Modeling of single phase four quadrant converter using a multifrequency averaging approach

A frequency-selective averaging approach for modeling and analysis of the single-phase four-quadrant pulse-width modulated converter is presented. The derived model is linear and time-invariant (LTI), so that classical control design techniques can be applied. The method allows for the model to be defined by algorithm so that it can be easily expanded to arbitrary accuracy. The steady state model allows for direct calculation of steady-state values and is valuable in the design process of the converters power circuit. As an example direct calculation of disturbance progressions from the DC-link into the grid current and vice-versa is presented. Application of the linearized small-signal model for transfer function derivation is presented. The mathematical models have been verified using results obtained from simulation and system identification techniques.