State-Space Model of a Stand-Alone Voltage-Controlled VSC Under Dual Reference Frame Control

Abstract

Considering the emergence of new energy sources in the market, the use of power electronics converters become essential for conditioning and managing this energy. This is the case of DC-AC converters, used to interface several resources to the existing AC grids. In this context, voltage-controlled converters are returning to be popular, especially because of their use in the so-called grid-forming converters. The stability of these converters requires investigation using state-space models. These models describe the converter dynamics based on various control strategies in synchronous reference, positive-sequence, and positive- and negative-sequence. In view of that, this work presents a state-space-averaged model that describes the positive and negative sequences of a three-phase voltage-controlled VSC. The model is step-by-step developed in the article, and a Python-based implementation is also proposed. Finally, the simulations of the proposed model is compared with simulations performed in PSIM to show its accuracy.