RETRACTED ARTICLE: Droop Control based Approach for Frequency and Voltage in Hybrid AC/DC Microgrid

Abstract

With the continuous increase of distributed energy resources (DERs) and renewable energy sources, the power system is facing different operational challenges i.e. reliability and resilience of the electrical grid. To solve these problems the concept of a microgrid, particularly hybrid microgrid, has gained significant attention worldwide. The Hybrid microgrid can accommodate both DC and AC grids and the existence of both grids leads to the idea where both grids are tied via inter-linking converter (ILC) that can facilitate the power transfer among both grids. In this paper, an improved droop control scheme for the control of hybrid microgrid is presented along with a frequency and active power-based droop of the ILC. Moreover, to determine the droop coefficient of the ILC, scaling factors are applied. Hence, this allows the ILC to facilitate the transfer of power between the overloaded and under-loaded grid. Two main scenarios involving single and multiple hybrid microgrids are considered in this study. The results show that the frequency variation in the AC grid occur, when any change in load occurs in the DC grid and vice versa. In this way, the droop-based ILC balances the power between the under-loaded and overloaded grids.