Correlation Between Multiple VSG Sources for Enhancing the Power Allocation in Microgrid

The different variants of droop controls for the multiple Virtual Synchronous Generator (VSG) sources to form an island microgrid is discussed in this paper. The droop control ω-P is basically a decentralized control that defines the frequency variation of a microgrid on the increase in load. The control equation for the equivalent ω-P slope for two VSGs is derived to see the effect of a load on the overall system's frequency. In the parallel VSG system, the power distribution among the multiple VSGs is dependent on the droop control. The correlation of multiple VSGs is presented in this paper that can bring the firm coordination between the different sources in stabilizing the system; by finding the dependency of each VSG on a microgrid. Furthermore, the master-slave control is introduced to acquire the maximum power of one VSG (e.g. solar) by following the instant frequency of a system as a reference, instead of constant reference frequency. Following controls are verified by performing the experiments on an island microgrid system and the results are shown through graphs.