Stability Evaluation of AC/DC Hybrid Microgrids Considering Bidirectional Power Flow Through the Interlinking Converters

The bidirectional power flow through the interlinking converter (IC), in ac/dc hybrid microgrids (HMGs) consisting of distributed generators (DGs) with droop controllers, plays an important role on stability such systems during islanding. This paper investigates impact direction small-signal islanded droop-based HMGs. Firstly, a linearized state-space model HMG is developed. Secondly, eigenvalue analysis carried out to realize dominant modes, which are rightmost eigenvalues. Thirdly, participation factor performed identify system and control parameters that effect most. Lastly, sensitivity conducted determine critical gains margin. It observed from modes HMGs become more stable as flows dc ac subgrid. On contrary, increase subgrid degrades stability. Additionally, changes studied under IC ascertain their margins. Finally, time-domain simulations, MATLAB/Simulink, suggest generation would enhance overall margin