Distributed Cooperative Secondary Control With Vitual Impedance for Islanded Microgrid

This paper presents a two-level layer control for microgrid (MG)in islanded mode. In the first level, a virtual impedance is designed based on the transfer function of the parallel inverter to correct the equivalent impedance of the inverter, with which active and reactive power can be decouped. The second level take part in power distribution and point of common coupling (PCC) voltage regulation. A PCC voltage regulation method is proposed to provides a proportionality coefficient to the reference voltage. The global positioning system (GPS) is utilized to provide the secondary compensation at the same time. The rationality of the proposed control strategy was tested by MATLAB/Simulink.