| In order to solve the shortcomings of traditional EMS suspension system and comply with the national development strategy for energy saving and speed-up of rail transit,National University of Defense Technology actively carries out the research of the medium speed maglev train with a speed of 200 km/h which is hybrid magnetic suspension,and successfully developed the fifth generation of new maglev testing train in 2018.The hybrid suspension medium speed maglev train adopts the permanent magnet and electromagnetic hybrid suspension scheme.Compared with the traditional magnetic suspension scheme,the former can effectively reduce the system’s suspension power consumption.However,with the addition of permanent magnets,for the hybrid suspension system,the control of the system is more difficult,and the question of suspension contact becomes more serious.In this paper,the hybrid suspension medium speed maglev train developed by the National university of defense technology is taken as the research object,and the research of flux feedback control and protection against suspension contact is carried out.(1)Firstly,the single-point open-loop mathematical model of the hybrid suspension system is established,and the corresponding linear model is respectively established with the current or flux density as one of the state variables;and the stability,controllability and observability of the established linear model are analyzed.Then,a single-point model control based on current feedback is established for the hybrid suspension system.The simulation results show that the control method can meet the performance requirements.(2)Secondly,this paper discusses the acquisition method of flux density and introduces the sensor measurement method and virtual flux observation technology respectively.The sensor measurement mainly analyzes the measurement methods based on Hall effect principle and electromagnetic induction principle;at the same time,the virtual flux observer based on current and voltage is studied,and the hybrid suspension control method based on flux feedback is designed.Compared with the hybrid control method based on current feedback,the method based on flux feedback has obvious advantages in the process of system overshoot and steady state.(3)The control method of hybrid suspension two-point model is explored.To solve the problem of two-point coupling in the hybrid suspension two-point model,a decoupling control method based on feedback linearization is proposed.By adopting the decoupling control,two mutually coupled systems can be transformed into two independent subsystems.The simulation shows that the method can reduce the interaction between two points and improve the control performance of the system.(4)Finally,the paper analyzes the more prominent problem of suspension contact in the hybrid suspension system.And the causes of the suspension contact are expounded,and the paper briefly describes the respective solutions.According to the analysis,there are few studies on the suspension contact caused by the sudden gap’s change caused by external force interference.This paper designs flux feedback control based on disturbance observer for protection against suspension contact.And the stability of the disturbance observer is analyzed.The experimental results show that the control scheme based on disturbance observer can effectively reduce the influence of disturbance on the system,improve the anti-interference ability of the system,and reduce the probability of the occurrence of the suspension contact.In this paper,for the permanent magnet and electromagnetic hybrid suspension system,the hybrid suspension control method based on flux feedback is established,and the control method for the protection against suspension contact based on disturbance observer is designed.The research results of this paper have been applied to the test of hybrid suspension bogie and the suspension control system of 160-type maglev train,which has certain reference value for the research and engineering of the hybrid suspension medium speed maglev train. |
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