Improved Droop Control with Washout Filter

• Main Authors: Yalong Hu, Wei Wei
• Format: Article
• Language: English
• Published: MDPI AG 2018-09-01
• Series: Energies
• Subjects: microgrid (MG); droop control; washout filter; hardware in the loop (HIL)
• Online Access: http://www.mdpi.com/1996-1073/11/9/2415

In this paper, a droop washout filter controller (DWC), composed of a conventional droop controller and a washout filter controller, is proposed. The droop controller is used to ensure the “plug-and-play” capability, and the droop gain is set small. The washout filter is introduced to compensate the active power dynamic performance (APDP). Compared to the droop controller, the DWC can achieve accurate active power sharing and smaller frequency difference without losing the APDP. Additionally, a novel modeling technology is proposed, using which a small-signal model for an island microgrid (MG) is constructed as a singular system. The system’s stability is analyzed and the DWC is verified using real-time (RT-LAB) simulation with hardware in the loop (HIL).