An enhancing fault current limitation hybrid droop/V-f control for grid-tied four-wire inverters in AC microgrids
PublisherMultidisciplinary Digital Publishing Institute
Rights accessOpen Access
Microgrid integration and fault protection in complex network scenarios is a coming challenge to be faced with new strategies and solutions. In this context of increasing complexity, this paper describes two specific overload control strategies for four-wire inverters integrated in low voltage four-wire alternating current (AC) microgrids. The control of grid-tied microgrid inverters has been widely studied in the past and mainly focused on the use of droop control, which hugely constrains the time response during grid-disconnected operation. Taking into account the previous knowledge and experience about this subject, the main contribution of these two proposals regards providing fault current limitation in both operation modes, over-load capability skills in grid-connected operation and sinusoidal short-circuit proof in grid-disconnected operation. In the complex operation scenarios mentioned above, a hybrid combination of AC droop control based on dynamic phasors with varying virtual resistance, and voltage/frequency master voltage control for grid-(dis)connected operation modes are adopted as the mechanism to enhance time response. The two proposals described in the present document are validated by means of simulations using Matlab/Simulink and real experimental results obtained from CENER (The National Renewable Energy Centre) experimental ATENEA four-wire AC microgrid, obtaining time responses in the order of two-three grid cycles for all cases.
CitationHeredero-Peris, D., Chillon, C., Pagès-Giménez, M., Montesinos-Miracle, D., Santamaria, M., Rivas, D., Aguado, M. An enhancing fault current limitation hybrid droop/V-f control for grid-tied four-wire inverters in AC microgrids. "Applied sciences", 22 Setembre 2018, vol. 8, núm. 10, p. 1-22.