A Distributed-Controlled Harmonic Virtual Impedance Loop for AC Microgrids

Proportional harmonic current sharing among inverters is desired in ac microgrid with nonlinear loads. Usually, virtual impedance emulated to achieve good at the cost of increased voltage distortion system. Existing schemes overcome this issue by communicating and/or values inverters, thereby requiring significant data exchange. Further, some them suffer from single point failure because their centralized architecture. This article proposes a distributed controller, which emulates sources addition impedance, reducing Furthermore, proposed scheme reduces congestion communication network, as compared existing communication-based methods, only two bits per frequency communicated inverters. The effect on stability system investigated. Additionally, impact delay error studied article. Finally, technique validated through simulation and experimentation scaled-down laboratory prototype.