A NEW ALGORITHM FOR SENSORLESS OPERATION OF PERMANENT-MAGNET MOTORS

In this paper, the authors propose and investigate a new algorithm for shaft position sensorless operation of permanent magnet motors, based on flux linkage and line current estimation. Measured line current an d terminal voltage are used to estimate the flux linkage of the motor. The algorithm has a two current-loop structure, with the outer loop u sed to correct the position, and the inner loop utilised to correct th e estimated flux linkage. The theoretical basis of the algorithm and i ndividual definition of the system blocks is explained. Dependencies o n motor parameters and measurement errors are discussed to show the ef fectiveness of the method using real data. As well as giving a detaile d explanation of the new algorithm, the paper presents a wide range of computed and experimental results, demonstrating the reliability of t he method even during acceleration of the motor from rest.