Modified Secondary-Control-Based Fault Current Limiter for Inverters

Fault Current Limiters (FCLs) are one of the main solutions to upcoming challenges in microgrid protection. Regarding the high penetration of distributed generations (DGs) in future power system, designing cheap and effective FCL is a necessity. The present study addresses this issue by proposing an embedded FCL operating based on modifying the secondary control of four-wire DG. As this method is presented for a four-wire system, besides very low implementing cost, it has independency and flexibility to only limit the current of DG faulted phase. This study also provides real-time simulation results by OPAL-RT to compare the proposed method with a virtual-impedance-based FCL to validate its effectiveness. Finally, experimental results are presented to validate the effectiveness of the proposed FCL.