Research on a Sensorless Control System for Dual-Branch Permanent Magnet Synchronous Motor with a Nonlinear Observer Based on Parameter Identification

The strongly coupled dual-branch motor adopts a multi-winding structure, where each phase of the motor has two sets of stator windings. This configuration reduces the capacity requirement of a single inverter and provides high fault tolerance. Based on the unique structure of the strongly coupled dual-branch motor, an isolated interleaved parallel driving strategy is employed, along with control algorithms such as carrier phase-shifting, to suppress high-frequency PWM noise at multiple carrier frequency multiples. To further enhance the reliability and control accuracy of this motor, this paper introduces parameter identification algorithms and sensorless control algorithms. For the motor's unique structure, the observer structure is reconstructed on the basis of a nonlinear flux observer, achieving sensorless control of the strongly coupled dual-branch motor. Simultaneously, the recursive least squares method is used for parameter identification of the motor. Finally, a parameter identification sensorless system is constructed based on the carrier phase-shift control of the strongly coupled dual-branch PMSM driven by an isolated interleaved parallel topology. Simulations demonstrate that the rotor position of the motor can be accurately observed at medium to high speeds, and the motor parameters can be obtained, advancing the control algorithms for the strongly coupled dual-branch motor.