Roles, challenges, and approaches of droop control methods for microgrids

The proper control of the distributed energy resources power converters connected in parallel is essential to provide energy supply of high quality and reliability inside microgrid. The control droop is widely utilized to control these converters in AC islanded microgrids. The control droop regulates frequency and voltage which causes the active and reactive power sharing, respectively. Although the control droop achieves an accurate active power sharing, it presents imprecisions in reactive power sharing which produces problems in voltage regulation. Therefore, this literature review is structured as follows. First, the introduction describes the importance of droop control and its application to power converters inside a microgrid. The second section shows the importance of using communication systems to solve power sharing problems. The third section presents the limitations of this control in power sharing. In the fourth section, we briefly discuss and analyze, the latest works about improved droop control methods.