-axis inductance measurements is reduced by about 23% and 21%, respectively. When considering magnetic flux leakage, TLSP-ACSM shows better measurement precision and tracking performance.