Dual-side virtual inertia control for stability enhancement in islanded AC-DC hybrid microgrids

With the increasing penetration of renewable energy sources in modern power systems, the reduction in system inertia has emerged as a critical challenge, compromising power smoothing and frequency regulation in hybrid AC-DC microgrids operating in islanded mode. To address these issues, a dual-side virtual inertia control strategy for bi-directional interface converter (BIC) is proposed, which ensures balanced power exchange between the AC and DC transmission grids through transient response by incorporating a virtual inductor into the virtual synchronous machine (VSM) framework. The proposed method enhances system stability and dynamic performance by stabilizing both AC frequency and DC voltage under load fluctuations. A small-signal model is developed to analyze the impact of virtual inertia parameters on system stability, with the root locus method applied to evaluate performance. Simulations in Simulink validate the effectiveness of the control strategy, demonstrating significant improvements in transient response and frequency regulation. This approach provides excellent power sharing and enhanced resilience in hybrid microgrids with a high degree of integration of renewable energy sources, offering promising applications for future power systems.