On-line parameter estimation of permanent magnet assisted synchronous reluctance motor drives

In comparison with the conventional synchronous reluctance machines, permanent magnet assisted synchronous reluctance motor drives (PMa-SynRM) have offered better torque capabilities and power factors. In order to achieve maximum efficiency knowledge of the motor parameters is necessary to implement advanced control algorithms. Variation of motor parameters due to temperature and airgap flux has been reported in the literatures. Using off-line models for estimating the motor parameters is known as a computationally intensive method, especially when the effect of cross saturation is included in the models. Therefore in practical applications, on-line parameter estimation is favored to achieve a high performance control system. In this paper, a simple practical method for parameter estimation of PMa-SynRM is introduced. This method is capable of identifying the d- and q-axes inductances and the permanent magnet back-EMF