Multiphase induction motor sensorless control for electric ship propulsion

This paper describes robust sensorless induction motor control applied to electrical ship propulsion. The control fulfils the marine process specific requirements and constraints. The flux estimation is based on a two step adaptive Kalman filter (KF). A fourth order KF estimates the flux and the currents, then the rotational speed is estimated by integration of a nonlinear equation of estimated flux and current errors. Polynomial regulators (RST) are used in preference to the classical proportional/integral control for improved robustness and performance.