Permanent magnet flux linkage adaptive observer for permanent magnet synchronous motor

In order to monitor the state of permanent magnet(PM) in PMSM, a design strategy of adaptive observer is proposed. The observer is built bases on the theory of Popov´s hyper-stability theory. Then the influences of parameter variations on the PM flux linkage estimation are investigated. It is shown that the q-axis inductance L_q mismatch has the most serious influence on the flux estimation. To reduce the sensitivity of L_q, a flux adaptive observer combined with L_q is proposed in this paper. Experimental results verify the effect of this method.