Sensorless control of printed permanent magnet synchronous motor

As a special disc motor, a printed permanent magnet synchronous motor (PMSM) uses a PCB printed board as the stator, which has the advantages of simple assembly, short axial distance, no stator slot, low eddy current loss, etc. Due to the stator-less core structure and the small number of winding turns, the inductance of the motor is very small. When vector control technology is used to drive the motor, the motor current pulse vibration is intense, there is a large number of integer multiples of the switching frequency high-frequency harmonics, there is also torque output pulse vibration, and it cannot be sampled to obtain the actual working state of the motor stator current, which affects the sliding mode sensorless control algorithm in terms of stator current estimation. Then it affects the motor speed and position estimation. In this paper, a solution involving high switching frequency control is proposed to obtain the characteristics of this kind of motor. In addition, the sensorless control of the motor based on the super-twisting sliding mode is realized. Simulation and experiments show the stability and effectiveness of the motor position free control system, and solve the problems related to severe motor stator current oscillation, motor output electromagnetic torque oscillation, and poor control performance of the sensorless algorithm caused by a small motor stator inductance.