I. Introduction
Microgrid has been well accepted as an effective way to integrate large number of neighboring distributed power sources and loads into the main grid. For islanded operation of a microgrid, both the power flow control and the power quality control shall be achieved via the regulation of distributed generation (DG) units. Regarding power flow control, an important task is to achieve proper power sharing between parallel DG units to avoid under/over loading DG units [1], [2].