Speed Sensorless Control of Axial Field Flux-Switching Permanent Magnet Machine Based on Improved Adaptive Sliding Mode Observer

In order to carry out the speed sensorless operation of a novel 6/13-pole axial field flux-switching permanent magnet machine (AFFSPMM), an improved control strategy based on adaptive sliding mode observer (ASMO) is proposed and researched, which combines the improved ASMO with phase-locked loop (PLL) to acquire extended electromotive force and realize tracking of rotor-pole position accurately. For further weakening the vibration and enhancing the robustness of the system, the second order generalized integrator (SOGI) is applied into PLL to improve the accuracy of position estimation. In this paper, the three speed sensorless control methods of the traditional ASMO, the improved ASMO and the improved ASMO with SOGI are compared and analyzed. The results indicate the improved ASMO with SOGI has better performance and higher accuracy for the machine.