Influence of time-delay on the performance of hybrid magnetic suspension system with permanent and electronic magnets

Three models of a hybrid magnetic suspension system are separately built under the condition of no time-delay, time-delay of the signal of suspension gap and time-delay of arithmetic. To research on the influence of time-delay on the performance of the hybrid magnetic suspension system, relationship between the latent roots of the closed-loop system and time-delay, and the relationship between the stable area of the control parameters and time-delay are analyzed. Results show that both the time-delay of suspension gap and arithmetic bring the latent roots closer to the image-axis and reduce the stable area of the control parameters, which reduce the system´s dynamic performance, and even bring the system to be unstable. Conclusions are proved by simulation and analysis.