Analysis of nonlinear oscillation of four-quadrant converter based on discrete describing function approach

抄録

The mechanism and characteristic of current oscillation of four-quadrant converter with predictive current controller caused by nonlinear characteristic of the system is analyzed in the paper. With the discrete model considering the digital control delay of the single-phase four-quadrant converter, the stability condition is derived. Using the describing function of saturation characteristic, the frequency and amplitude of the nonlinear oscillation is obtained. The simulation and experiment results verify the analyses.