Fluctuation Analysis of Electromagnetic Force in Magnetic Levitation Planar Motor

The magnetic levitation planar motor (MLPM) employs electromagnetic force to directly propel the mover in the horizontal plane, and its motion precision is highly susceptible to the fluctuations of electromagnetic force. This paper, based on an accurate electromagnetic model of the MLPM, examines the origins and magnitude of influence contributing to system gain variations. Among these factors, key contributors are identified as defects in the simplified coil model and deviations in the initial position, both resulting in electromagnetic force fluctuations of approximately 3%. The current driver leads to a minimal fluctuation of around 0.4
^%
in electromagnetic force due to the current ripples. Furthermore, inaccuracies in position sensor mounting and errors in coil array assembly can induce fluctuations of approximately 1% in electromagnetic force. Collectively, these factors will culminate in an approximate 10
^%
fluctuation in electromagnetic force. Consequently, ensuring stability in the frequency domain and dynamic response characteristics in the time domain necessitates fortifying the position controller against gain variations.