Design for independent and self-adequate microgrids in distribution systems considering optimal allocation of DG units

Introducing the concept of distributed generations (DGs) and local demand supply have led to significant changes in distribution networks. The idea of aggregating loads and DGs in an appropriate way have resulted in microgrids' (MGs) appearance. Considering the economic and environmental concerns, MGs will play important roles in future distribution systems. However, it is necessary to implement an efficient procedure for the optimal design of MGs. This study proposes optimised methods in order to construct a set of independent, self-sufficient MGs in distribution networks. Increasing self-adequacy of constructed MGs is obtained by minimising the power imbalance within them or minimising transferred power between them. The stochastic nature of DGs and consumed loads are also considered. In this regard, optimal allocating and sizing of distributed resources are also studied. In this study, the optimal DG placement is considered with the aim of improving system load factor and decreasing system losses. The presented strategy facilitates controlling strategies of smart distribution systems, such as self-healing, by using virtual MGs in the future distribution systems. The related formulation and solution algorithms are presented in this study. Moreover, the proposed strategy is studied in the PG&E 69-bus distribution system.