Asynchronous Motor Parameter Identification Based On EKF

The veracity of induction motor's parameter is always one of the concerned problems in the AC drive system. In order to implement an energy-saving method which keeps iron loss equal to copper loss using variable-voltage in light load, induction motor parameter identification at any moment is a key problem. The application of conventional approach of measuring the motor's parameter is limited seriously because they require some kinds of special operating pattern to measure the parameters. In this paper, a new method is proposed, using the instant response of the induction motor to voltage pulse and current break when the motor stops. The merit of this method is that it is not limited by any additional condition. The simulation result proves this method's feasibility.Motor's rotor resistance is easily varied in its operation, inaccurate parameters will deteriorate the control arithmetic's precision of the system. So this paper builds the rotor resistance's identification model of the three-phase asynchronous motor on the basis of the four-class accurate mathematics model of the three-phase induction motor in the a-b coordinate. The rotor resistance's identification has been completed by simulate and investigated using the EKF (Extended Kalman Filter) arithmetic. This paper makes an in-depth study on the arithmetic's effect. This arithmetic will be applicated into practice by the high performance digital signal processor (DSP)'s development.