Research Of Hybrid Suspension System Made Of Hts And Normal Condector Coil Control Methods Based On Feedback Linearization

The technology of Magnetic suspension control is one of the key technologies of EMS maglev train. The performance of magnetic suspension is determined mainly by its control system. Therefore,it has great significance to study control method of suspension system. Aiming at the nonlinearization problems of suspension system of hybrid electromagnets made of high temperature superconductor and normal conductor coil. The traditional control method using Talor expansion near the equilibrium point, obtaining the approximate linear model, but the suspension system deviates from the equilibrium point will affect the suspension system stability. Using feedback linearization techniques then the model is linearized by means of feedback linearization and an equivalent linear model is obtained. Based on which, a nonlinear controller is achieved.The nonlinear model of hybrid suspension system is linearized by using feedback linearization method, and the linear current control model was obtained in this paper. Then, classical control strategy-linear state feedback control is adopted to design the controller that is validated in magnetic levitation system. According to dynamic performance, the control parameters are designed. This control method compared with linear model found by expanding the nonlinear system model, obtaining the advantages and disadvantages between the two control methods.Introduce the modern control technology-variable structure control method, switch function is constructed, then a sliding model controller with integral sliding surface based on feedback linearization is designed. Simulation results show that sliding model controller can overcome the uncertainty of system model, the closed-loop system is robust and insensitive to change of parameters.In the analysis of the hybrid suspension system, study the principles of EMS with pure high-temperature superconducting. Using the same method to establish a second-order linear model with coil's current as the input. Simulation show that nonlinear controller based on feedback linearization method has a good robustness.