D-Q-axis magnetic field design and investigation of asymmetrical multi-layer flux barriers PM motor for speed regulation enhancement

In this paper, an asymmetrical multi-layer flux barriers permanent magnet (AMFB-PM) motor is proposed. The key of this study is to design the d-q-axis magnetic field reasonably. Firstly, the influence of d-axis inductance on the constant power speed range is analyzed. To optimize the constant power speed regulation performance, an asymmetric flux barrier is employed to adjust the saturation degree of the d-axis magnetic circuit under flux-weakening state. Additionally, the introduction of the asymmetrical flux barrier enables directional deflection of reluctance torque, thereby enhancing the output torque. The analysis results verify the effectiveness of the asymmetrical flux barrier design, which provide a wide speed regulation with constant power operation and high torque density for PM motors.