Control of Interlinking AC-DC Interface Converter Using Dual Droop Control in Hybrid Microgrid

Abstract

Due to the fast proliferation of distributed generators (DGs) in power systems, managing the power of different DGs and the grid has become crucial, and microgrid provides a promising solution. Therefore, focus on ac and dc microgrids has grown rapidly with their architectural [1], [2], modeling [3], stability analysis and enhancement [4]–[6], power quality improvement [7]–[9], power sharing control [10]–[13], and other issues. Most developments mentioned above on microgrids are, however, directed at DG control mainly within one microgrid. Autonomous operation and modified droop control schemes of such hybrid microgrids were discussed in [15] and [16] and extended in [17] and [18] by integrating an energy storage system to the dc microgrid. Another droop control scheme was followed in [19] for bidirectional power flow between the inter-tied microgrids. In [20], hierarchical control of multiple parallel ac-dc converter interfaces between ac and dc buses was proposed to achieve proportional current sharing.

In the proposed work, investigates the coordinated power sharing issues of interlinked ac/dc microgrids. An appropriate control strategy is developed to control the interlinking converter (IC) to realize proportional power sharing between ac and dc microgrids. Using the proposed scheme, the IC, just like the hierarchical controlled distributed generator units, will have the ability to regulate and restore the dc terminal voltage and ac frequency. Simulation results can be validating using Matlab/Simulink environment.