High Precision Off-line Parameters Identification of PMSM Considering Dead-time Effect

This paper proposes a novel off-line parameters identification strategy of permanent magnet synchronous motors based on equivalent dead-time identification. Off-line parameters identification is greatly significant to the start-up of motors on the condition that the controller is unknown, but the identification results are largely influenced by the dead-time of inverters in the application. And this influence is different from theoretical analysis owing to the non-ideal switching characteristic of inverters. In our method, identify the resistance and equivalent dead-time voltage using voltage position and least square method firstly, then identify the d-axis and q-axis inductance using high frequency rotating voltage injection and recursive least square method. Compared with the strategy that modifies the instruction voltage of inverters, dead-time identification fully takes into account the differences between the actual and ideal situation. Besides, it doesn’t need to know the dead-time value beforehand.