Power-Sharing in Microgrids by Adaptive Virtual Impedance and Fuzzy Logic

Abdalfatah, Samia; E. El-kholy, E.; Awad, Hilmy

doi:10.21608/erj.2023.315739

Power-Sharing in Microgrids by Adaptive Virtual Impedance and Fuzzy Logic

Document Type : Original Article

Authors

¹ Department of Electrical Technology, Helwan University, Cairo, Egypt

² Professor, Dean Institute of Aviation Engineering and Technology, Egyptian Aviation Academy, Ministry of Civil Aviation

10.21608/erj.2023.315739

Abstract

Microgrid is a new paradigm for current and future energy distribution
systems that enable renewable energy integration. The microgrid generally
consists of multiple distributed generators interfacing with the grid through
power inverters. When the islanded microgrids are concerned, it is essential
to maintain the system stability and achieve load power sharing among the
multiple parallel-connected distributed generation units. However, poor
active and reactive power-sharing is expected due to the influence of
impedance mismatch of the distributed generation feeders. The key
objective of this work is to estimate the virtual impedance value to nullify
the power-sharing errors without the need for communication links. A fuzzy
logic controller is proposed to estimate the value for virtual impedance
based on the instantaneous real and reactive power demands. The virtual
impedance dynamically changes depending on the load demand to
compensate for the feeder impedance mismatch, hence called adaptive
virtual impedance. The proposed power-sharing control strategies are
validated using Matlab/Simulink simulation under four operational
scenarios. The proposed fuzzy controller provides precise reactive power
sharing and helps to eliminate the need for communication links. In
addition, it provides superior dynamic performance

Keywords