Optimal PM arc ratio determination and vector-control of vernier machine with consequent pole rotor.

The purpose of this paper is to optimize the PM arc ratio of consequent pole permanent magnet vernier machine (CP_PMVM). The operation principle of the CP_PMVM is discussed. An optimization parameter K related to the PM arc ratio is derived. For the CP_PMVM, the amplitudes of the 4th and 14th order harmonics of the air-gap flux density, the amplitude of the back electromotive force (back-EMF) and the average torque all have positive correlations with K. The optimal PM arc ratio is 0.64. The three phase inductances are approximately constants, and the d-axis inductance is equal to the q-axis inductance. The PM flux linkages are sinusoidal. The no-load back-EMF waveform of the measured phase is nearly sinusoidal. The gear ratio of the CP_PMVM evaluated from the back-EMF is close to the design value. Furthermore, a controller according to the mathematical model is designed. The CP_PMVM vector control with a sliding-mode (SM) speed controller exhibits a smooth starting, and has an anti-jamming capability. [ABSTRACT FROM AUTHOR]