Field Weakening with Nonlinear Controller Design for an Interior Permanent Magnet Synchronous Motor

This paper proposes a field weakening control algorithm with a nonlinear speed-loop controller for an interior permanent magnet synchronous motor. By using the proposed method, the adjustable speed range can be extended to 1.6 times that of the based speed. The method includes the constant torque region and the constant power region. In addition, an adaptive backstepping speed-loop controller is designed to improve the transient response and load disturbance rejection capability. A DSP based full digital speed-control system is implemented. Several experimental results validate the theoretical analysis