高温超导钉扎磁悬浮系统分岔和混沌特性研究

Study on Bifurcation and Chaos Characteristics of High Temperature Superconducting Magnetic Levitation System

高温超导钉扎磁悬浮系统的应用十分广泛,但由于其悬浮力的非线性特性,导致在实际应用中经常引起设备的异常振动。为了探究高温超导钉扎磁悬浮系统的非线性振动特性和寻找避免发生异常振动的措施,首先,通过实验装置测量不同悬浮间隙下的悬浮力数据,将其拟合成指数模型,然后,基于该模型建立简谐激励下高温超导钉扎磁悬浮系统的动力学模型,最后,研究系统的分岔和混沌特性。研究表明,系统存在丰富的非线性动力学行为;系统的混沌阈值随着激励频率的增大先减小后增大,即系统在低频阶段和高频阶段不易发生混沌运动,而在中频阶段易发生混沌运动;质量、阻尼和场冷高度对混沌阈值均存在一定影响。研究结果为高温超导钉扎磁悬浮系统的参数设计及其抑振方法提供参考。

High temperature superconducting(HTS)flux pinned magnetic levitation(FP maglev)system is widely used,however,due to the nonlinear feature of the levitation force,anomalous vibration of the equipment is commonly created in the real applications.In order to examine the nonlinear vibration characteristics of HTS FP maglev system and identify strategies to avoid anomalous vibration,firstly,the levitation force data under different gaps were measured by experimental equipment and fitted into an exponential model,then the dynamic model of HTS FP maglev system under harmonic excitation was established based on the model,finally,the bifurcation and chaotic properties of the system were investigated.The research shows that:the system exhibits rich nonlinear dynamic characteristics;the chaotic threshold of the system decreases first and then increases with the growing of the excitation frequency,that is,the system is not prone to be into chaotic motion in low frequency and high frequency,but prone to chaotic motion in the intermediate frequency;the system mass,damping and field cooling height have a certain impact on the chaos threshold.The findings of this study might serve as a guidance for designing parameters and suppressing vibrations in HTS maglev systems.