Global Power flow for Microgrids

The power flow is an essential tool for any study on the planning and operation of microgrids (MGs). The power flow for MG in grid-connected mode is like the power flow in distribution system. Thus, the voltage in the point of common couple can be considered constant, and the main grid can represent the MG as a load. However, the use of these representations may ignore some behaviors of the systems. This is especially true due to the renewable sources and their intermittency. In this context, this paper aims to evaluate the global power flow applied in MG, and the steady-state interaction between the MG and the MV distribution system. The CIGRE benchmark MV and LV networks are employed in this paper. The conventional Newton Raphson is employed in the MV system, and the Newton Raphson current injection is employed in the MG. Two cases are considered, one evaluates the MG connected with the MV system, and the other considers the MG with a volt-var control connected with the MV. Both cases show that the MG and the MV systems present influences in each other that may be captured by global power flow.