Induction Coil Magnetic System Performance

Proper system damping is an important condition to keep the stability and provide the ability with restrain disturbance. Suspension system of EMS maglev is intrinsically unstable, and can be stabilized by the active control system which provides damping; the provided damping which is abtained from the measure system is sensitive to the measure error and noise, so the improvement of the suspension system performance is restricted. Suspension system of EDS maglev is intrinsically stable, it need not active control, but there is no other damping exist, so the suspension system has bad performance of restraining disturbance. According to the references, the induction coils just be used to reduce the vibration of supercondution EDS.The opinion of using induction coils to increase the system damping of the EMS maglev and EDS maglev is offered in this paper, also the feasibility is analysed. The main contents of the paper is listed below:1. The mathematical model of single mganet suspension with induction coils is establish- ed ,from which the relationship between the induction current and the excitation current is gained. By comparing the root locus of the transfer function before and after appending coils, it is concluded that appending induction coils will improve the difficulty of controlling.The controller is designed by the method of state-feedback and pole placement to analyse the change of dynamic performance, and the computer simulation is employed to verify the analyzing result. The analyzing results indicate that the induction coils will dent the influence of the controller to the system, and also increase the overshoot of the system, the method of increasing damping by using induction coils is infeasible.2. The effect of appending the induction coils on the hybrid EMS system which the magnetic path of the permanent and the electromagnetic magnet is disjoined is researched. The root locus of the opened-loop transfer function shows that appending the induction coils can slower the volatilization speed of it. Using PD controller to make the system stable, the step respond is obtaind by computer simulation and the effect of induction coils to the system is analysed. The result shows that the damping will be increased in this type of hybrid system by using induction coils,and the effect will be enhanced by increasing the number of coil or reducing the resistance of the induction loop.3. The change of the force the train moving horizontally acted on by the permanent magnet arrange in"Halbach"array is analysed, the result indicates that compared with the above analysis, there is heavier force act on the train after appending induction coils. If the speed on the vertical is considered, appending the induction coils can make the poles far from the imaginary axis, it shows that the damping of the system is increased..This paper testified that appending the induction coils in some suspension system will increase damping by don't changing other parameters.