Sensorless Control of High-speed PMSM with LC Filter Based on Adaptive Full-Order Observer in Discrete-Time Domain

This paper proposes an adaptive full-order observer for sensorless control of high-speed PMSM with an inverter output LC filter. The only measured quantities are the inverter phase currents and the DC-link voltage. First, a full-order state observer is designed in the discrete-time domain using direct pole placement. Second, the estimation-error dynamics of observer are linearized, enabling the independent estimation of both the permanent-magnet flux and rotor speed. This approach also facilitates the subsequent derivation of the adaptive laws and their corresponding gains. Finally, the effectiveness of the studied sensorless algorithm is verified on a 40-kW high-speed motor bench with a maximum speed of 90 kr/min (1500Hz).