Sensorless Control Strategy for High-Speed PMSM Based on Discrete Complex Vector Model

High-speed permanent magnet synchronous motors (PMSMs) are constrained by inverter output voltage limitations and severe the d-q axis current cross-coupling during operation, resulting in limited operating speed range and insufficient system stability. To solve the issue, a position sensorless field weakening strategy based on discrete complex vector decoupling is proposed. A speed-dependent zero point is introduced in the current controller to cancel the coupling pole, addressing the coupling voltage disturbance issue. By combining complex vector decoupling with field weakening control, a full-order state observer is designed to estimate the speed and rotor position information during high-speed operation. Experimental results verify that the proposed strategy achieves high estimation accuracy and fast dynamic response.