Automatic Tuning Procedure at Standstill for Extended Kalman Filter in Sensorless Control of Permanent Magnet Synchronous Motors

In modern ac drives the reliability issue is pushing towards sensorless control. Extended Kalman filter is a valid candidate for the estimation of rotor position in permanent magnet synchronous motor drives. The traditional weak point is the tuning of its covariance matrices, which is still a loose thread to tie up after many years. This work proposes an innovative automatic procedure for the covariance matrices tuning based on both the rated values of the motor and the result of signal injection tests. The output of the automatic procedure was tested on an experimental motor prototype.