Coordination of adaptive virtual resistance controller and flux-coupling-type fault current limiter for LVRT fulfillment of virtual synchronous generator

The virtual synchronous generator (VSG) technology equips power inverters with virtual inertia and damping to access generation and storage more friendly. However, the VSG's weak performance to withstand fault current inrush and fulfill low-voltage ride-through (LVRT) operation should be carefully addressed. This paper presents an innovative method to coordinate adaptive virtual resistance controller (AVRC) and flux-coupling-type fault current limiter (FC-FCL). First, the theoretical modeling and transient characteristics of the VSG are illustrated. Then, the implementation of the coordinated AVRC and FC-FCL is done, with an elaboration of the coordination philosophy and the proposed approach's parameter design rules. Further, simulation validations are performed in MATLAB/Simulink. Different severities and types of faults are imitated, and the comparisons of the proposed method against the traditional VSG strategy, the single AVRC or FC-FCL, the inner current control, and the virtual voltage control are conducted. The results prove that: i) the proposed approach offers superior abilities to repress the fault current, alleviate the terminal voltage fluctuation and keep the VSG power balance. ii) the proposed approach can handle different severities and types of faults in the VSG. A satisfactory LVRT is obtained for the VSG with favorable frequency stability and power angle stability.