Page 61 - Hybrid-Renewable Energy Systems in Microgrids

Integrated renewable energy sources with droop control techniques-based microgrid operation 45

transient stability, and voltage stability are the various stability problems that occur in
the microgrid. In this case, small signal stability problem creates the continuous load
switching, RES power limit, and feedback controller. Transient stability problem is
related to energy storage, protective devices, and load shedding of the system. Also
voltage stability problem in microgrid is related to load dynamics, tap changers, and
reactive power limits [24]. The stability of the AC microgrid is manipulated by the
microgrid grid-connected and islanded mode of operation.

4 Proposed structure of grid connected microgrid system

The overall structure of the grid connected hybrid energy sources-based microgrid
operation is shown in Fig. 3.5. The proposed configuration contains three phase grid
tied solar PV and BESS connected to the loads. In the proposed grid connected sys-
bus
tem, the inverter controls the reactive power Q AC and DC bus voltage V , which is VDCbus
DC
changed to the AC side. Solar PV is connected to the utility grid through a DC-DC
converter, which controls the output power of the solar PV array. BESS is connected
to regulate the input voltage and it is connected to the converter, which generates the

Figure 3.5 Grid connected solar PV and BESS based micro grid [25].