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

Abstract

Abstract:The mechanism and characteristic of current oscillation of fourquadrant 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.

Vienna Rectifier Modeling and Harmonic Coupling Analysis Based on Harmonic State-Space

“…The analysis of harmonic characteristics can be carried out through harmonic source modeling, which includes methods such as the small-signal averaging method [9], describing function method [10], dynamic phase modeling [11], HSS modeling [12], and others. The principles of both the small-signal averaging technique and the describing function method largely rely on the idea of converting discrete, fluctuating systems into linear time-invariant (LTI) systems.…”