An optimized method based on maximum torque-per-ampere control for permanent magnet synchronous motor

The paper presents an optimized control method of permanent magnet synchronous motor (PMSM) based on maximum torque-per-ampere (MTPA). Since it exists a complex nonlinear relation between the d, q axis current and the torque in PMSM, an optimized curve-fitting method is introduced to simplify the nonlinear equations of d, q axis and the toque. Based on the approximation algorithms, a new speed-current double close-loop control model is established and comparing with the traditional I_d=0 and MTPA control, it balances stator current and responses quickly, and thereby improves system efficiency.