| Superconducting electrodynamic suspension(EDS)train equipped with light car body is a ground vehicle achieving a manned speed of more than 600 km/h.The lightweight design of the car body is beneficial to reducing production and transportation costs.When the vehicle is in stable operation,the levitation gap of more than 100 mm reduces the vehicle’s requirements for the irregularity of the guide-way,which in turn can decrease the cost of construction and maintenance.However,measures to save these costs,such as light-weighting of the car body and reducing line smoothness,will increase vehicle vibration.For example,the lighter car body will reduce the vibration isolation performance of the vehicle,and reducing the smoothness of the guide-way will intensify the guide-way disturbance caused by irregularity.In order to solve the contradiction between riding quality and economy,damper may be added to the suspension to suppress the vibration of the vehicle.If the cost saved by economic measures is significantly higher than the cost of the damper,the damping device can be widely used in superconducting EDS trains.Therefore,the study on the vibration control is essential for the commercialization of EDS trains.The small passive damping between the vehicle and the guide-way makes it difficult to attenuate the vibration of bogie.Therefore,active damper needs to be applied between the bogie and the guide-way to dissipate the vehicle’s vibration energy.Since the electromagnetic coupling takes place of the traditional mechanical contract between bogie and the guide-way in EDS system,the electromagnetic damping coil was employed in this thesis as the active damper.The electromagnetic damping coil combined with the onboard linear generator coil can not only supply power to the onboard power system,but also apply electromagnetic damping force between the guide-way and bogie without increasing the vehicle structure.For the purpose of simulating the disturbance from irregularity of guide-way,a proper track irregularity spectrum for EDS system was selected in this work.The power spectral density(PSD)inversion program based on the inverse Fourier transform was used to restore the time domain wave of track irregularity with MATLAB.Then based on the parameters of Japanese Yamanashi Test Line,a fourteen-degree-of-freedom dynamics model for vertical and pitch movements of EDS train was established taking the time domain wave as the input of the vehicle system.The proportional force law and maximum force law are two common control law for the control of electromagnetic damper.In order to determine the appropriate control strategy for the electromagnetic damping force,the electromagnetic damper was applied to the primary suspension based on the dynamics model,and the damping effect and energy loss under the two control laws were analyzed and compared.The results show that the electromagnetic damping performance controlled by the maximum force is better.The optimization of the control strategy determines that the value of maximum force should be between 5 kN to 7 kN.The related studies show that the electromagnetic damper can only suppress the bogie main frequency vibration,but not the car body main frequency vibration.In order to inhibit car body main frequency vibration,the “ON-OFF” semi-active sky-hook damper was introduced into secondary suspension in this thesis too.The dynamics model of vehicle with synergistic control of electromagnetic damping and sky-hook damping was established,and the dynamic response of model was solved and analyzed.The results show that the“ON-OFF” semi-active sky-hook damping can effectively suppress the car body main frequency vibration,but it has no obvious effect on the bogie main frequency vibration.Only by the synergy of primary control and secondary control,can the vibration of the car body meet UTACV standard.With optimization,it can be determined that the value of sky-hook damping should be between 5 kN·s/m to 10 kN·s/m. |
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