Introduction

The necessity to use non-conventional sources of energy in power systems has increased as a result of rising pollution, dwindling fossil fuel resources, and rising energy demand. Natural resources such as sunlight and wind are abundant and may be utilised to generate electricity. A microgrid is made up of energy sources and storage devices that provide load to loads that are either off-grid or on-grid (MG). The MGs are dynamic systems that experience constant changes in load and generation. Many researchers are working on renewable-energy-powered microgrids [1]. MGs are available in three different configurations: DC MG, AC MG, and HMG. In DC MG architecture, the energy sources and storage devices are integrated into a DC bus, while in an AC MG structure; they are integrated into an AC bus. The HMG is made up of DC and AC subgrids. This setup is both dependable and efficient.

A microgrid (MG) is a small-scale localised power system that is primarily made up of distributed energy resources (DERs), loads, converters, and monitoring and protection devices [2]. MGs are classified as AC, DC, or hybrid AC/DC according on the power supply method of the internal network. Due to the direct connection of DC-based sources and loads to DC buses, DC MGs have lower power losses than most common AC MGs. DC MGs, on the other hand, must rely on large-capacity inverters at their common points of coupling when linked to the utility grid [3]. Furthermore, connecting AC-based sources and loads in a DC MG demands the use of extra AC-DC converters, which results in unavoidable power losses during the conversion process. As a result, a hybrid AC/DC MG is a more cost-effective and flexible way to integrate both AC and DC-based DERs and loads within welldefined electrical limits [4]. This is a standard AC/DC hybrid MG. Energy storage systems (ESSs), wind turbines (WTs), photovoltaic arrays (PVs), diesel generators, micro turbines (MTs), and AC and DC loads are all examples of DERs interfaced with AC or DC buses through pertinent converters. The advantages of AC and DC MGs are effectively combined in this hybrid network design to improve the efficiency, flexibility, and sustainability of energy provision. However, in a hybrid AC/DC MG, deploying DERs and AC/DC network components at the same time remains a difficult problem.

References

1. Uzunoglu M, Onar OC, Alam MS (2009) Modelling, control and simulation of a PV/FC/UC based hy-brid power generation system for stand-alone applications. Renewable Energy 34 (3): 509-520.
2. Jayalakshmi NS, Gaonkar DN (2012) Operation of grid integrated wind/PV hybrid system with grid perturbations. Int J Renewable Energy Res 5(4): 1106-1111.
3. Abdullah MA, Yatim AH, Tan CW, Saidur R (2012) A review of maximum power point tracking algo-rithms for wind energy systems. Renewable Sustainable Energy Reviews 16(5): 3220-3227.
4. Ayyappa SK, Gaonkar DN (2016) Performance analysis of a variablespeed wind and fuel cell-based hybrid distributed generation system in grid-connected mode of operation. Electric Power Components Systems 44(2): 142-151.