DC-Link Voltage Stability-Based Control Strategy for Grid-Connected Hybrid AC/DC Microgrid

In this paper, a grid-connected hybrid DC/AC microgrid including a PV-based DC/DC converter, a bidirectional Lithium Battery (LB)-based DC/DC converter and a grid-connected DC/AC converter is controlled by proposing various linear compensators embedded in the inner dynamics of the used power converters. The proposed control strategies are designed for the power converters in such a way that all DC-link voltage fluctuations are instantaneously combined with other parts of closed-loop systems through suitable compensators design. The best performance for the compensators components is achieved by evaluating the natural frequencies and amplitude of transfer functions realized from the proposed control techniques-based closed-loop systems. To assess the proposed control technique performance, comparative simulation results in MATLAB/SIMULINK are presented to verify desired DClink voltage, the appropriate control of DC/DC power converters output currents, AC grid stability, and accurate performance of AC power-sharing.