A Novel Luenberger Observer for the Sensorless Speed Control of PMSM

Abstract:
Luenberger observer is widely used in the sensorless speed control for permanent magnet synchronous motor(PMSM). Conventional Luenberger observer generates one step delay. The back electromotive force (BEMF) input time and the feedback time of phase lock loop (PLL) model are in the different time sequences. With the analysis of the model error of Luenberger observer, a novel Luenberger observer and PLL model are proposed based on the present value observer. The estimated error of the observer was adjusted from the previous calculation to the present calculation, and the BEMF input of PLL was delayed by one control cycle, which was set at the same time as PLL feedback. Both error compensation and time compensation improve the BEMF tracking performance and position estimation accuracy. Sensorless speed regulation performance of PMSM is enhanced.