A Discrete Frequency-Adaptive Resonant Controller with Reset Function and Anti-Windup Scheme

Abstract:
Resonant controllers are useful for the current control of voltage source inverters. However, there are some disadvantages that should be considered, including high sensitivity to incorrect zero and pole placements, and an output windup, which can be a consequence of incorrect poles and which leads to undesirable results. Some existing anti-windup schemes are based on a simple truncation of the sinusoidal waveform which leads to high harmonic content. Others, were analyzed only in the continuous time- or frequency domains where the feedback path is ideal or non-delayed respectively. This paper presents a switchable discrete resonant controller with exact pole placements and an anti-windup scheme that avoids output distortions by maintaining the sinusoidal waveform with low computational burden.