Horizontal I-PD position control of a levitated hybrid electromagnet driven by 3 phase ac long stator L-PMSM

Abstract

In this paper, a flexible conveyance system consists of 4 pole hybrid electromagnet and linear synchronous motor is introduced. Firstly, modeling of 4 pole hybrid electromagnet was derived based on well -known magnetic circuit principles. Then, the control method in which the currents converge virtually to zero is called as “zero power control” is applied to hybrid electromagnet to stabilize the system and provide levitation against gravity. Secondly, PM-LSM, which enables to move hybrid electromagnet horizontally, is modeled. According to modeling basis, I-PD controller is designed to provide moving action in a desired position reference. Simulation and experimental studies of position control for both levitation and horizontal motion verify validity of the proposed methods.