Modelling and analysis of a synchronous machine-emulated active intertying converter in hybrid AC/DC microgrids

Abstract

The integration of renewable energy resources into the electrical distribution systems faces several stability challenges especially in the low inertia conditions. To address these issues, this study introduces a virtual synchronous machine (VSM) control strategy for the intertying power electronic converters in the autonomous AC/DC hybrid microgrids. It is shown that the VSM-based controller improves the system damping following the frequency disturbances and the AC/DC voltage variations. Moreover, a power management regulation topology is implemented in the active intertying converter to achieve an accurate bidirectional power flow under different loading conditions. A small-signal state-space model for the entire hybrid system is developed to assess the overall system performance. Time-domain simulation results under the PSCAD/EMTDC environment are also presented to investigate the effectiveness of the proposed techniques. The introduction of the VSM control for the intertying converters in the hybrid AC/DC microgrids provides a significant improvement in the dynamic performance and increases the robustness against external disturbances.