Research on Improvement in Working and Non-working Magnetic Fields Harmonics of Permanent Magnet Vernier Machine

Permanent magnet vernier machines can generate rich harmonics through magnetic field modulation effects, including not only the working harmonics that generate torque, but also many non-working harmonics that generate losses. Based on this, this paper theoretically analyzes the principle of non-uniform modulation poles generating more working harmonics, increasing back electromotive force and torque density. In addition, the magnetic circuit model and theoretical analysis have shown that setting flux barriers in the stator teeth can reduce the first non-working harmonic in the air gap flux, effectively reducing the core loss and eddy current loss of the stator without sacrificing torque. Finally, through finite element simulation calculations, compared with traditional permanent magnet synchronous motors, the permanent magnet vernier machines with non-uniform modulation poles can increase the output torque by 12.8%. with stator magnetic barriers structure has no decrease in output torque and the iron core loss has decreased by 38%, further verifying the effectiveness of the adopted method.