Active vibration control of secondary suspension based on high-temperature superconducting maglev vehicle system

Abstract

The high-temperature superconducting (HTS) magnetic levitation (maglev) vehicle system is a kind of self-stable levitation mode, which is benefited from the characteristic of flux pinning of non-ideal type II superconductor. And this novel prototype has the outstanding advantages of simple structure, reliable principle, friendly environment and so on. But in the HTS maglev vehicle system, the damping coefficients of the primary suspension are very small. The vibration of the YBCO bulks over a permanent magnet guideway (PMG) will be incurred by the fluctuant external magnetic field, which is easily transmitted to the car body to affect the running comfort. The primary goal of this paper is to apply active vibration control into two linear electromagnetic actuators on each bogie. Each electromagnetic actuator is combined with an air spring as a kind of active suspension system in secondary suspension. Initially, the primary suspension stiffness coefficient and damping coefficient of YBCO bulks are measured by experiments. And the mathematical model of HTS maglev vehicle with active actuators was built using the German track spectrum of low interference as PMG irregularity. Then, the dynamic responses of HTS maglev vehicle system were simulated with PID and Fuzzy-PID controllers used in the active actuator to verify the feasibility of the control methods, and compared with the uncontrolled system. Finally, the results of the simulation indicate that both control strategies could improve vehicle comfortable and greatly improve the stability of the system compared to the passive bogie system.