Flux Feedback Power Amplifiers Based on a Disturbance Observer

The magnetic suspension effect of magnet levitation systems can be influenced by noise,parameter perturbation and other nonlinear characteristics in power amplifiers with flux feedback loops.In order to research this problem,a simulation model of power amplifiers with flux feedback loops and electromagnet was built,including the parameter perturbation caused by variational air gap of the flux generate model.In order to reduce perturbation of flux outputs from conventional PID control power amplifiers with flux feedback loops,a novel disturbance observer was designed.The novel disturbance observer had a multiplexed sensor signal integration structure.This structure can reduce influence to observation from the noise of feedback signals,and make the control system more stable than conventional DOB.The simulation results indicate that the composite control method,which combine the novel disturbance observer with the PID feedback,can effectively restrain the dither of flux outputs caused by the model parameter perturbation,nonlinear characteristics and noise.This composite control method is better than the conventional PID control method.