In the lock-down period, the islanding mode of operation with droop controllers has several advantages in the alternating current grid. This study focuses on an improvised droop controller. It consists of an advanced filtering segment embedded with a conventional droop controller, which overcomes the drawback of droop controllers of the non-handling of non-linear loads in an ordinary situation. A selective harmonic elimination technique in grid-connected mode and lock-down mode and an advanced filter embedded with droop control are used so that the proposed controller can also work as an Active Harmonic Filter (AHF). The simulation results in different cases show that the proposed controller can control the active and reactive power in the lock-down period as well as the harmonics in the normal period up to an extent.
Power Sharing and Control by Droop Controller with Advanced Filter Design: A Case Study in Lock-down Periods